Iron-catalyzed benzylic C-H thiolation via photoinduced ligand-to-metal charge-transfer.

Here, we describe an iron-catalyzed benzylic C-H thiolation of alkylarenes via photoinduced ligand-to-metal charge-transfer. The protocol features operational simplicity, mild reaction conditions, and the use of FeCl3 as catalyst and thiols/disulfides as sulfur sources, which enables the transformation of diverse benzylic C-H bonds into C-S bonds with a high efficiency.

A novel reverse perilesional home phototherapy can promote the repigmentation of vitiligo patches with complete leukotrichia: A 12-week, open-label, double-arm, multicenter, randomized clinical trial.

BACKGROUND/PURPOSE: Existing phototherapies are ineffective for treating patients with vitiligo with complete leukotrichia. We compared the efficacy of reverse perilesional irradiation, during which only the lesional areas are covered, with conventional narrowband ultraviolet B (NB-UVB) home phototherapy for repigmentation of non-segmental vitiligo in patients with complete leukotrichia. METHODS: This was a 12-week, open-label, double-arm, multicenter clinical trial, with a total of 121 patients with non-segmental vitiligo who were randomly divided into two groups (both received topical tacrolimus): the conventional NB-UVB irradiation (CI) and reverse perilesional NB-UVB irradiation (RI) groups. RESULTS: A statistically significant difference in improvement from baseline was observed in the RI group compared with the findings in the CI group (-30.8% ± 11.8% vs. -25.5% ± 11.05%, respectively [p = .010]; pair-wise comparison p = .900 at week 4, p = .104 at week 8, and p = .010 at week 12). At week 12, the average percentage change from baseline of leukotrichia in the irradiation area significantly decreased from 100% to 82.2% ± 13.65% in the RI group, and from 100% to 88.7% ± 9.64% in the CI group (p = .027). Adverse events were minor, including desquamation, dryness, erythema, and blisters. No severe or lasting side effects were observed during the study. CONCLUSION: RI mediated better repigmentation of vitiligo with complete leukotrichia than CI.

MIFAM-DTI: a drug-target interactions predicting model based on multi-source information fusion and attention mechanism.

Accurate identification of potential drug-target pairs is a crucial step in drug development and drug repositioning, which is characterized by the ability of the drug to bind to and modulate the activity of the target molecule, resulting in the desired therapeutic effect. As machine learning and deep learning technologies advance, an increasing number of models are being engaged for the prediction of drug-target interactions. However, there is still a great challenge to improve the accuracy and efficiency of predicting. In this study, we proposed a deep learning method called Multi-source Information Fusion and Attention Mechanism for Drug-Target Interaction (MIFAM-DTI) to predict drug-target interactions. Firstly, the physicochemical property feature vector and the Molecular ACCess System molecular fingerprint feature vector of a drug were extracted based on its SMILES sequence. The dipeptide composition feature vector and the Evolutionary Scale Modeling -1b feature vector of a target were constructed based on its amino acid sequence information. Secondly, the PCA method was employed to reduce the dimensionality of the four feature vectors, and the adjacency matrices were constructed by calculating the cosine similarity. Thirdly, the two feature vectors of each drug were concatenated and the two adjacency matrices were subjected to a logical OR operation. And then they were fed into a model composed of graph attention network and multi-head self-attention to obtain the final drug feature vectors. With the same method, the final target feature vectors were obtained. Finally, these final feature vectors were concatenated, which served as the input to a fully connected layer, resulting in the prediction output. MIFAM-DTI not only integrated multi-source information to capture the drug and target features more comprehensively, but also utilized the graph attention network and multi-head self-attention to autonomously learn attention weights and more comprehensively capture information in sequence data. Experimental results demonstrated that MIFAM-DTI outperformed state-of-the-art methods in terms of AUC and AUPR. Case study results of coenzymes involved in cellular energy metabolism also demonstrated the effectiveness and practicality of MIFAM-DTI. The source code and experimental data for MIFAM-DTI are available at https://github.com/Search-AB/MIFAM-DTI.

Perioperative versus adjuvant S-1 plus oxaliplatin chemotherapy for stage II/III resectable gastric cancer (RESONANCE): a randomized, open-label, phase 3 trial.

Evidence from Europe shows that perioperative chemotherapy may be beneficial for the treatment of locally advanced gastric cancer, but reliable and robust data is lacking. To rectify this, the phase 3 RESONANCE trial investigated the efficacy and safety of S-1 plus oxaliplatin (SOX) as a perioperative chemotherapy regimen for gastric cancer. This randomized, open-label trial enrolled patients from 19 medical centers with stage II/III resectable gastric cancer who were centrally randomly assigned to either perioperative chemotherapy (PC) arm or adjuvant chemotherapy (AC) arm. Patients in the PC arm received two to four cycles of SOX followed by surgery and four to six cycles of SOX. Patients in the AC arm received upfront surgery and eight cycles of SOX. 386 patients in each group were enrolled and 756 (382 in PC and 374 in AC) were included in the mITT population. The three-year DFS rate was 61.7% in the PC arm and 53.8% in the AC arm (log-rank p = 0.019). The R0 resection rate in the PC arm was significantly higher than that in the AC arm (94.9% vs. 83.7%, p < 0.0001). There was no difference between two arms in surgical outcomes or postoperative complications. Safety-related data were like the known safety profile. In conclusion, from a clinical perspective, this trial indicated a trend towards higher three-year disease-free survival rate with perioperative SOX in stage II/III resectable gastric cancer with well-tolerated toxicity compared to adjuvant SOX, which might provide a theoretical basis for applying perioperative SOX in advanced gastric cancer patients. (ClinicalTrials.gov NCT01583361).

DIMOND: DIffusion Model OptimizatioN with Deep Learning.

Diffusion magnetic resonance imaging is an important tool for mapping tissue microstructure and structural connectivity non-invasively in the in vivo human brain. Numerous diffusion signal models are proposed to quantify microstructural properties. Nonetheless, accurate estimation of model parameters is computationally expensive and impeded by image noise. Supervised deep learning-based estimation approaches exhibit efficiency and superior performance but require additional training data and may be not generalizable. A new DIffusion Model OptimizatioN framework using physics-informed and self-supervised Deep learning entitled "DIMOND" is proposed to address this problem. DIMOND employs a neural network to map input image data to model parameters and optimizes the network by minimizing the difference between the input acquired data and synthetic data generated via the diffusion model parametrized by network outputs. DIMOND produces accurate diffusion tensor imaging results and is generalizable across subjects and datasets. Moreover, DIMOND outperforms conventional methods for fitting sophisticated microstructural models including the kurtosis and NODDI model. Importantly, DIMOND reduces NODDI model fitting time from hours to minutes, or seconds by leveraging transfer learning. In summary, the self-supervised manner, high efficacy, and efficiency of DIMOND increase the practical feasibility and adoption of microstructure and connectivity mapping in clinical and neuroscientific applications.

Comparison of uncut Roux-en-Y anastomosis and Billroth-II with Braun anastomosis after distal gastrectomy.

Background: This study aimed to compare the clinical outcomes and patient benefits of uncut Roux-en-Y (URY) anastomosis and Billroth-II with Braun (BB) anastomosis after distal gastrectomy. Methods: We retrospectively reviewed the data of patients who underwent URY or BB anastomosis after distal gastrectomy between March 2015 and December 2017. Clinical characteristics, survival data, postoperative recovery data, and long-term outcomes were recorded and compared between the two groups. Results: A total of 231 patients were included, with 167 in the URY group and 64 in the BB group. Kaplan-Meier curves for overall survival showed no differences after propensity score matching (p = 0.488). Long-term postoperative quality of life evaluation also showed no significant differences. Compared to the BB group, patients in the URY group had a significantly shorter time to start a liquid diet after propensity score matching (67.6 h vs. 46.5 h, p = 0.003), and a lower occurrence of bile reflux on follow-up gastroscopy (p < 0.001). Conclusion: The URY anastomosis appears to be a feasible method for digestive tract reconstruction after distal gastrectomy, resulting in less bile reflux and better postoperative recovery. However, there is no significant difference between URY and BB anastomosis in terms of overall survival and long-term quality of life.

Reverse water-gas shift catalyzed by RhnVO3,4- (n = 3-7) cluster anions under variable temperatures.

A fundamental understanding of the exact structural characteristics and reaction mechanisms of interface active sites is vital to engineering an energetic metal-support boundary in heterogeneous catalysis. Herein, benefiting from a newly developed high-temperature ion trap reactor, the reverse water-gas shift (RWGS) (CO2 + H2 → CO + H2O) catalyzed by a series of compositionally and structurally well-defined RhnVO3,4- (n = 3-7) clusters were identified under variable temperatures (298-773 K). It is discovered that the Rh5-7VO3,4- clusters can function more effectively to drive RWGS at relatively low temperatures. The experimentally observed size-dependent catalytic behavior was rationalized by quantum-chemical calculations; the framework of RhnVO3,4- is constructed by depositing the Rhn clusters on the VO3,4 "support", and a sandwiched base-acid-base [Rhout--Rhin+-VO3,4-; Rhout and Rhin represent the outer and inner Rh atoms, respectively] feature in Rh5-7VO3,4- governs the adsorption and activation of reactants as well as the facile desorption of the products. In contrast, isolated Rh5-7- clusters without the electronic modification of the VO3,4 "support" can only catalyze RWGS under relatively high-temperature conditions.

Machine Learning for Experimental Reactivity of a Set of Metal Clusters toward C-H Activation.

Understanding the mechanisms of C-H activation of alkanes is a very important research topic. The reactions of metal clusters with alkanes have been extensively studied to reveal the electronic features governing C-H activation, while the experimental cluster reactivity was qualitatively interpreted case by case in the literature. Herein, we prepared and mass-selected over 100 rhodium-based clusters (RhxVyOz- and RhxCoyOz-) to react with light alkanes, enabling the determination of reaction rate constants spanning six orders of magnitude. A satisfactory model being able to quantitatively describe the rate data in terms of multiple cluster electronic features (average electron occupancy of valence s orbitals, the minimum natural charge on the metal atom, cluster polarizability, and energy gap involved in the agostic interaction) has been constructed through a machine learning approach. This study demonstrates that the general mechanisms governing the very important process of C-H activation by diverse metal centers can be discovered by interpreting experimental data with artificial intelligence.

An oncolytic virus delivering tumor-irrelevant bystander T cell epitopes induces anti-tumor immunity and potentiates cancer immunotherapy.

Tumor-specific T cells are crucial in anti-tumor immunity and act as targets for cancer immunotherapies. However, these cells are numerically scarce and functionally exhausted in the tumor microenvironment (TME), leading to inefficacious immunotherapies in most patients with cancer. By contrast, emerging evidence suggested that tumor-irrelevant bystander T (TBYS) cells are abundant and preserve functional memory properties in the TME. To leverage TBYS cells in the TME to eliminate tumor cells, we engineered oncolytic virus (OV) encoding TBYS epitopes (OV-BYTE) to redirect the antigen specificity of tumor cells to pre-existing TBYS cells, leading to effective tumor inhibition in multiple preclinical models. Mechanistically, OV-BYTE induced epitope spreading of tumor antigens to elicit more diverse tumor-specific T cell responses. Remarkably, the OV-BYTE strategy targeting human severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cell memory efficiently inhibited tumor progression in a human tumor cell-derived xenograft model, providing important insights into the improvement of cancer immunotherapies in a large population with a history of SARS-CoV-2 infection or coronavirus disease 2019 (COVID-19) vaccination.

Preparation of κ-carrageenan oligosaccharides by photocatalytic degradation: Structural characterization and antioxidant activity.

To accurately, efficiently, and environmentally prepare carrageenan oligosaccharides, we have developed a method that uses H2O2 and TiO2 as catalysts for the photodegradation of κ-carrageenan (KC). The photodegradation of KC was monitored using various amounts of TiO2 and H2O2 and different concentrations of KC via HPLC and it could decrease the average molecular weight of KC into 1.6 kDa within 2 h. Further research under optimal conditions. As a control, the effects of UV, UV/H2O2, UV/TiO2, and H2O2/TiO2 treatments were studied. In contrast, UV/H2O2/TiO2 treatments showed a coordinated effect. The effect of degradation on the structure of KC was investigated by FT-IR, XRD, and there was no obvious remotion of sulfate groups. Furthermore, oral administration of KCO prolonged the healthy lifespan of nematodes induced by ultraviolet stress and significantly regulated oxidative stress. This study suggests that the precise preparation and application of KCO may be beneficial.

Chinese national clinical practice guidelines on the prevention, diagnosis, and treatment of early gastric cancer.

BACKGROUND: Gastric cancer is one of the most common malignant tumors in the digestive system in China. Few comprehensive practice guidelines for early gastric cancer in China are currently available. Therefore, we created the Chinese national clinical practice guideline for the prevention, diagnosis, and treatment of early gastric cancer. METHODS: This clinical practice guideline (CPG) was developed in accordance with the World Health Organization's recommended process and with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) in assessing evidence quality. We used the Evidence to Decision framework to formulate clinical recommendations to minimize bias and increase transparency in the CPG development process. We used the Reporting Items for practice Guidelines in HealThcare (RIGHT) statement and the Appraisal of Guidelines for Research and Evaluation II (AGREE II) as reporting and conduct guidelines to ensure completeness and transparency of the CPG. RESULTS: This CPG contains 40 recommendations regarding the prevention, screening, diagnosis, treatment, and follow-up of early gastric cancer based on available clinical studies and guidelines. We provide recommendations for the timing of Helicobacter pylori eradication, screening populations for early gastric cancer, indications for endoscopic resection and surgical gastrectomy, follow-up interval after treatment, and other recommendations. CONCLUSIONS: This CPG can lead to optimum care for patients and populations by providing up-to-date medical information. We intend this CPG for widespread adoption to increase the standard of prevention, screening, diagnosis, treatment, and follow-up of early gastric cancer; thereby, contributing to improving national health care and patient quality of life.

Management and outcome of adult generalized tetanus in a Chinese tertiary hospital.

Background: Tetanus is a rare surgical infectious disease with a high reported relevant mortality. It still remains a serious problem in public health, particularly in low-income and middle-income countries. The purpose of this study was to investigate the management and prognosis of adult generalized tetanus in our hospital. Methods: A total of 20 adult generalized tetanus patients were recruited in this retrospective observational study. Patients were retrieved from the hospital data base via discharge diagnosis. Patients were divided into two groups (Severe or Non-severe tetanus group) based on the severity of tetanus by using the Ablett classification. The differences between the two groups were compared. Results: The study included 11 males (55%) and 9 females (45%). All tetanus patients recovered. The median age was 53.5 years [IQR: 19-78]. There were 1 mild (Grade 1) case (5%),5 moderate (Grade 2) cases (25%), 2 severe (Grade 3) cases (10%), and 12 very severe (Grade 4) cases (60%). Nineteen patients (95%) did not have tetanus immunization before. The majority of patients were farmers (60%), and came from rural areas (60%). Thirteen (65%) patients had a history of puncture injury. The rate of wound debridement after admission was 60% overall. Thirteen (65%) patients required mechanical ventilation for a median of 21 [IQR:12-41] days. Autonomic instability occurred in 13 (65%) patients. Pulmonary infections occurred in 12 (60%) patients. Median duration of hospital stay was 29.5 [IQR:12-68] days. More patients in the Severe group needed ICU admission, wound debridement, mechanical ventilation and heavy sedation combined with muscle relaxants (p < 0.05). The hospital stay was significantly longer in patients in the Severe group (p < 0.05). Conclusion: After effective treatment, all adult patients with generalized tetanus in this study were cured and discharged. Severe tetanus requires early ICU treatment, wound debridement and effective treatment of autonomic instability.

Rapid Silicification of a DNA Origami with Shape Fidelity.

High-fidelity patterning of DNA origami nanostructures on various interfaces holds great potential for nanoelectronics and nanophotonics. However, distortion of a DNA origami often occurs due to the strong interface interactions, e.g., on two-dimensional (2D) materials. In this study, we discovered that the adsorption of silica precursors in rapid silicification can prevent the distortion caused by graphene and generates a high shape-fidelity DNA origami-silica composite on a graphene interface. We found that an incubation time of 1 min and silicification time of 16 h resulted in the formation of DNA origami-silica composites with the highest shape fidelity of 99%. By comparing the distortion of the DNA origami on the graphene interface with and without silicification, we observed that rapid silicification effectively preserved the integrity of the DNA origami. Statistical analysis of scanning electron microscopy data indicates that compared to bare DNA origami, the DNA origami-silica composite has an increased shape fidelity by more than two folds. Furthermore, molecular dynamics simulations revealed that rapid silicification effectively suppresses the distortion of the DNA origami through the interhelical insertion of silica precursors. Our strategy provides a simple yet effective solution to maintain the shape-fidelity DNA origami on interfaces that have strong interaction with DNA molecules, expanding the applicable interfaces for patterning 2D DNA origamis.

Responses of Yield and Photosynthetic Characteristics of Rice to Climate Resources under Different Crop Rotation Patterns and Planting Methods.

Climate is the most important environmental factor influencing yield during rice growth and development. To investigate the relationships between climate and yield under different crop rotation patterns and planting methods, three typical rotation patterns (vegetable-rice (V), rape-rice (R), and wheat-rice (W)) and two mechanical planting methods (mechanical transplanting (T1) and mechanical direct seeding (T2)) were established. The results showed that compared to the V rotation pattern, the average daily temperature (ADT) during the sowing to heading stage increased under both R and W rotation patterns, which significantly shortened the growth period. Thus, the effective accumulated temperature (EAT), photosynthetic capacity, effective panicle (EP), and spikelet per panicle (SP) under R and W rotation patterns significantly decreased, leading to reductions in grain yield (GY). VT2 had a higher ratio of productive tillers (RPT), relative chlorophyll content (SPAD), leaf area index (LAI), and net photosynthetic rate (Pn) than those of VT1, which significantly increased panicle dry matter accumulation (DMA), resulting in an increase in GY. Although RT2 and WT2 had a higher RPT than those of RT1 and WT1, the GY of RT1 and WT1 decreased due to the significant reductions in EAT and photosynthetic capacity. Principal component analysis (PCA) showed that the comprehensive score for different rotation patterns followed the order of V > R > T with VT2 ranking first. The structural equation model (SEM) showed that EAT and ADT were the most important climate factors affecting yield, with total effects of 0.520 and -0.446, respectively. In conclusion, mechanical direct seeding under vegetable-rice rotation pattern and mechanical transplanting under rape-rice or wheat-rice rotation pattern were the rice-planting methods that optimized the climate resources in southwest China.

Comparison of the Clinical Efficacy and Bone Cement Distribution Difference Between Kummell's Disease and Osteoporotic Vertebral Compression Fracture After Percutaneous Kyphoplasty.

BACKGROUND: Kummell's disease (KD) and osteoporotic vertebral compression fracture (OVCF) are commonly found in patients with osteoporosis. Several studies have been conducted on bone cement distribution in OVCF or KD; a comparison between the 2 diseases is rarely reported. OBJECTIVES: To compare the clinical efficacy and bone cement distribution difference between KD and OVCFs after percutaneous kyphoplasty (PKP). STUDY DESIGN: This was a retrospective, nonrandomized controlled study. SETTING: Department of Orthopedics from an affiliated hospital. METHODS: From January 2018 to December 2020, 61 patients who underwent PKP surgery for single KD or OVCF and met the inclusion criteria were retrospectively reviewed. All patients were assigned to 2 groups: the KD group and the OVCF group. Clinical and radiologic characteristics, including the bone cement volume, leakage, bone cement dispersion scale, anterior vertebral height (AVH), median vertebral height (MVH), posterior vertebral height (PVH), Cobb angle and Visual Analog Scale (VAS) were analyzed and compared using Mimics three-dimensional (3D) reconstruction images and 3D reconstruction computed tomography, preoperatively, postoperatively, and 2 years after the operation, respectively. The correlations between the bone cement dispersion scale and the VH improvement rate (VHIR), VH change rate (VHCR), VAS improvement rate (VASIR), and follow-up VAS improvement rate (f-VASIR) were also evaluated. RESULTS: The mean follow-up time was 24.0 months. Postoperative VH, Cobb angle, vertebra volume, and VAS score were significantly improved in the 2 groups (P < 0.05). There was no statistical difference in postoperative parameters between the 2 groups. While a strong positive correlation between VHIR and bone cement dispersion scale was observed in the OVCF group (P < 0.01), no significant correlation between VHIR and bone cement dispersion scale was found in the KD group. There was no correlation between VASIR and bone cement dispersion scale in both groups. Compared with postoperation, VH was lower in both groups in later follow-up, and the difference between the 2 groups was statistically significant (P < 0.05). VH, VAS, f-VASIR, and VHCR had a worse manifestation in the KD group than in the OVCF group. However, no significant correlation was found between VHCR, f-VASIR, and bone cement dispersion scale in the 2 groups. LIMITATIONS: This study was limited by the non-randomized design, small sample size, and lack of a comprehensive follow-up period. CONCLUSIONS: Although there was no significant difference in the bone cement distribution and early clinical efficacy between KD and OVCF patients under the same surgical plan and surgeon, OVCF patients exhibited better long-term radiologic and clinical outcomes.

Genomic characterization of peritoneal lavage cytology-positive gastric cancer.

Objective: Positive peritoneal lavege cytology (CY1) gastric cancer is featured by dismal prognosis, with high risks of peritoneal metastasis. However, there is a lack of evidence on pathogenic mechanism and signature of CY1 and there is a continuous debate on CY1 therapy. Therefore, exploring the mechanism of CY1 is crucial for treatment strategies and targets for CY1 gastric cancer. Methods: In order to figure out specific driver genes and marker genes of CY1 gastric cancer, and ultimately offer clues for potential marker and risk assessment of CY1, 17 cytology-positive gastric cancer patients and 31 matched cytology-negative gastric cancer patients were enrolled in this study. The enrollment criteria were based on the results of diagnostic laparoscopy staging and cytology inspection of exfoliated cells. Whole exome sequencing was then performed on tumor samples to evaluate genomic characterization of cytology-positive gastric cancer. Results: Least absolute shrinkage and selection operator (LASSO) algorithm identified 43 cytology-positive marker genes, while MutSigCV identified 42 cytology-positive specific driver genes. CD3G and CDKL2 were both driver and marker genes of CY1. Regarding mutational signatures, driver gene mutation and tumor subclone architecture, no significant differences were observed between CY1 and negative peritoneal lavege cytology (CY0). Conclusions: There might not be distinct differences between CY1 and CY0, and CY1 might represent the progression of CY0 gastric cancer rather than constituting an independent subtype. This genomic analysis will thus provide key molecular insights into CY1, which may have a direct effect on treatment recommendations for CY1 and CY0 patients, and provides opportunities for genome-guided clinical trials and drug development.

Alcalase-hydrolyzed insoluble soybean meal hydrolysate aggregates: Structure, bioactivity, function properties, and influences on the stability of oil-in-water emulsions.

We studied the influences of hydrolysis time on the structure, functional properties, and emulsion stability of insoluble soybean meal hydrolysate aggregates (ISMHAs). We assume that the ISMHAs produced by soybean meal can be used as emulsifiers to prepare stable emulsions. The molecular weights of these ISMHAs were below 53 kDa. After hydrolysis, a decrease in α-helices and an increase in random coils indicated that the soybean meal proteins were unfolding. Moreover, the fluorescence intensity, UV absorption, and surface hydrophobicity of ISMHAs increased. These results would contribute to their antioxidant activity and functional properties. Additionally, the 90-min ISMHA sample exhibited the highest ABTS+• scavenging activity (80.02 ± 4.55 %), foaming stability (52.92 ± 8.06 %), and emulsifying properties (emulsifying activity index of 97.09 m2/g; emulsifying stability index of 371.47 min). The 90-min ISMHA emulsion exhibited the smallest particle size and excellent storage stability. Soybean meal peptide by-product emulsifier has potential for sustainable application.

Spectroscopic Characterization of Thermal Methane Activation by Lewis-Acid-Base Pair in a Gas-Phase Metal Nitride Anion Ta2N3.

Activation and transformation of methane is one of the "holy grails" in catalysis. Understanding the nature of active sites and mechanistic details via spectroscopic characterization of the reactive sites and key intermediates is of great challenge but crucial for the development of novel strategies for methane transformation. Herein, by employing photoelectron velocity-map imaging (PEVMI) spectroscopy in conjunction with quantum chemistry calculations, the Lewis acid-base pair (LABP) of [Taδ+-Nδ-] unit in Ta2N3 - acting as an active center to accomplish the heterolytic cleavage of C-H bond in CH4 has been confirmed by direct characterization of the reactant ion Ta2N3 - and the CH4-adduct intermediate Ta2N3CH4 -. Two active vibrational modes for the reactant (Ta2N3 -) and four active vibrational modes for the intermediate (Ta2N3CH4 -) were observed from the vibrationally resolved PEVMI spectra, which unequivocally determined the structure of Ta2N3 - and Ta2N3CH4 -. Upon heating, the LABP intermediate (Ta2N3CH4 -) containing the NH and Ta-CH3 unit can undergo the processes of C-N coupling and dehydrogenation to form the product with an adsorbed HCN molecule.

High-Level Biosynthesis of Chlorogenic Acid from Mixed Carbon Sources of Xylose and Glucose through a Rationally Refactored Pathway Network.

Chlorogenic acid (CGA) has incredible potential for various pharmaceutical, nutraceutical, and agricultural applications. However, the traditional extraction approach from plants is time-consuming, further limiting its production. Herein, we design and construct the de novo biosynthesis pathway of CGA using modular coculture engineering in Escherichia coli, which is composed of MG09 and BD07 strains. To accomplish this, the phenylalanine-deficient MG09 strain was engineered to utilize xylose preferentially and to overproduce precursor caffeic acid, while the tyrosine-deficient BD07 strain was constructed to consume glucose exclusively to enhance another precursor quinic acid availability for the biosynthesis of CGA. Further pathway modularization and balancing in the context of syntrophic cocultures resulted in additional production improvement. The coculture strategy avoids metabolic flux competition in the biosynthesis of two CGA precursors, caffeic acid and quinic acid, and allows for production improvement by balancing module proportions. Finally, the optimized coculture based on the aforementioned efforts produced 131.31 ± 7.89 mg/L CGA. Overall, the modular coculture engineering strategy in this study provides a reference for constructing microbial cell factories that can efficiently biomanufacture complex natural products.

Modulation the Synergistic Effect of Chitosan-Sodium Alginate Nanoparticles with Ca2+: Enhancing the Stability of Pickering Emulsion on D-Limonene.

Pickering emulsions (PEs) have been regarded as an effective approach to sustaining and preserving the bioactivities of essential oils. The aim of this research is to prepare a PE stabilized by chitosan/alginate nanoparticles (CS-SA NPs) for the encapsulation and stabilization of D-limonene. In this work, the influence of calcium ions (Ca2+) on the morphology and interaction of nanoparticles was studied, and then the preparation technology of CS-SA/Ca2+ NPs was optimized. The results showed that the presence of Ca2+ reduced the size of the nanoparticles and made them assume a spherical structure. In addition, under the conditions of 0.2 mg/mL CaCl2, 0.6 mg/mL SA, and 0.4 mg/mL CS, the CS-SA/Ca2+ NPs had the smallest size (274 ± 2.51 nm) and high stability (-49 ± 0.69 mV). Secondly, the PE was prepared by emulsifying D-limonene with CS-SA/Ca2+ NPs, and the NP concentrations and homogenization speeds were optimized. The results showed that the small droplet size PE could be prepared with 2 mg/mL NP and a homogenization speed of 20,000 r/min, and it had excellent antibacterial and antioxidant activities. Most importantly, the emulsion showed higher activity, higher resistance to ultraviolet (UV) and a higher temperature than free D-limonene. This research provides a feasible solution for the encapsulation, protection and delivery of essential oils.