Von Willebrand factor exacerbates heart failure through formation of neutrophil extracellular traps.

BACKGROUND AND AIMS: Heart failure (HF) is a leading cause of mortality worldwide and characterized by significant co-morbidities and dismal prognosis. Neutrophil extracellular traps (NETs) aggravate inflammation in various cardiovascular diseases; however, their function and mechanism of action in HF pathogenesis remain underexplored. This study aimed to investigate the involvement of a novel VWF-SLC44A2-NET axis in HF progression. METHODS: NET levels were examined in patients with HF and mouse models of transverse aortic constriction (TAC) HF. PAD4 knockout mice and NET inhibitors (GSK-484, DNase I, NEi) were used to evaluate the role of NETs in HF. RNA sequencing was used to investigate the downstream mechanisms. Recombinant human ADAMTS13 (rhADAMTS13), ADAMTS13, and SLC44A2 knockouts were used to identify novel upstream factors of NETs. RESULTS: Elevated NET levels were observed in patients with HF and TAC mouse models of HF. PAD4 knockout and NET inhibitors improved the cardiac function. Mechanistically, NETs induced mitochondrial dysfunction in cardiomyocytes, inhibiting mitochondrial biogenesis via the NE-TLR4-mediated suppression of PGC-1α. Furthermore, VWF/ADAMTS13 regulated NET formation via SLC44A2. Additionally, sacubitril/valsartan amplifies the cardioprotective effects of the VWF-SLC44A2-NET axis blockade. CONCLUSIONS: This study established the role of a novel VWF-SLC44A2-NET axis in regulating mitochondrial homeostasis and function, leading to cardiac apoptosis and contributing to HF pathogenesis. Targeting this axis may offer a potential therapeutic approach for HF treatment.

A CT-based radiomics tumor quality and quantity model to predict early recurrence after radical surgery for colorectal liver metastases.

PURPOSE: This study aimed to develop a tumor radiomics quality and quantity model (RQQM) based on preoperative enhanced CT to predict early recurrence after radical surgery for colorectal liver metastases (CRLM). METHODS: A retrospective analysis was conducted on 282 cases from 3 centers. Clinical risk factors were examined using univariate and multivariate logistic regression (LR) to construct the clinical model. Radiomics features were extracted using the least absolute shrinkage and selection operator (LASSO) for dimensionality reduction. The LR learning algorithm was employed to construct the radiomics model, RQQM (radiomics-TBS), combined model (radiomics-clinical), clinical risk score (CRS) model and tumor burden score (TBS) model. Inter-model comparisons were made using area under the curve (AUC), decision curve analysis (DCA) and calibration curve. Log-rank tests assessed differences in disease-free survival (DFS) and overall survival (OS). RESULTS: Clinical features screening identified CRS, KRAS/NRAS/BRAF and liver lobe distribution as risk factors. Radiomics model, RQQM, combined model demonstrated higher AUC values compared to CRS and TBS model in training, internal and external validation cohorts (Delong-test P < 0.05). RQQM outperformed the radiomics model, but was slightly inferior to the combined model. Survival curves revealed statistically significant differences in 1-year DFS and 3-year OS for the RQQM (P < 0.001). CONCLUSIONS: RQQM integrates both "quality" (radiomics) and "quantity" (TBS). The radiomics model is superior to the TBS model and has a greater impact on patient prognosis. In the absence of clinical data, RQQM, relying solely on imaging data, shows an advantage in predicting early recurrence after radical surgery for CRLM.

Protosappanin A Protects DOX-Induced Myocardial Injury and Cardiac Dysfunction by Targeting ACSL4/FTH1 Axis-Dependent Ferroptosis.

Doxorubicin (DOX) is an effective anticancer agent, but its clinical utility is constrained by dose-dependent cardiotoxicity, partly due to cardiomyocyte ferroptosis. However, the progress of developing cardioprotective medications to counteract ferroptosis has encountered obstacles. Protosappanin A (PrA), an anti-inflammatory compound derived from hematoxylin, shows potential against DOX-induced cardiomyopathy (DIC). Here, it is reported that PrA alleviates myocardial damage and dysfunction by reducing DOX-induced ferroptosis and maintaining mitochondrial homeostasis. Subsequently, the molecular target of PrA through proteome microarray, molecular docking, and dynamics simulation is identified. Mechanistically, PrA physically binds with ferroptosis-related proteins acyl-CoA synthetase long-chain family member 4 (ACSL4) and ferritin heavy chain 1 (FTH1), ultimately inhibiting ACSL4 phosphorylation and subsequent phospholipid peroxidation, while also preventing FTH1 autophagic degradation and subsequent release of ferrous ions (Fe2+) release. Given the critical role of ferroptosis in the pathogenesis of ischemia-reperfusion (IR) injury, this further investigation posits that PrA can confer a protective effect against IR-induced cardiac damage by inhibiting ferroptosis. Overall, a novel pharmacological inhibitor is unveiled that targets ferroptosis and uncover a dual-regulated mechanism for cardiomyocyte ferroptosis in DIC, highlighting additional therapeutic options for chemodrug-induced cardiotoxicity and ferroptosis-triggered disorders.

Visitor preferences in rural gastronomic tourism environment and the related design implications.

Since COVID-19, people have suffered tremendous impacts in all aspects of their lives and work, with subtle changes in their environment preferences. The rural areas, with their natural green space, low density, and leisurely habitat, have played an important role after the pandemic and are widely favored by people. Research on rural environments after COVID-19 has received much attention. In the wake of the pandemic, people's needs for the environment have changed not only in terms of physical space, but also in terms of psychological needs. To address the issue of adaptability and resiliency of the future tourism development of the rural areas, this study takes the real subjective feelings of rural visitors as the evaluation standard, and takes the rural gastronomic tourism environment as the research object. We analyzed a sample of 14,373 images and 324,676 comments in Chinese posted by 3484 visitors on social media to explore whether and how people's preferences for rural environments have changed since the pandemic. Findings revealed significant differences in preference for the rural gastronomic tourism environment factors before and after the pandemic. There is variability in environment preferences depending on different gender, environment flexibility and the region. From the perspective of the rural gastronomic tourism environment, the research results provide suggestions for rural planning and rural tourism sustainability, and provide feasible paths for sustainable development and conservation of rural landscapes oriented to human needs, to enhance the resilience and sustainability of rural environments in the future.

Sleep disturbances in children and adolescents after kidney transplantation.

BACKGROUND: Disturbances of sleep are prevalent among children with chronic kidney disease. However, the aetiology of sleep disorders in children particularly after kidney transplantation is not clear. We sought to ascertain the prevalence and type of sleep disturbances in paediatric kidney transplant recipients and to identify predictors of sleep disturbances in this population. METHODS: Caregivers of kidney transplant recipients completed online questionnaires about their child's sleep. The questionnaires utilised were the Sleep Disturbance Scale for Children (SDSC), the Epworth Sleepiness Scale for Children and Adolescents (ESS-CHAD), questions about sleep hygiene, and questions about restless leg syndrome. Demographic and clinical details were collected from medical records. RESULTS: Thirty-five children were included in the study, with a median (IQR) age of 14.1 years (9.5-16.1) and median years (IQR) since transplant of 3.7 (0.7-8.7) years, and 72.0% were identified to have at least one category of sleep disturbance according to scores on the SDSC. The most common sleep disturbances reported were disorders of initiating and maintaining sleep (DIMS) (40.0%) and disorders of excessive somnolence (DOES) (31.4%). Statistically significant predictors of sleep disturbances include low estimated glomerular filtration rate and increased age. Among children who screened positive for DIMS and DOES, the majority indicated use of electronic devices in 1 h before bed. CONCLUSIONS: A high prevalence of sleep disturbances has been identified in children after kidney transplants, and some risk factors may be modifiable. Further studies are required to understand whether there are other readily modifiable predictors of sleep disturbances.

Evaluation of cell surface vimentin positive circulating tumor cells as a prognostic biomarker for stage III/IV colorectal cancer.

Currently, little is known about the phenotypes of circulating tumor cells (CTCs), particularly epithelial and mesenchymal phenotypes, and their impact on the prognosis of colorectal cancer (CRC) patients. This study aims to investigate the CTC phenotypes and their prognostic implications in stage III/IV CRC. Patients who were diagnosed with CRC and underwent CTC detection at two hospitals were included. CTCs were detected using a mesenchymal CTC kit, and the clinical and pathological characteristics of CTCs were compared with those of cell surface vimentin-positive CTCs (CSV-CTCs). Disease-free survival (DFS) was assessed and used as an indicator of CTC phenotype-related prognosis. Univariate and multivariate Cox regression analyses were made to identify risk factors, and nomogram models were employed for prognostic prediction. A total of 82 patients were enrolled, with a CTC detection rate of 86.6%. Among the detected CTCs, 60% were CSV-CTCs. The CSV-CTC count showed a positive correlation with the T-stage, the M-stage, and the location of the primary tumor (P = 0.01, P = 0.014, and P = 0.01, respectively). Kaplan-Meier survival analysis revealed that CSV-CTCs were associated with worse DFS in patients receiving first-line oxaliplatin chemotherapy (hazard ratio (HR) = 3.78, 95% CI 1.55-9.26, p = 0.04). When the cut-off value of the CSV-CTC count was 3, the optimal prognostic prediction was achieved. Compound models considering CSV-CTCs, TNM staging, the site of the primary tumor and the Ras gene status yielded the best results in both the receiver operating characteristic (ROC) analysis and the decision curve analysis (DCA). This study indicates that CSV-CTCs predominate in CTCs of CRC patients, and a count of CSV-CTCs ≥ 3 is an independent risk factor for worse prognosis.

A Dual Heat Shock Protein Down-Regulation Strategy Using PDA/Cu/ICG/R Controlled by NIR "Switch" Enhances Mild-Photothermal Therapy Effect.

The purpose of this study is to down-regulate heat shock proteins and improve the mild photothermal therapy (mild-PTT) effect of polydopamine (PDA) by preparing the nanosystem of Cu2+ and indocyanine green (ICG)-loaded PDA nanospheres with surface modification of integrin-targeted cyclic peptide (cRGD) (PDA/Cu/ICG/R), which can limit ATP synthesis through the double mitochondrial destruction pathway. In vitro and in vivo experiments using PDA/Cu/ICG/R irradiated with an NIR laser demonstrate that when NIR is "OFF," Cu2+ can undergo Fenton-like reaction in tumor cells, producing a large amount of hydroxyl radicals (·OH), which leads to oxidative stress in cells. This oxidative stress can cause mitochondrial oxidative phosphorylation dysfunction, resulting in limited ATP synthesis. When NIR is "ON," mild-PTT can accelerate Cu2+ to produce ·OH. Simultaneously, NIR can activate ICG to produce reactive oxygen species (ROS) storm, amplify intracellular oxidative stress, and continuously damage mitochondria. The biodegradability of PDA greatly reduces the risk of toxicity caused by long-term retention of PDA/Cu/ICG/R in organisms. Finally, the improvement of the mild-PTT effect of PDA is successfully achieved through the double mitochondrial destruction pathway of Cu2+ and ICG controlled by NIR "switch."

Engineering Rich Active Sites and Efficient Water Dissociation for Ni-Doped MoS2/CoS2 Hierarchical Structures toward Excellent Alkaline Hydrogen Evolution.

Besides improving charge transfer, there are two key factors, such as increasing active sites and promoting water dissociation, to be deeply investigated to realize high-performance MoS2-based electrocatalysts in alkaline hydrogen evolution reaction (HER). Herein, we have demonstrated the synergistic engineering to realize rich unsaturated sulfur atoms and activated O-H bonds toward the water for Ni-doped MoS2/CoS2 hierarchical structures by an approach to Ni doping coupled with in situ sulfurizing for excellent alkaline HER. In this work, the Ni-doped atoms are evolved into Ni(OH)2 during alkaline HER. Interestingly, the extra unsaturated sulfur atoms will be modulated into MoS2 nanosheets by breaking Ni-S bonds during the formation of Ni(OH)2. On the other hand, the higher the mass of the Ni precursor (mNi) for the fabrication of our samples, the more Ni(OH)2 is evolved, indicating a stronger ability for water dissociation of our samples during alkaline HER. Our results further reveal that regulating mNi is crucial to the HER activity of the as-synthesized samples. By regulating mNi to 0.300 g, a balance between increasing active sites and promoting water dissociation is achieved for the Ni-doped MoS2/CoS2 samples to boost alkaline HER. Consequently, the optimal samples present the highest HER activity among all counterparts, accompanied by reliable long-term stability. This work will promise important applications in the field of electrocatalytic hydrogen evolution in alkaline environments.

The Evaluation of Rural Outdoor Dining Environment from Consumer Perspective.

The quality of the environment should be measured by the satisfaction of the public and guided by the issues of public concern. With the development of the internet, social media as the main platform for people to exchange information has become a data source for planning and management analysis. Nowadays, the rural catering industry is becoming increasingly competitive, especially after the pandemic. How to further enhance the competitiveness of the rural catering industry has become a hot topic in the industry. From the perspective of consumers, we explored consumers' preferences in a rural outdoor dining environment through social media data. The research analyzed the social media data through manual collection and object detection, divided the landscape of the rural outdoor dining environment into eight categories with 35 landscape elements, and then used BP (Back Propagation) neural network nonlinear fitting and least square linear fitting to analyze the 11,410 effective review pictures from eight rural restaurants' social media comments in Chengdu. We derived the degree of consumer preference for the landscape quality of the rural outdoor dining environment and analyzed the differences in preference among three different groups (regular customers, customers with children, and customers with the elderly). The study found that agricultural resources are an important factor in the competitiveness of rural restaurant environments; that children's emotions when using activity facilities can positively influence consumers' dining experiences; that safety and hygiene environment are important factors influencing the decisions of parent-child dining; and that older people are more interested in outdoor nature, etc. The research results provide suggestions and knowledge for rural restaurant managers and designers through human-oriented needs from the perspective of consumers, and clarify the preferences and expectations of different consumer groups for rural restaurant landscapes while achieving the goal of rural landscape protection.

Histone Lactylation Boosts Reparative Gene Activation Post-Myocardial Infarction.

BACKGROUND: Inflammation resolution and cardiac repair initiation after myocardial infarction (MI) require timely activation of reparative signals. Histone lactylation confers macrophage homeostatic gene expression signatures via transcriptional regulation. However, the role of histone lactylation in the repair response post-MI remains unclear. We aimed to investigate whether histone lactylation induces reparative gene expression in monocytes early and remotely post-MI. METHODS: Single-cell transcriptome data indicated that reparative genes were activated early and remotely in bone marrow and circulating monocytes before cardiac recruitment. Western blotting and immunofluorescence staining revealed increases in histone lactylation levels, including the previously identified histone H3K18 lactylation in monocyte-macrophages early post-MI. Through joint CUT&Tag and RNA-sequencing analyses, we identified Lrg1, Vegf-a, and IL-10 as histone H3K18 lactylation target genes. The increased modification and expression levels of these target genes post-MI were verified by chromatin immunoprecipitation-qPCR and reverse transcription-qPCR. RESULTS: We demonstrated that histone lactylation regulates the anti-inflammatory and pro-angiogenic dual activities of monocyte-macrophages by facilitating reparative gene transcription and confirmed that histone lactylation favors a reparative environment and improves cardiac function post-MI. Furthermore, we explored the potential positive role of monocyte histone lactylation in reperfused MI. Mechanistically, we provided new evidence that monocytes undergo metabolic reprogramming in the early stage of MI and demonstrated that dysregulated glycolysis and MCT1 (monocarboxylate transporter 1)-mediated lactate transport promote histone lactylation. Finally, we revealed the catalytic effect of IL (interleukin)-1ß-dependent GCN5 (general control non-depressible 5) recruitment on histone H3K18 lactylation and elucidated its potential role as an upstream regulatory element in the regulation of monocyte histone lactylation and downstream reparative gene expression post-MI. CONCLUSIONS: Histone lactylation promotes early remote activation of the reparative transcriptional response in monocytes, which is essential for the establishment of immune homeostasis and timely activation of the cardiac repair process post-MI.

Modified rubber band ligation for treatment of grade II/III hemorrhoids: clinical efficacy and safety evaluation-a retrospective study.

BACKGROUND: Massive, delayed bleeding (DB) is the most common major complication of Rubber Band Ligation (RBL) for internal hemorrhoids caused by premature band slippage. In this study we modified conventional RBL to prevent early rubber band slippage and evaluated its clinical efficacy and safety. METHODS: Study participants were consecutive patients with grade II or III internal hemorrhoids treated with RBL at Ningbo Medical Center of Lihuili Hospital from January 2019 to December 2020. Postoperative minor complications such as pain, swelling, anal edema, prolapse recurrence and major complications like DB were retrospectively reviewed. RESULTS: A total of 274 patients were enrolled, including 149 patients treated with modified RBL and 125 treated with conventional RBL. There was no statistically significant difference between the two groups at baseline. Five cases of postoperative DB have been observed in the conventional RBL group, compared to none in the modified ones, with a significant difference (P < 0.05). Within three months after surgery, 8 cases in the modified RBL group experienced a recurrence rate of 5.4%, whereas 17 patients in the conventional RBL group experienced a recurrence rate of 13.6%. The difference was statistically significant (P < 0.05). The VAS score, edema, and incidence of sensation of prolapse between the two groups were not significantly different at 3 and 7 days after surgery (P < 0.05). There were also no significant differences in HDSS and SHS scores between the two groups after surgery (P > 0.05). CONCLUSION: Modified RBL may be associated with a lower rate of complications, especially with lower DB rate in comparison with standard RBL. Further studies in larger samples and different design are necessary to confirm these results.

Identification of 9 Gene Signatures by WGCNA to Predict Prognosis for Colon Adenocarcinoma.

Background: A risk assessment model for prognostic prediction of colon adenocarcinoma (COAD) was established based on weighted gene co-expression network analysis (WGCNA). Methods: From the Cancer Genome Atlas (TCGA) database, RNA-seq data and clinical data of COAD patients were retrieved. After screening of differentially expressed genes (DEGs), WGCNA was performed to identify gene modules and screen those associated with COAD progression. Then, via protein-protein interaction (PPI) network construction of module genes, hub genes were obtained, which were then subjected to the least absolute shrinkage and selection operator (LASSO) and Cox regression to build a hub gene-based prognostic scoring model. The receiver operating characteristic curve (ROC curve) was plotted for the optimal cutoff (OCO) of the risk score, based on which, patients were assigned to high or low-risk groups. Areas under the ROC curve (AUCs) were calculated, and model performance was visualized using Kaplan-Meier (KM) survival curves and verified in the external dataset GSE29621. Finally, the model's independent prognostic value was evaluated by univariate and multivariate Cox regression analyses, and a nomogram was built. Results: Totally 2840 DEGs were screened from COAD dataset of TCGA, including 1401 upregulated ones and 1439 downregulated ones, which were divided into 10 modules by WGCNA. The eigenvalue of the black module was found to have a high correlation with COAD progression. PPI interaction networks were constructed for genes in the black module, and 34 hub genes were obtained by using the MCODE plug-in. A LASSO-Cox regression approach was utilized to analyze the hub genes, and a prognostic risk score model based on the signatures of 9 genes (CHEK1, DEPDC1B, FANCI, MCM10, NCAPG, PARPBP, PLK4, RAD51AP1, and RFC4) was constructed. KM analysis identified shorter overall lower survival in the high-risk group. The model was verified to have favorable predictive ability through training set and validation set. The nomogram, composed of tumor node metastasis (TNM) staging and risk score, was of good predictability. Conclusions: The COAD prognostic risk model constructed upon the signatures of 9 genes (CHEK1, DEPDC1B, FANCI, MCM10, NCAPG, PARPBP, PLK4, RAD51AP1, and RFC4) can effectively predict the survival status of COAD patients.

Predictive Value of Circulating Tumor Cells in Prognosis of Stage III/IV Colorectal Cancer After Oxaliplatin-based First-line Chemotherapy.

BACKGROUND/AIM: Insufficient data exist to support the concept of the circulating tumor cell (CTC) level as a prognostic factor for platinum-based first-line chemotherapy. This study investigated the impact of CTCs on the prognosis of patients with advanced colorectal cancer (CRC) after receiving platinum-based chemotherapy. Analyses were carried out of clinicopathological features and molecular phenotypes to clarify independent risk factors for a high CTC count. PATIENTS AND METHODS: Patients diagnosed with stage III/IV CRC (n=76) were included in the study. The blood samples of patients were evaluated for CTCs using the CellRich™ platform system. Immunohistochemistry (Ias used to analyze epithelial-mesenchymal transition-associated biomarkers E-cadherin and vimentin. Univariate and logistic regression analyses were then conducted to analyze the risk factors for CTC expression. Additionally, the influence of oxaliplatin on disease-free survival after first-line chemotherapy or during chemotherapy was analyzed through a 2-year follow-up. RESULTS: Patients in the CTC+ group experienced shorter DFS after receiving oxaliplatin first-line chemotherapy than patients in the CTC- group (p<0.01). In addition, univariate analysis revealed that the tumor M-stage, tumor location, RAS mutation, high expression of vimentin, and deletion of E-cadherin expression were correlated with a high CTC count. Multivariate analysis suggested that the presence of RAS gene mutations and high vimentin expression were independent risk factors for high CTC loads (p<0.01). CONCLUSION: CTC positivity can indicate the efficacy of first-line chemotherapy with oxaliplatin in stage III/IV colorectal cancer. This may be linked to tumor epithelial-mesenchymal transition in patients with CTCs. Moreover, RAS gene mutation and high expression of vimentin were identified as independent risk factors for a high CTC count.

Effects of Rural Restaurants' Outdoor Dining Environment Dimensions on Customers' Satisfaction: A Consumer Perspective.

The catering industry is one of the important industries that promote rural tourism development. Hence, rural restaurants have high research value. However, few studies have examined rural restaurants and their outdoor dining environments (ODE). In this study, from the perspective of consumers and using exploratory factor analysis, three ODE dimensions (quality and facilities, image and atmosphere, and landscape elements) were proposed that affect customers' satisfaction with rural restaurants. Moreover, the differences between different customer groups in terms of the various dimensions were analyzed. The research results provide management recommendations and fundamental knowledge for rural restaurant managers and rural restaurant designers and articulate different consumer groups' expectations with regard to rural restaurants.

Quantitative Approach for Protein Analysis in Small Cell Ensembles by an Integrated Microfluidic Chip with MALDI Mass Spectrometry.

Increasing evidence has demonstrated that cells are individually heterogeneous. Advancing the technologies for single-cell analysis will improve our ability to characterize cells, study cell biology, design and screen drugs, and aid cancer diagnosis and treatment. Most current single-cell protein analysis approaches are based on fluorescent antibody-binding technology. However, this technology is limited by high background and cross-talk of multiple tags introduced by fluorescent labels. Stable isotope labels used in mass cytometry can overcome the spectral overlap of fluorophores. Nevertheless, the specificity of each antibody and heavy-metal-tagged antibody combination must be carefully validated to ensure detection of the intended target. Thus, novel single-cell protein analysis methods without using labels are urgently needed. Moreover, the labeling approach targets already known motifs, hampering the discovery of new biomarkers relevant to single-cell population variation. Here, we report a combined microfluidic and matrix-assisted laser desorption and ionization (MALDI) mass spectrometric approach for the analysis of protein biomarkers suitable for small cell ensembles. All necessary steps for cell analysis including cell lysis, protein capture, and digestion as well as MALDI matrix deposition are integrated on a microfluidic chip prior to the downstream MALDI-time-of-flight (TOF) detection. For proof of principle, this combined method is used to assess the amount of Bcl-2, an apoptosis regulator, in metastatic breast cancer cells (MCF-7) by using an isotope-labeled peptide as an internal standard. The proposed approach will eventually provide a new means for proteome studies in small cell ensembles with the potential for single-cell analysis and improve our ability in disease diagnosis, drug discovery, and personalized therapy.

A facile dual-function fluorescent probe for detection of phosgene and nitrite and its applications in portable chemosensor analysis and food analysis.

Due to the potential threats of phosgene and nitrite to public health and safety, in this work, we first proposed the application of a facile dual-function fluorescent probe 2-(1H-Benzimidazol-2-yl)Aniline (BMA) for the detection of phosgene and nitrite in different solvent environments. BMA had fast response (1 min), high selectivity and sensitivity (the limit of detection was 1.27 nM) to phosgene in CH3CN solution (containing 10% DMSO), which manifested as a ratiometric fluorescent mode from 416 nm to 480 nm. The response of BMA to nitrite in HCl solution (pH = 1, containing 10% CH3CN) was also highly selective and sensitive (the limit of detection was 60.63 nM), which shown as a turn-off fluorescent mode at 485 nm. In addition, two portable chemosensors (BMA-loaded TLC plates and test strips) had also been successfully manufactured for the detection of phosgene in the gas phase and nitrite in solution, which displayed good responses. Most importantly, BMA had also been successfully used for detection of nitrite in food samples, and a good recovery (88.5%-107.2%) was obtained by adding standard sodium nitrite.

Efficient conversion of chitin-derived carbon sources into microbial lipid by the oleaginous yeast Cutaneotrichosporon oleaginosum.

Chitin represents the second most abundant biomass after lignocelluloses in the biosphere. It can be depolymerized into either N-acetylglucosamine (GlcNAc) or glucosamine (GlcN) and acetate by different degradation strategies. However, these chitin-derived carbon sources have been scarcely compared for lipid production. Here, GlcNAc was found superior to GlcN or acetate for lipid accumulation by Cutaneotrichosporon oleaginosum. The lipid accumulation potential of these carbon sources was calculated based on a small scale metabolic model of C. oleaginosum. Co-fermentation of GlcN and acetate under phosphate limitation rendered improved lipid production. GlcN and acetate were assimilated simultaneously. The highest lipid titer and yield of 10.1 g/L and 0.25 g/g, respectively, was reached when GlcNAc was used under phosphate limitation. The fatty acids composition of the lipid samples showed similarities to vegetable oils, demonstrating the suitability in biodiesel industry. This study provides profitable guidance for the design of chitin-to-lipids routes.