Epidemiologic trends and changes in humoral immunity and lymphocyte subsets levels among hospitalized children with Mycoplasma pneumoniae infection during 2019-2023.

PURPOSE: To understand the changes in humoral immunity and lymphocyte subsets levels among hospitalized children with Mycoplasma pneumoniae (MP) infection from 2019 to 2023. METHODS: This study retrospectively analyzed inpatients aged 0-14 years who were diagnosed with MP infection or MP pneumonia in a tertiary hospital from January 2019 to December 2023. The children were divided into three groups: before the implementation of nonpharmaceutical interventions (NPIs), during the implementation of NPIs, and after the NPIs being lifted. RESULTS: A total of 4103 patients were enrolled in this study, of whom 2125 were diagnosed with MP infection and 1978 were diagnosed with MP pneumonia. The number of MP infection cases dramatically decreased early during the implementation of NPIs, and the previous epidemic trend resumed after the NPIs were lifted, with the number of cases during the period 2019-2023 peaked in November 2023. In children aged < 5 years, the levels of IgA and IgM and the percentages of total T cells and cytotoxic T cells in the "before the implementation of NPIs" group were greater than those in the other groups, and the percentage of total B cells was lower than that in the other groups. In children aged ≥ 5 years, the IgM level in the "before the implementation of NPIs" group was greater than that in the other groups. CONCLUSION: The number of MP-infected hospitalized children decreased significantly after NPI implementation and reached its highest peak during 2019-2023 in November 2023. After the NPIs were lifted, the level of humoral immunity was decreased and balance lymphocyte subsets were disrupted, especially in children aged < 5 years. We should pay close attention to and prevent MP infection in a timely manner after epidemics caused by large respiratory pathogens.

Revealing a 3D Fermi Surface Pocket and Electron-Hole Tunneling in UTe_{2} with Quantum Oscillations.

Spin triplet superconductor UTe_{2} is widely believed to host a quasi-two-dimensional Fermi surface, revealed by first-principles calculations, photoemission, and quantum oscillation measurements. An outstanding question still remains as to the existence of a three-dimensional Fermi surface pocket, which is crucial for our understanding of the exotic superconducting and topological properties of UTe_{2}. This 3D Fermi surface pocket appears in various theoretical models with different physics origins, but has not been unambiguously detected in experiment. Here for the first time we provide concrete evidence for a relatively isotropic, small Fermi surface pocket of UTe_{2} via quantum oscillation measurements. In addition, we observed high frequency quantum oscillations corresponding to electron-hole tunneling between adjacent electron and hole pockets. The coexistence of 2D and 3D Fermi surface pockets, as well as the breakdown orbits, provide a test bed for theoretical models and aid the realization of a unified understanding of the superconducting state of UTe_{2} from the first-principles approach.

Shinella sedimenti sp. nov., isolated from sediment of Zhairuo Island located in the East China Sea.

A Gram-negative, rod-shaped and aerobic bacterial strain B3.7T, was isolated from the sediment of Zhairuo Island, Zhoushan city, Zhejiang Province, PR China. Maximum growth of strain B3.7T was observed at 30 °C when cultured in a medium containing 0.5 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that strain B3.7T belonged to the genus Shinella; it showed the highest sequence similarity of 98.47 % to Shinella kummerowiae CCBAU 25048T. The average nucleotide identity and digital DNA-DNA hybridization values between strain B3.7T and its reference strains were 82.9-84.2 % and 26.1-27.3 %, respectively. Chemotaxonomic analysis indicated that the sole respiratory quinone was Q-10 and the predominant cellular fatty acids were C19 : 0 cyclo ω8c, C16 : 0, C18 : 1 ω7c 11-methyl and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The polar lipid profile was composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified phospholipids and two unidentified aminolipids. Collectively, strain B3.7T can be considered to represent a novel species, for which the name Shinella sedimenti sp. nov. is proposed. The type strain is B3.7T (=MCCC 1K07163T=LMG 32559T).

Atopomonas sediminilitoris sp. nov., isolated from beach sediment of Zhairuo Island, China.

A novel bacterium designated A3.4T was isolated from the beach sediment of Zhairuo Island, which is located in the East China Sea. Strain A3.4T was found to be Gram-stain negative, cream coloured, rod-shaped, aerobic and motile via a single monopolar flagellum. The isolate grows at 20-37 °C (optimum 25-30 °C), at pH 6.0-8.0 (optimum pH 7.0-8.0), and in the presence of 0-5.0% (w/v) NaCl (optimum 0.5-1%). A3.4T has catalase and oxidase activity. The predominant fatty acids (≥ 10%) of the strain were identified as C16:0, summed feature 3 (C16:1 ω7c /C16:1 ω6c) and summed feature 8 (C18:1 ω7c /C18:1 ω6c). Q-9 was identified as the major isoprenoid quinone, with trace levels of Q-8 present. The major polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The draft genome size is 3.55 Mb, with a DNA G + C content of 57.7 mol%. Analysis of the 16S rRNA gene sequence of strain A3.4T indicates that it belongs to the genus Atopomonas and shares high sequence similarity with Atopomonas hussainii JCM 19513T (97.60%). This classification was also supported by phylogenetic analysis using rpoB and several core genes. The genome of strain A3.4T shows an average nucleotide identity of 82.3%, an amino acid identity of 83.0%, and a digital DNA-DNA hybridization value of 22.1% with A. hussainii. In addition, 20 conserved signature indels (CSIs) were identified to be specific for A3.4T and A. hussainii, demonstrating that the strain A3.4T is closely related to A. hussainii rather than other species of family Pseudomonadaceae. Hundreds of unique genes were identified in the genomes of A3.4T and A. hussainii, which may underly multiple phenotypic differences between these strains. Based on phenotypic, chemotaxonomic, phylogenetic, and genomic investigations, strain A3.4T is concluded to represent a novel species of the genus Atopomonas, for which the name Atopomonas sediminilitoris sp. nov. is proposed. The type strain is A3.4T (= LMG 32563T = MCCC 1K07166T).

Ancylobacter gelatini sp. nov., isolated from beach sediment of Zhairuo Island, China.

A Gram-negative, aerobic, non-motile, oxidase-positive, catalase-positive, methyl red-positive, and lipase-negative bacterium, designated A5.8T, was isolated from beach sediment of Zhairuo Island located in the East China Sea. Growth occurred at 10-40 °C (optimum, 30 °C), pH 5.5-9.5 (optimum, 7.5), and 0-2% NaCl (optimum, 1.5%). Based on 16S rRNA gene sequence analysis, strain A5.8T belongs to the genus Ancylobacter, sharing the highest similarity with Ancylobacter aquaticus JCM 20518T (98.0%). Its polar lipids mainly consist of phosphatidylethanolamine (PE) and phosphatidylcholine (PC). The predominant fatty acids are summed feature 8 (C18:1ω7c and/or C18:1ω6c, 91.0%), and the major respiratory quinone is Q-10. The DNA G + C content is 67.2 mol%. Based on above analysis, as well as digital DNA-DNA hybridization (22.5-22.9%) and average nucleotide identity (83.0-83.6%) of strain A5.8T with reference type strains of the genus Ancylobacter, strain A5.8T was suggested to represent a novel species of the genus Ancylobacter, for which the name Ancylobacter gelatini sp. nov. is proposed. The type strain is A5.8T (= MCCC 1K07167T = LMG 32566T).

Acinetobacter sedimenti sp. nov., isolated from beach sediment.

A Gram-stain-negative, aerobic, non-motile, non-haemolytic, oxidase-negative, catalase-positive bacillus strain (A3.8T) was isolated from beach sediment from Zhairuo Island, PR China. The strain grew at pH 6.0-9.0 (optimum, 7.0), with 0-4.5 % NaCl (optimum, 2 %) and at 10-35 °C (optimum, 30 °C). Its whole-genome sequence was 2.5 Mb in size, with a DNA G+C content of 41.6 mol%. On the basis of the results of core genome phylogenetic analysis, A3.8T represents a separate branch within the clade formed by five species of the genus Acinetobacter with 'Acinetobacter marinus' as the most closely related species. The average nucleotide identity compared with the closely related species of the genus Acinetobacter was below 83.66 % and digital DNA-DNA hybridization values were less than 28.80 %. The predominant fatty acids included C18 : 1ω9c, C16 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). Q-9 was the major respiratory quinone. The polar lipids are mainly composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two phospholipids, an aminolipid and four unknown lipids. A3.8T cannot assimilate dl-lactate and weakly utilizes l-glutamate, l-leucine, l-phenylalanine and l-tartrate, which distinguishes it from other species of the genus Acinetobacter. On the basis of the genotype, phenotype and biochemical data, strain A3.8T represents a novel species of the genus Acinetobacter, for which the name Acinetobacter sedimenti sp. nov. is proposed. The type strain is A3.8T (=MCCC 1K07161T=LMG 32568T).

Recent Advances in the Heterologous Expression of Biosynthetic Gene Clusters for Marine Natural Products.

Marine natural products (MNPs) are an important source of biologically active metabolites, particularly for therapeutic agent development after terrestrial plants and nonmarine microorganisms. Sequencing technologies have revealed that the number of biosynthetic gene clusters (BGCs) in marine microorganisms and the marine environment is much higher than expected. Unfortunately, the majority of them are silent or only weakly expressed under traditional laboratory culture conditions. Furthermore, the large proportion of marine microorganisms are either uncultivable or cannot be genetically manipulated. Efficient heterologous expression systems can activate cryptic BGCs and increase target compound yield, allowing researchers to explore more unknown MNPs. When developing heterologous expression of MNPs, it is critical to consider heterologous host selection as well as genetic manipulations for BGCs. In this review, we summarize current progress on the heterologous expression of MNPs as a reference for future research.

The correlation between skeletal muscle index of the L3 vertebral body and malnutrition in patients with advanced lung cancer.

BACKGROUND: Studies have shown that the skeletal muscle index at the third lumbar vertebra (L3 SMI) had reasonable specificity and sensitivity in nutritional assessment and prognostic prediction in digestive system cancers, but its performance in lung cancer needs further investigation. METHODS: A retrospective study was performed on 110 patients with advanced lung cancer. The L3 SMI, the Patient-Generated Subjective Global Assessment score (PG-SGA score), body mass index (BMI), and serological indicators were analyzed. According to PG-SGA scores, patients were divided into severe malnutrition (≥9 points), mild to moderate malnutrition (≥3 points and ≤ 8 points), and no malnutrition (≤2 points) groups. Pearson correlation and logistic regression analysis were adopted to find factors related to malnutrition, and a forest plot was drawn. The receiver operating characteristic (ROC) curve was performed to compare the diagnostic values of malnutrition among factors, which were expressed by the area under curve (AUC). RESULTS: 1. The age of patients in the severe malnutrition group, the mild to moderate malnutrition group, and the no malnutrition group significantly differed, with mean ages of 63.46 ± 10.01 years, 60.42 ± 8.76 years, and 55.03 ± 10.40 years, respectively (OR = 1.062, 95%CI: 1.008 ~ 1.118, P = 0.024; OR = 1.100, 95%CI: 1.034 ~ 1.170, P = 0.002). Furthermore, the neutrophil to lymphocyte ratio (NLR) of the severe malnutrition group was significantly higher than that of the no malnutrition group, with statistical significance. The difference between the mild to moderate malnutrition group and the no malnutrition group were not statistically significant, with NLR of 4.07 ± 3.34 and 2.47 ± 0.92, respectively (OR = 1.657,95%CI: 1.036 ~ 2.649, P = 0.035). The L3 SMI of patients in the severe malnutrition and mild to moderate malnutrition groups were significantly lower than that of the patients in the no malnutrition group, with statistical significance. The L3 SMI of patients in the severe malnutrition group, mild to moderate malnutrition group, and no malnutrition group were 27.40 ± 4.25 cm2/m2, 38.19 ± 6.17 cm2/m2, and 47.96 ± 5.02 cm2/m2, respectively (OR = 0.600, 95%CI: 0.462 ~ 0.777, P < 0.001; OR = 0.431, 95%CI: 0.320 ~ 0.581, P < 0.001). 2. The Pearson correlation analysis showed that the PG-SGA score positively correlated with age (r = 0.296, P < 0.05) but negatively correlated with L3 SMI (r = - 0.857, P < 0.05). The L3 SMI was also negatively correlated with age (r = - 0.240, P < 0.05). 3. The multivariate analysis showed that the L3 SMI was an independent risk factor for malnutrition (OR = 0.446, 95%CI: 0.258 ~ 0.773, P = 0.004; OR = 0.289, 95%CI: 0.159 ~ 0.524, P < 0.001). CONCLUSION: 1. The differences in the L3 SMI was statistically significant among advanced lung cancer patients with different nutritional statuses. 2. In the nutritional assessment of patients with lung cancer, the L3 SMI was consistent with the PG-SGA. 3. The L3 SMI is an independent predictor of malnutrition in patients with advanced lung cancer.

Design, expression, and characterization of a novel cecropin A-derived peptide with high antibacterial activity.

In recent years, antimicrobial peptides have received increased interest and are potential substitutes for antibiotics. However, natural antimicrobial peptides are always toxic to mammalian cells and usually exhibit weak antibacterial activity, which restrict their wide application. In this study, a novel antibacterial peptide named PEW300 was designed with three mutations to the parental peptide cecropin A. As predicted by bioinformatic programs, the positive charge of PEW300 increased from + 6 to + 9 compared with cecropin A, and the grand average of hydropathicity increased from - 0.084 to - 0.008. Expression of PEW300 resulted in serious inhibition of Escherichia coli BL21(DE3) cells, indicating designed PEW300 may have stronger antibacterial activity. A simple, fast, and low-cost approach without tedious protein purification steps was selected for the efficient production of PEW300 by fusion with ELK16 and about 7.38 µg/mg wet cell weight PEW300 was eventually obtained. Purified PEW300 exhibited strong antibacterial activity against various Gram-positive and Gram-negative bacteria which was enhanced four- to sevenfold compared with the parental peptide cecropin A. Besides, PEW300 had no hemolytic activity toward mammalian cells even at high concentration (224 ng/µl). PEW300 showed good stability in neutral and alkaline solutions. Moreover, PEW300 was thermally stable even at up to 100 °C and resistant to proteinase K, pepsin, snailase, and trypsin. The incubation with human serum had no effect on the antibacterial activity of PEW300. All these results demonstrated that PEW300 designed in this work may have good potential as a candidate pharmaceutical agent.

Rapid and efficient production of cecropin A antibacterial peptide in Escherichia coli by fusion with a self-aggregating protein.

BACKGROUND: Cecropin A (CeA), a natural cationic antimicrobial peptide, exerts potent antimicrobial activity against a broad spectrum of Gram-positive and Gram-negative bacteria, making it an attractive candidate substitute for antimicrobials. However, the low production rate and cumbersome, expensive processes required for both its recombinant and chemical synthesis have seriously hindered the exploitation and application of CeA. Here, we utilized a short ß-structured self-aggregating protein, ELK16, as a fusion partner of CeA, which allowed the efficient production of high-purity CeA antibacterial peptide with a simple inexpensive process. RESULTS: In this study, three different approaches to the production of CeA peptide were investigated: an affinity tag (His-tag)-fused protein expression system (AT-HIS system), a cell-free protein expression system (CF system), and a self-assembling peptide (ELK16)-fused protein expression system (SA-ELK16 system). In the AT-HIS and CF systems, the CeA peptide was obtained with purities of 92.1% and 90.4%, respectively, using one or more affinity-chromatographic purification steps. The procedures were tedious and costly, with CeA yields of only 0.41 and 0.93 µg/mg wet cell weight, respectively. Surprisingly, in the SA-ELK16 system, about 6.2 µg/mg wet cell weight of high-purity (approximately 99.8%) CeA peptide was obtained with a simple low-cost process including steps such as centrifugation and acetic acid treatment. An antimicrobial test showed that the high-purity CeA produced in this study had the same antimicrobial activity as synthetic CeA peptide. CONCLUSIONS: In this study, we designed a suitable expression system (SA-ELK16 system) for the production of the antibacterial peptide CeA and compared it with two other protein expression systems. A high yield of high-purity CeA peptide was obtained with the SA-ELK16 system, which greatly reduced the cost and time required for downstream processing. This system may provide a platform for the laboratory scale production of the CeA antibacterial peptide.

Checking transfer efficiency and equal loading via qualitative optical way in western blotting.

The ability to determine that successful transfer and equal loading occur prior to using primary antibodies is important. And total protein staining is commonly used to check transfer efficiency and normalization, which play a crucial role in western blotting. Ponceau S and coomassie blue are commonly used, but there are disadvantages reported in recent years. Therefore, we are interested in finding another method, which is cheap, easy and fast. As we know, protein binding region of PVDF membrane is still hydrophilic when carbinol volatilizes, however, the non-protein binding region of PVDF membrane became hydrophobic again. And this different wettability between non-protein binding region and protein binding region of Polyvinylidene difluoride membrane may be used to check transfer efficiency and equal loading in western blotting. Based on the principle above, we describe an optical approach where an experimenter can observe that the proteins have been transferred to the membrane without any staining within minutes.

Ecological insights into hematopoiesis regulation: unraveling the influence of gut microbiota.

The gut microbiota constitutes a vast ecological system within the human body, forming a mutually interdependent entity with the host. In recent years, advancements in molecular biology technologies have provided a clearer understanding of the role of the gut microbiota. They not only influence the local immune status and metabolic functions of the host's intestinal tract but also impact the functional transformation of hematopoietic stem cells (HSCs) through the gut-blood axis. In this review, we will discuss the role of the gut microbiota in influencing hematopoiesis. We analyze the interactions between HSCs and other cellular components, with a particular emphasis on the direct functional regulation of HSCs by the gut microbiota and their indirect influence through cellular components in the bone marrow microenvironment. Additionally, we propose potential control targets for signaling pathways triggered by the gut microbiota to regulate hematopoietic function, filling crucial knowledge gaps in the development of this research field.

Comparative Analysis of Hyaline Cartilage Characteristics and Chondrocyte Potential for Articular Cartilage Repair.

This study aimed to compare the histological, biochemical, and mechanical characteristics of hyaline cartilage in different regions and evaluate the potential of chondrocytes extracted from each region as donor sources for articular cartilage repair. The cartilage tissues of the femoral head and knee joint, ribs, nasal septum, thyroid, and xiphoid process of adult Bama pigs were isolated for histological, biochemical, and mechanical evaluation and analysis. The corresponding chondrocytes were isolated and evaluated for proliferation and redifferentiation capacity, using biochemical and histological analysis and RT-PCR experiments. Compared with articular cartilage, non-articular hyaline cartilage matrix stained more intensely in Safranin-O staining. Glycosaminoglycan and total collagen content were similar among all groups, while the highest content was measured in nasal septal cartilage. Regarding biomechanics, non-articular cartilage is similar to articular cartilage, but the elastic modulus and hardness are significantly higher in the middle region of costal cartilage. The chondrocytes extracted from different regions had no significant difference in morphology. Hyaline cartilage-like pellets were formed in each group after redifferentiation. The RT-PCR results revealed similar expressions of cartilage-related genes across the groups, albeit with lower expression of Col2 in the xiphoid chondrocytes. Conversely, higher expression of Col10 was observed in the chondrocytes from the rib, thyroid, and xiphoid cartilage. This study provides valuable preclinical data for evaluating heterotopic hyaline cartilage and chondrocytes for articular cartilage regeneration. The findings contribute to the selection of chondrocyte origins and advance the clinical translation of technology for cartilage regeneration.

CT-based muscle and adipose measurements predict prognosis in patients with digestive system malignancy.

The role of skeletal muscle and adipose tissue in the progression of cancer has been gradually discussed, but it needs further exploration. The objective of this study was to provide an in-depth analysis of skeletal muscle and fat in digestive malignancies and to construct novel predictors for clinical management. This is a retrospective study that includes data from Cancer Center, the First Hospital of Jilin University. Basic characteristic information was analyzed by T tests. Correlation matrices were drawn to explore the relationship between CT-related indicators and other indicators. Cox risk regression analyses were performed to analyze the association between the overall survivals (OS) and various types of indicators. A new indicator body composition score (BCS) was then created and a time-dependent receiver operating characteristic curve was plotted to analyze the efficacy of the BCS. Finally, a nomogram was produced to develop a scored-CT system based on BCS and other indicators. C-index and calibration curve analyses were performed to validate the predictive accuracy of the scored-CT system. A total of 575 participants were enrolled in the study. Cox risk regression model revealed that VFD, L3 SMI and VFA/SFA were associated with prognosis of cancer patients. After adjustment, BCS index based on CT was significantly associated with prognosis, both in all study population and in subgroup analysis according to tumor types (all study population: HR 2.036, P < 0.001; colorectal cancer: HR 2.693, P < 0.001; hepatocellular carcinoma: HR 4.863, P < 0.001; esophageal cancer: HR 4.431, P = 0.008; pancreatic cancer: HR 1.905, P = 0.016; biliary system malignancies: HR 23.829, P = 0.035). The scored-CT system was constructed according to tumor type, stage, KPS, PG-SGA and BCS index, and it was of great predictive validity. This study identified VFD, L3 SMI and VFA/SFA associated with digestive malignancies outcomes. BCS was created and the scored-CT system was established to predict the OS of cancer patients.

Influence of Subchondral Cysts on the Outcomes of Surgical Treatment for Osteochondral Lesions of the Talus: A Systematic Review and Meta-analysis.

Background: Limited literature is available regarding the effect of subchondral cysts on the surgical outcomes for treatment of osteochondral lesion of the talus (OLT). Purpose: To conduct a systematic review and meta-analysis of studies comparing surgical outcomes between OLTs with and without cysts. Study Design: Systematic review; Level of evidence, 4. Methods: Following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, the authors searched PubMed, Embase, Web of Science, and the Cochrane Library for relevant studies published up to January 7, 2023. The 4375 retrieved studies were screened, and 9 articles (level of evidence, 2-4) were included, which comprised 165 patients with OLT and subchondral cysts (cyst group) and 223 without cysts (noncyst group). After data extraction, mean differences in outcome scores (American Orthopaedic Foot and Ankle Society [AOFAS] Ankle Hindfoot Scale, visual analog scale [VAS] score for pain) and adverse events were compared between the groups. Results: Functional scores improved after surgery in both groups, with the cyst group having a significantly higher AOFAS score than the noncyst group (P = .005; I2 = 0%); subgroup analysis revealed that this difference was attributable to the size of the osteochondral lesion and the type of surgical procedure. No significant difference was found between the cyst and noncyst groups in VAS pain scores (P = .77; I2 = 0%) or postoperative adverse events (P = .35; I2 = 0%). Conclusion: The results of this review indicated that patients with subchondral cysts improved with surgical treatment of OLT. A relatively low level of evidence was available to indicate that surgical treatment for small OLTs with subchondral cysts will result in better clinical outcomes compared with OLTs without cysts.

Enhanced articular cartilage regeneration using costal chondrocyte-derived scaffold-free tissue engineered constructs with ascorbic acid treatment.

Background: Cartilage tissue engineering faces challenges related to the use of scaffolds and limited seed cells. This study aims to propose a cost-effective and straightforward approach using costal chondrocytes (CCs) as an alternative cell source to overcome these challenges, eliminating the need for special culture equipment or scaffolds. Methods: CCs were cultured at a high cell density with and without ascorbic acid treatment, serving as the experimental and control groups, respectively. Viability and tissue-engineered constructs (TEC) formation were evaluated until day 14. Slices of TEC samples were used for histological staining to evaluate the secretion of glycosaminoglycans and different types of collagen proteins within the extracellular matrix. mRNA sequencing and qPCR were performed to examine gene expression related to cartilage matrix secretion in the chondrocytes. In vivo experiments were conducted by implanting TECs from different groups into the defect site, followed by sample collection after 12 weeks for histological staining and scoring to evaluate the extent of cartilage regeneration. Hematoxylin-eosin (HE), Safranin-O-Fast Green, and Masson's trichrome stainings were used to examine the content of cartilage-related matrix components in the in vivo repair tissue. Immunohistochemical staining for type I and type II collagen, as well as aggrecan, was performed to assess the presence and distribution of these specific markers. Additionally, immunohistochemical staining for type X collagen was used to observe any hypertrophic changes in the repaired tissue. Results: Viability of the chondrocytes remained high throughout the culture period, and the TECs displayed an enriched extracellular matrix suitable for surgical procedures. In vitro study revealed glycosaminoglycan and type II collagen production in both groups of TEC, while the TEC matrix treated with ascorbic acid displayed greater abundance. The results of mRNA sequencing and qPCR showed that genes related to cartilage matrix secretion such as Sox9, Col2, and Acan were upregulated by ascorbic acid in costal chondrocytes. Although the addition of Asc-2P led to an increase in COL10 expression according to qPCR and RNA-seq results, the immunofluorescence staining results of the two groups of TECs exhibited similar distribution and fluorescence intensity. In vivo experiments showed that both groups of TEC could adhere to the defect sites and kept hyaline cartilage morphology until 12 weeks. TEC treated with ascorbic acid showed superior cartilage regeneration as evidenced by significantly higher ICRS and O'Driscoll scores and stronger Safranin-O and collagen staining mimicking native cartilage when compared to other groups. In addition, the immunohistochemical staining results of Collgan X indicated that, after 12 weeks, the ascorbic acid-treated TEC did not exhibit further hypertrophy upon transplantation into the defect site, but maintained an expression profile similar to untreated TECs, while slightly higher than the sham-operated group. Conclusion: These results suggest that CC-derived scaffold-free TEC presents a promising method for articular cartilage regeneration. Ascorbic acid treatment enhances outcomes by promoting cartilage matrix production. This study provides valuable insights and potential advancements in the field of cartilage tissue engineering. The translational potential of this article: Cartilage tissue engineering is an area of research with immense clinical potential. The approach presented in this article offers a cost-effective and straightforward solution, which can minimize the complexity of cell culture and scaffold fabrication. This simplification could offer several translational advantages, such as ease of use, rapid scalability, lower costs, and the potential for patient-specific clinical translation. The use of costal chondrocytes, which are easily obtainable, and the scaffold-free approach, which does not require specialized equipment or membranes, could be particularly advantageous in clinical settings, allowing for in situ regeneration of cartilage.

Direct and Rapid Visualization of the Spatial Distribution of Cholesterol in Alzheimer's and Cancer Tissue via MALDI Mass Spectrometry Imaging.

Cholesterol is a vital component of the central nervous system and tissues, and understanding its spatial distribution is crucial for biology, pathophysiology, and diagnostics. However, direct imaging of cholesterol using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) remains challenging and time-consuming due to the difficulty in ionizing the sterol molecule. To tackle this issue, a MALDI-MSI method is established for direct and rapid analysis of the spatial distribution of cholesterol in Alzheimer's disease (AD), different cancer tissues and organs via MALDI-MSI. This excellent imaging performance depends on the study and systemic optimization of various conditions that affect the imaging of MALDI-MSI. In this case, we report the distribution and levels of cholesterol across specific structures of the AD mouse brain and different tumor tissue and organs. According to the results, the content of cholesterol in the AD mouse cerebellum, especially in the arborvitae, was significantly higher than that in the wild type (WT) model. Furthermore, we successfully visualize the distribution of cholesterol in other organs, such as the heart, liver, spleen, kidney, pancreas, as well as tumor tissues parenchyma and interstitium using MALDI-MSI. Notably, the attribution of cholesterol MS/MS hydrocarbon fragments was systematically investigated. Our presented optimization strategy and established MALDI-MSI method can be easily generalized for different animal tissues or live samples, thereby facilitating the potential for applications of MALDI-MSI in clinical, medical and biological research.

Effects of different solid particle sizes on oat protein isolate and pectin particle-stabilized Pickering emulsions and their use as delivery systems.

Oat protein isolate (OPI)/high methoxyl pectin (HMP) complexes (OPP) were prepared to stabilized Pickering emulsions and applied as nutraceutical delivery systems. The different mass ratios and pH changed the interactions between OPI and HMP that caused the different size of OPP. Specifically, smaller particle size of OPP (125.7-297.6 nm) were formed when hydrophobic interactions along with electrostatic forces predominant in OPP (OPI:HMP = 3:1, pH 4, 5). Among these particles, OPP-2 could stabilize Pickering emulsion efficiently through formation of dense interfacial film, which exhibited the highest apparent viscosity and the smallest average droplet size (23.39 µm). Moreover, OPP-2 stabilized Pickering emulsions with superior stability not only exhibited higher encapsulation efficiency of 85.63%, but also could control curcumin release in simulated gastrointestinal fluids to improve curcumin's bioaccessibility. These results verified the possibility of OPP to be a Pickering emulsions stabilizer, and also identified its potential to be a stable delivery system for bioactive compounds.

Effective Activation of Peroxymonosulfate by Oxygen Vacancy Induced Musa Basjoo Biochar to Degrade Sulfamethoxazole: Efficiency and Mechanism.

Biochar materials have garnered attention as potential catalysts for peroxymonosulfate (PMS) activation due to their cost-effectiveness, notable specific surface area, and advantageous structural properties. In this study, a suite of plantain-derived biochar (MBB-400, MBB-600, and MBB-800), possessing a well-defined pore structure and a substantial number of uniformly distributed active sites (oxygen vacancy, OVs), was synthesized through a facile calcination process at varying temperatures (400, 600, and 800 °C). These materials were designed for the activation of PMS in the degradation of sulfamethoxazole (SMX). Experimental investigations revealed that OVs not only functioned as enriched sites for pollutants, enhancing the opportunities for free radicals (•OH/SO4•-) and surface-bound radicals (SBRs) to attack pollutants, but also served as channels for intramolecular charge transfer leaps. This role contributed to a reduction in interfacial charge transfer resistance, expediting electron transfer rates with PMS, thereby accelerating the decomposition of pollutants. Capitalizing on these merits, the MBB-800/PMS system displayed a 61-fold enhancement in the conversion rate for SMX degradation compared to inactivated MBB/PMS system. Furthermore, the MBB-800 exhibited less cytotoxicity towards rat pheochromocytoma (PC12) cells. Hence, the straightforward calcination synthesis of MBB-800 emerges as a promising biochar catalyst with vast potential for sustainable and efficient wastewater treatment and environmental remediation.

Enhanced osteochondral regeneration with a 3D-Printed biomimetic scaffold featuring a calcified interfacial layer.

The integrative regeneration of both articular cartilage and subchondral bone remains an unmet clinical need due to the difficulties of mimicking spatial complexity in native osteochondral tissues for artificial implants. Layer-by-layer fabrication strategies, such as 3D printing, have emerged as a promising technology replicating the stratified zonal architecture and varying microstructures and mechanical properties. However, the dynamic and circulating physiological environments, such as mass transportation or cell migration, usually distort the pre-confined biological properties in the layered implants, leading to undistinguished spatial variations and subsequently inefficient regenerations. This study introduced a biomimetic calcified interfacial layer into the scaffold as a compact barrier between a cartilage layer and a subchondral bone layer to facilitate osteogenic-chondrogenic repair. The calcified interfacial layer consisting of compact polycaprolactone (PCL), nano-hydroxyapatite, and tasquinimod (TA) can physically and biologically separate the cartilage layer (TA-mixed, chondrocytes-load gelatin methacrylate) from the subchondral bond layer (porous PCL). This introduction preserved the as-designed independent biological environment in each layer for both cartilage and bone regeneration, successfully inhibiting vascular invasion into the cartilage layer and preventing hyaluronic cartilage calcification owing to devascularization of TA. The improved integrative regeneration of cartilage and subchondral bone was validated through gross examination, micro-computed tomography (micro-CT), and histological and immunohistochemical analyses based on an in vivo rat model. Moreover, gene and protein expression studies identified a key role of Caveolin (CAV-1) in promoting angiogenesis through the Wnt/ß-catenin pathway and indicated that TA in the calcified layer blocked angiogenesis by inhibiting CAV-1.