Regulation of cellulase production via calcium signaling in Trichoderma reesei under PEG8000 stress.

In this study, the effect of polyethylene glycol 8000 (PEG8000) stress on cellulase biosynthesis in Trichoderma reesei CICC2626 via calcium signaling was investigated, and a plausible mechanism by which intracellular Ca2+ regulates the transcription of cellulase genes was proposed. The results indicated that the total cellulase (filter paper-hydrolyzing activity [FPase]), endoglucanase (carboxymethyl cellulase activity [CMCase]), and ß-glucosidase activities of the strain were 1.3-, 1.2-, and 1.3-fold higher than those of the control (no PEG8000 addition) at a final concentration of 1.5% (w/v) PEG8000. Moreover, the transcriptional levels of cellulase genes, protein concentrations, and biomass increased. With the synergistic use of commercial cellulase and T. reesei CICC2626 cellulase to hydrolyze alkali-pretreated rice straw, the released reducing sugar concentration reached 372.7 mg/g, and the cellulose content (22.7%, 0.32 g) was significantly lower than the initial content (62.5%, 1.88 g). Transcriptome data showed that 12 lignocellulose degradation-related genes were significantly upregulated in the presence of 1.5% PEG8000. Furthermore, the addition of Ca2+ inhibitors and deletion of crz1 (calcineurin-responsive zinc finger 1-encoding gene, which is related to the calcium signaling pathway) demonstrated that calcium signaling plays a dominant role in PEG8000-induced cellulase genes overexpression. These results revealed a link between PEG8000 induction and calcium signaling transduction in T. reesei CICC2626. Moreover, this study also provides a novel inducer for enhanced cellulase production. KEY POINTS: • Cellulase biosynthesis in Trichoderma reesei could be enhanced by PEG8000 • PEG8000 could induce a cytosolic Ca2+ burst in Trichoderma reesei • The activated calcium signaling was involved in cellulase biosynthesis.

Alleviation of Oxidative Stress during Hemodialysis Sessions by Hemodialysis Membrane Innovation: A Multidisciplinary Perspective.

Oxidative stress is prevalent in end-stage kidney disease patients receiving chronic hemodialysis and is associated with heavy cardiovascular disease burdens and increased mortality risks. Hemoincompatible hemodialysis membranes per se contribute to the activation of oxidative reactions and the generation of oxygen free radicals. Since the early 1990s, vitamin E-coated membranes have been extensively used in hemodialysis patients to reduce oxidative stress during hemodialysis sessions. However, the beneficial effects of vitamin E-coated membranes versus unmodified synthetic membranes on long-term patient-centered outcomes, such as survival, quality of life, and prevalence of cardiovascular diseases, remain controversial. Accordingly, novel antioxidant hemodialysis membranes were prepared to replace the use of vitamin E-coated membranes despite the translational research on these membranes unfortunately coming to a standstill. In this review, we first summarize the state-of-the-art on the use of vitamin E-coated membranes in hemodialysis patients to highlight their strengths and limitations. Then, we discuss the latest advances in fabricating antioxidant hemodialysis membranes and provide perspectives to bridge knowledge gaps between laboratorial investigations and clinical practice in fabricating antioxidant hemodialysis membranes.

Tracheal microbiome and metabolome profiling in iatrogenic subglottic tracheal stenosis.

BACKGROUND: To study the role of microecology and metabolism in iatrogenic tracheal injury and cicatricial stenosis, we investigated the tracheal microbiome and metabolome in patients with tracheal stenosis after endotracheal intubation. METHODS: We collected 16 protected specimen brush (PSB) and 8 broncho-alveolar lavage (BAL) samples from 8 iatrogenic subglottic tracheal stenosis patients, including 8 PSB samples from tracheal scar sites, 8 PSB samples from scar-free sites and 8 BAL samples, by lavaging the subsegmental bronchi of the right-middle lobe. Metagenomic sequencing was performed to characterize the microbiome profiling of 16 PSB and 8 BAL samples. Untargeted metabolomics was performed in 6 PSB samples (3 from tracheal scar PSB and 3 from tracheal scar-free PSB) using high-performance liquid chromatography‒mass spectrometry (LC‒MS). RESULTS: At the species level, the top four bacterial species were Neisseria subflava, Streptococcus oralis, Capnocytophaga gingivals, and Haemophilus aegyptius. The alpha and beta diversity among tracheal scar PSB, scar-free PSB and BAL samples were compared, and no significant differences were found. Untargeted metabolomics was performed in 6 PSB samples using LC‒MS, and only one statistically significant metabolite, carnitine, was identified. Pathway enrichment analysis of carnitine revealed significant enrichment in fatty acid oxidation. CONCLUSION: Our study found that carnitine levels in tracheal scar tissue were significantly lower than those in scar-free tissue, which might be a new target for the prevention and treatment of iatrogenic tracheal stenosis in the future.

Improvement of Lignocellulolytic Enzyme Production Mediated by Calcium Signaling in Bacillus subtilis Z2 under Graphene Oxide Stress.

An increase in exoenzyme production can be enhanced by environmental stresses such as graphene oxide (GO) stress, but the link between the two events is still unclear. In this work, the effect of GO as an environmental stress factor on exoenzyme (lignocellulolytic enzyme, amylase, peptidase, and protease) biosynthesis was investigated in Bacillus subtilis Z2, and a plausible mechanism by which cytosolic Ca2+ regulates lignocellulolytic enzyme production in B. subtilis Z2 subjected to GO stress was proposed. The filter paper-hydrolyzing (FPase [representing total cellulase]), carboxymethylcellulase (CMCase [representing endoglucanase]), and ß-glucosidase activities and extracellular protein concentration of the wild-type strain under 10 µg/mL GO stress were 1.37-, 1.64-, 1.24-, and 1.16-fold those of the control (without GO stress), respectively. Correspondingly, the transcription levels of lignocellulolytic enzyme genes, cytosolic Ca2+ level, and biomass concentration of B. subtilis were all increased. With lignocellulolytic enzyme from B. subtilis used to hydrolyze alkali-pretreated rice straw, the released reducing sugar concentration reached 265.53 mg/g, and the removal rates of cellulose, hemicellulose, and lignin were 52.4%, 30.1%, and 7.5%, respectively. Furthermore, transcriptome data revealed that intracellular Ca2+ homeostasis played a key role in regulating the levels of gene transcription related to the synthesis of lignocellulolytic enzymes and exoenzymes. Finally, the use of Ca2+ inhibitors (LaCl3 and EDTA) and deletion of spcF (a calmodulin-like protein gene) further demonstrated that the overexpression of those genes was regulated via calcium signaling in B. subtilis subjected to GO stress. IMPORTANCE To effectively convert lignocellulose into fermentable sugars, high lignocellulolytic enzyme loading is needed. Graphene oxide (GO) has been shown to promote exoenzyme (lignocellulolytic enzyme, amylase, peptidase, and protease) production in some microorganisms; however, the regulatory mechanism of the biosynthesis of lignocellulolytic enzymes under GO stress remains unclear. In this work, the lignocellulolytic enzyme production of B. subtilis under GO stress was investigated, and the potential mechanism by which B. subtilis enhanced lignocellulolytic enzyme production through the calcium signaling pathway under GO stress was proposed. This work revealed the role of calcium signaling in the production of enzymes under external environmental stress and provided a direction to facilitate lignocellulolytic enzyme production by B. subtilis.

Preparation of bimetal-polydopamine organic frameworks with core-shell structure and their application in HER2 detection.

Human epidermal growth factor receptor 2 (HER2) is one of the specific markers of breast cancer, which is of great significance to the early diagnosis and prognosis of breast cancer. Here, a fluorescence biosensor was established to detect HER2 based on the fluorescence resonance energy transfer (FRET) and photoinduced electron transfer (PET) occurring between the bimetal-polydopamine organic framework with core-shell structure Au@PDA@UiO-66 and the Cy5 fluorophore in HER2-Cy5-Apt. Au@PDA@UiO-66 owns high-efficiency fluorescence quenching ability due to its large specific surface area and strong adsorption of single-stranded DNA. When the target appears, the fluorescence recovery space mediated by the target is large, so the proposed biosensor has better sensitivity in theory. Under optimized conditions, the proposed fluorescent biosensor can detect HER2 in a range of 0.005 ng mL-1 to 15 ng mL-1, with an actual detection limit as low as 0.005 ng mL-1. Corresponding selective experiments, reproducible experiments, and spiked experiments performed well, showing its great potential in HER2 detection.

All-in-one theranostic nano-platform based on polymer nanoparticles for BRET/FRET-initiated bioluminescence imaging and synergistically anti-inflammatory therapy for ulcerative colitis.

BACKGROUND: Ulcerative colitis (UC), a subtype of inflammatory bowel disease (IBD), has evolved into a global burden given its high incidence. There is a clinical need to create better diagnostic and therapeutic approaches to UC. RESULTS: We fabricated P-selectin binding peptide-decorated poly lactic-co-glycolic acid (PBP-PLGA-NP) doped with two lipophilic dyes, DiL and DiD. Meanwhile, two low-toxic anti-inflammatory natural products (betulinic acid [BA] and resveratrol [Res]) were co-loaded in the PBP-PLGA-NP system. The BA/Res-loaded NPs had an average size of around 164.18 nm with a negative zeta potential (- 25.46 mV). Entrapment efficiencies of BA and Res were 74.54% and 52.33%, respectively, and presented a sustained drug release profile. Further, the resulting PBP-PLGA-NP could be internalized by RAW 264.7 cells and Colon-26 cells efficiently in vitro and preferentially localized to the inflamed colon. When intravenously injected with luminol, MPO-dependent bioluminescence imaging to visualize tissue inflammation was activated by the bioluminescence and fluorescence resonance energy transfer (BRET-FRET) effect. Importantly, injected NPs could remarkably alleviate UC symptoms yet maintain intestinal microbiota homeostasis without inducing organ injuries in the mice models of colitis. CONCLUSIONS: This theranostic nano-platform not only serves as a therapeutic system for UC but also as a non-invasive and highly-sensitive approach for accurately visualizing inflammation.

A novel de novo missense mutation in EFTUD2 identified by whole-exome sequencing in mandibulofacial dysostosis with microcephaly.

BACKGROUND: Mandibulofacial dysostosis with microcephaly (MFDM) is a rare multiple malformation syndrome characterized by malar and mandibular hypoplasia and congenital- or postnatal-onset microcephaly induced by haploinsufficiency of (elongation factor Tu GTP-binding domain-containing 2) EFTUD2. METHODS: We report the case of a 16-month-old boy with MFDM symptoms, including malar and mandibular hypoplasia, microcephaly, micrognathia, midline cleft palate, microtia, auditory canal atresia, severe sensorineural hearing loss, and developmental delay. Whole-exome sequencing (WES) analysis of the patient's family was performed to identify the genetic etiology responsible for this phenotype. RESULTS: We identified a novel de novo missense mutation (c.671G>T, p.Gly224Val) in the EFTUD2. According to the American College of Medical Genetics and Genomics (ACMG) 2015 guidelines, the c.671G>T mutation was classified as likely pathogenic (PS2, PM1, PM2, and PP3). Based on our findings, prenatal diagnosis was performed on the second baby of the proband's parents to exclude the mutation and it was confirmed that the baby did not have the MFDM phenotype after 14 months of follow-up. Furthermore, the zebrafish model confirmed that the EFTUD2 c.671G>T mutation caused a loss of gene function in EFTUD2, and the pathogenicity of the EFTUD2 c.671G>T mutation was classified as pathogenic (PS2, PS3, PM1, and PM2). CONCLUSION: Our results indicate that WES is a useful tool for identifying potentially pathogenic mutations, particularly in rare disorders, and is advantageous for genetic counseling and subsequent prenatal diagnosis. Moreover, the importance of functional assays cannot be underestimated, which could further confirm the pathogenicity of the genetic variants.

Oxygen content-related DNA damage of graphene oxide on human retinal pigment epithelium cells.

Arguments regarding the biocompatibility of graphene-based materials (GBMs) have never ceased. Particularly, the genotoxicity (e.g., DNA damage) of GBMs has been considered the greatest risk to healthy cells. Detailed genotoxicity studies of GBMs are necessary and essential. Herein, we present our recent studies on the genotoxicity of most widely used GBMs such as graphene oxide (GO) and the chemically reduced graphene oxide (RGO) toward human retinal pigment epithelium (RPE) cells. The genotoxicity of GO and RGOs against ARPE-19 (a typical RPE cell line) cells was investigated using the alkaline comet assay, the expression level of phosphorylated p53 determined via Western blots, and the release level of reactive oxygen species (ROS). Our results suggested that both GO and RGOs induced ROS-dependent DNA damage. However, the DNA damage was enhanced following the reduction of the saturated C-O bonds in GO, suggesting that surface oxygen-containing groups played essential roles in the reduced genotoxicity of graphene and had the potential possibility to reduce the toxicity of GBMs via chemical modification.

Management of bone metastasis with intravenous bisphosphonates in breast cancer: a systematic review and meta-analysis of dosing frequency.

BACKGROUND: Bisphosphonates are wildly used in breast cancer patients with bone metastasis and generally administrated every 4 weeks to lessen the risk of subsequent skeletal-related events. Bisphosphonates administration every 12 weeks is also recommended in some guidelines. Recent clinical trials suggested that bisphosphonate treatment with reduced frequency (every 12 weeks) to be non-inferior to standard therapy. The object of this analysis was to contrast the efficacy and safety of these two treatment strategies. METHOD: We systematically retrieved databases such as MEDLINE, PubMed, Embase, and Cochrane library from 1947 to present for clinical trials comparing the efficacy between standard (every 4 weeks) and de-escalation (every 12 weeks) treatment of bisphosphates. RESULTS: We identified 4 articles with available data from 4 randomized clinical trials (n = 1721). Administration of bisphosphate every 12 weeks was non-inferior to administration every 4 weeks. There existed no significant difference in on-study skeletal-related events, renal dysfunction, and osteonecrosis of jaw. In the exploratory study, patients who received intravenous bisphosphates before enrollment experienced less on-study skeletal-related events and significant difference was observed between groups. CONCLUSION: This analysis suggested that de-escalation treatment with bisphosphates may be superior to standard treatment in terms of efficacy, safety, and economic costs. But it would be better that all the patients receive bisphosphates every 4 weeks for several months before de-escalation.

Fam83h mutation inhibits the mineralization in ameloblasts by activating Wnt/ß-catenin signaling pathway.

FAM83H was identified as the major causative gene for autosomal dominant hypocalcified amelogenesis imperfect (ADHCAI). The pathogenic mechanism of FAM83H in ADHCAI remains elusive. The present study aims to investigate the effect of Fam83h mutation on the mineralization of mouse ameloblast cell line LS8 and to explore the possible pathogenesis of ADHCAI. Lentivirus package was performed for the plasmids with mouse Fam83h mutant cDNA (c.1186C > T, M3) and empty vector (Control) and transfected into LS8, which were divided into M3-FLAG and Control groups. Immunoprecipitation, western-blot and immunofluorescence were performed to detect the expression and subcellular localization of Fam83 h, CK1α and ß-catenin. ALP activity, ALP staining, expression of the mineralization factors were detected in two groups during mineralization induction. Expression of the mineralization factors was also detected in M3-FLAG and LS8 exposing to pyrvinium pamoate. Compared with the Control, the Fam83h mutation altered the expression and localization of Fam83 h, CK1α and ß-catenin in LS8, inhibited the mineralization and down-regulated the expression of mineralization factors in M3-FLAG. Pyrvinium pamoate, an inhibitor of the Wnt/ß-catenin signaling pathway, up-regulated expression of mineralization factors in LS8 and rescued the inhibited mineralization in M3-FLAG. The results indicated that the Fam83h mutation could inhibit the mineralization in ameloblasts by activating Wnt/ß-catenin signaling pathway.

The predictive value of drug-induced sleep endoscopy for CPAP titration in OSA patients.

PURPOSE: The aim of this study was to identify possible upper airway obstructions causing a higher continuous positive airway pressure (CPAP) titration level, utilizing drug-induced sleep endoscopy (DISE). METHODS: A total of 76 patients with obstructive sleep apnea (OSA) underwent CPAP titration and DISE. DISE findings were recorded using the VOTE classification system. Polysomnographic (PSG) data, anthropometric variables, and patterns of airway collapse during DISE were analyzed with CPAP titration levels. RESULTS: A significant association was found between the CPAP titration level and BMI, oxygen desaturation index (ODI), apnea-hypopnea index (AHI), and neck circumference (NC) (P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively, by Spearman correlation). Patients with concentric collapse of the velum or lateral oropharyngeal collapse were associated with a significantly higher CPAP titration level (P < 0.001 and P = 0.043, respectively, by nonparametric Mann-Whitney U test; P < 0.001 and P = 0.004, respectively, by Spearman correlation). No significant association was found between the CPAP titration level and any other collapse at the tongue base or epiglottis. CONCLUSIONS: By analyzing PSG data, anthropometric variables, and DISE results with CPAP titration levels, we can better understand possible mechanisms resulting in a higher CPAP titration level. We believe that the role of DISE can be expanded as a tool to identify the possible anatomical structures that may be corrected by oral appliance therapy or surgical intervention to improve CPAP compliance.

Two New Preyssler-Type Polyoxometalate-Based Coordination Polymers and Their Application in Horseradish Peroxidase Immobilization.

Enzyme immobilization is of increasing importance for biocatalysis, for which good supports are critical. Herein, two new Preyssler-type polyoxometalate (POM)-based coordination polymers, namely, {[Cu(H2 biim)2 ][{Cu(H2 biim)2 (µ-H2 O)}2 Cu(H2 biim)(H2 O)2 ]H[({Cu(H2 biim)(H2 O)2 }0.5 )2 ((µ-C3 HN2 Cl2 ){Cu(H2 biim)}2 ){Z(H2 O)P5 W30 O110 }]⋅x H2 O}n (1: Z=Na, x=9; 2: Z=Ag, x=10; H2 biim=2,2'-biimidazole) were designed and synthesized. Compounds 1 and 2 exhibit the same skeletons, which contain multiple CuII complex fragments and penta-supported {ZP5 W30 } (Z=Na, Ag) clusters. They were first employed to immobilize horseradish peroxidase (HRP). Results show that compounds 1 and 2 are good supports for HRP immobilization, and exhibit higher enzyme loading, lower loading times, and excellent reusability. The immobilized HRP (HRP/1 or HRP/2) was further applied to detect H2 O2 , and good sensitivity, wide linear range, low detection limit, and fast response were achieved. This work shows that POM-based hybrid materials are a new kind of promising support for enzyme immobilization.

Preparation and evaluation of HPMC-based pirfenidone solution in vivo.

CONTEXT: Pirfenidone (PFD) has exhibited therapeutic potential in the treatment of cell proliferative disorders. The previously developed 0.5% water-based PFD eye drops by our team exhibited antiscarring effectiveness and ocular safety but with a limit of short half-life and poor bioavailability. OBJECTIVE: To increase bioavailability of the water-based PFD eye drops, we prepared a viscous solution by adding hydroxypropyl methylcellulose (HPMC, F4M), which acted as a viscosity-enhancer. Subsequently, we compared the HPMC-based PFD solution with the water-based PFD eye drops. MATERIALS AND METHODS: PFD solution with 1% HPMC (w/v) was prepared, and the viscosities at different shear rates were measured to investigate its rheology. PFD concentrations in the tear, aqueous humor, conjunctiva, cornea, and sclerae of New Zealand rabbits were detected at different time points with high-performance liquid chromatography (HPLC) following single instillation of the 0.5% PFD (w/v) water-based eye drops or HPMC-based solution. RESULTS: Compared with the 0.5% water-based PFD eye drops, the HPMC-based solution increased the PFD levels in tears and prolonged the residence time from 10 to more than 20 min (p < .01). Consequently, the concentrations of PFD in aqueous humor, conjunctiva, cornea, and sclera were elevated to varying degrees until 90 min after topical administration. CONCLUSIONS: The developed formulation possesses a same readily administration and simple preparation as the PFD eye drops; however, the HPMC-based solution exhibited the higher bioavailability.

P38/JNK signaling pathway mediates the fluoride-induced down-regulation of Fam83h.

BACKGROUND/AIM: The similar clinical and pathological feature in fluorosis and amelogenesis imperfect with FAM83H mutations imply that excess fluoride could have effects on the expression of FAM83H and could elaborate this process by some signal pathways regulation. The present study aims to investigate the effects of fluoride on Fam83h expression and try to explore the molecular signaling regulation between them as well as the association of high concentration fluoride with mineralization in ameloblast lineage cells. METHODS: Protein expression and signaling pathways of mouse ameloblast-like LS8 cells, exposed to fluoride or MAPK inhibitors, were compared to control cells without exposure. Fam83h, proteins of MAPK signal pathways (ERK, P38 and JNK) were examined by Quantitative real-time PCR and/or Western-blot. ALP activity and ALP staining were used to detect the mineralization in the cells with exposure during 7-day mineralization inducing differentiation. RESULTS: The results showed that Fam83h protein level in LS8 cells decreased in the presence of fluoride and MAPK inhibitors. Down-regulation of Fam83h by fluoride was related to suppression of JNK and P38 phosphorylation, and the descending degree of P38 was more obvious. Fluoride and MAPK inhibitors treatment significantly decreased the mineralization level in LS8 cells. CONCLUSION: The findings suggest that JNK and P38 could be key regulatory element for Fam83h expression, and that LS8 cells can respond to fluoride by down-regulating Fam83h expression through the regulation of JNK and p38 signaling pathways.

Enterovirus-related diarrhoea in Guangdong, China: clinical features and implications in hand, foot and mouth disease and herpangina.

BACKGROUND: A series of complications caused by enteroviruses, including meningitis, encephalitis, acute flaccid paralysis, acute cardiopulmonary failure, respiratory infection, and myocardial injury have been reported in hand, foot and mouth disease/herpangina (HFMD/HA). However, the complication of diarrhoea caused by enteroviruses has been neglected, and a summary of its clinical features and impact on HFMD/HA is unavailable. METHODS: We included inpatients with HFMD/HA admitted to the Paediatric Department of Zhujiang Hospital during 2009-2012. We summarised and compared clinical data for cases with and without diarrhoea, and determined enterovirus serotypes by reverse transcriptase polymerase chain reaction and genotyping based on a partial-length fragment of viral protein 1 or the 5'-untranslated region. RESULTS: There were 804 inpatients with HFMD/HA and 28 (3.5%) presented with diarrhoea. Gastrointestinal symptoms were mild in most cases of diarrhoea (82.1%), with high prevalence of no dehydration (82.1%), short duration of diarrhoea (78.6%) and watery stools (75.0%). The prevalence of multi-organ dysfunction syndrome (10.7 vs 0.40%) (p = 0.001), hepatic injury (14.3 vs 3.4%) (p = 0.019), myocardial injury (21.4 vs 6.1%) (p = 0.002) and convulsion (21.4 vs 7.2%) (p = 0.016) was significantly higher in the diarrhoea than no diarrhoea group. There was no significant difference between the two groups regarding prevalence of death, altered consciousness, paralysis, central nervous system involvement, or acute respiratory infection. CONCLUSIONS: Most patients with diarrhoea caused by enteroviruses circulating in Guangdong Province in 2009-2012 had mild or moderate gastrointestinal symptoms. Although enterovirus-related diarrhoea caused additional multi-organ dysfunction syndrome, hepatic injury and myocardial injury in children with HFMD/HA, timely intervention efficiently reduced disease severity and improved outcome.

[Pharmacokinetics and Intestinal Absorption of Curcumin Chitosan Hydrochloride Coated Liposome in Rats].

OBJECTIVE: To investigate the pharmacokinetics and intestinal absorption characteristic of curcumin chitosan hydrochloride coated liposome(CCLP) in SD rats. METHODS: Blood samples were collected after oral administration. Pharmacokinetic parameters were analyzed by DAS program. Rat single pass intestinal perfusion method was employed to investigate the absorption mechanism. RESULTS: The AUC0-t, AUC0-∞, t1/2, and Cmax of CCLP were 1. 73-fold, 1. 95-fold, 1. 56-fold and 1. 91-fold of the free drug. The intestinal absorption rate constant (Ka) of CCLP in duodenum, jejunum, ileum and colon were 1. 48, 1. 28, 1. 17 , and 4. 01 times as much as the free drug and the effective permeability(Peff) of CCLP were 1. 58, 1.-33, 1. 30 and 4. 55 times of the free drug, respectively. CONCLUSION: The bioavailability of CCLP in rats is increased remarkably and Ka is increased in various intestinal segments by CCLP, especially in colon, as well as Peff.

[Determination of ochratoxin A in human urine by HPLC-FLD after cleaned-up by molecularly imprinted polymer solid phase extraction column].

A method was developed for the determination of ochratoxin A (OTA) in human urine by HPLC-FLD after molecularly imprinted polymer solid phase extraction (MIP-SPE) column. After the pH being adjusted to 2.5 with 0.1 mol x L(-1) HC1, sample was cleaned up with MIP-SPE column for ochratoxin A, the analyte was analyzed by high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD), and finally all the positive results were confirmed by LC-MS/MS. Recoveries from urine samples spiked with OTA at levels ranging from 2 to 20 ng x mL(-1) were 90.6%-101.9%, and RSDs were 0.1%-1.6%. Sixty-five volunteers living in Beijing took part in the study, of which 5 were found containing OTA in their urine and the highest value was 0.091 ng x mL(-1). The MIP-SPE column was firstly applied to purify and concentrate OTA in human urine, this method is simple, rapid and reliable and can be used to determine the contents of OTA in human urine.

Recent Progress on Second Near-Infrared Emitting Carbon Dots in Biomedicine.

Second near-infrared (NIR-II) carbon dots, with absorption or emission between 1000 and 1700 nm, are gaining increasing attention in the biomaterial field due to their distinctive properties, which include straightforward preparation processes, stable photophysical characteristics, excellent biocompatibility, and low cost. As a result, there is a growing focus on the controlled synthesis and modulation of the photochemical and photophysical properties of NIR-II carbon dots, with the aim to further expand their biomedical applications, a current research hotspot. This account aims to provide a comprehensive overview of the recent advancements in NIR-II carbon dots within the biomedical field. The review will cover the following topics: (i) the design, synthesis, and purification of NIR-II carbon dots, (ii) the surface modification strategies, and (iii) the biomedical applications, particularly in the domain of cancer theranostics. Additionally, this account addresses the challenges encountered by NIR-II carbon dots and will outline future directions in the realm of cancer theranostics. By exploring carbon-based NIR-II biomaterials, we can anticipate that this contribution will garner increased attention and contribute to the development of next-generation advanced functional carbon dots, thereby offering enhanced tools and strategies in the biomedical field.

Preparation of an injectable zinc-containing hydrogel with double dynamic bond and its potential application in the treatment of periodontitis.

Periodontal tissue regeneration continues to face significant clinical challenges. Periodontitis leads to alveolar bone resorption and even tooth loss due to persistent microbial infection and persistent inflammatory response. As a promising topical drug delivery system, the application of hydrogels in the controlled release of periodontal bioactive drugs has aroused great interest. Therefore, the design and preparation of an injectable hydrogel with self-repairing properties for periodontitis treatment is still in great demand. In this study, polysaccharide-based self-healing hydrogels with antimicrobial osteogenic properties were developed. Zinc ions are introduced into a dynamic cross-linking network formed by dynamic Schiff bases between carboxymethyl chitosan and oxidized hyaluronic acid via coordination bonds. The OC-Zn hydrogels exhibited good tissue adhesion, good fatigue resistance, excellent self-healing ability, low cytotoxicity, good broad-spectrum antimicrobial activity, and osteogenic activity. Therefore, the designed hydrogels allow the development of drug delivery systems as a potential treatment for periodontitis.

Finite element analysis and clinical study of chest wall reconstruction using carbon fiber artificial rib.

Carbon fiber composites are emerging as a promising new biomaterial for chest wall reconstruction implants due to their mechanical properties and biocompatibility. This work evaluates the biomechanics of carbon fiber artificial ribs using finite element analysis and clinical implementation. Static simulations of normal breathing process show the maximum stress on the implant is only 2.83 MPa, far below the material ultimate strength of 60 MPa, indicating the excellent fit for maintaining respiratory function. Dynamic collision simulations demonstrate the artificial rib model could withstand a 4 kg rigid object impact at 2 m/s without fracture. Reconstructing the artificial rib with a human rib in the finite element analysis model increases the overall stress tolerance. The impact force required for fracture increases 48% compared to the artificial rib alone, suggesting improved strength from rib integration. Clinically, 10 of 13 patients receiving the artificial rib implants show no significant loss of pulmonary function based on spirometry tests. Based on our findings, the combined simulations and clinical results validate the strong mechanical performance and biocompatibility of the carbon fiber artificial ribs for chest wall reconstruction under static and dynamic loading while maintaining normal respiratory function.