Exosomes derived from bone marrow mesenchymal stem cells induce the proliferation and osteogenic differentiation and regulate the inflammatory state in osteomyelitis in vitro model.

Chronic osteomyelitis is a chronic bone infection characterized by progressive osteonecrosis and dead bone formation, which is closely related to persistent infection and chronic inflammation. Exosomes derived from bone marrow-derived mesenchymal stem cells (BMSC) play an important role in bone tissue regeneration and the modulation of inflammatory processes. However, their role and mechanism of action in osteomyelitis have not been reported so far. This paper explores the potential effect of BMSC-derived exosomes on osteomyelitis in vitro model with the aim of providing a theoretical basis for the treatment of osteomyelitis in the future. In this study, exosomes were isolated and extracted from BMSCs and identified. MC3T3-E1 cells were treated with Staphylococcal protein A (SPA) to establish an in vitro model of osteomyelitis. Next, the effects of BMSC-derived exosomes on cell proliferation, apoptosis, angiogenesis, and autophagy in MC3T3-E1 cells treated with SPA were evaluated. Results showed that the proliferation ability of MC3T3-E1 cells increased after co-culture with BMSC-derived exosomes. Moreover, exosomes induced autophagy and osteogenic differentiation in MC3T3-E1 cells. The mRNA and protein levels of factors related to proliferation, differentiation, apoptosis, autophagy, and angiogenesis including ß-Catenin, Runx2, Bcl-2, VEGFA, and Beclin-1 upregulated in SPA-treated MC3T3-E1 cells, whereas the levels of inflammatory cytokines including TNF-α, IL-1ß, and IL-6 decreased in the supernatant. The results showed that exosomes derived from BMSCs may participate in the attenuation of osteomyelitis by inducing proliferation and osteogenic differentiation and regulating the inflammatory state in bone cells.

Fluorescent probe applications and prospects in gastrointestinal cancer: A bibliometric analysis.

BACKGROUND: Gastrointestinal tumors, as one of the most common cancers worldwide, pose a significant threat to human health. In this context, the advent of fluorescence probe technology has offered new perspectives and methods for the diagnosis and surgical treatment of gastrointestinal tumors. However, there is currently a lack of systematic bibliometric analysis on the research concerning gastrointestinal cancer and fluorescence probes. METHOD: This study retrieved and comprehensively analyzed 1816 documents from the Web of Science database using the Cite Space tool, exploring the spatiotemporal distribution, author and subject category distribution, research themes, and keywords in this field. RESULTS: As of February 3, 2024, a total of 1816 records were retrieved, encompassing nine document types. Original research papers dominated the dataset, accounting for 89.922 %, followed by review articles at 6.773 %. We conducted a comprehensive analysis from various perspectives including countries, authors, institutions, keywords, journals, and references. Our findings reveal a strengthening trend in research on gastrointestinal cancer and fluorescent probes since 2010, with primary focus on drug delivery, endoscopy techniques, and genomic hybridization. CONCLUSION: In recent years, there has been a growing interest in the design, application, and quantitative analysis techniques of fluorescent probes, marking a notable frontier in this field. Our research findings offer fundamental insights and aid in identifying potential collaborators for future endeavors in this area.

Lipid Metabolism, Methylation Aberrant, and Osteoporosis: A Multi-omics Study Based on Mendelian Randomization.

BACKGROUND: Observational studies have shown a causal association between dyslipidemia and osteoporosis, but the genetic causation and complete mechanism of which are uncertain. The disadvantage of previous observational studies is that they are susceptible to confounding factors and bias, that makes it difficult to infer a causal link between those two diseases. Abnormal epigenetic modifications, represented by DNA methylation, are important causes of many diseases. However, there are no studies showing a bridging role for methylation modifications in blood lipid metabolism and osteoporosis. METHODS: SNPs for lipid profile (Blood VLDL cholesterol (VLDL-C), blood LDL cholesterol (LDL-C), blood HDL cholesterol (HDL-C), blood triglycerides (TG), diagnosed pure hypercholesterolaemia, blood apolipoprotein B (Apo B), blood apolipoprotein A1(Apo A1)), and bone mineral density (BMD) in different body parts (Heel BMD, lumbar BMD, whole-body BMD, femoral neck BMD) were obtained from large meta-analyses of genome-wide association studies as instrumental variables for two-sample Mendelian randomization. Assessment of the genetic effects of lipid profile-associated methylation sites and bone mineral density was carried out using the summary-data-based Mendelian randomization (SMR) method. RESULTS: Two-sample Mendelian randomization showed that there was a negative causal association between hypercholesterolaemia and heel BMD (p = 0.0103, OR = 0.4590), and total body BMD (p = 0.0002, OR = 0.2826). LDL-C had a negative causal association with heel BMD (p = 8.68E-05, OR = 0.9586). VLDL-C had a negative causal association with heel BMD (p = 0.035, OR = 0.9484), lumbar BMD (p = 0.0316, OR = 0.9356), and total body BMD (p = 0.0035, OR = 0.9484). HDL-C had a negative causal association with heel BMD (p = 1.25E-05, OR = 0.9548), lumbar BMD (p = 0.0129, OR = 0.9358), and total body BMD (p = 0.0399, OR = 0.9644). Apo B had a negative causal association with heel BMD (p = 0.0001, OR = 0.9647). Apo A1 had a negative causal association with heel BMD (p = 0.0132, OR = 0.9746) and lumbar BMD (p = 0.0058, OR = 0.9261). The p-values of all positive results corrected by the FDR method remained significant and sensitivity analysis showed that there was no horizontal pleiotropy in the results despite the heterogeneity in some results. SMR identified 3 methylation sites associated with lipid profiles in the presence of genetic effects on BMD: cg15707428(GREB1), cg16000331(SREBF2), cg14364472(NOTCH1). CONCLUSION: Our study provides insights into the potential causal links and co-pathogenesis between dyslipidemia and osteoporosis. The genetic effects of dyslipidaemia on osteoporosis may be related to certain aberrant methylation genetic modifications.

Machine learning algorithm predicts fibrosis-related blood diagnosis markers of intervertebral disc degeneration.

BACKGROUND: Intervertebral disc cell fibrosis has been established as a contributing factor to intervertebral disc degeneration (IDD). This study aimed to identify fibrosis-related diagnostic genes for patients with IDD. METHODS: RNA-sequencing data was downloaded from Gene Expression Omnibus (GEO) database. The diagnostic genes was identified using Random forest based on the differentially expressed fibrosis-related genes (DE-FIGs) between IDD and control samples. The immune infiltration states in IDD and the regulatory network as well as potential drugs targeted diagnostic genes were investigated. Quantitative Real-Time PCR was conducted for gene expression valifation. RESULTS: CEP120 and SPDL1 merged as diagnostic genes. Substantial variations were observed in the proportions of natural killer cells, neutrophils, and myeloid-derived suppressor cells between IDD and control samples. Further experiments indicated that AC144548.1 could regulate the expressions of SPDL1 and CEP120 by combininghsa-miR-5195-3p and hsa-miR-455-3p, respectively. Additionally, transcription factors FOXM1, PPARG, and ATF3 were identified as regulators of SPDL1 and CEP120 transcription. Notably, 56 drugs were predicted to target these genes. The down-regulation of SPDL1 and CEP120 was also validated. CONCLUSION: This study identified two diagnostic genes associated with fibrosis in patients with IDD. Additionally, we elucidated their potential regulatory networks and identified target drugs, which offer a theoretical basis and reference for further study into fibrosis-related genes involved in IDD.

GREM1, LRPPRC and SLC39A4 as potential biomarkers of intervertebral disc degeneration: a bioinformatics analysis based on multiple microarray and single-cell sequencing data.

BACKGROUND: Low back pain (LBP) has drawn much widespread attention and is a major global health concern. In this field, intervertebral disc degeneration (IVDD) is frequently the focus of classic studies. However, the mechanistic foundation of IVDD is unclear and has led to conflicting outcomes. METHODS: Gene expression profiles (GSE34095, GSE147383) of IVDD patients alongside control groups were analyzed to identify differentially expressed genes (DEGs) in the GEO database. GSE23130 and GSE70362 were applied to validate the yielded key genes from DEGs by means of a best subset selection regression. Four machine-learning models were established to assess their predictive ability. Single-sample gene set enrichment analysis (ssGSEA) was used to profile the correlation between overall immune infiltration levels with Thompson grades and key genes. The upstream targeting miRNAs of key genes (GSE63492) were also analyzed. A single-cell transcriptome sequencing data (GSE160756) was used to define several cell clusters of nucleus pulposus (NP), annulus fibrosus (AF), and cartilaginous endplate (CEP) of human intervertebral discs and the distribution of key genes in different cell clusters was yielded. RESULTS: By developing appropriate p-values and logFC values, a total of 6 DEGs was obtained. 3 key genes (LRPPRC, GREM1, and SLC39A4) were validated by an externally validated predictive modeling method. The ssGSEA results indicated that key genes were correlated with the infiltration abundance of multiple immune cells, such as dendritic cells and macrophages. Accordingly, these 4 key miRNAs (miR-103a-3p, miR-484, miR-665, miR-107) were identified as upstream regulators targeting key genes using the miRNet database and external GEO datasets. Finally, the spatial distribution of key genes in AF, CEP, and NP was plotted. Pseudo-time series and GSEA analysis indicated that the expression level of GREM1 and the differentiation trajectory of NP chondrocytes are generally consistent. GREM1 may mainly exacerbate the degeneration of NP cells in IVDD. CONCLUSIONS: Our study gives a novel perspective for identifying reliable and effective gene therapy targets in IVDD.

Upper trapezius muscle elasticity in cervical myofascial pain syndrome measured using real-time ultrasound shear-wave elastography.

Background: Myofascial pain syndrome (MPS) is a common cause of neck pain, which is a global public health problem. Because MPS does not present morphological changes within lesioned muscles, there are no imaging diagnostic criteria for this condition. In this study, we evaluate elasticity changes in upper trapezius muscles most frequently involved in cervical MPS using real-time ultrasound shear-wave elastography, and we examine their potential diagnostic value. Methods: We consecutively enrolled 109 right posterior neck pain patients for this prospective study. Of these, 51 were diagnosed with MPS and 58 with non-MPS in the right side of their neck. Among MPS patients, 19 fell into the 1-3 range (mild pain) for pain scores on the visual analog scale (VAS), 25 fell into the 4-6 range (moderate pain), and 7 into the 7-10 range (severe pain). MPS was diagnosed by two independent clinicians using the diagnostic criteria proposed by Simons et al. Using real-time ultrasound shear-wave elastography, we measured right trapezius mean shear-wave velocity (SWVmean). The midpoint of the line between the foramen magnum and the end of the right acromion served as measuring point. Regions of interest were scaled to span 0-8.0 m/s. Results: Trapezius SWVmean was significantly higher in MPS patients compared with non-MPS patients (P<0.001). Stratified analysis of MPS patients according to pain severity revealed similar trapezius SWVmean between mild pain and non-MPS patients (P=0.324), however SWVmean was higher in moderate and severe pain MPS patients compared with non-MPS patients (P<0.001). The area under the curve (AUC) value for upper trapezius SWVmean in MPS patients was 0.791 (95% CI: 0.703-0.863). Corresponding sensitivity and specificity values were 86.27% (95% CI: 73.7-94.3%) and 62.07% (95% CI: 48.4-74.5%). Stratified analysis of MPS patients by pain severity produced the following AUC values for trapezius SWVmean in MPS patients with mild, moderate, and severe pain: 0.578 (95% CI: 0.460-0.690), 0.899 (95% CI: 0.814-0.955), and 0.983 (95% CI: 0.914-0.999), respectively. Conclusions: Elasticity changes and increased stiffness in the trapezius occur in cervical MPS patients with moderate and severe pain. The SWVmean parameter reflecting trapezius muscle elasticity may be valuable for successful screening of cervical MPS, especially in patients with moderate and severe pain.

Near-infrared magnetic core-shell nanoparticles based on lanthanide metal-organic frameworks as a ratiometric felodipine sensing platform.

Felodipine is an effective drug to treat hypertension, but its abuse can cause bardycardia. It is significant to develop highly sensitive detection platform for felodipine to enable the efficient treatment of hypertension diseases. In this work, to highly efficiently detect felodipine, multi-emission near-infrared (NIR) hierarchical magnetic core-shell lanthanide-MOF nanoparticles, namely Nd-MOF@Yb-MOF@SiO2@Fe3O4 (NIR-1), has been synthesized by layer-by-layer (LBL) method. LBL method can adjust the optical properties of NIR-1 and expose more active sites to improve sensitivity in detection process. NIR-1 has near-infrared luminescence emission, which can efficiently avoid the interference of autofluorescence in biological tissues. Photo-luminescent (PL) experiments also reveal that NIR-1 could be used as a near-infrared ratiometric luminescent sensor for felodipine detection with high selectivity and sensitivity, the low of detection limit (LOD) is 6.39 nM in felodipine detection, which is also performed using real biological samples. In addition, NIR-1 can be used as a ratiometric thermometer could also be applied in the temperature sensing from 293 K to 343 K. Finally, detection mechanisms for felodipine and temperature sensing performance based on near-infrared (NIR) emission were also investigated and discussed in detail.

["Houxi (SI 3) communicating the governor vessel" verified with the infrared thermal imaging technology].

OBJECTIVE: To compare the effect on facial acupoint temperature between acupuncture at Houxi (SI 3) and Dazhui (GV 14) so as to verify "Houxi (SI 3) communicating the governor vessel" based on the infrared thermal imaging technology. METHODS: Thirty-five healthy subjects (5 cases dropped off) were collected and before-after study in the same subject was adopted. The subjects were successively assigned into a sham-acupuncture group, a Houxi group, a Wangu group and a Dazhui group. Sham-acupuncture at Houxi (SI 3) on the left, acupuncture at Houxi (SI 3) on the left, Wangu (SI 4) on the left and Dazhui (GV 14) were given respectively. One intervention was given and the needles were retained for 30 min in each group. 30 min before and after acupuncture, the infrared thermal images of the face were collected, and the facial temperature was compared among the following 5 acupoints, i.e. Yintang (GV 24+), Suliao (GV 25), Shuigou (GV 26), Duiduan (GV 27) and Chengjiang (CV 24). RESULTS: After acupuncture, the facial temperature at Yintang (GV 24+) and Chengjiang (CV 24) was increased compared before acupuncture in the sham-acupuncture group (P<0.01, P<0.05). The facial temperature at Suliao (GV 25) in the Houxi group was reduced after acupuncture (P<0.05). In the Wangu group, the temperature at Yintang (GV 24+) was increased compared before acupuncture (P<0.01). The facial temperature was increased at Duiduan (GV 27) and Chengjiang (CV 24) compared before acupuncture in the Dazhui group (P<0.01, P<0.05). The differences of facial temperature at Chengjiang (CV 24) and Suliao (GV 25) after acupuncture were larger than before acupuncture in the Houxi group and the Dazhui group (P<0.01). In comparison with the temperature at Suliao (GV 25) of the same group, the differences of facial temperature before and after acupuncture at Yintang (GV 24+), Shuigou (GV 26), Duiduan (GV 27) and Chengjiang (CV 24) were increased in the Houxi group (P<0.01, P<0.05); while, the increase was also obtained at Yintang (GV 24+), Shuigou (GV 26), Duiduan (GV 27) and Chengjiang (CV 24) in the Dazhui group (P<0.05, P<0.01). The difference of facial temperature at Yintang (GV 24+) before and after acupuncture was increased compared with Suliao (GV 25) in the Wangu group (P<0.05). CONCLUSION: Acupuncture at Houxi (SI 3) generates a similar thermal effect as Dazhui (GV 14). It regulates and dissipates the core temperature to "govern the yang qi of the whole body".

Circ_C4orf36 Promotes the Proliferation and Osteogenic Differentiation of BMSCs by Regulating VEGFA.

Fracture healing is a complicated process containing the regulation of cellular process. It has been reported that circRNAs are involved in fracture healing. Our study aims to explore the role and mechanism of circ_C4orf36 in fracture healing. Here, we found that the expressions of Circ_C4orf36 and VEGFA were increased during osteoblast differentiation in MC3T3-E1 cells. Circ_C4orf36 overexpression could accelerate the proliferation and migration, as well as osteoblast differentiation in MC3T3-E1 cells, as well as increased ALP activity and osteogenic markers (Runx2, OCN) via upregulating VEGFA expression. Mechanistically, circ_C4orf36 facilitated the expression of VEGFA by recruiting EIF4A3. Taken together, our results elucidated that circ_C4orf6 promoted the migration, proliferation and osteoblast differentiation in BMSCs by upregulating VEGFA, which indicated that circ_C4orf36 might be a potential target in fracture healing treatment.

Chiral Luminescent Sensor Eu-BTB@d-Carnitine Applied in the Highly Effective Ratiometric Sensing of Curing Drugs and Biomarkers for Diabetes and Hypertension.

Chiral drugs are of great significance in drug development and life science because one pair of enantiomers has a different combination mode with target biological active sites, leading to a vast difference in physical activity. Metal-organic framework (MOF)-based chiral hybrid materials with specific chiral sites have excellent applications in the highly effective sensing of drug enantiomers. Sitagliptin and clonidine are effective curing drugs for controlling diabetes and hypertension, while insulin and norepinephrine are the biomarkers of these two diseases. Excessive use of sitagliptin and clonidine can cause side effects such as stomach pain, nausea, and headaches. Herein, through post-synthetic strategy, MOF-based chiral hybrid material Eu-BTB@d-carnitine (H3BTB = 1,3,5-benzenetrisbenzoic acid) was synthesized. Eu-BTB@d-carnitine has dual emission peaks at 417 and 616 nm when excited at 330 nm. Eu-BTB@d-carnitine can be applied in luminescent recognition toward sitagliptin and clonidine with high sensitivity and low detection limit (for sitagliptin detection, Ksv is 7.43 × 106 [M-1]; for clonidine detection, Ksv is 9.09 × 106 [M-1]; limit of detection (LOD) for sitagliptin is 10.21 nM, and LOD of clonidine is 8.34 nM). In addition, Eu-BTB@d-carnitine can further realize highly sensitive detection of insulin in human fluids with a high Ksv (2.08 × 106 [M-1]) and a low LOD (15.48 nM). On the other hand, norepinephrine also can be successfully discriminated by the hybrid luminescent platform of Eu-BTB@d-carnitine and clonidine with a high Ksv value of 4.79 × 106 [M-1] and a low LOD of 8.37 nM. As a result, the chiral hybrid material Eu-BTB@d-carnitine can be successfully applied in the highly effective ratiometric sensing of curing drugs and biomarkers for diabetes and hypertension.

Comparison of Clinical Efficacy and Recovery Effect between Lateral and Posterior Foraminoscopy and PELD in LDH Patients.

In order to analyze the clinical efficacy and recovery of lumbar disc herniation (LDH) treated by lateral and posterior foraminoscopy and posterior approach foraminoscopy (PELD), the comparison of clinical efficacy and recovery effect between lateral and posterior foraminoscopy and PELD in LDH patients was conducted. A total of 96 LDH patients admitted to our hospital from July 2020 to July 2021 were selected, and the lateral and posterior foraminoscopy group and PELD group were, respectively, established according to different surgical intervention methods. The lateral posterior foraminoscopy group is treated with lateral posterior foraminoscopy intervention, and the PELD group is treated with posterior foraminoscopy intervention. The intraoperative and postoperative indicators of the two groups were observed, and the pain improvement, lumbar function, clinical efficacy, and incidence of adverse complications were compared between the two groups before and 3 months after surgery. The Spearman correlation coefficient is used to analyze the correlation between visual analogue scale (VAS) score, lumbar function (ODI) score, and the incidence of complications. For patients with LDH in implementing lientang road intervertebral foramen mirror, the clinical efficacy of the intervertebral foramen to a rear mirror was more apparent. It demonstrates that the treatment can reduce intraoperative blood loss, shorten hospitalization time, improve lumbar vertebral function, and reduce a patient's risk of complications.

Solvo-thermal synthesis of a unique cluster-based nano-porous zinc(II) luminescent metal-organic framework for highly sensitive detection of anthrax biomarker and dichromate.

In this work a flexible multi-dentate 4,4'-(1H-1,2,4-triazole-1-yl) methylene-bis(benzonic acid) (H2L) ligand has been employed, a unique cluster-based nano-porous luminescent zinc(II) metal-organic framework {[Zn(µ6-L)]·(DMAC)2}n (1) (DMAC = Dimethylacetamide) has been isolated under solvo-thermal conditions. The H2L ligand adopts hexa-dentate coordination modes via one triazole nitrogen atom and four aromatic carboxylate oxygen atoms, which bridge the neighboring six-coordinated ZnII centers, leading to a three-dimensional (3D) nano-porous metal organic framework. A PLATON program analysis suggests the total potential solvent area volume is 2028.9 Å3, which occupy 62.5% percent of the unit cell volume (3248.4 Å3). PXRD Patterns of the as-synthesized samples 1 have been determined confirming the purity of the bulky samples. Photo-luminescent properties indicate strong fluorescent emissions of 1 at the room temperature. Further photo-luminescent measurements show that 1 can exhibit highly sensitive real-time luminescence sensing of anthrax biomarker dipicolinic acid (DPA) with high quenching efficiency (KSV = 1.48 × 105 M-1) and low detection limit (0.298 µM (S/N = 3)). Meanwhile 1 also exhibits highly selective and sensitive luminescence sensing for Cr2O72- ions in aqueous solutions with high quenching efficiency KSV = 1.22 × 104 L·mol-1 and low detection limit (0.023 µM (S/N = 3)). Therefore 1 can be used a unique multi-functional 3D cluster-based metal organic material in sensitive detection and effective detection of environment pollutants and biomarker molecules.

Solvothermal Preparation of a Lanthanide Metal-Organic Framework for Highly Sensitive Discrimination of Nitrofurantoin and l-Tyrosine.

Metal-organic frameworks (MOFs) have been rapidly developed for their broad applications in many different chemistry and materials fields. In this work, a multi-dentate building block 5-(4-(tetrazol-5-yl)phenyl)-isophthalic acid (H3L) containing tetrazole and carbolxylate moieties was employed for the synthesis of a two-dimensional (2D) lanthanide MOF [La(HL)(DMF)2(NO3)] (DMF = N,N-dimethylformamide) (1) under solvothermal condition. The fluorescent sensing application of 1 was investigated. 1 exhibits high sensitivity recognition for antibiotic nitrofurantoin (Ksv: 3.0 × 103 M-1 and detection limit: 17.0 µM) and amino acid l-tyrosine (Ksv: 1.4 × 104 M-1 and detection limit: 3.6 µM). This work provides a feasible detection platform of 2D MOFs for highly sensitive discrimination of antibiotics and amino acids.

Hydrothermal synthesis of two-dimensional cadmium(II) micro-porous coordination material based on Bi-functional building block and its application in highly sensitive detection of Fe3+ and Cr2O72.

Metal-organic framework (MOFs), also known as porous coordination polymers (PCPs), is a new kind of crystalline porous materials, which has received extensive attention in the past few decades. As a new type of sensing material, MOFs stand out from many other traditional fluorescence sensors because of its crystal characteristics, structural diversity, stable porosity and adjustable functional characteristics. In this work, the bi-functional building block containing aromatic carboxylic acid and triazole moieties, namely 3-(1H-1,3,4-triazol-1-yl) benzoic acid, was selected as the linker to synthesize {[Cd(µ5-L)⋅I}n (1, HL = 3-(1H-1,3,4-triazol-1-yl)benzoic acid) by hydrothermal method with transition CdII metal centers. Firstly, the preliminary characterization of 1 was carried out by means of PXRD, FT-IR, and then the UV and fluorescence tests were conducted to study the fluorescence properties of 1. The crystal structure analysis indicates that CdII is the center and the ligand is bridged to form a two-dimensional porous structure. In addition, 1 has good selectivity for Fe3+ and Cr2O72-, meanwhile, it has high detection sensitivity (Ksv quenching efficiency for Fe3+: 1.2 × 104 M-1 and Cr2O72- 1.85 × 104 M-1) and low detection limit (Fe3+: 19.21 µM and Cr2O72-: 12.46 µM). The results of photoluminescence test show that 1 can detect cations and anions with high sensitivity, resist the interference of other ions, and have good reusability. As far as we know, 1 is the first example of ultra-stable two-dimensional (2D) Cadmium (II) microporous coordination material as a fluorescence sensor for Fe3+ and Cr2O72-.

Surface Modification of Co3O4 Nanoplates as Efficient Peroxidase Nanozymes for Biosensing Application.

Nanomaterial-based mimetic enzymes, called nanozymes, received more and more attention in recent decades; however, their lack of biocompatibility limited the biomedical applications, which could be solved by surface modification. In this work, the Co3O4 nanoplates were modified by different functional groups, including the amino group, carboxyl group, hydroxyl group, and sulfhydryl group (NH2-Co3O4, COOH-Co3O4, OH-Co3O4, and SH-Co3O4). And the modified Co3O4 nanoplates were characterized by XRD, SEM, TEM, XPS, FTIR, TG, and the Zeta potential, verifying the successful modification of different functional groups. Their mimetic peroxidase properties and kinetics process were further studied and showed that the order of their catalytic activities was as follows: NH2-Co3O4 > SH-Co3O4 > COOH-Co3O4 > pure Co3O4 > OH-Co3O4, and the catalysis of modified Co3O4 nanozymes all followed Michaelis-Menten kinetics. The results indicated that the different functional groups changed their electron transfer ability, and further affected their catalytic activity. H2O2 detection was selected as an application model system to evaluate the modified Co3O4 nanozymes. Compared with other Co3O4 nanozymes, a wider linear range from 0.01 to 40 mmol L-1 and a lower detection limit of 1.5 µmol L-1 was constructed with NH2-Co3O4 nanozymes. The results suggested that surface modification by functional groups was a robust strategy to improve the application of Co3O4 nanozymes. The enhanced catalytic activity and good biocompatibility of modified Co3O4 nanozymes provided valuable materials for the relative application, such as medical detection and antioxidation.

Convenient ultrasonic preparation of a water stable cluster-based Cadmium(II) coordination material and highly sensitive fluorescent sensing for biomarkers DPA and 5-HT.

In recent years, a new type of micro-porous material, namely metal organic framework material, has received more and more attention from many basic and industrial fields because these materials possess unique advantages. In this work, through the powerful sonochemical preparation method, a three-dimensional cluster-based CdII-MOFs, {[Cd(abtz)2(H2O)2]·(ClO4)2·H2O}n (1, abtz = 1-(4-aminobenzyl)-1H-1,2,4-triazole) can be quickly synthesized in the facile ultrasonic method. Powder X-ray diffraction (PXRD) measurement confirms that these bulky samples 1 (synthesized on different ultrasonic powers and ultrasonic time conditions) were pure. In addition, ultrasonic chemical time and irradiation power did not change the structure of composites materials 1. SEM and morphological changes of 1 in the ultrasonic synthesis are also determined. Moreover, 1 exhibits good stability, the structure of 1 can be maintained not just in various solvents, and in aqueous environments with pH values from 2 to 12. Photo-luminescent experiment also reveals that complex 1 has the excellent application prospect as highly sensitive sensing material for the biomarker DPA (2,6-pyridine dicarboxylic acid) and 5-HT (5-hydroxytryptamine) through the photo-luminescence "turn-on" and "turn-off" effect, respectively. Further photo-luminescent measurements also show that different ultrasonic powers and ultrasonic time can effectively induce fluorescent sensing enhancement for biomarkers DPA and 5-HT based on the water stable clustered-based cadmium(II) coordination framework.

Simvastatin inhibits the adipogenesis of bone marrow­derived mesenchymal stem cells through the downregulation of chemerin/CMKLR1 signaling.

Simvastatin is effective in the treatment of osteoporosis, partly through the inhibition of the adipogenesis of bone­marrow derived mesenchymal stem cells (BMSCs). The present study focused on the mechanisms responsible for the inhibitory effects of simvastatin on adipogenesis and examined the effects of simvastatin on the expression of peroxisome proliferator­activated receptor γ (PPARγ), chemerin, chemokine­like receptor 1 (CMKLR1), G protein­coupled receptor 1 (GPR1) and the adipocyte marker gene, adiponectin. BMSCs were isolated from 4­week­old female Sprague­Dawley (SD) rats, and adipogenesis was measured by the absorbance values at 490 nm of Oil Red O dye. The expression of each gene was evaluated by western blot analysis or reverse transcription­quantitative PCR (RT­qPCR). The expression of chemerin increased during adipogenesis, while CMKLR1 exhibited a trend towards a decreased expression. On days 7 and 14, the simvastatin­treated cells exhibited a downregulated expression of chemerin, whereas the upregulated expression of its receptor, CMKLR1 was observed. The results also revealed that CMKLR1 is required for adipogenesis and the simvastatin­mediated inhibitory effect on adipogenesis. Simvastatin regulated adipogenesis by negatively modulating chemerin­CMKLR1 signaling. Importantly, simvastatin stimulation inhibited the upregulation of PPARγ and PPARγ­mediated chemerin expression to prevent adipogenesis. Treatment with the PPARγ agonist, rosiglitazone, partially reversed the negative regulatory effects of simvastatin. On the whole, the findings of the present study demonstrate that simvastatin inhibits the adipogenesis of BMSCs through the downregulation of PPARγ and subsequently prevents the PPARγ­mediated induction of chemerin/CMKLR1 signaling.

A multi-throughput mechanical loading system for mouse intervertebral disc.

Mechanical loading plays an important role in maintaining disc health and function, and in particular, excessive mechanical loading has been identified as one of major reasons of disc degeneration. Intervertebral disc organ culture serves as a valuable tool to study disc biology/pathology. In this study, we report the development and validation of a new mouse disc organ culture system by dynamically applying compression loading in a customized micro-culture device tailored for mouse lumbar discs. Precise axial compression force was delivered by a computer-controlled system consisting of a robust micromechanical linear actuator, a force sensitive resistor, and a precision micro-stepping machinery. Customized PDMS-based loading chambers allowed simultaneous loading of six discs per regimen, which streamlined the workflow to reach sufficient statistic power. The detrimental loading regimen of mouse lumbar discs (0.5 MPa of axial compression at 1Hz for 7 days) was demonstrated through live-dead assay, histology, and fluorescence probe based collagen staining. In addition, various mechanical compression profiles were simulated using different materials and geometry designs, potentiating for more sophisticated loading protocols. In summary, we developed a new mechanical loading system for dynamic axial compression of mouse discs, which created a unique avenue to study disc pathogenesis with enriched mouse species-related resources, and complemented the existing spectrum of bioreactor systems predominately for discs of human and large animals.

A "turn-on" sensor based on MnO2 coated UCNPs for detection of alkaline phosphatase and ascorbic acid.

Alkaline phosphatase (ALP), an extraordinary enzyme, can catalyze the dephosphorylation of small molecules, proteins and nucleic acids. ALP has been confirmed as a crucial serum diagnostic indicator, since the abnormal level of ALP is closely related to a variety of pathological processes, especially in the early diagnosis and screening of cancer. Herein, we designed a "turn-on" sensor to detect ALP and ascorbic acid (AA) based on the redox reaction between manganese dioxide (MnO2) coated upconversion nanoparticles (UCNPs) and AA. Firstly, 2 nm sized NaYF4:Yb3+,Tm3+ UCNPs were synthesized by a facile one-pot hydrothermal method. Then MnO2 coated UCNPs were prepared via electrostatic interactions between MnO2 nanosheets and UCNPs. MnO2 nanosheets could absorb blue light emitted by UCNPs near 471 nm under laser excitation at 980 nm, and so the luminescence of UCNPs was quenched based on luminescence energy transfer (LET). In the presence of AA, the luminescence was recovered again by the redox reaction between AA and MnO2 coated UCNPs. MnO2 nanosheets were reduced to Mn2+ and UCNPs were released. Furthermore, the "turn-on" sensor was applied to monitor ALP since the phosphate group of 2-phospho-l-ascorbic acid (AAP) was removed by ALP to yield AA. The bio-assay showed a good linear relationship between the restored luminescence intensities (ΔI = I-I0) and ALP concentrations ranging from 0.25 to 150 mU mL-1 with a limit of detection (LOD) of 0.045 mU mL-1 and between ΔI and AA concentrations ranging from 0.5 to 250 µM with an LOD of 0.29 µM. The luminescent sensor was also successfully applied for detection of ALP and AA in human serum samples with recoveries from 94.9% to 104.6% and 99.4% to 104.9%.

Room-temperature Chelate Vapor Generation of Lead Using Ammonium O,O-Diethyl Dithiophosphate as a Chelating Reagent and Determination by Atomic Fluorescence Spectrometry in Environmental Water Samples.

A novel gas-liquid separator (GLS) system for chelate vapor generation (Che-VG) combined with AFS was developed for the determination of trace Pb. It was shown that Pb can form a volatile chelate by mixing of Pb with ammonium O,O-diethyldithiophosphate (DEDTP) in various aqueous solutions. Under the optimal conditions (frit pores of the GLS, 5 - 15 µm; solution pH, 6.7; DEDTP concentration, 0.4%; flow rate of the two feed solutions in the on-line mode, 1.2 mL min-1; and carrier gas flow rate, 150 mL min-1), the calibration curve was linear up to 100 ng mL-1 Pb. The limit of detection (LOD) was 1.1 ng mL-1. The relative standard deviation was 5.6% for eleven replicate determinations of 10 ng mL-1 Pb. The efficiency of Che-VG was estimated to be 12%, and the volatile Pb species was preliminarily studied by ICP-OES. This method was applied to determine trace Pb in water samples.