Identifying the grade of bladder cancer cells using microfluidic chips based on impedance

Bladder cancer diagnosis is made by microfluidic chip based-on impedance analysis.

Prediction and verification of survival in patients with non-small-cell lung cancer based on an integrated radiomics nomogram

AIM

To develop and validate a nomogram to predict 1-, 2-, and 5-year survival in patients with non-small-cell lung cancer (NSCLC) by combining optimised radiomics features, clinicopathological factors, and conventional image features extracted from three-dimensional (3D) computed tomography (CT) images.

MATERIALS AND METHODS

A total of 172 patients with NSCLC were selected to construct the model, and 74 and 72 patients were selected for internal validation and external testing, respectively. A total of 828 radiomics features were extracted from each patient's 3D CT images. Univariable Cox regression and least absolute shrinkage and selection operator (LASSO) regression were used to select features and generate a radiomics signature (radscore). The performance of the nomogram was evaluated by calibration curves, clinical practicability, and the c-index. Kaplan-Meier (KM) analysis was used to compare the overall survival (OS) between the two subgroups.

RESULT

The radiomics features of the NSCLC patients correlated significantly with survival time. The c-indexes of the nomogram in the training cohort, internal validation cohort, and external test cohort were 0.670, 0.658, and 0.660, respectively. The calibration curves showed that the predicted survival time was close to the actual survival time. Decision curve analysis shows that the nomogram could be useful in the clinic. According to KM analysis, the 1-, 2- and 5-year survival rates of the low-risk group were higher than those of the high-risk group.

CONCLUSION

The nomogram, combining the radscore, clinicopathological factors, and conventional CT parameters, can improve the accuracy of survival prediction in patients with NSCLC.

Clinical outcomes of keratinized mucosa augmentation in jaws reconstructed with fibula or iliac bone flaps

This prospective study was undertaken to evaluate the treatment outcomes of keratinized mucosa augmentation (KMA) on the buccal and palatal/lingual sides of implants in jaws reconstructed after oncological surgery. Forty-two implants in 12 patients whose jaws had been reconstructed with a fibula or iliac bone flap were included. KMA was performed at 3 months after implant placement; this included an apically displaced partial-thickness flap and a free gingival graft (FGG) around the implants to increase the keratinized mucosa width (KMW). Patients were followed up for at least 6 months post-surgery. KMW, shrinkage, and patient pain and discomfort measured on a visual analogue scale were analysed. A histological analysis was performed of tissue epithelium from two patients. The results showed that KMW was >2 mm on both the buccal and palatal/lingual sides during follow-up. Before surgery, histological analysis showed epithelium with no epithelial spikes; normal keratinized epithelial spikes were observed at 8 weeks after KMA. Greater KMW was observed around implants in reconstructed maxillae than around those in reconstructed mandibles (P < 0.001). Patients felt more pain at the donor site than at the recipient site during the first 3 days post-surgery. KMA with FGG was predictable in reconstructed jaws and may help maintain the long-term stability of implants.

Complete chloroplast genome of Stephania tetrandra (Menispermaceae) from Zhejiang Province: insights into molecular structures, comparative genome analysis, mutational hotspots and phylogenetic relationships

BACKGROUND

The Stephania tetrandra S. Moore (S. tetrandra) is a medicinal plant belonging to the family Menispermaceae that has high medicinal value and is well worth doing further exploration. The wild resources of S. tetrandra were widely distributed in tropical and subtropical regions of China, generating potential genetic diversity and unique population structures. The geographical origin of S. tetrandra is an important factor influencing its quality and price in the market. In addition, the species relationship within Stephania genus still remains uncertain due to high morphological similarity and low support values of molecular analysis approach. The complete chloroplast (cp) genome data has become a promising strategy to determine geographical origin and understand species evolution for closely related plant species. Herein, we sequenced the complete cp genome of S. tetrandra from Zhejiang Province and conducted a comparative analysis within Stephania plants to reveal the structural variations, informative markers and phylogenetic relationship of Stephania species.

RESULTS

The cp genome of S. tetrandra voucher ZJ was 157,725 bp, consisting of a large single copy region (89,468 bp), a small single copy region (19,685 bp) and a pair of inverted repeat regions (24,286 bp each). A total of 134 genes were identified in the cp genome of S. tetrandra, including 87 protein-coding genes, 8 rRNA genes, 37 tRNA genes and 2 pseudogene copies (ycf1 and rps19). The gene order and GC content were highly consistent in the Stephania species according to the comparative analysis results, with the highest RSCU value in arginine (1.79) and lowest RSCU value in serine of S. tetrandra, respectively. A total of 90 SSRs have been identified in the cp genome of S. tetrandra, where repeats that consisting of A or T bases were much higher than that of G or C bases. In addition, 92 potential RNA editing sites were identified in 25 protein-coding genes, with the most predicted RNA editing sites in ndhB gene. The variations on length and expansion extent to the junction of ycf1 gene were observed between S. tetrandra vouchers from different regions, indicating potential markers for further geographical origin discrimination. Moreover, the values of transition to transversion ratio (Ts/Tv) in the Stephania species were significantly higher than 1 using Pericampylus glaucus as reference. Comparative analysis of the Stephania cp genomes revealed 5 highly variable regions, including 3 intergenic regions (trnH-psbA, trnD-trnY, trnP) and two protein coding genes (rps16 and ndhA). The identified mutational hotspots of Stephania plants exhibited multiple SNP sites and Gaps, as well as different Ka/Ks ratio values. In addition, five pairs of specific primers targeting the divergence regions were accordingly designed, which could be utilized as potential molecular markers for species identification, population genetic and phylogenetic analysis in Stephania species. Phylogenetic tree analysis based on the conserved chloroplast protein coding genes indicated a sister relationship between S. tetrandra and the monophyletic group of S. japonica and S. kwangsiensis with high support values, suggesting a close genetic relationship within Stephania plants. However, two S. tetrandra vouches from different regions failed to cluster into one clade, confirming the occurrences of genetic diversities and requiring further investigation for geographical tracing strategy.

CONCLUSIONS

Overall, we provided comprehensive and detailed information on the complete chloroplast genome and identified nucleotide diversity hotspots of Stephania species. The obtained genetic resource of S. tetrandra from Zhejiang Province would facilitate future studies in DNA barcode, species discrimination, the intraspecific and interspecific variability and the phylogenetic relationships of Stephania plants.

Cryptotanshinone enhances the efficacy of Bcr-Abl tyrosine kinase inhibitors via inhibiting STAT3 and eIF4E signalling pathways in chronic myeloid leukaemia

CONTEXT

A portion of patients with chronic myeloid leukaemia (CML) develop resistance to the Bcr-Abl tyrosine kinase inhibitors (TKIs), limiting the clinical applications. Previous results have demonstrated the synergistic effects between cryptotanshinone (CPT) and imatinib on apoptosis of CML cells in vitro.

OBJECTIVE

To determine the antileukemia effects of CPT and TKIs on the resistant CML cells, and further investigate the effect of combined treatment of CPT and imatinib on tumour growth and apoptosis in the xenograft model and clarify its regulatory mechanisms.

MATERIALS AND METHODS

The combination effects of CPT and second-generation TKIs were evaluated in resistant CML cells K562-R. CPT and imatinib were orally administered once daily for 21 days on K562-R xenografts in nude mice (6 per group). Tumour proliferation and apoptosis were examined by Ki-67, PCNA and TUNEL staining. The expression levels of apoptotic markers and activities of STAT3 and eIF4E pathways were determined via immunohistochemistry staining and western blotting analysis.

RESULTS

CPT significantly enhanced the antiproliferative effects of TKIs, via triggering cleavages of caspase proteins, and inhibiting activities of STAT3 and eIF4E pathways. The administration of CPT and imatinib dramatically inhibited the tumour growth of xenografts and achieved a suppression of 60.2%, which is 2.6-fold higher than that of single imatinib group. Furthermore, CPT and imatinib increased the apoptotic rates and markedly decreased the phosphorylation levels of STAT3 and eIF4E.

CONCLUSIONS

Our results demonstrated that CPT could significantly enhance the antileukemia efficacy of TKIs, suggesting the therapeutic potential of CPT to overcome CML resistance.

Transcript expression profiling of fibromelanosis-related genes in black-bone chickens

1. The aim of the present study was to identify differentially expressed genes (DEGs) and metabolic pathways involved in this phenotype. Fibromelanosis is the most striking feature of black-bone chickens, such as the Silkie and Dongxiang indigenous breeds. Due to the accumulation of eumelanin in connective tissues, fibromelanosis manifests as black colouration of the skin, muscles, gut, and periosteum. Studies on fibromelanosis can provide useful information pertaining to human diseases and offer commercial value to the poultry industry. However, the genetic basis of fibromelanosis remains unclear.2. Digital gene expression analysis was performed on black and white skin samples collected from the HW1 black-bone chicken line to detect differences in genome-wide expression patterns. A total of >30 billion bp were sequenced, and 2,707,926,466 bp and 2,948,782,964 bp of clean data obtained for creation of libraries for black and white skin, respectively. In total, 252 DEGs from 15,508 mapped genes were identified with 83 up-regulated in white skin and 169 up-regulated in black skin.3. Gene ontology analysis highlighted that genes from the extracellular region and associated components were abundant among the DEGs. Pathway analysis revealed that many DEGs were linked to amino acid metabolism and the immune system. qRT-PCR validation using 14 genes showed good conformity with the sequence analysis of fibromelanosis-related genes.4. The results showed that L-dopachrometautomerase precursor (DCT), tyrosine aminotransferase (TAT), 4-hydroxyphenylpyruvate dioxygenase (HPD) from the tyrosine metabolism pathway, coagulation factor II (F2), fibrinogen beta chain (FGB), plasminogen (PLG) and complement component 7 (C7) from the complement and coagulation cascades were important genes in the fibromelanosis process in black-bone chickens. These candidate genes require further correlation analysis and functional verification.

Plasma miR-146a and miR-365 expression and inflammatory factors in patients with osteoarthritis

OBJECTIVE

To investigate the expression levels of micro-ribonucleic acid (miR)-146a and miR-365 in the plasma of osteoarthritis (OA) patients, to study their expression with the inflammatory factors and the severity of disease in patients and to analyse their diagnostic significance.

MATERIALS AND METHODS

A total of 42 OA patients diagnosed with OA and treated in our hospital from January 2017 to January 2018 were selected as the subjects, and 28 healthy people were enrolled as controls. The expressions of interleukin-1 beta (IL-1β) and IL-6 in the plasma of OA patients were detected via immunohistochemical staining. Moreover, the knee joint function of OA patients was evaluated by Lysholm score, Western Ontario and McMaster Universities (WOMAC) score and Visual Analogue Scale (VAS) score. The expression levels of plasma miR-146a and miR-365 in OA patients were measured through RT-PCR. Besides, the significance of the expression levels of miR-146a and miR-365 for the diagnosis of OA was analysed by ROC curves.

RESULTS

As compared with healthy people, OA patients had elevated expression levels of plasma IL-1β and IL-6, decreased Lysholm score, increased WOMAC and VAS scores as well as significantly up-regulated levels of plasma miR-146a and miR-365, which were of important significance for diagnosis.

CONCLUSION

The expression levels of plasma miR-146a, miR-365 and inflammatory factors are notably higher, the disease is more severe, and the function of knee joint movement is weaker in OA patients than those in healthy controls. It can be concluded that the levels of both miR-146a and miR-365 can serve as biomarkers of OA diagnosis.

An eye tracking study: positive emotional interface design facilitates learning outcomes in multimedia learning?

Unlike the other studies on emotional design in multimedia learning, the present study differentiated the two confounding variables of visual interface design and structured content to manipulate the instructional material. Specifically, we investigated how the visual aesthetics of positive emotional interface design influenced learners' cognitive processes, emotional valences, learning outcomes, and subjective experience. Eighty-one college students took part in the experimental study. They were divided into the three experimental groups: a holistic layout of positive emotional design group (HPED), a local layout of positive emotional design group (LPED), and a neutral emotional design group (ND). By using a mixed approach of questionnaires and eye tracking, we further explored the differences among the three groups in cognitive processing, learning outcomes, and subjective experience. Results indicated that the LPED group invested higher cognitive effort, put more attentional focus in the relevant knowledge content module, and achieved better learning performance (i.e., retention and transfer tests) in contrast to the HPED group and the ND group. However, no significant difference in dynamic changes of emotional state among the three groups was detected. The analytical results can provide researchers and practitioners with valuable insights into the positive emotional design of multimedia learning, which allows for the facilitation of mental engagement, learning outcomes and subjective perception.

Factors associated with Scrub Typhus infection: A case-control study from Luhe, China

INTRODUCTION

Scrub typhus (ST) is an acute febrile infection and remains a significant health problem globally. This study aimed to determine the factors associated with ST infection in Luhe District, China.

MATERIAL AND METHODS

The case-control study was conducted among 116 cases identified through passive surveillance systems over three years.The control subjects were 232 living in the same village for more than six months without any history of ST infection were selected by matching to the age (within 5-years) and identified through active surveillance. Statistical analyses were performed using SPSS v. 25.0 for Windows (IBM SPSS, Chicago, IL, USA).

RESULTS

The mean age of confirmed persons was 58.1(SD=10.15) years, while control subjects were 56.14 (11.57).There is no significant difference in gender, age, education, and occupations between case and control. Farmers had the most significant number of cases among occupational groups. The three factors that were significantly associated with an increased odds of having ST infection are bundling or moving waste straw (OR: 1.94, 95%CI; 0.99,381), morning exercise in the park or field (OR: 4.74 95%CI; 1.19, 18.95), and working as labourer in the vegetable field (OR:1.02, 95%CI:1.02,3.19).

CONCLUSIONS

Our findings suggested establishing a prevention and control strategy for these groups to lower ST development risk.

Tanshinone I inhibited growth of human chronic myeloid leukemia cells via JNK/ERK mediated apoptotic pathways

Tanshinone I (Tan I) is one of the main bioactive ingredients derived from Salvia miltiorrhiza Bunge, which has exhibited antitumor activities toward various human cancer cells. However, its effects and underlying mechanisms on human chronic myeloid leukemia (CML) cells still require further investigation. This study determined the effects and mechanisms of anti-proliferative and apoptosis induction activity induced by Tan I against K562 cells. The cytotoxic effect of Tan I at varying concentrations on K562 cells was evaluated via MTT assay. Cell apoptosis was further investigated through DAPI staining and flow cytometry analysis. The expression levels of apoptosis-related proteins and activities of JNK/ATF2 and ERK signaling pathways were analyzed by western blot. Quantitative PCR was performed to further determine mRNA expression levels of JNK1/2 and ERK1/2 after Tan I treatment. The results indicated that Tan I significantly inhibited K562 cell growth and induced apoptosis in a concentration- and time-dependent manner. It induced significant cellular morphological changes and increased apoptosis rates in CML cells. Tan I promoted the cleavages of caspase-related proteins, as well as increased the expression levels of PUMA. Furthermore, Tan I significantly activated JNK and inhibited ATF-2 and ERK signaling pathways. The mRNA expression levels of JNK1/2 and ERK1/2 were up-regulated by Tan I, further confirming its regulatory effects on JNK/ERK signaling pathways. Overall, our results indicated that Tan I suppressed cell viability via JNK- and ERK-mediated apoptotic pathways in K562 cells, suggesting that it might be a promising candidate as a novel anti-leukemia drug.

Characterization of the complete chloroplast genome of Oxalis corymbosa DC. (Oxalidaceae), a medicinal plant from Zhejiang Province

Oxalis corymbosa DC. is an important medicinal and edible perennial herb belonging to the wood-sorrel family Oxalidaceae. In this study, we report the complete chloroplast (cp) genome sequence of O. corymbosa. The assembled chloroplast genome was 151,351 bp in length, containing two inverted repeated (IR) regions of 24,587 bp each, a large single copy (LSC) region of 85,476 bp, and a small single copy (SSC) region of 16,701 bp. The genome encodes 128 genes, consisting of 82 protein-coding genes, 37 tRNA genes, eight rRNA genes, and one pseudogene (ycf1). The 82 protein-coding genes encode 25,751 amino acids in total, most of which use the initiation codon ATG, except rps19 and psbC genes start with GTG. The lengths of the tRNA genes range from 71 bp to 93 bp, with the highest GC content of 62.16% in tRNA-Arg (ACG). The overall GC content of O. corymbosa is 36.47%, with the highest GC content of 42.64% in IR region. In addition, a total of 74 simple sequence repeats were identified in the cp genome of O. corymbosa. Phylogenetic analysis indicated a sister relationship between O. corymbosa and O. drummondii, suggesting a close genetic relationship between the two Oxalis species. This work provides basic genetic resources for investigating the evolutionary status and population genetics diversities for this medicinal species.

Complete chloroplast genome sequence of the medicinal plant ramie (Boehmeria nivea L. gaud) and its phylogenetic relationship to other Urticaceae species

Ramie (Boehmeria nivea L. Gaud) is a traditional fiber crop and important medicinal plant belonging to the family Urticaceae. In this study, we determine the complete chloroplast genome sequence of B. nivea. The assembled chloroplast genome is 156065 bp in length and shares the conserved quadripartite structure as other cp genomes in Boehmeria. The genome contains 131 genes, including 84 protein genes, 8 rRNA genes, 37 tRNA genes and 2 pseudo genes. There are 17 duplicated genes in the IR region. The overall GC content of B. nivea is 36.33%, with the highest GC content of 42.72% in IR region. A total of 67 simple sequence repeats are identified in the cp genome of B. nivea. Phylogenetic analysis demonstrated that B. nivea clustered together with B. tomentosa, further forming a monophyletic group with the species of Debregeasia and Pipturus. This work provides basic genetic resources for developing robust markers and investigating the population genetics diversities for B. nivea.

[The 485th case: fever of undetermined origin and hypoxemia]

A 49-year-old male was admitted to Peking Union Medical College Hospital presented with fever for more than half a year. The patient was diagnosed as Sjogren's syndrome at local hospital. After oral prednisone 60 mg per day was given, the fever alleviated, but recurred after prednisone tapered to 40 mg/d. Both blood culture and stool culture were positive for Salmonella enteritidis. Antibiotics including ceftazidime, ceftriaxone, cilastatin-imipenem were sequentially administrated for 4 weeks, yet not effective. Although there were not respiratory symptoms or certain abnormalities on high-resolution chest CT, arterial blood gas indicated hypoxemia. Serum lactate dehydrogenase and β2 micro-globulin were elevated, and the lung function test demonstrated significant impairment of diffusion function. Positron emission tomography-computed tomography (PET/CT)scan suggested that high fluorodeoxyglucose uptake was diffusely seen in both lungs. The patient was finally diagnosed as pulmonary intravascular large B-cell lymphoma (IVLBCL) by transbronchial lung biopsy. This case aims to emphasize the differentiation diagnoses of pulmonary intravascular lymphoma from common situations.

Ultrasensitive electrochemical determination of phosphate in water by using hydrophilic TiO2 modified glassy carbon electrodes

In this paper, ultrasensitive electrochemical determination of phosphate in water is achieved by using hydrophilic TiO₂ modified glassy carbon electrodes for the first time. The differential pulse voltammetry (DPV) method is proposed to measure phosphate in water as pulse techniques offer higher sensitivity compared with the conventional cyclic voltammetry (CV) method. Hydrophilic TiO₂ films were obtained upon ultraviolet (UV) illumination after TiO₂ precursor emulsions were coated on the surfaces of glassy carbon electrodes, and used for phosphate determination. Contact angle measurements (around 23.4°) proved the good hydrophilicity of the TiO₂ modified surface upon UV illumination. A detection limit of 0.1 μg L^-1 is obtained, and a linear relationship (R² = 0.99) between the phosphate concentration (ranging from 0.1 μg L^-1 to 1 μg L^-1) and the peak current was observed.

[Consistency of effective orifice area of prosthetic mitral valve estimated using 2-dimensional and 3-dimensional transesophageal echocardiography]

OBJECTIVE

To analyze the consistency of effective orifice area (EOA) of prosthetic mitral valve estimated using 2- dimensional (2D) and 3-dimensional (3D) transesophageal echocardiography (TEE).

OBJECTIVE

This study was conducted among 34 patients undergoing mitral valve replacement surgery in Nanjing First Hospital between March and June in 2019. The diameter of the left ventricular outflow tract (LVOT) measured by 2D-TEE was used to calculate the cross sectional area of LVOT (CSALVOT). In 3D-TEE method, LVOT area was measured directly by planimetry on an enface view. The EOAs of the prosthetic mitral valve were calculated for both methods using the continuity equation. Bland-Altman plot consistency test was used to analyze the consistency between the two sets of EOA results, and linear regression analysis was used to analyze their correlation.

OBJECTIVE

The EOA of the prosthetic mitral valve differed significantly between 2D method and 3D method (2.22±0.71 cm² vs 2.35±0.70 cm², P < 0.001) with a mean difference of -0.14±0.20 cm² and 95% coherence boundaries of (-0.53, 0.25 cm²). The regression equation for EOA-3D and EOA-2D is y=0.27 + 0.94x, showing a good correlation between the two methods.

OBJECTIVE

EOA estimation of the prosthetic mitral valve using 2D and 3D TEE has a good consistency, and the results estimated by the 2D method are slightly lower by about 6% than those by the 3D method.

On-site analysis of COVID-19 on the surfaces in wards

SARS-Cov-2 has erupted across the globe, and confirmed cases of COVID-19 pose a high infection risk. Infected patients typically receive their treatment in specific isolation wards, where they are confined for at least 14 days. The virus may contaminate any surface of the room, especially frequently touched surfaces. Therefore, surface contamination in wards should be monitored for disease control and hygiene purposes. Herein, surface contamination in the ward was detected on-site using an RNA extraction-free rapid method. The whole detection process, from surface sample collection to readout of the detection results, was finished within 45 min. The nucleic acid extraction-free method requires minimal labor. More importantly, the tests were performed on-site and the results were obtained almost in real-time. The test confirmed that 31 patients contaminated seven individual sites. Among the sampled surfaces, the electrocardiogram fingertip presented a 72.7% positive rate, indicating that this surface is an important hygiene site. Meanwhile, the bedrails showed the highest correlation with other surfaces, so should be detected daily. Another surface with high contamination risk was the door handle in the bathroom. To our knowledge, we present the first on-site analysis of COVID-19 surface contamination in wards. The results and applied technique provide a potential further reference for disease control and hygiene suggestions.

Autoimmune experimental orchitis and chronic glomerulonephritis with end stage renal disease are controlled by Cgnz1 for susceptibility to end organ damage

Cgnz1 on chromosome 1 mapped into a 1.34 Mb region of chromosome 1 in NZM2328 confers the progression of immune complex (IC)-mediated glomerulonephritis (GN) from acute GN (aGN) to chronic GN (cGN) with severe proteinuria and end stage renal disease in female mice. This genetic locus mediates podocyte susceptibility to IC-mediated damage. Taking advantage of the published observation that Cgnz1 is derived from NZW and that NZW is susceptible to orchitis, epididymitis and vasitis while C57L/J is resistant to these diseases, the possibility that this genetic region also confers germ cells susceptible to damage with aspermatogenesis and sterility in an active experimental autoimmune orchitis (EAO) model was investigated. Male mice from multiple intrachromosome (chromosome 1) recombinant strains were subjected to immunization with a sperm homogenate in CFA with concomitant administration of Bordetella pertussis toxin. There was concordance of the progression from aGN to cGN, severe proteinuria and end stage renal disease with susceptibility of EAO in NZM2328 and its congenic strains with various chromosome 1 genetic intervals introgressed from C57L/J to NZM2328. Both resistant and susceptible strains made comparable anti-testis and anti-sperm Abs. Thus the genetic interval that determines susceptibility to EAO is identical to that of Cgnz1 and mapped to the 1.34 Mb region in chromosone 1. This region likely confers germ cells in the male gonad susceptible to damage by immunologically mediated inflammation. This region has been tentatively renamed Cgnz1/Eaoz1. These observations further emphasize the importance of end organ susceptibility to damage in the pathogenesis of both systemic and organ specific autoimmune diseases.

Structure and thermal properties of beeswax-based oleogels with different types of vegetable oil

Beeswax-based oleogels with different types of vegetable oil, including camellia oil (CO), soybean oil (SO), sunflower oil (SFO), or flaxseed oil (FO), were prepared and their structure and thermal properties were evaluated. The critical concentration of oleogel obtained from each of CO, SO, and SFO at 25 °C was 3% (w/w), and that from FO was 4%. Thermal measurements revealed similar thermodynamic curves for oleogels in different lipid phases. X-Ray diffraction showed orthorhombic perpendicular subcell packing and characteristic peaks of the β’ form. Furthermore, a morphology analysis of the crystals showed that they were needle shaped. Fourier transform-infrared spectra revealed that beeswax-based oleogels were formed via non-covalent bonds and may be stabilized with physical entanglements. The oleogels showed oil type-dependent oxidative abilities, but they were all stable and showed no obvious changes in peroxide value during 90 days of storage at 5 °C.

Magnetic sensor based on image processing for dynamically tracking magnetic moment of single magnetic mesenchymal stem cell

Developing an economical and universal method to measure the magnetic moments of magnetic mesenchymal stem cells (MSCs) labelled with superparamagnetic iron oxide (SPIO) nanoparticles is crucial for cell tracking. In this study, we used a gradient magnetic field created by a nickel needle to track the motion of cells. A simple and quantifiable magnetic sensor was employed to evaluate the magnetic properties of single viable MSCs. We measured the magnetic moments of microbeads and MSCs using the proposed method and compared the results with magnetic moments measured using a superconducting quantum interference device and with iron contents measured using an inductively coupled plasma spectrometer, respectively. The correlation coefficients indicated satisfactory agreement in both cases, thus confirming the accuracy of the system. By labelling MSCs with SPIOs, we implemented a miniature magnetic sensor to measure the magnetic moments of single magnetic MSCs quantitatively using an image-processing algorithm. Existing methods for the measurement of magnetic moments at the micro/nanoscale have various limitations. Our system realised the measurement of single viable cells, thereby providing a theoretical foundation for the labelling and tracking of MSCs with SPIO nanoparticles. Additionally, the proposed system is both economical and universal.