Accurate and High-Resolution Particle Mass Measurement Using a Peak Filtering Algorithm.

Charge detection quadrupole ion trap mass spectrometry (CD-QIT MS) is an effective way of achieving the mass analysis of microparticles with ultrahigh mass. However, its mass accuracy and resolution are still poor. To enhance the performance of CD-QIT MS, the resolution Rpeak of each peak in the mass spectra resulting from an individual particle was assessed, and a peak filtering algorithm that can filter out particle adducts and clusters with a lower Rpeak was proposed. By using this strategy, more accurate mass information about the analyzed particles could be obtained, and the mass resolution of CD-QIT MS was improved by nearly 2-fold, which was demonstrated by using the polystyrene (PS) particle size standards and red blood cells (RBCs). Benefiting from these advantages of the peak filtering algorithm, the baseline separation and relative quantification of 3 and 4 µm PS particles were achieved. To prove the application value of this algorithm in a biological system, the mass of yeast cells harvested at different times was measured, and it was found that the mixed unbudded and budded yeast cells, which otherwise would not be differentiable, were distinguished and quantified with the algorithm.

Maturity degree assessment of hospital ward system using integrated fuzzy AHP-TOPSIS model.

BACKGROUND: The hospital ward system is the core service unit of a hospital and an important aspect of hospital management. The maturity of the hospital ward system represents the level of development and improvement in ward management and services. In order to improve the quality of hospital services, it is significant to assess the maturity of the ward system. Although various assessment methods have been proposed in existing studies, there are some issues such as a single-dimensional factor system, subjectivity in qualitative factor values, and insufficient objectivity in the evaluation methods. METHODS: Therefore, based on the data collection of the factors used in the existing literature, this study made correlation analysis, determined the similarity of factors, and established a maturity assessment factor system satisfying distinctiveness and comprehensiveness. Furthermore, an evaluation method for the weights of each factor was proposed based on the fuzzy analytic hierarchy process, while taking account of the ambiguity of expert information. In addition, through the technique for order of preference by similarity to ideal solution method, an objective evaluation method for the maturity of the hospital ward system was established. Finally, a case study involving 6 hospitals in a specific location was conducted. RESULTS: There are a total of 16 factors used to assess the maturity of the hospital ward system, among which the most important is Doctor service. The maturity degree of the 6 researched hospitals are 0.4517, 0.0035, 0.4254, 0.8681, 0.6636, 0.1586, and the maturity degree of the 6 researched hospitals are II, I, II, IV, III, I. CONCLUSION: The factor system constructed in this study effectively reflected the importance of human-related factors in the development process of ward system. The evaluation results were consistent with the actual situation, demonstrating the effectiveness of the proposed method.

Biofluid Metabolic Profiling for Lung Cancer Screening via Reactive Matrix-Assisted Laser Desorption Ionization Mass Spectrometry.

Lung cancer (LC) has the highest mortality rate among various cancer diseases. Developing an early screening method for LC with high classification accuracy is essential. Herein, 2-hydrazinoquinoline (2-HQ) is utilized as a dual-mode reactive matrix for metabolic fingerprint analysis and LC screening via matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). Metabolites in both positive mode and negative mode can be detected using 2-HQ as the matrix, and derivative analysis of aldehyde and ketone compounds can be achieved simultaneously. Hundreds of serum and urine samples from LC patients and healthy volunteers were analyzed. Combined with machine learning, LC patients and healthy volunteers were successfully distinguished with a high area under the curve value (0.996 for blind serum samples and 0.938 for urine). The MS signal was identified for metabolic profiling, and dysregulated metabolites of the LC group were analyzed. The above results showed that this method has great potential for rapid screening of LC.

Nasal Alar and Scalp Metastases From Lung Carcinoma: A Case Report and Literature Review.

Both nasal alar and scalp metastases from lung carcinoma are exceedingly rare. Herein, we report a case of an elderly male smoker who had left lung carcinoma and underwent radical resection. Seven months later, masses began to appear on his nasal alar and parietal scalp which gradually increased in size. The nasal computed tomography and head magnetic resonance imaging scan revealed a dense soft tissue shadow in the right nasal alar and nasal cavity, as well as a soft tissue nodule in the middle of the parietal scalp. A biopsy was performed and immunohistochemistry suggested poorly differentiated metastatic carcinoma that was consistent with the characteristics of primary lung carcinoma and supported the diagnosis of nasal alar and scalp metastases. Then, he received a combined treatment of Albumin paclitaxel and Xindirizumab. However, he passed away 3 months later. In addition to this case, we also review the clinical features of nose and/or scalp metastases from lung carcinoma based on previously reported cases as well as this case.

Interfacial and rheological properties of long-lived foams stabilized by rice proteins complexed to transition metal ions in the presence of alkyl polyglycoside.

HYPOTHESIS: Transition-metal coordination complexes are hopeful to make advanced structural materials, since the metal-coordination bonds, unlike typical covalent bonds, can regenerate after rupture, allowing for dynamic, tunable, and reversible mechanical characteristics. Integration of metal-coordinate crosslinking in foam material has rarely been reported. EXPERIMENTS: We developed the hydrolyzed rice proteins (HRP) as the building block for amphiphilic transition-metal coordination complexes that could be used to make long-lived foams with high yield stress. Surface properties of the foaming solution were determined using equilibrium and dynamic tensiometers. Structural information of aggregates in the foaming solution was detected by small-angle X-ray scattering (SAXS) and Cryo-Tem. Visualization of liquid flow in the interfacial liquid film was studied by the reflective optical interference technique. Rheological response of liquid foam was characterized by a rheometer with amplitude-sweep and frequency-sweep modes. FINDINGS: In the presence of transition metal ions, HRP formed a mechanically strong rigid film. In the absence of transition metal ions or the addition of alkyl polyglycoside (APG), HRP was desorbed to produce a mobile film with a detergent state. The two interfacial states could be actively switched based on facile changes in bulk solution composition (metal ions or alkyl glycoside or chelating agent), and the switching between the two states led to the formation of extremely stable foam with high yield stress or the collapse of foam with a significant decrease in yield limit. The transition-metal coordination complexes adsorbed on the surface of the liquid film could increase the elastic modulus of liquid foam by more than an order of magnitude without increasing the viscosity of the foaming solution. We further revealed the origin of foam stability/instability and used other well-characterized proteins to prepare transition-metal coordination complexes to make long-lived foams. The cases described in this work illustrate the universal nature of the strategy, which in principle can be extended to many types of protein.

High Speed Mass Measurement of a Single Metal-Organic Framework Nanocrystal in a Paul Trap.

Mass spectrometry (MS) has emerged as an excellent tool for the characterization of metal-organic frameworks (MOFs) based on the characteristic metal ions and organic ligands. Mass measurement of intact MOF nanocrystals, however, remains a challenge for MS technology. Here, we reported the development of a probe particles based charge detection-quadrupole ion trap mass spectrometry (probe CD-QIT MS) method, where charge detection and mass measurement of a single MOF nanocrystal were achieved under the assistance of probe particles of micrometer size. As a validation of the method, the masses of a series of polystyrene (PS) size standards from 493 nm to 1.6 µm were measured with 3 µm PS particles as probes, and the measured masses were found to match well with their certified masses. Then, charge detections and mass analysis of single ZIF-8 and GOx@ZIF-8 with a size around 600 nm were achieved successfully. The method presented here demonstrates simplicity, high speed, and accuracy. Notably, it allows quantitative measurement of the amount of immobilized GOx enzyme by using the mass difference between ZIF-8 and GOx@ZIF-8. In addition, based on the determined mass, the size analysis of these MOF particles with irregular shape was carried out and demonstrated to be complementary to transmission electron microscopy (TEM).

Effect of static magnetic field extended supercooling preservation on beef quality.

Supercooling can preserve beef without freezing damage, whereas maintaining the supercooled state is difficult. An innovative method of static magnetic field extended supercooling (SM-ES) was proposed to maintain the non-frozen state of beef. Effect of SM-ES (-4 °C + SMF) compared with refrigerated (4 °C), slow-frozen (-4 °C) and frozen (-18 °C) treatment on beef quality was investigated. Results demonstrated that SM-ES successfully preserved beef at -4 °C without ice nucleation for 14 days. The SEM images revealed that the microstructure of slow-frozen/frozen samples was damaged due to crystallizing, while the ice nucleation was not observed in SM-ES treated beef. Compared with refrigerated, slow-frozen and frozen treatment, the drip loss of SM-ES decreased by 21.9%, 47.8% and 30.9%, respectively. The lipid oxidation degree of beef decreased following SM-ES treatment. SM-ES treatment extended the shelf-life of beef for more than 6 days compared with refrigeration while prevented its crystallizing.

Collagen Family Genes Associated with Risk of Recurrence after Radiation Therapy for Vestibular Schwannoma and Pan-Cancer Analysis.

BACKGROUND: The safety of radiotherapy techniques in the treatment of vestibular schwannoma (VS) shows a high rate of tumor control with few side effects. Neuropeptide Y (NPY) may have a potential relevance to the recurrence of VS. Further research is still needed on the key genes that determine the sensitivity of VS to radiation therapy. MATERIALS AND METHODS: Transcriptional microarray data and clinical information data from VS patients were downloaded from GSE141801, and vascular-related genes associated with recurrence after radiation therapy for VS were obtained by combining information from MSigDB. Logistics regression was applied to construct a column line graph prediction model for recurrence status after radiation therapy. Pan-cancer analysis was also performed to investigate the cooccurrence of these genes in tumorigenesis. RESULTS: We identified eight VS recurrence-related genes from the GSE141801 dataset. All of these genes were highly expressed in the VS recurrence samples. Four collagen family genes (COL5A1, COL3A1, COL4A1, and COL15A1) were further screened, and a model was constructed to predict the risk of recurrence of VS. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that these four collagen family genes play important roles in a variety of biological functions and cellular pathways. Pan-cancer analysis further revealed that the expression of these genes was significantly heterogeneous across immune phenotypes and significantly associated with immune infiltration. Finally, Neuropeptide Y (NPY) was found to be significantly and negatively correlated with the expression of COL5A1, COL3A1, and COL4A1. CONCLUSIONS: Four collagen family genes have been identified as possible predictors of recurrence after radiation therapy for VS. Pan-cancer analysis reveals potential associations between the pathogenesis of VS and other tumorigenic factors. The relevance of NPY to VS was also revealed for the first time.

[Effects of different dosages of oral glucocorticoids on short-term recovery and recurrence of eosinophilic chronic rhinosinusitis with nasal polyps].

Objective:To analyze the effects of different dosages of oral glucocorticoids on short-term recovery and recurrence in patients with eosinophilic chronic rhinosinusitis with nasal polyps（ECRSwNP）. Methods:150 patients with ECRSwNP who underwent functional endoscopic sinus surgery for the first time after the failure of maximum drug therapy were recruited. They were randomly divided into group A, B and C, and their baseline demographic and clinical characteristics were recorded. Group A, B and C were treated with 30 mg, 45 mg and 60 mg oral prednisone tablets once a day separately for 14 consecutive days. Patients in the three groups were regularly followed up at 1, 3 and 6 months after surgery. Visual analogue score （VAS）, 20 item Sino-Nasal Outcome Test （SNOT-20） and Lund-Kennedy endoscopic score （LKS） were completed. The subjective and objective scores and the recurrence of polys 6 months after surgery were compared, and the related factors were analyzed. Results:There were 49 patients in group A, 44 patients in group B and 45 patients in group C in this study. The age of the three groups was significant difference （0.021）, but no significant difference was found in other demographic characteristics such as sex, smoking and so on, and the baseline subjective and objective scores of diseases between three groups（P>0.05）. The VAS, SNOT-20 and LKS score in group B and C was significantly lower than that in group A at 1 month after surgery, but there was no significant difference between group B and C. The LKS score in group C was significantly lower than that in group A and B at 3 months after surgery, but there was no significant difference between group A and group B. There was no significant difference in subjective and objective scores as well as disease recurrence among three groups at 6 months after surgery. However, the recurrence rate of patients with asthma was significantly higher than that in patients without asthma in three groups （62.50% vs 4.88%, 55.56% vs 5.71%, 66.67% vs 7.69% respectively）. Conclusion:Postoperative oral glucocorticoids therapy at moderate or higher dosage can improve the subjective and objective scores of ECRSwNP patients 1 month after surgery, but increasing the dosage did not increase its benefit. Different dosages of oral glucocorticoids had no significant effect on the subjective scores at 3 months, the subjective and objective scores as well as the recurrence of polyps at 6 months after surgery. Asthma is an important factor affecting the recurrence of polyps at 6 months after surgery in patients with ECRSwNP.

[Clinical analysis and surgical discussion of juvenile ossifying fibroma in nasal root].

Objective:To analyze the clinical features of juvenile ossifying fibroma in nasal root and to compare different surgical methods. Methods:Seven cases of juvenile ossifying fibroma occurring in the nasal root were treated via surgery, 5 cases were resected under nasal endoscopy guided by Image Guidance System-based electromagnetic navigation, and 2 cases were resected by lateral nasal butterfly incision. Postoperative follow-up included endoscopy and CT scan of the sinuses. Results:The pathological results of 7 patients were consistent with juvenile ossifying fibroma. Follow-up period ranged from 6 to 45 months, and there were no recurrence or surgical complications. Conclusion:Surgery is the only effective treatment. Endoscopic sinus surgery with image navigation and lateral nasal butterfly incision resection has been deemed available. The external nasal butterfly incision has less bleeding and shorter operation time, but with mild nasal face swelling after surgery, and nasal endoscopy is a surgical method with less damage.

MALDI-TOF/TOF tandem mass spectrometry imaging reveals non-uniform distribution of disaccharide isomers in plant tissues.

Mass spectrometry imaging (MSI) is a powerful technique for investigating the biomolecular locations within tissues. However, the isomeric compounds are rarely distinguished due to inability of MSI to differentiate isomers in the probing area. Coupling tandem mass spectrometry with MSI can facilitate differentiating isomeric compounds. Here MALDI-TOF/TOF tandem mass spectrometry imaging approach was applied to probing the spatial distributions of isomeric disaccharides in plant tissues. First, MS/MS imaging analysis of disaccharide-matrix droplet spots demonstrated the feasibility of distinguishing isomeric species in tissues, by measuring the relative intensity of specific fragments. Then, tandem MS imaging of disaccharides in onion bulb tissues indicated that sucrose and other unknown non-sucrose disaccharides exhibit heterogeneous locations throughout the tissues. This method enables us to image disaccharide isomers differentially in biological tissues, and to discover new saccharide species in plant. This work also emphasizes the necessity of considering isobaric compounds when interpreting MSI results.

Circulating miR-214-3p predicts nasopharyngeal carcinoma recurrence or metastasis.

BACKGROUND: Due to the remarkably stable form in the bloodstream, circulating microRNAs (miRNAs) are indicated as promising novel minimally invasive biomarkers in many cancers. However, available data of miRNAs in nasopharyngeal carcinoma (NPC) are relatively limited. METHODS: Based on the GEO database and previous published reports, 21 dysregulated miRNAs were selected for screening via microarray analysis (20 NPC samples vs 10 controls). Dysregulated miRNAs were then detected and verified by the method of quantitative reverse transcription-polymerase chain reaction (qRT-PCR) in the training and validation sets. The candidate miR-214-3p was then evaluated in the evaluation set, including the association between miR-214-3p and clinicopathological characteristics, dynamic changes in NPC patients and the predictive value for NPC recurrence or metastasis. RESULTS: Seven miRNAs were significantly altered in comparison with healthy controls by microarray analysis. MiR-214-3p was the most significantly expressed in training and validation sets by qRT-PCR. Plasma miR-214-3p expressions were significantly associated with UICC stages and NPC recurrence or metastasis. Plasma miR-214-3p expressions showed a gradual decrease during the follow-up after treatment in NPC patients. Patients with recurrence or metastasis were always accompanied with higher levels of plasma miR-214-3p at the same time point. High pretreatment miR-214-3p expression (≥3.12) was significantly associated with NPC recurrence or metastasis by log-rank test using Kaplan-Meier survival curve analysis (P = 0.006). CONCLUSIONS: Circulating miR-214-3p can serve as a noninvasive biomarker for the prediction of recurrence or metastasis in NPC patients.

Correction: Laser cleavable probes for in situ multiplexed glycan detection by single cell mass spectrometry.

[This corrects the article DOI: 10.1039/C9SC03912K.].

Enhancing surface-assisted laser desorption ionization mass spectrometry performance by integrating plasmonic hot-electron transfer effect through surface modification.

Surface-assisted laser desorption ionization mass spectrometry (SALDI MS) performances were enhanced by modifying surfaces to include a plasmonic hot-electron transfer effect. After modification, the core material's specificity was not only maintained but also enhanced. The MS imaging of ischemic tissues with the modified material indicated some sulfatide changes, which have been barely reported.

Laser cleavable probes for in situ multiplexed glycan detection by single cell mass spectrometry.

Glycans binding on the cell surface through glycosylation play a key role in controlling various cellular processes, and glycan analysis at a single-cell level is necessary to study cellular heterogeneity and diagnose diseases in the early stage. Herein, we synthesized a series of laser cleavable probes, which could sensitively detect glycans on single cells and tissues by laser desorption ionization mass spectrometry (LDI-MS). This multiplexed and quantitative glycan detection was applied to evaluate the alterations of four types of glycans on breast cancer cells and drug-resistant cancer cells at a single-cell level, indicating that drug resistance may be related to the upregulation of glycan with a ß-d-galactoside (Galß) group and Neu5Aca2-6Gal(NAc)-R. Moreover, the glycan spatial distribution in cancerous and paracancerous human tissues was also demonstrated by MS imaging, showing that glycans are overexpressed in cancerous tissues. Therefore, this single-cell MS approach exhibits promise for application in studying glycan functions which are essential for clinical biomarker discovery and diagnosis of related diseases.

Hot electron transfer promotes ion production in plasmonic metal nanostructure assisted laser desorption ionization mass spectrometry.

Plasmonic metal nanostructures have been used as effective materials for enhancing the laser desorption ionization (LDI) efficiency in mass spectrometry analysis. But the ionization mechanism and the origin of initial charges have not been fully understood yet. Here we provided experimental evidence showing that the hot electron transfer in localized surface plasmon resonance (LSPR) plays a key role in ionizing molecules during the LDI process.

N-Phenyl-2-naphthylamine as a Novel MALDI Matrix for Analysis and in Situ Imaging of Small Molecules.

Due to its strong ultraviolet absorption, low background interference in the small molecular range, and salt tolerance capacity, N-phenyl-2-naphthylamine (PNA) was developed as a novel matrix in the present study for analysis and imaging of small molecules by matrix-assisted laser desorption/ionization mass spectrometry time-of-fight (MALDI-TOF MS). The newly developed matrix displayed good performance in analysis of a wide range of small-molecule metabolites including free fatty acids, amino acids, peptides, antioxidants, and phospholipids. In addition, PNA-assisted LDI MS imaging of small molecules in brain tissue of rats subjected to middle cerebral artery occlusion (MCAO) revealed unique distributions and changes of 89 small-molecule metabolites including amino acids, antioxidants, free fatty acids, phospholipids, and sphingolipids in brain tissue 24 h postsurgery. Fifty-nine of the altered metabolites were identified, and all the changed metabolites were subject to relative quantitation and statistical analysis. The newly developed matrix has great potential application in the field of biomedical research.

Hexagonal boron nitride nanosheets as a multifunctional background-free matrix to detect small molecules and complicated samples by MALDI mass spectrometry.

Here we report the innovation of using hexagonal boron nitride (h-BN) nanosheets as the first background-free matrix among the full laser pulse energy range for the analysis and imaging of small molecule metabolites and as an adsorbent for the enrichment of samples. Due to its totally free background and high efficiency as an adsorbent and matrix, h-BN has promising prospects in metabolomics, MALDI imaging, and environmental analysis.

Mass Spectrometry Imaging of Kidney Tissue Sections of Rat Subjected to Unilateral Ureteral Obstruction.

Chronic kidney disease (CKD) poses a serious threat to the quality of human life and health with an increasing incidence worldwide. Renal fibrosis is closely related to CKD and regarded as the final common pathophysiological pathway in most cases of end-stage renal diseases. Elucidating the mechanisms underlying renal fibrosis and developing novel therapeutic strategies are of great importance. Herein, matrix assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) based on 1, 5-diaminonaphthalene hydrochloride was applied to the rat model of unilateral ureteral obstruction (UUO) to investigate metabolic changes during renal fibrosis. Among identified endogenous compounds, twenty-one metabolites involved in metabolic networks such as glycolysis, tricarboxylic acid (TCA) cycle, ATP metabolism, fatty acids metabolism, antioxidants, and metal ions underwent relatively obvious changes after 1 and 3 weeks of UUO. Unique distribution of the metabolites was obtained, and metabolic changes of kidneys during renal fibrosis were investigated simultaneously for the first time. These findings once again highlighted the promising potential of the organic salt matrix for application in small molecule in situ MSI and in the field of biomedical research.