CT-based radiographic measurements and effectiveness estimates of full-endoscopic surgery in thoracic myelopathy caused by ossification of ligamentum flavum.

BACKGROUND: Evaluate the effectiveness of posterior percutaneous full-endoscopic technique for patients with thoracic myelopathy caused by ossification of ligamentum flavum (TOLF). METHODS: A prospective study was conducted for 16 patients with TOLF, who were treated with posterior endoscopic technique from 2017 to 2019. The sagittal and cross-sectional CT images are used to measure the area of ossified ligamentum and evaluate the decompression of surgery, respectively. The effectiveness was evaluated with visual analog scale (VAS), modified Japanese Orthopedic Association scale (mJOA), The Oswestry Disability Index (ODI), and Macnab efficacy evaluation. RESULTS: The average area of TOLF on sagittal and cross-sectional CT images in the 16 patients was (116.62 ± 32.72) mm2 and (141.59 ± 27.25) mm2 preoperatively, (15.99 ± 12.54) mm2 and (11.72 ± 8.64) mm2 at 3 days after the operation, (16.78 ± 11.49) mm2 and (10.82 ± 7.57) mm2 postoperative 1 year, respectively. The invasive proportion of spinal canal at preoperative sagittal and cross-sectional CT images was (48.10 ± 10.04) % and (57.58 ± 11.37) %, which decreased to (6.83 ± 4.48) % and (4.40 ± 3.01) % at the final follow-up. The average score of mJOA, VAS and ODI improved. The excellent and good rate was 87.50% according to Macnab evaluation. Compared with preoperative, differences in areas of TOLF, proportions of spinal canal, and clinical assessments of postoperative 3 days and 1 year were all statistically significant. Two cases of dural tear were observed. CONCLUSION: Endoscopic surgery has a good clinical effect on TOLF, which has the advantage of less trauma to the paraspinal muscles and no impact on the spinal structure. The CT-based radiographic measurements can quantitatively evaluate the degree of spinal canal stenosis in TOLF.

Septin 9 methylation analysis of lymph node micrometastases for predicting relapse of colorectal cancer.

BACKGROUND: Molecular markers for the detection of lymph node micrometastases of malignant tumors have been extensively investigated. However, epigenetic signatures have rarely been reported for identification of metastatic lymph nodes and disease relapse. Septin 9 is the most frequently reported hypermethylated gene in colorectal cancer (CRC). This study aimed to assess the clinical relevance of Septin 9 methylation in regional lymph nodes in recurrence/metastases of CRC. METHODS: We analyzed Septin 9 methylation of DNA from resected lymph nodes in 75 CRC patients with or without tumor recurrence using quantitative methylation-sensitive PCR (qMS-PCR). RESULTS: Of the 30 histologically negative lymph node CRC patients without recurrence (group 1), methylated Septin 9 was detected in 3 (10 %) cases. The positivity rate of methylated Septin 9 in group 2 containing 30 histologically node-negative CRC patients with recurrence was 30 % (9/30). For group 3, lymphatic invasion as well as tumor recurrence, 11 (73 %) out of 15 subjects had Septin 9 methylation-positive lymph nodes. Moreover, patients in group 3 had a higher level of methylated Septin 9 compared to subjects in group 1 and group 2 (p < 0.05). In addition, CRC patients with Septin 9 methylation in lymph nodes had significantly reduced survival (Log-rank P < 0.0001). CONCLUSION: Our data support the predictive role of Septin 9 methylation analysis of lymph node micrometastases for tumor relapse after surgery.

[Application of Three Dimensional Confocal Micro X-Ray Fluorescence Technology Based on Polycapillary X-Ray Lens in Analysis of Rock and Mineral Samples].

Confocal three dimensional (3D) micro X-ray fluorescence (XRF) spectrometer based on a polycapillary focusing X-ray lens (PFXRL) in the excitation channel and a polycapillary parallel X-ray lens (PPXRL) in the detection channel was developed. The PFXRL and PPXRL were placed in a confocal configuration. This was helpful in improving the signal-to-noise ratio of the XRF spectra, and accordingly lowered the detection limitation of the XRF technology. The confocal configuration ensured that only the XRF signal from the confocal micro-volume overlapped by the output focal spot of the PFXRL and the input focal spot of the PPXRL could be detected by the detector. Therefore, the point-to-point information of XRF for samples could be obtained non-destructively by moving the sample located at the confocal position. The magnitude of the gain in power density of the PFXRL was 10(3). This let the low power conventional X-ray source be used in this confocal XRF, and, accordingly, decreased the requirement of high power X-ray source for the confocal XRF based on polycapillary X-ray optics. In this paper, we used the confocal 3D micro X-ray fluorescence spectrometer to non-destructively analyzed mineral samples and to carry out a 3D point-to-point elemental mapping scanning, which demonstrated the capabilities of confocal 3D micro XRF technology for non-destructive analysis elements composition and distribution for mineral samples. For one mineral sample, the experimental results showed that the area with high density of element of iron had high density of copper. To some extent, this reflected the growth mechanisms of the mineral sample. The confocal 3D micro XRF technology has potential applications in such fields like the analysis identification of ore, jade, lithoid utensils, "gamble stone" and lithoid flooring.

A dominant CD4(+) T-cell response to Helicobacter pylori reduces risk for gastric disease in humans.

BACKGROUND & AIMS: Immunodominance is an important feature of antiviral, antitumor, and antibacterial cellular immune responses, but it is not well demonstrated in the immune responses against Helicobacter pylori. Antigen-specific CD4(+) T cells protect mice against infection with H pylori. We investigated the immunodominant CD4(+) T-cell response to neuraminyllactose-binding hemagglutinin (HpaA), which is a conserved, H pylori-specific colonization factor that is being investigated as an antigen for vaccination strategies. METHODS: HpaA-specific CD4(+) T cells were expanded with autologous peripheral blood mononuclear cells that had been incubated with recombinant HpaA and characterized using overlapping synthetic peptides. We compared the percentage of CD4(+) T cells with specificity for HpaA(88-100), restricted to HLA-DRB1*1501, among 59 H pylori-infected subjects with different gastric diseases. RESULTS: We identified and characterized several immunodominant CD4(+) T-cell epitopes derived from HpaA. The immunodominant CD4(+) T-cell responses specific to HpaA(88-100) were observed in most H pylori-infected individuals who expressed HLA-DRB1*1501 and were significantly more abundant in patients with less severe diseases (P < .05). CONCLUSIONS: The HLA-DRB1*1501-restricted immunodominant CD4(+) T-cell response to HpaA(88-100) is associated with reduced risk of severe gastric diseases. Further study of these and other immunodominant CD4(+) T-cell responses to H pylori will provide insight into mechanisms of protective immunity and aid in vaccine design.

Alistipes indistinctus-derived hippuric acid promotes intestinal urate excretion to alleviate hyperuricemia.

Hyperuricemia induces inflammatory arthritis and accelerates the progression of renal and cardiovascular diseases. Gut microbiota has been linked to the development of hyperuricemia through unclear mechanisms. Here, we show that the abundance and centrality of Alistipes indistinctus are depleted in subjects with hyperuricemia. Integrative metagenomic and metabolomic analysis identified hippuric acid as the key microbial effector that mediates the uric-acid-lowering effect of A. indistinctus. Mechanistically, A. indistinctus-derived hippuric acid enhances the binding of peroxisome-proliferator-activated receptor γ (PPARγ) to the promoter of ATP-binding cassette subfamily G member 2 (ABCG2), which in turn boosts intestinal urate excretion. To facilitate this enhanced excretion, hippuric acid also promotes ABCG2 localization to the brush border membranes in a PDZ-domain-containing 1 (PDZK1)-dependent manner. These findings indicate that A. indistinctus and hippuric acid promote intestinal urate excretion and offer insights into microbiota-host crosstalk in the maintenance of uric acid homeostasis.

Selection strategy for endoscopic necrosectomy approaches of infected walled-off pancreatic necrosis: Analysis of 101 patients from a single center with long-term follow-up.

OBJECTIVES: Endoscopic necrosectomy (EN) is a promising minimally invasive approach for treating infected walled-off pancreatic necrosis (WOPN). Multiple EN approaches are currently available, though criteria for selecting the optimal approaches are lacking. We aimed to propose a rational selection strategy of EN and to retrospectively evaluate its safety and effectiveness. METHODS: Altogether 101 patients who underwent EN for infected WOPN at a tertiary hospital between June 2009 and February 2023 were retrospectively included for analysis. Demographic characteristics, details of the EN procedures, procedure-related adverse events, and clinical outcomes were investigated. RESULTS: Among these 101 patients with WOPN, 56 (55.4%) underwent transluminal EN, 38 (37.6%) underwent percutaneous EN, and seven (6.9%) underwent combined approach, respectively. Clinical success was achieved in 94 (93.1%) patients. Seven (6.9%) experienced procedure-related adverse events, and seven (6.9%) died during the treatment period. During a median follow-up of 50 months, 5 (5.3%) of the 94 patients had disease recurrence, 17.0% (16/94) had new-onset diabetes mellitus, and 6.4% (6/94) needed oral pancreatic enzyme supplementation. The clinical success rate, procedure-related adverse event rate, and long-term follow-up outcomes were not significantly different among the three groups. High APACHE-II scores (≥15) and organ failure were identified as factors related to treatment failure. CONCLUSIONS: A selection strategy for EN approaches, based on the extent of necrosis and its distance from the gastrointestinal lumen (using a threshold of 15 mm), is safe and effective for treating infected WOPN in both short-term and long-term outcomes.

Enhanced interactions among gut mycobiomes with the deterioration of glycemic control.

BACKGROUND: The gut mycobiome is closely linked to health and disease; however, its role in the progression of type 2 diabetes mellitus (T2DM) remains obscure. Here, a multi-omics approach was employed to explore the role of intestinal fungi in the deterioration of glycemic control. METHODS: 350 participants without hypoglycemic therapies were invited for a standard oral glucose tolerance test to determine their status of glycemic control. The gut mycobiome was identified through internal transcribed spacer sequencing, host genetics were determined by genotyping array, and plasma metabolites were measured with untargeted liquid chromatography mass spectrometry. FINDINGS: The richness of fungi was higher, whereas its dissimilarity was markedly lower, in participants with T2DM. Moreover, the diversity and composition of fungi were closely associated with insulin sensitivity and pancreatic ß-cell functions. With the exacerbation of glycemic control, the co-occurrence network among fungus taxa became increasingly complex, and the complexity of the interaction network was inversely associated with insulin sensitivity. Mendelian randomization analysis further demonstrated that the Archaeorhizomycetes class, Fusarium genus, and Neoascochyta genus were causally linked to impaired glucose metabolism. Furthermore, integrative analysis with metabolomics showed that increased 4-hydroxy-2-oxoglutaric acid, ketoleucine, lysophosphatidylcholine (20:3/0:0), and N-lactoyl-phenylalanine, but decreased lysophosphatidylcholine (O-18:2), functioned as key molecules linking the adverse effect of Fusarium genus on insulin sensitivity. CONCLUSIONS: Our study uncovers a strong association between disturbance in gut fungi and the progression of T2DM and highlights the potential of targeting the gut mycobiome for the management of T2DM. FUNDINGS: This study was supported by MOST and NSFC of China.

Autologous olfactory mucosa mesenchymal stem cells treatment improves the neural network in chronic refractory epilepsy.

BACKGROUND AND AIMS: Refractory epilepsy is also known as drug-resistant epilepsy with limited clinical treatment. Benefitting from its safety and easy availability, olfactory mucosa mesenchymal stem cells (OM-MSCs) are considered a preferable MSC source for clinical application. This study aims to investigate whether OM-MSCs are a promising alternative source for treating refractory epilepsy clinically and uncover the mechanism by OM-MSCs administration on an epileptic mouse model. METHODS: OM-MSCs were isolated from turbinal and characterized by flow cytometry. Autologous human OM-MSCs treatment on a patient was carried out using intrathecal administration. Epileptic mouse model was established by 1 mg/kg scopolamine and 300 mg/kg pilocarpine treatment (intraperitoneal). Stereotaxic microinjection was employed to deliver the mouse OM-MSCs. Mouse electroencephalograph recording was used to investigate the seizures. Brain structure was evaluated by magnetic resonance imaging (MRI). Immunohistochemical and immunofluorescent staining of GFAP, IBA1, MAP2, TUBB3, OLIG2, CD4, CD25, and FOXP3 was carried out to investigate the neural cells and Treg cells. QRT-PCR and ELISA were performed to determine the cytokines (Il1b, Il6, Tnf, Il10) on mRNA and protein level. Y-maze, the object location test, and novel object recognition test were performed to measure the cognitive function. Footprint test, rotarod test, balance beam test, and grip strength test were conducted to evaluate the locomotive function. Von Frey testing was carried out to assess the mechanical allodynia. RESULTS: Many beneficial effects of the OM-MSC treatment on disease status, including seizure type, frequency, severity, duration, and cognitive function, and no apparent adverse effects were observed at the 8-year follow-up case. Brain MRI indicated that autologous OM-MSC treatment alleviated brain atrophy in epilepsy patients. A study in an epileptic mouse model revealed that OM-MSC treatment recruited Treg cells to the brain, inhibited inflammation, rebuilt the neural network, and improved the cognitive, locomotive, and perceptive functions of epileptic mice. CONCLUSIONS: Autologous OM-MSC treatment is efficacious for improving chronic refractory epilepsy, suggesting a future therapeutic candidate for epilepsy. TRIAL REGISTRATION: The study was registered with Chinese Clinical Trial Registry (ChiCTR2200055357).

Non-hepatitis-associated mixed cryoglobulinemia with polyclonal plasma cells disease and alcoholic cirrhosis: A rare case report.

Mixed cryoglobulinemia refers to the serum presence of a variety of cryoglobulins, which are defined as immunoglobulins that precipitate at temperatures of < 37°C. The most common cause of mixed cryoglobulinemia is hepatitis C virus (HCV), while other infections, including hepatitis B virus (HBV) and HIV infections, and lymphoproliferative and autoimmune disorders have also been associated with the disease. We reported a rare case of type II-III mixed cryoglobulinemia caused by alcoholic cirrhosis. We need to increase the awareness of and facilitate the early identification of mixed cryoglobulinemia in our clinical study when encountering a patient with liver cirrhosis combined with renal impairment so that treatment can begin early to improve the success rate of therapy and reduce the fatality rate in a potentially life-saving therapy.

Therapeutic Effect of Melatonin in Premature Ovarian Insufficiency: Hippo Pathway Is Involved.

Objective: Premature ovarian insufficiency (POI) is a female reproductive disorder of unknown etiology with no definite pathogenesis. Melatonin (MT) is an endogenous hormone synthesized mainly by pineal cells and has strong endogenous effects in regulating ovarian function. To systematically explore the pharmacological mechanism of MT on POI therapy, a literature review approach was conducted at the signaling pathways level. Methods: Relevant literatures were searched and downloaded from databases, including PubMed and China National Knowledge Infrastructure, using the keywords "premature ovarian insufficiency," "Hippo signaling pathways," and "melatonin." The search criteria were from 2010 to 2022. Text mining was also performed. Results: MT is involved in the regulation of Hippo signaling pathway in a variety of modes and has been correlated with ovarian function. Conclusions: The purpose of this review is to summarize the research progress of Hippo signaling pathways and significance of MT in POI, the potential crosstalk between MT and Hippo signaling pathways, and the prospective therapy.

Polyelectrolyte Complex with Controllable Viscosity by Doping Cu2+ Protects Nylon-Cotton Fabric against Fire.

Nylon-cotton (NC) blend fabrics are widely used in military and industrial applications, but their high flammability still remains a serious problem. In an effort to effectively and quickly impart flame retardancy to the NC fabric, it was treated by simply blade coating with a Cu2+-doped polyelectrolyte complex (CPEC) that consists of ammonium polyphosphate (APP), polyethylenimine (PEI), and copper sulfate. The viscosity of the CPEC can be adjusted by altering the content of CuSO4, which controls the amount of extrinsic and intrinsic ion pairs. By adjusting the proportion and content of PEI, APP, and CuSO4, CPEC suitable for treating the NC fabric was obtained. Only 0.067 wt % Cu2+ was needed to adjust the viscosity and impart self-extinguishing behavior in a vertical burning test. This simple two-step treatment provides a promising technology to protect flammable polymeric substrates with ultralow metal-doped polyelectrolyte complexes.

Effects of SiC and Resorcinol-Formaldehyde (RF) Carbon Coatings on Silicon-Flake-Based Anode of Lithium Ion Battery.

Silicon flakes of about 100 × 1000 × 1000 nm in sizes recycled from wastes of silicon wafer manufacturing processes were coated with combined silicon carbide (SiC) and graphitic (Resorcinol-Formaldehyde (RF)) carbon coatings to serve as active materials of the anode of lithium ion battery (LIB). Thermal carbonization of silicon at 1000 °C for 5 h forms 5-nm SiC encapsulating silicon flakes. SiC provides physical strength to help silicon flakes maintain physical integrity and isolating silicon from irreversible reactions with the electrolyte. Lithium diffuses through SiC before alloying with silicon. The SiC buffer layer results in uniform alloying reactions between lithium and silicon on the surface around a silicon flake. RF carbon coatings provide enhanced electrical conductivity of SiC encapsulated silicon flakes. We characterized the coatings and anode by SEM, TEM, FTIR, XRD, cyclic voltammetry (CV), electrochemical impedance spectra (EIS), and electrical resistance measurements. Coin half-cells with combined SiC and RF carbon coatings exhibit an initial Coulombic efficiency (ICE) of 76% and retains a specific capacity of 955 mAh/g at 100th cycle and 850 mAh/g at 150th cycle of repetitive discharge and charge operation. Pre-lithiation of the anode increases the ICE to 97%. The SiC buffer layer reduces local stresses caused by non-uniform volume changes and improves the capacity retention and the cycling life.

Major Characteristics of Severity and Mortality in Diabetic Patients With COVID-19 and Establishment of Severity Risk Score.

Objectives: Diabetes is a risk factor for poor COVID-19 prognosis. The analysis of related prognostic factors in diabetic patients with COVID-19 would be helpful for further treatment of such patients. Methods: This retrospective study involved 3623 patients with COVID-19 (325 with diabetes). Clinical characteristics and laboratory tests were collected and compared between the diabetic group and the non-diabetic group. Binary logistic regression analysis was applied to explore risk factors associated in diabetic patients with COVID-19. A prediction model was built based on these risk factors. Results: The risk factors for higher mortality in diabetic patients with COVID-19 were dyspnea, lung disease, cardiovascular diseases, neutrophil, PLT count, and CKMB. Similarly, dyspnea, cardiovascular diseases, neutrophil, PLT count, and CKMB were risk factors related to the severity of diabetes with COVID-19. Based on these factors, a risk score was built to predict the severity of disease in diabetic patients with COVID-19. Patients with a score of 7 or higher had an odds ratio of 7.616. Conclusions: Dyspnea is a critical clinical manifestation that is closely related to the severity of disease in diabetic patients with COVID-19. Attention should also be paid to the neutrophil, PLT count and CKMB levels after admission.

Fully automated magnetically controlled capsule endoscopy for examination of the stomach and small bowel: a prospective, feasibility, two-centre study.

BACKGROUND: The use of magnetically controlled capsules for gastroscopy is in the early stages of clinical adoption. We aimed to evaluate the safety and efficacy of a fully automated magnetically controlled capsule endoscopy (FAMCE) system in clinical practice for gastroscopy and small bowel examination. METHODS: We did a prospective, comparative study to evaluate the safety and efficacy of FAMCE. Patients from two hospitals in Chongqing, China were consecutively enrolled. Eligible participants were aged 18-80 years with suspected gastric pathology and no previous surgery. Participants underwent FAMCE for screening of gastric lesions, then conventional transoral gastroscopy 2 h later, and stomach examination results were compared. The primary outcome was the rate of complete detection of gastric anatomy landmarks (cardia, fundus, body, angulus, antrum, and pylorus) by FAMCE. Secondary outcomes were the time required for gastric completion by FAMCE, the rate of detection of gastric lesions by FAMCE compared with conventional transoral gastroscopy, and the rate of complete small bowel examination. Adverse events were also evaluated. The study was registered in the Chinese Clinical Trial Registry, ChiCTR2000040507. FINDINGS: Between May 12 and Aug 17, 2020, 114 patients (mean age 44·0 years [IQR 34·0-55·0]; 63 [55%] female) were enrolled. The rate of complete detection of gastric anatomical structures by FAMCE was 100% (95% CI 99·3-100·0). The concordance between FAMCE and conventional transoral gastroscopy was 99·61% (99·45-99·78). The mean completion time of a gastroscopy with FAMCE was 19·17 min (SD 1·43; median 19·00, IQR 19·00-20·00), compared with 5·21 min (2·00; 5·18, 3·68-6·45) for conventional transoral gastroscopy. In 114 enrolled patients, 214 lesions were detected by FAMCE and conventional transoral gastroscopy. Of those, 193 were detected by both modalities. FAMCE missed five pathologies (four cases of gastritis and one polyp), whereas conventional transoral gastroscopy missed 16 pathologies (12 cases of gastritis, one polyp, one fundal xanthoma, and two antral erosions). FAMCE was able to provide a complete small bowel examination for all 114 patients and detected intestinal lesions in 50 (44%) patients. During the study, two (2%) patients experienced adverse events. No serious adverse events were recorded, and there was no evidence of capsule retention. INTERPRETATION: The performance of FAMCE is similar to conventional transoral gastroscopy in completion of gastric examination and lesion detection. Furthermore, it can provide a complete small bowel examination. Therefore, FAMCE could be effective method for examination of the gastrointestinal tract. FUNDING: Chinese National Key Research and Development Program.

Silicon-Based Anode of Lithium Ion Battery Made of Nano Silicon Flakes Partially Encapsulated by Silicon Dioxide.

Ubiquitous mobile electronic devices and rapidly increasing electric vehicles demand a better lithium ion battery (LIB) with a more durable and higher specific charge storage capacity than traditional graphite-based ones. Silicon is among the most promising active media since it exhibits ten times of a specific capacity. However, alloying with lithium by silicon and dissociation of the silicon-lithium alloys induce high volume changes and result in pulverization. The loss of electrical contacts by silicon with the current collector of the anode causes rapid capacity decay. We report improved anode cycling performance made of silicon flakes partially encapsulated by silicon dioxide and coated with conductive nanocarbon films and CNTs. The silicon dioxide surface layer on a silicon flake improves the physical integrity for a silicon-based anode. The exposed silicon surface provides a fast transport of lithium ions and electrons. CNTs and nanocarbon films provide electrical connections between silicon flakes and the current collector. We report a novel way of manufacturing silicon flakes partially covered by silicon dioxide through breaking oxidized silicon flakes into smaller pieces. Additionally, we demonstrate an improved cycling life and capacity retention compared to pristine silicon flakes and silicon flakes fully encapsulated by silicon dioxide. Nanocarbon coatings provide conduction channels and further improve the anode performance.

Chronic Sleep Restriction Induces Cognitive Deficits and Cortical Beta-Amyloid Deposition in Mice via BACE1-Antisense Activation.

AIMS: To clarify the correlation between chronic sleep restriction (CSR) and sporadic Alzheimer disease (AD), we determined in wild-type mice the impact of CSR, on cognitive performance, beta-amyloid (Aß) peptides, and its feed-forward regulators regarding AD pathogenesis. METHODS: Sixteen nine-month-old C57BL/6 male mice were equally divided into the CSR and control groups. CSR was achieved by application of a slowly rotating drum for 2 months. The Morris water maze test was used to assess cognitive impairment. The concentrations of Aß peptides, amyloid precursor protein (APP) and ß-secretase 1 (BACE1), and the mRNA levels of BACE1 and BACE1-antisense (BACE1-AS) were measured. RESULTS: Following CSR, impairments of spatial learning and memory consolidation were observed in the mice, accompanied by Aß plaque deposition and an increased Aß concentration in the prefrontal and temporal lobe cortex. CSR also upregulated the ß-secretase-induced cleavage of APP by increasing the protein and mRNA levels of BACE1, particularly the BACE1-AS. CONCLUSIONS: This study shows that a CSR accelerates AD pathogenesis in wild-type mice. An upregulation of the BACE1 pathway appears to participate in both cortical Aß plaque deposition and memory impairment caused by CSR. BACE1-AS is likely activated to initiate a cascade of events that lead to AD pathogenesis. Our study provides, therefore, a molecular mechanism that links CSR to sporadic AD.

Correction: A Novel Top-k Strategy for Influence Maximization in Complex Networks with Community Structure.

[This corrects the article DOI: 10.1371/journal.pone.0145283.].

A Novel Top-k Strategy for Influence Maximization in Complex Networks with Community Structure.

In complex networks, it is of great theoretical and practical significance to identify a set of critical spreaders which help to control the spreading process. Some classic methods are proposed to identify multiple spreaders. However, they sometimes have limitations for the networks with community structure because many chosen spreaders may be clustered in a community. In this paper, we suggest a novel method to identify multiple spreaders from communities in a balanced way. The network is first divided into a great many super nodes and then k spreaders are selected from these super nodes. Experimental results on real and synthetic networks with community structure show that our method outperforms the classic methods for degree centrality, k-core and ClusterRank in most cases.

Correlations between community structure and link formation in complex networks.

BACKGROUND: Links in complex networks commonly represent specific ties between pairs of nodes, such as protein-protein interactions in biological networks or friendships in social networks. However, understanding the mechanism of link formation in complex networks is a long standing challenge for network analysis and data mining. METHODOLOGY/PRINCIPAL FINDINGS: Links in complex networks have a tendency to cluster locally and form so-called communities. This widely existed phenomenon reflects some underlying mechanism of link formation. To study the correlations between community structure and link formation, we present a general computational framework including a theory for network partitioning and link probability estimation. Our approach enables us to accurately identify missing links in partially observed networks in an efficient way. The links having high connection likelihoods in the communities reveal that links are formed preferentially to create cliques and accordingly promote the clustering level of the communities. The experimental results verify that such a mechanism can be well captured by our approach. CONCLUSIONS/SIGNIFICANCE: Our findings provide a new insight into understanding how links are created in the communities. The computational framework opens a wide range of possibilities to develop new approaches and applications, such as community detection and missing link prediction.