The performance of microbial fuel cell with sodium alginate and super activated carbon composite gel modified anode.

Microbial fuel cells (MFCs) have the functions of wastewater treatment and power generation. The incorporation of modified anodes enhances the sustainable power generation performance of MFCs. In this study, to evaluate the feasibility of sodium alginate (SA) as a biocompatible binder, hydrogel mixed with super activated carbon (SAC) and SA was modified the carbon cloth anode of MFC. The results showed that the maximum output voltage in the SAC/SA hydrogel modified anode MFC was 0.028 V, which was increased by 115%, compared with the blank carbon cloth anode. The internal resistance of MFC was 9429 Ω, which was 18% lower than that of control (11560 Ω). The maximum power density was 6.14 mW/m2, which was increased by 365% compared to the control. After modification of SAC/SA hydrogel, the chemical oxygen demand (COD) removal efficiency reached to 56.36% and was 12.72% higher than the control. Coulombic efficiency with modified anode MFC reached 17.65%, which was increased by 104%, compared with the control. Our findings demonstrate the feasibility of utilizing SA as a biocompatible binder for anode modification, thereby imparting sustainable and enhanced power generation performance to MFCs. This study presented a new selectivity for harnessing algal bioresources and improving anode binders in future MFC applications.

Kinetic study of electron transfer process in methyl orange decolorization by shewanella in MFCs with covalent organic frameworks modified anode.

As a new electrode material for electrochemical systems, covalent organic framework (COF) materials have been gradually applied to bioelectrochemical systems. In our previous study, the COFBTA-DPPD-rGO composite was synthesized via Schiff-base coupling between benzene-1,3,5-tricarbaldehyde (BTA) and 3,8-diamino-6-phenylphenanthridine (DPPD) on reduced graphene oxide (rGO) at room temperature. Here, COFBTA-DPPD-rGO modified MFC anode was used to assist microorganisms to decolorize methyl orange (MO), and the properties of MFCs were studied. The results showed that compared to the unmodified electrode MFC (28 mA m-2, 4.20 mW m-2) the current density and maximum power density of the anode MFC modified by COFBTA-DPPD-rGO (134.5 mA m-2, 21.78 mW m-2) were increased by 380.3% and 423.6%, respectively. The transferred electron number n and charge transfer coefficient α of the modified COFBTA-DPPD-rGO anode (4 and 0.43) compared to the unmodified electrode (2.4 and 0.38) were increased by 67% and 13%, respectively. The decolorization ratio of MO could reach 90.3% at 10 h. Compared with the unmodified electrode MFC (53.0%), the decolorization ratio and kinetic constant of decolorization process were enhanced by 26% and 372%, respectively. Therefore, COFBTA-DPPD-rGO could be a new choice for applying to the MFCs.

Cloning and Characterization of a Novel Alginate Lyase from Paenibacillus sp. LJ-23.

As a low molecular weight alginate, alginate oligosaccharides (AOS) exhibit improved water solubility, better bioavailability, and comprehensive health benefits. In addition, their biocompatibility, biodegradability, non-toxicity, non-immunogenicity, and gelling capability make them an excellent biomaterial with a dual curative effect when applied in a drug delivery system. In this paper, a novel alginate lyase, Algpt, was cloned and characterized from a marine bacterium, Paenibacillus sp. LJ-23. The purified enzyme was composed of 387 amino acid residues, and had a molecular weight of 42.8 kDa. The optimal pH of Algpt was 7.0 and the optimal temperature was 45 °C. The analysis of the conserved domain and the prediction of the three-dimensional structure indicated that Algpt was a novel alginate lyase. The dominant degradation products of Algpt on alginate were AOS dimer to octamer, depending on the incubation time, which demonstrated that Algpt degraded alginate in an endolytic manner. In addition, Algpt was a salt-independent and thermo-tolerant alginate lyase. Its high stability and wide adaptability endow Algpt with great application potential for the efficient preparation of AOS with different sizes and AOS-based products.

Application of electric potential improves ethanol production from xylose by active sludge.

BACKGROUND: Low-cost raw materials such as lignocellulosic materials have been utilized in second-generation ethanol production process. However, the sequential and slow conversion of xylose into target products remains one of the main challenges for realizing efficient industrial lignocellulosic biorefinery. RESULTS: By applying different constant potentials to different microbial electrolysis cells with xylose as the sole carbon source, we analyzed the output of metabolites, microbial community structures, electron flow, and carbon flow in the process of xylose electro-fermentation by domesticated activated sludge. The bioreactors produced currents when applying positive potentials. The peak currents of the + 0.242 V, + 0.542 V and + 0.842 V reactors were 0.96 × 10-6 A, 3.36 × 10-6 A and 6.43 × 10-6 A, respectively. The application of potentials promoted the xylose consumption, and the maximum consumption rate in the + 0.542 V reactor was 95.5%, which was 34.8 times that of the reactor without applied potential. The potential application also promoted the production of ethanol and acetate. The maximum ethanol yield (0.652 mol mol-1 xylose) was obtained in the + 0.842 V reactor. The maximum acetate concentration (1,874 µmol L-1) was observed in the + 0.842 V reactor. The optimal potential for ethanol production was + 0.842 V with the maximum ethanol yield and energy saving. The application of positive potential caused the microorganisms to carry out ethanol fermentation, and the application of negative potential forced the microorganisms to carry out acetic fermentation. The potential application changed the diversity and community structure of microorganisms in the reactors, and the two most significantly changed families were Paenibacillaceae and Bacillaceae. CONCLUSION: The constructed microbial electrolysis cells with different potentials obtained better production yield and selectivity compared with the reactor without applied potential. Our work provides strategies for the subsequent fermentation processes with different needs.

Potential applications of alginate oligosaccharides for biomedicine - A mini review.

Extensive research on marine algae, especially on their health-promoting properties, has been conducted. Various ingredients with potential biomedical applications have been discovered and extracted from marine algae. Alginate oligosaccharides are low molecular weight alginate polysaccharides present in cell walls of brown algae. They exhibit various health benefits such as anti-inflammatory, anti-microbial, anti-oxidant, anti-tumor and immunomodulation. Their low-toxicity, non-immunogenicity, and biodegradability make them an excellent material in biomedicine. Alginate oligosaccharides can be chemically or biochemically modified to enhance their biological activity and potential in pharmaceutical applications. This paper provides a brief overview on alginate oligosaccharides characteristics, modification patterns and highlights their vital health promoting properties.

Enhancement of magnetic field on fermentative hydrogen production by Clostridium pasteurianum.

Microbial fermentation plays important roles in hydrogen production. Various methods to promote hydrogen production are being developed. Here, different magnetic field intensities (2.7 mT, 3.2 mT and 9.1 mT) were applied to the glucose fermentation system of Clostridium pasteurianum to evaluate the feasibility and effect of statistic magnetic field on hydrogen production. The results showed that the magnetic field intensity of 3.2 mT effectively enhanced the hydrogen production. The total glucose consumption reached 0.64 ± 0.010 mmol, the maximum hydrogen yield reached 2.34 ± 0.020 mol H2/mol glucose, and the maximum hydrogen production rate reached 0.065 ± 0.002 mmol/h. Compared with the control, the maximum biomass, carbon conversion efficiency and energy conversion efficiency were elevated by 366%, 114%, and 26.8%, respectively. Our results provide a new way for promotion of hydrogen production, better understanding of the interaction mechanism between magnetic field and microorganisms and for optimizing the hydrogen production.

Production of bioelectricity may play an important role for the survival of Xanthomonas campestris pv. campestris (Xcc) under anaerobic conditions.

The plant pathogen Xanthomonas is commonly found in biocontaminated bioreactors; however, few studies have evaluated the growth and impacts of this microorganism on bioreactors. In this study, we examined the characteristics of Xanthomonas campestris pv. campestris (Xcc). Our results showed that Xcc could reduce metal Fe (III) and decolorise methyl orange in vitro. Moreover, I-t and cyclic voltammetry curves showed that Xcc could generate bioelectricity and had two extracellular electron transfer pathways, similar to that of Shewanella. Based on the spectral analysis of intact cells and scanning electron microscopy analysis, one pathway was speculated to involve cytochrome C by direct contact with the pili or cell surface. The other pathway may involve indirect mediators, such as redox substrates, among extracellular polymeric substances. For the direct extracellular electron transfer process, the charge transfer coefficient α, electron number n, and the electron transfer rate constant ks were determined to be 0.49, 2.6, and 2.2 × 10-3 s-1, respectively. In the indirect extracellular electron transfer processes, the values of α, n, and ks were 0.52, 4, and 1.21 s-1, respectively. Of these two transfer methods, indirect electron transfer is dominant and faster than direct electron transfer. Moreover, after mutation of the dsbD gene, which is important for indirect electron transfer, the electrochemical parameters α, n, and ks decreased. Our findings reveal a new anaerobic mechanism mediating the survival of Xcc during wastewater treatment, and may help develop new strategies for preventing Xcc growth during wastewater treatment.

Effects of Magnetic Minerals Exposure and Microbial Responses in Surface Sediment across the Bohai Sea.

Extensive production and application of magnetic minerals introduces significant amounts of magnetic wastes into the environment. Exposure to magnetic minerals could affect microbial community composition and geographic distribution. Here, we report that magnetic susceptibility is involved in determining bacterial α-diversity and community composition in surface sediment across the Bohai Sea by high-throughput sequencing analysis of the 16S rRNA gene. The results showed that environmental factors (explained 9.80%) played a larger role than spatial variables (explained 6.72%) in conditioning the bacterial community composition. Exposure to a magnetite center may shape the geographical distribution of five dissimilatory iron reducing bacteria. The microbial iron reduction ability and electroactive activity in sediment close to a magnetite center are stronger than those far away. Our study provides a novel understanding for the response of DIRB and electroactive bacteria to magnetic minerals exposure.

Evaluation of a High Concentrated Contrast Media Injection Protocol in Combination with Low Tube Current for Dose Reduction in Coronary Computed Tomography Angiography: A Randomized, Two-center Prospective Study.

RATIONALE AND OBJECTIVES: The study aimed to prospectively evaluate the radiation dose reduction potential and image quality (IQ) of a high-concentration contrast media (HCCM) injection protocol in combination with a low tube current (mAs) in coronary computed tomography angiography. MATERIALS AND METHODS: Eighty-one consecutive patients (mean age: 62 years; 34 females; body mass index: 18-31) were included and randomized-assigned into two groups. All computed tomography (CT) examinations were performed in two groups with the same tube voltage (100 kV), flow rate of contrast medium (5.0 mL/s), and iodine dose (22.8 g). An automatic mAs and low concentration contrast medium (300 mgI/mL) were used in group A, whereas effective mAs was reduced by a factor 0.6 along with HCCM (400 mgI/mL) in group B. Radiation dose was assessed (CT dose index [CTDIvol] and dose length product), and vessel-based objective IQ for various regions of interest (enhancement, noise, signal-to-noise ratio, and contrast-to-noise ratio), subjective IQ, noise, and motion artifacts were analyzed overall and vessel-based with a 5-point Likert scale. RESULTS: The CT attenuation of coronary arteries and image noise in group B were significantly higher than those in group A (ranges: 507.5-548.1 Hounsfield units vs 407.5-444.5 Hounsfield units; and 20.3 ± 8.6 vs 17.7 ± 8.0) (P ≤ 0.0166). There was no significant difference between the two groups in signal-to-noise ratio, contrast-to-noise ratio, and subjective IQ of coronary arteries (29.4-31.7, 30.0-37.0, and medium score of 5 in group A vs 29.4-32.4, 27.7-36.3, and medium score of 5 in group B, respectively, P ≥ 0.1859). Both mean CTDIvol and dose length product in group B were 58% of those of group A. CONCLUSIONS: HCCM combined with low tube current allows dose reduction in coronary computed tomography angiography and does not compromise IQ.

XC_0531 encodes a c-type cytochrome biogenesis protein and is required for pathogenesis in Xanthomonas campestris pv. campestris.

BACKGROUND: The phytopathogenic Xanthomonas campestris pv.campestris is a gram-negative bacterium and the causal agent of black-rot disease of cruciferous crops. Many gram-negative bacteria possess a family of proteins, called Dsbs, which are involved in disulfide bond formation in certain periplasmic proteins. In our preliminary screening of the virulence to the plants we identified that gene XC_0531 which annotated gene dsbD of Xanthomonas campestris pv. campestris (Xcc) is related to the virulence to the host plants. RESULTS: Here, we found XC_0531 encoded a DsbD like protein. Its deletion is sensitive to DTT and copper, decreased accumulation of free thiols in periplasm. Its deletion also affected heme synthesis, position of Soret band and the production of peak c550. This suggests that XC_0531 is related to c-type cytochromes biogenesis. XC_0531 mutation decreased the utilization of different carbon sources (such as galactose, xylose, maltose, saccharose and glucose), reduced extracellular polysaccharide (EPS) production, decreased extracellular enzyme activities (protease, cellulose and amylase), slowed down growth rate of Xcc and weakened virulence to the plants. These results suggest that these phenotypes caused by XC_0531 mutation is possibly due to deficient biosynthesis of c-type cytochromes in respiration chain and the formation of disulfide bonds. Our work confirmed the function of XC_0531 and provide theory basis for scientists working on molecular mechanisms of cytochrome c biogenesis, pathogenesis of Xcc, development of EPS commercial values and protecting plant from black rot. CONCLUSION: We confirmed the function of gene XC_0531, which encodes a DsbD like protein, a protein correlated with c-type cytochrome biogenesis. This gene is related to the virulence to plants by affecting funtion of cytochromes c and probably disulfide bonds modification of proteins in type II secretion system (T2SS).

Screening of alginate lyase-excreting microorganisms from the surface of brown algae.

Alginate lyase is a biocatalyst that degrades alginate to produce oligosaccharides, which have many bioactive functions and could be used as renewable biofuels. Here we report a simple and sensitive plate assay for screening alginate lyase-excreting microorganisms from brown algae. Brown algae Laminaria japonica, Sargassum horneri and Sargassum siliquatrum were cultured in sterile water. Bacteria growing on the surface of seaweeds were identified and their capacity of excreting alginate lyase was analyzed. A total of 196 strains were recovered from the three different algae samples and 12 different bacterial strains were identified capable of excreting alginate lyases. Sequence analysis of the 16S rRNA gene revealed that these alginate lyase-excreting strains belong to eight genera: Paenibacillus (4/12), Bacillus (2/12), Leclercia (1/12), Isoptericola (1/12), Planomicrobium (1/12), Pseudomonas (1/12), Lysinibacillus (1/12) and Sphingomonas (1/12). Further analysis showed that the LJ-3 strain (Bacillus halosaccharovorans) had the highest enzyme activity. To our best knowledge, this is the first report regarding alginate lyase-excreting strains in Paenibacillus, Planomicrobium and Leclercia. We believe that our method used in this study is relatively easy and reliable for large-scale screening of alginate lyase-excreting microorganisms.

HAL2 overexpression induces iron acquisition in bdf1Δ cells and enhances their salt resistance.

The yeast Saccharomyces cerevisiae is capable of responding to various environmental stresses, such as salt stress. Such responses require a complex network and adjustment of the gene expression network. The goal of this study is to further understand the molecular mechanism of salt stress response in yeast, especially the molecular mechanism related to genes BDF1 and HAL2. The Bromodomain Factor 1 (Bdf1p) is a transcriptional regulator, which is part of the basal transcription factor TFIID. Cells lacking Bdf1p are salt sensitive with an abnormal mitochondrial function. We previously reported that the overexpression of HAL2 or deletion of HDA1 lowers the salt sensitivity of bdf1Δ. To better understand the mechanism behind the HAL2-related response to salt stress, we compared three global transcriptional profiles (bdf1Δ vs WT, bdf1Δ + HAL2 vs bdf1Δ, and bdf1Δhda1Δ vs bdf1Δ) in response to salt stress using DNA microarrays. Our results reveal that genes for iron acquisition and cellular and mitochondrial remodeling are induced by HAL2. Overexpression of HAL2 decreases the concentration of nitric oxide. Mitochondrial iron-sulfur cluster (ISC) assembly also decreases in bdf1Δ + HAL2. These changes are similar to the changes of transcriptional profiles induced by iron starvation. Taken together, our data suggest that mitochondrial functions and iron homeostasis play an important role in bdf1Δ-induced salt sensitivity and salt stress response in yeast.

Isolation of a novel alginate lyase-producing Bacillus litoralis strain and its potential to ferment Sargassum horneri for biofertilizer.

Algae have long been used to augment plant productivity through their beneficial effects. Alginate oligosaccharide is believed to be one of the important components to enhance growth and crop yield. In this study, we isolated and characterized a Bacillus litoralis strain, named Bacillus M3, from decayed kelps. We further demonstrated that the M3 strain could secrete alginate lyase to degrade alginate. The crude enzyme exhibited the highest activity (33.74 U/mg) at pH 7.0 and 50°C. The M3 strain was also able to ferment the brown alga Sargassum horneri. Fermentation results revealed that a fermentation period of 8-12 hr was the best harvest time with the highest level of alginate oligosaccharides. Plant growth assay showed that the seaweed fermentation extract had an obvious promotion effect on root and seedling growth of Lycopersicon eseulentum L. Our results suggest that fermentation extract of Sargassum horneri by the novel strain of Bacillus litoralis M3 has significant development potential for biofertilizer production and agriculture application.

The yeast BDF1 regulates endocytosis via LSP1 under salt stress.

Bromodomain-containing transcription factor, a kind of important regulating protein, can recognize and bind to acetylated histone. The homologous genes, BDF1 and BDF2, in Saccharomyces cerevisiae, respectively, encode a bromodomain-containing transcription factor. Previously study has demonstrated that both BDF1 and BDF2 participate in yeast salt stress response. Bdf1p deletion cells are sensitive to salt stress and this phenotype is suppressed by its homologue BDF2 in a dosage-dependent manner. In this study, we show that the histone deacetylase SIR2 over-expression enhanced dosage-dependent compensation of BDF2. SIR2 over-expression induced a global transcription change, and 1959 gene was down-regulated. We deleted some of the most significant down-regulated genes and did the spot assay. The results revealed that LSP1, an upstream component of endocytosis pathway, and CIN5, a transcription factor that mediates cellular resistance to stresses, can enhance salt resistance of bdf1∆. Further analysis demonstrated that under salt stress the endocytosis is over-activated in bdf1∆ but was recovered in bdf1∆ lsp1∆. To our best knowledge, this is the first report that the transcription factor Bdf1p regulates endocytosis under salt stress via LSP1, a major component of eisosomes that regulate the sites of endocytosis.

Regulation of Saccharomyces cerevisiae MEF1 by Hda1p affects salt resistance of bdf1Δ mutant.

Bromodomain factor 1 (Bdf1p) is a transcriptional regulator. The absence of Bdf1p causes salt sensitivity with abnormal nucleus and mitochondrial dysfunction. In this study, we reported that the salt sensitivity, mitochondrial dysfunction, and nuclear instability of bdf1Δ mutant were suppressed by HDA1 deletion or MEF1 overexpression. Hda1p overexpression inhibited the relieving effects of low-copy overexpression of MEF1. Further analysis showed that Bdf1p regulated HDA1 transcription positively by binding to its promoter at −201 to +6 bp, whereas Hda1p modulated MEF1 expression negatively by binding to its promoter at −201 to +6 bp. These results suggested that Bdf1p likely regulated MEF1 expression negatively by regulating HDA1 positively. Mitochondrial proteomics analysis showed that the expression levels of six mitochondrial proteins were significantly changed by MEF1 overexpression. Among the six genes, over-expression of PDB1, ILV5, or ATP2 partially recovered the salt stress sensitivity of bdf1Δ. However, none of these mitochondrial proteins could recover mitochondrial respiration indicating that the individual functional proteins could not replace Mef1p activity. It indicated that positive regulation of MEF1 was important in recovering the salt sensitivity of bdf1Δ mutant.

Hal2p functions in Bdf1p-involved salt stress response in Saccharomyces cerevisiae.

The Saccharomyces cerevisiae Bdf1p associates with the basal transcription complexes TFIID and acts as a transcriptional regulator. Lack of Bdf1p is salt sensitive and displays abnormal mitochondrial function. The nucleotidase Hal2p detoxifies the toxic compound 3' -phosphoadenosine-5'-phosphate (pAp), which blocks the biosynthesis of methionine. Hal2p is also a target of high concentration of Na(+). Here, we reported that HAL2 overexpression recovered the salt stress sensitivity of bdf1Δ. Further evidence demonstrated that HAL2 expression was regulated indirectly by Bdf1p. The salt stress response mechanisms mediated by Bdf1p and Hal2p were different. Unlike hal2Δ, high Na(+) or Li(+) stress did not cause pAp accumulation in bdf1Δ and methionine supplementation did not recover its salt sensitivity. HAL2 overexpression in bdf1Δ reduced ROS level and improved mitochondrial function, but not respiration. Further analyses suggested that autophagy was apparently defective in bdf1Δ, and autophagy stimulated by Hal2p may play an important role in recovering mitochondrial functions and Na(+) sensitivity of bdf1Δ. Our findings shed new light towards our understanding about the molecular mechanism of Bdf1p-involved salt stress response in budding yeast.

Interplay between BDF1 and BDF2 and their roles in regulating the yeast salt stress response.

The homologous genes BDF1 and BDF2 in Saccharomyces cerevisiae encode bromodomain-containing transcription factors. Although double deletion of BDF1 and BDF2 is lethal, single deletion does not affect cell viability. The bdf2∆ cells showed normal growth upon salt stress. However, the absence of Bdf1p resulted in a salt-sensitive phenotype, and the salt sensitivity was suppressed by overexpression of BDF2. In this study, we further demonstrated that BDF2 shows dosage compensation in suppressing the salt sensitivity of bdf1∆. None of the tested domains replaced the function of intact Bdf1p. The 494-626 region in Bdf1p was more important than the other domains for salt resistance. In addition, Bdf1p negatively regulated the expression of BDF2 by binding its promoter at loci -387 to -48. However, Bdf2p did not affect the expression of BDF1. In addition, Bdf1p and its defective functional domain mutants could combine with Bdf2p. This physical interaction increased the salt tolerance of bdf1∆. The mitochondrial dysfunctions caused by BDF1 deletion were restored by overexpression of BDF2 under salt stress conditions.

Feature selection and performance evaluation of support vector machine (SVM)-based classifier for differentiating benign and malignant pulmonary nodules by computed tomography.

There are lots of work being done to develop computer-assisted diagnosis and detection (CAD) technologies and systems to improve the diagnostic quality for pulmonary nodules. Another way to improve accuracy of diagnosis on new images is to recall or find images with similar features from archived historical images which already have confirmed diagnostic results, and the content-based image retrieval (CBIR) technology has been proposed for this purpose. In this paper, we present a method to find and select texture features of solitary pulmonary nodules (SPNs) detected by computed tomography (CT) and evaluate the performance of support vector machine (SVM)-based classifiers in differentiating benign from malignant SPNs. Seventy-seven biopsy-confirmed CT cases of SPNs were included in this study. A total of 67 features were extracted by a feature extraction procedure, and around 25 features were finally selected after 300 genetic generations. We constructed the SVM-based classifier with the selected features and evaluated the performance of the classifier by comparing the classification results of the SVM-based classifier with six senior radiologists' observations. The evaluation results not only showed that most of the selected features are characteristics frequently considered by radiologists and used in CAD analyses previously reported in classifying SPNs, but also indicated that some newly found features have important contribution in differentiating benign from malignant SPNs in SVM-based feature space. The results of this research can be used to build the highly efficient feature index of a CBIR system for CT images with pulmonary nodules.

[Differential diagnosis of benign and malignant solitary pulmonary nodule with computer-aided detection].

OBJECTIVE: To investigate the morphological features of benign and malignant solitary pulmonary nodules (SPNs) and explore the radiological evidences for the differentiation of SPNs. METHODS: With SPN Dicom View software, we analyzed and compared images obtained from 23 patients with malignant SPNs and 22 patients with benign SPNs who received CT scanning with or without contrast medium injection. RESULTS: The enhancement in malignant SPNs group was significantly higher than in the benign SPNs group (P < 0.0001). The irregular enhancement in malignant SPNs group was significantly higher than in the benign SPNs group (P = 0. 0084). The mean range of enhancement was (45.04 +/- 26.76) HU in malignant SPNs group, which was significantly higher than that in the benign SPNs group [(15.70 +/- 17.84) HU, P = 0.033]. The mean peak enhancement value was (136.09 +/- 41.72) HU in malignant SPNs group, which was significantly higher than in benign SPNs group [ (60.60 +/- 60.27) HU, P = 0.007]. The mean enhancement area was (21.69 +/- 21.01)% in malignant SPNs group and (8.61 +/- 10.83)% in benign SPNs group (P = 0.203). CONCLUSION: The enhancement range and peak enhancement value as well as the morphologically irregular enhancement of SPNs may provide useful information in the clinical radiological diagnosis of SPNs.

Computer assisted solitary pulmonary nodules morphological enhancement characteristics - a preliminary study.

The quantity analysis on Solitary Pulmonary Nodules (SPN) is very important for pulmonary disease diagnosis and prediction, especially, in the early phase or small sizes. Due to the breathing activity of patients, the SPN region is translated and deformed after the injection of bolus so that it is hard to obtain the exact enhancement patterns. In this presentation, we give an approach to combine plain CT images and enhanced CT images to assist the radiologists in SPN diagnosis or prediction. First we segmented SPN region in both the plain image and the enhanced image, then rigid and deformable registration method were carried out to match the enhanced SPN region to the plain SPN region, then we subtracted the SPN region from the enhanced SPN region to show the enhancement, finally we correlated the enhancement characteristics with corresponding diagnosis results.