Nodulation Efficiency Research Articles

Multi-scale dense selective network based on border modeling for lung nodule segmentation.

Accurate quantification of pulmonary nodules helps physicians to accurately diagnose and treat lung cancer. We try to improve the segmentation efficiency of irregular nodules while maintaining the segmentation accuracy of simple types of nodules. In this paper, we obtain the unique edge part of pulmonary nodules and process it as a single branch stream, i.e., border stream, to explicitly model the nodule edge information. We propose a multi-scale dense selective network based on border modeling (BorDenNet). Its overall framework consists of a dual-branch encoder-decoder, which achieves parallel processing of classical image stream and border stream. We design a dense attention module to facilitate a strongly coupled status of feature images to focus on key regions of pulmonary nodules. Then, during the process of model decoding, the multi-scale selective attention module is proposed to establish long-range correlation relationships between different scale features, which further achieves finer feature discrimination and spatial recovery. We introduce border context enhancement module to mutually fuse and enhance the edge-related voxel features contained in the image stream and border stream and finally achieve the accurate segmentation of pulmonary nodules. We evaluate the BorDenNet rigorously on the lung public dataset LIDC-IDRI. For the segmentation of the target nodules, the average Dice score is 92.78[Formula: see text], the average sensitivity is 91.37[Formula: see text], and the average Hausdorff distance is 3.06 mm. We further test on a private dataset from Shanxi Provincial People's Hospital, which verifies the excellent generalization of BorDenNet. Our BorDenNet relatively improves the segmentation efficiency for multi-type nodules such as adherent pulmonary nodules and ground-glass pulmonary nodules. Accurate segmentation of irregular pulmonary nodules can obtain important clinical parameters, which can be used as a guide for clinicians and improve clinical efficiency.

Computed tomographic features of pulmonary pure ground-glass nodule: a comparison between neoplastic and non-neoplastic nodules

BackgroundGround-glass nodules (GGNs) are detected more frequently nowadays with the increase in MDCT resolution and applications. On CT GGN is a well circumscribed nodule with mild increase attenuation and not obscuring bronchial and vascular markings. This study aimed to discriminate neoplastic from non-neoplastic pure ground-glass nodules (pGGNs) by performing comparative quantitative and qualitative assessment of main features in computed tomography (CT) chest imaging. This prospective study involved 72 patients, who were referred to perform multidetector computed tomography of the chest in the radiology department. Cases with ground-glass pulmonary nodules were included in the study, and each nodule was assessed and followed for 2 years by a radiomics software for density and histogram analysis and then classified to neoplastic and non-neoplastic nodules. Neoplastic and non-neoplastic nodules morphology and radiomics were compared, and statistical analysis was done.ResultsAfter histopathology, positron emission tomography and computed tomography, or close follow-up, pGGNs were classified to neoplastic and non-neoplastic nodules. There was statistically significant difference regarding the mean size, where in cases of neoplastic nodules it was 6.66 mm and the mean size of benign nodules was 11.25 mm. Moreover, irregularity index and histogram peak frequency had a significant correlation with a P value of 0.007 and 0.022, respectively. The cutoff level for peak frequency percentage was 20.5% with 56.3% sensitivity and 79.2% specificity.ConclusionsRadiomics had a growing role in pulmonary nodule assessment. Radiomics along with morphologic features assessment improved the detection efficiency of neoplastic versus non-neoplastic ground-glass nodules with histogram peak frequency, nodule size, and irregularity index as the main differentiating factors in this study.

Bioleaching Test of Polymetallic Nodule Samples from the IOM Exploration Area

The Interoceanmetal Joint Organization’s (IOM) exploration license is granted in the area located within the Clarion–Clipperton Zone of the Eastern Central Pacific. All activities related to exploration of minerals in this area are beyond the limits of national jurisdiction and come under the provision of the United Nations Convention on the Law of the Sea and related regulations. The geological survey, which was the subject of the exploration, focused on the polymetallic nodule deposits. Other activities covered the tests of nodule processing, including alternative methods of metal extraction. This article describes the methodology of the bioleaching process and provides a summary of the initial results of the bioleaching test, applied to the samples of polymetallic nodules taken from the H22 exploration block of the IOM exploration area. The bioleaching efficiency under different pulp density conditions was studied. The enrichment of heterotrophic Mn-reducing microorganisms was prepared as the leaching medium. Bioleaching of the samples took place with different sample weights in order to determine the maximum possible extraction yield and the highest concentration of elements obtained in the leachate. During the bioleaching, the media were also exchanged to achieve maximum polymetallic nodule decomposition with regular addition of nutrients for heterotrophic Mn-reducing bacteria. The bioleaching efficiency of the polymetallic nodules increased to 100% (without Cu) when the pulp density was reduced to 0.1% (w/v). The discontinuous bioleaching and washing process recovered 55% Mn, 36% Ni, 15% Co, 27% Zn, and 38% Cu when the pulp density was increased to 10% (w/v). To achieve total Mn, Cu, Zn, Co, and Ni recovery from the polymetallic nodules, an intermittent bioleaching with about 25 changes of 60% of the medium was required when the pulp density was increased to 10% (w/v). Bioleaching has the potential to be used as an environmentally friendly alternative to other commonly used options for leaching and processing.

The efficiency of Nitrogen utilization and root nodules' life cycle in Alfalfa after various mineral fertilization and cultivation of soil

Abstract: The efficiency of the Nitrogen utilization and root nodules' life cycle in alfalfa after various mineral fertilizing and cultivation of soil methods have been investigated. The field test has been performed in the Forage Crops Institute, Pleven, Bulgaria on leached chernozem subsoil kinds and with no irrigation. The next cures have experimented: 1) for fertilization as below: N0P0K0 (controlling); N60P100K80 (an admitted technology); N23P100K35 (nitrogen has been used 1/2 in the first year of grow and 1/2 in the third year); N23P100K35 (nitrogen has been provided pre-sowing); N35P80K50, and Amophose – 250 kg/ha, estimated at fertilization rate N27P120K0; ii) for soil cultivation as below: soil losing 10-12 cm, plow at depth 12 to 15 cm, 22 to 24 cm (an admitted technologies), 18 to 22 cm and 30 to 35 cm. It has been seen that the cultivation of soil and mineral fertilizing had an impact on nitrogen utilization efficiency and the root nodules' life cycle in Alfalfa. Nitrogen utilization efficiency has been discovered for being maximum at N23P100K35 and plow at the depth of 22 to 24 cm. The root nodules' life cycle has been the longest at N35P80K50 and plows at the depth of 18 to 22 cm. The more useful root mass for nodule number ratio has been seen at N23P100K35 and plow at the depth of 22 to 24 cm.

Biological N fixation activity in soybean can be estimated based on nodule dry weight and is increased by additional inoculation

The response of soybean to biological nitrogen fixation (BNF) varies due to factors such as plant variety, soil, and environmental conditions, which can compromise the N2 fixation capacity. The objective of this study was to evaluate additional inoculation with B. japonicum at different soybean growth stages as a strategy to improve N2 fixation. This was determined by studying plant nodulation and BNF with the isotope dilution method. The experiment was carried out under greenhouse conditions in a soil without soybean cropping history. Inoculated soybean increased nodulation, plant biomass, BNF and yield components compared to un-inoculated soybean. Additional inoculation at the V3 growth stage showed promising results by maintaining BNF at later growth stages. A strong correlation was observed between nodule dry weight and N2 fixation, providing an easily available method to estimate differences in BNF activity between treatments. Moreover, efficient nodulation is crucial to sustain high yields with BNF, as shown by the correlation between nodule dry weight and pod dry weight.

The Effect of Frankia and Hebeloma crustiliniforme on Alnus alnobetula subsp. Crispa Growing in Saline Soil.

The mining of the oil sands region of Canada’s boreal forest creates disturbed land with elevated levels of salts. Understanding how native plants respond to salt stress is critical in reclaiming these lands. The native species, Alnus alnobetula subsp. crispa forms nitrogen-fixing nodules with Frankia, and ectomycorrhizae with a number of fungal species. These relationships may make the plant particularly well suited for restoring disturbed land. We inoculated A. alnobetula subsp. crispa with Frankia and Hebeloma crustiliniforme and exposed the plants to 0, 50, or 100 mM NaCl for seven weeks. Frankia-inoculated plants had increased biomass regardless of salt exposure, even though salt exposure reduced nitrogen fixation and reduced the efficiency of nitrogen-fixing nodules. The nitrogen-fixing symbiosis also decreased leaf stress and increased root phosphatase levels. This suggests that N-fixing plants not only have increased nitrogen nutrition but also have increased access to soil phosphorus. Mycorrhizae did not affect plant growth but did reduce nodule numbers and nodule efficiency. These results suggest that the nitrogen-fixing trait is more critical than mycorrhizae. While salt stress inhibits nitrogen-fixing symbiosis, plants still benefit from nitrogen fixation when exposed to salt.

A newly evolved chimeric lysin motif receptor-like kinase in Medicago truncatula spp. tricycla R108 extends its Rhizobia symbiotic partnership.

Rhizobial lipochitooligosaccharidic Nod factors (NFs), specified by nod genes, are the primary determinants of host specificity in the legume-Rhizobia symbiosis. We examined the nodulation ability of Medicago truncatula cv Jemalong A17 and M. truncatula ssp. tricycla R108 with the Sinorhizobium meliloti nodF/nodL mutant, which produces modified NFs. We then applied genetic and functional approaches to study the genetic basis and mechanism of nodulation of R108 by this mutant. We show that the nodF/nodL mutant can nodulate R108 but not A17. Using genomics and reverse genetics, we identified a newly evolved, chimeric LysM receptor-like kinase gene in R108, LYK2bis, which is responsible for the phenotype and can allow A17 to gain nodulation with the nodF/nodL mutant. We found that LYK2bis is involved in nodulation by mutants producing nonO-acetylated NFs and interacts with the key receptor protein NFP. Many, but not all, natural S. meliloti and S. medicae strains tested require LYK2bis for efficient nodulation of R108. Our findings reveal that a newly evolved gene in R108, LYK2bis, extends nodulation specificity to mutants producing nonO-acetylated NFs and is important for nodulation by many natural Sinorhizobia. Evolution of this gene may present an adaptive advantage to allow nodulation by a greater variety of strains.

Biopolymers in the preservation of rhizobacteria cells and efficiency in soybean inoculation

Soybean (Glycine max (L). Merr.) is among the most important legumes worldwide performing a significant role in biological fixation of nitrogen through rhizobacteria. These microorganisms that act in the plant root system are inoculated by biological products, which must contain viable cells. The viability of inoculants is a market challenge, and biopolymers have been studied for the preservation of microorganisms. Thus, this study aimed to assess the influence of adding xanthan gum and carboxymethylcellulose biopolymers on the preservation of cells of Bradyrhizobium elkanii, Bradyrhizobium diazoefficiens, Azospirillum sp., and Pseudomonas fluorescens, and inoculation of soybean seeds. The inoculants were produced and stored added with biopolymers. Soybean seeds were inoculated at 0, 90 and 210 inoculant storage days and sown in pots of 1 L. 50 days after emergence for assessing physiological parameters of stomatal conductance (gs - mol H20 m-2 s-1), CO2 assimilation rate (A - µmol CO2 m-2 s-1), transpiration rate (E - mmol H2O m-2 s-1), in addition to morphological parameters of plant height (H), fresh mass of aerial part (FMAP), root fresh mass (RFM), number of nodules (NNo), fresh mass of nodules (FMNo), dry mass of aerial part (DMAP), root dry mass (RDM), and dry mass of nodules (DMNo). The use of biopolymers proved efficient at preserving the cells of the microorganisms tested at 210 storage days through the responses obtained from an increase in aerial and root plant biomass resulting from a more efficient nodulation in the inoculant with biopolymer.

The Genome of the Acid Soil-Adapted Strain Rhizobium favelukesii OR191 Encodes Determinants for Effective Symbiotic Interaction With Both an Inverted Repeat Lacking Clade and a Phaseoloid Legume Host.

Although Medicago sativa forms highly effective symbioses with the comparatively acid-sensitive genus Ensifer, its introduction into acid soils appears to have selected for symbiotic interactions with acid-tolerant R. favelukesii strains. Rhizobium favelukesii has the unusual ability of being able to nodulate and fix nitrogen, albeit sub-optimally, not only with M. sativa but also with the promiscuous host Phaseolus vulgaris. Here we describe the genome of R. favelukesii OR191 and genomic features important for the symbiotic interaction with both of these hosts. The OR191 draft genome contained acid adaptation loci, including the highly acid-inducible lpiA/acvB operon and olsC, required for production of lysine- and ornithine-containing membrane lipids, respectively. The olsC gene was also present in other acid-tolerant Rhizobium strains but absent from the more acid-sensitive Ensifer microsymbionts. The OR191 symbiotic genes were in general more closely related to those found in Medicago microsymbionts. OR191 contained the nodA, nodEF, nodHPQ, and nodL genes for synthesis of polyunsaturated, sulfated and acetylated Nod factors that are important for symbiosis with Medicago, but contained a truncated nodG, which may decrease nodulation efficiency with M. sativa. OR191 contained an E. meliloti type BacA, which has been shown to specifically protect Ensifer microsymbionts from Medicago nodule-specific cysteine-rich peptides. The nitrogen fixation genes nifQWZS were present in OR191 and P. vulgaris microsymbionts but absent from E. meliloti-Medicago microsymbionts. The ability of OR191 to nodulate and fix nitrogen symbiotically with P. vulgaris indicates that this host has less stringent requirements for nodulation than M. sativa but may need rhizobial strains that possess nifQWZS for N2-fixation to occur. OR191 possessed the exo genes required for the biosynthesis of succinoglycan, which is required for the Ensifer-Medicago symbiosis. However, 1H-NMR spectra revealed that, in the conditions tested, OR191 exopolysaccharide did not contain a succinyl substituent but instead contained a 3-hydroxybutyrate moiety, which may affect its symbiotic performance with Medicago hosts. These findings provide a foundation for the genetic basis of nodulation requirements and symbiotic effectiveness with different hosts.

Beneficial effects of magnetite nanoparticles on soybean-Bradyrhizobium japonicum and alfalfa-Sinorhizobium meliloti associations

Nanoparticles (NPs)-based growth stimulators have promising usage in agriculture. This research analyzed the impact of citric acid-coated magnetite nanoparticles (Fe3O4-NPs; 50 mg Fe L−1) added once at pre-sowing on soybean and alfalfa seedlings growing in association with their corresponding microsymbiont partners, Bradyrhizobium japonicum and Sinorhizobium meliloti; also on the in vitro growth rate of these microorganisms. Fe-EDTA (50 mg Fe L−1) was used as a comparator.Fe3O4-NPs significantly augmented the growth rate constant (7–17%) and extracellular polysaccharides production of both microsymbionts (B. japonicum: 2-fold; S. meliloti: 43%), which probably favored bacterial adhesion to the root hairs.In both legumes, Fe3O4-NPs increased chlorophyll content (up to 56% in soybean) and improved plant growth, evidenced by a greater root biomass system (80–90% higher than the control), and increased shoot biomass (30–40%). Besides, Fe3O4-NPs addition resulted in earlier nodule formation and enhanced nodule biomass (about 2.5-fold in both species). Nodules were mainly located in the crown of the root in the NP50 treatment, while they were evenly distributed along lateral roots in the control and the comparator. Fe3O4-NPs also augmented significantly nodule leghemoglobin content (∼50–70%) and total N in legumes’ shoots (ca. 20%). CAT activity increased only under NP50 treatment and no symptoms of oxidative damage were evidenced. In this work, we found that besides not being toxic neither to soybean and alfalfa plants nor to their microsymbiont partners, Fe3O4-NPs do not exert adverse effects on the symbioses establishment; oppositely, a more efficient nodulation pattern was verified in both plant species.

Increased nodular P level induced by intercropping stimulated nodulation in soybean under phosphorus deficiency

Low P availability is a vital constraint for nodulation and efficient N2 fixation of legume, including soybean. To elucidate the mechanisms involved in nodule adaption to low P availability under legume/cereal intercropping systems, two experiments consisting of three cropping patterns (monocropped soybean, monocropped maize, soybean/maize intercropping) were studied under both sufficient- and deficient-P levels. Our results demonstrated that intercropped soybean with maize showed a higher nodulation and N2 fixation efficiency under low P availability than monocropped soybean as evidenced by improvement in the number, dry weight and nitrogenase activity of nodules. These differences might be attributed to increase in P level in intercropping-induced nodules under low P supply, which was caused by the elevated activities of phytase and acid phosphatases in intercropping-induced nodules. Additionally, the enhanced expression of phytase gene in nodules supplied with deficient P level coincided with an increase in phytase and acid phosphatase activities. Our results revealed a mechanism for how intercropped maize stimulated nodulation and N2 fixation of soybean under P deficient environments, where enhanced synthesis of phytase and acid phosphatases in intercropping-induced nodules, and stimulated nodulation and N2 fixation.

Correlations and Path Analysis in Segregating Cowpea Generations Regarding Biological Nitrogen Fixation

The objective of this research was to evaluate the correlations between variables related to the biological nitrogen fixation (BNF) in segregating generations of cowpea and to unfold these correlations in direct and indirect effects, through path analysis. An outdoor bench experiment was conducted at Carpina Experimental Sugarcane Station of, located at the Zona da Mata region of the State of the Pernambuco, Northeast of Brazil (Federal Rural University of Pernambuco), between March and April 2016. The seeds were planted in 20 cm × 30 cm polyethylene bags, using a substrate composed of a mixture of vermiculite and sand washed in a ratio of 1:1. Bradyrhizobium references, recommended for culture, were used as a mixture of two strains. Parental and F2, F3 and F4 generations were evaluated in a randomized block design with four replicates. Data collection was performed 45 days after the emergency (DAE). Phenotypic correlations and path analysis of the number of nodules per plant (NN), nodules dry mass (NDM), dry roots mass (DRM), dry mass of aerial part (DMAP), nodulation efficiency (NODE) and nitrogen accumulated in the aerial part (NAAP). The phenotypic correlations between the variables related to the BNF showed high magnitudes, demonstrating that there is a great influence of each of the variables on the others, furthermore the path analysis of the coefficients indicated that all the primary components (NN, NDM, DRM, DMAP and NODE) must be considered when it is desired to increase the NAAP in segregating generations of cowpea.

Emulation pulmonary nodules localization model:a novel non-invasive localization technique in resection of pulmonary nodules

Objective: To explore the accuracy and efficiency of a novel 3D-printed emulation localization model of small pulmonary nodules in lung surgery. Methods: From April 2020 to April 2021, a total of 66 patients were selected in the study, who underwent localization and resection of pulmonary nodules with video-assisted thoracoscopic surgery (VATS) guided by the 3D-printed emulation localization model at Department of Thoracic Surgery, West China Hospital of Sichuan University. There were 13 males and 53 females, aged from 25 to 79 (52.7±11.4) years. Of all patients, 24 (36.4%) had single pulmonary nodule, and 42 (63.6%) had synchronous multiple pulmonary nodules. The chest high-resolution CT image data were utilized for digital reconstruction and 3D printing to make a tailored life-size emulation pulmonary nodules localization model, which was used to navigate real-time intraoperative localization of nodules. Clinical data including operative parameters, localization information, resection types and pathological findings of nodules were analyzed. The pulmonary nodules that doctors planned to resect were categorized into two categories:major nodules and additional nodules, according to their presence of invasion and radiological risk factors. The accuracy of localization and resection efficiency of nodules were evaluated in accordance with the categories of the nodules respectively. Results: On the basis of preoperative evaluation, there were 71 major nodules with median maximal diameter of 0.9 (0.6-1.3) cm, and 77 additional nodules with median maximal diameter of 0.5 (0.4-0.7) cm. All patients underwent VATS surgery, 52 of them (78.8%) were treated with uniportal VATS and 14 (21.2%) with triportal VATS. Among the patients with single nodule, 18 segmentectomies and 6 wedge resections were performed; whereas among the patients with multiple nodules, 5 segmentectomies, 14 wedge resections, and 23 combined pulmonary resections (including 2 cases of lobectomy+segmentectomy, 7 cases of lobectomy+wedge resections, and 14 cases of segmentectomy+wedge resections) were achieved. The median operative time was 93 (45-240) min, and the median resection time for all nodules was 51.4 (6.7-147.0) min. All major nodules were successfully resected and visibly dissected after removal, and all additional nodules were successfully resected with 85.7%(66/77) nodules visibly dissected. The accuracy rate of localization of both types of nodules was 100%. All major nodules were malignant, and the malignancy rate of additional nodules was 21.2%(14/66). Conclusion: This novel 3D-printed emulation localization model of small pulmonary nodules proved to be a non-invasive, accurate and efficient technique. Not only that, it has a unique advantage in localization of synchronous multiple pulmonary nodules.

Meta-Analysis of Contrast Enhanced Ultrasound in Judging Benign and Malignant Thyroid Tumors.

In recent years, the incidence of thyroid cancer (TC) patients has gradually increased, and it ranks first among all endocrine tumors. TC has no obvious characteristics at the initial stage of onset. Thyroid tumors (TT) have formed when they are discovered, and they are easy to see when they are diagnosed. The disease is confused, so it is necessary to rely on imaging methods for tumor diagnosis. Contrast-enhanced ultrasound (CEUS), as the most commonly used imaging method in current clinical testing, is simple, safe, highly sensitive, can accurately display tumor conditions, and has high clinical value in the judgment of TC tumors. This article uses meta-analysis to select 63 published studies on CEUS to determine benign and malignant (BAM) TT to analyze and explore its clinical application value. This article understands the analysis of BAM TT and its diagnostic methods, clarifies the diagnostic efficiency of CEUS for TT, imaging methods, and imaging characteristics, and uses statistical analysis to analyze its heterogeneity. In this paper, the meta-analysis of CEUS in judging BAM TT is mainly based on references. The sensitivity, specificity, and difference of CEUS in diagnosing BAM TT are analyzed. Real-time elastography (RTE) is the comparison experiment object, and CEUS is used to compare the diagnostic efficiency, pathological results, and diagnostic efficiency of thyroid nodules in CEUS mode. The results of the study show that the nodule with higher diagnostic sensitivity is the echo feature, with a sensitivity of 97.73%, followed by the halo feature, with a sensitivity of 86.36%. In terms of diagnostic specificity, the boundary feature is the most specific. The specificity is 89.47%. In the judgment of BAM tumor nodules, the most obvious difference is the echo feature, which is as high as 14.09, followed by the acoustic halo feature, and the difference is 10.65.

Surface Properties and Adherence of Bradyrhizobium diazoefficiens to Glycine max Roots Are Altered When Grown in Soil Extracted Nutrients

Soybean roots are colonized and nodulated by multiple strains of compatible nitrogen-fixing rhizobia primarily belonging to the Genus Bradyrhizobium. Motility towards the root and attachment to root hairs are key determinants of competitive colonization and subsequent nodulation. Bacterial surface properties and motility are known to vary with chemical composition of the culture medium, and root adhesion and nodulation occur in a soil environment rather than laboratory medium. We asked whether the nodulation-promoting factors motility, surface hydrophobicity and surface adhesion of Bradyrhizobium are affected by growth in a soil nutrient environment. B. diazoefficiens USDA 110, 126, 3384, and B. elkanii USDA 26 were grown in mineral salt medium with peptone, yeast extract and arabinose (PSY), and in a soil extracted soluble organic matter (SESOM) medium. Surface hydrophobicity was determined by partitioning into hydrocarbon, motility by transition through soft agar, and surface-exposed saccharides by lectin profiling, followed by biofilm formation and soybean root adhesion capacity of populations. SESOM-grown populations were generally less motile and more hydrophobic. They bound fewer lectins than PSY-grown populations, indicating a simpler surface saccharide profile. SESOM populations of USDA 110 did not form detectable biofilm, but showed increased binding to soy roots. Our results indicate that growth in a soil environment impacts surface properties, motility, and subsequent soy root adhesion propensity. Hence, evaluation of Bradyrhizobium for nodulation efficiency should be performed using soil from the specific field where the soybeans are to be planted, rather than laboratory culture media.

The Bradyrhizobium Sp. LmicA16 Type VI Secretion System Is Required for Efficient Nodulation of Lupinus Spp.

Many bacteria of the genus Bradyrhizobium are capable of inducing nodules in legumes. In this work, the importance of a type VI secretion system (T6SS) in a symbiotic strain of the genus Bradyrhizobium is described. T6SS of Bradyrhizobium sp. LmicA16 (A16) is necessary for efficient nodulation with Lupinus micranthus and Lupinus angustifolius. A mutant in the gene vgrG, coding for a component of the T6SS nanostructure, induced less nodules and smaller plants than the wild-type (wt) strain and was less competitive when co-inoculated with the wt strain. A16 T6SS genes are organized in a 26-kb DNA region in two divergent gene clusters of nine genes each. One of these genes codes for a protein (Tsb1) of unknown function but containing a methyltransferase domain. A tsb1 mutant showed an intermediate symbiotic phenotype regarding vgrG mutant and higher mucoidity than the wt strain in free-living conditions. T6SS promoter fusions to the lacZ reporter indicate expression in nodules but not in free-living cells grown in different media and conditions. The analysis of nodule structure revealed that the level of nodule colonization was significantly reduced in the mutants with respect to the wt strain.

Computed Tomography Image under Convolutional Neural Network Deep Learning Algorithm in Pulmonary Nodule Detection and Lung Function Examination.

The objective of this study was to perform segmentation and extraction of CT images of pulmonary nodules based on convolutional neural networks (CNNs). The Mask-RCNN algorithm model is a typical end-to-end image segmentation model, which uses the R-FCN structure for nodule detection. The effect of applying the two algorithm models to the computed tomography (CT) diagnosis of pulmonary nodules was analyzed, and different indexes of pulmonary nodule CT images in lung function examination after algorithm optimization were compared. A total of 56 patients diagnosed with pulmonary nodules by surgery or puncture were taken as the research objects. Based on the Mask-RCNN algorithm, a model for CT image segmentation processing of pulmonary nodules was proposed. Subsequently, the 3D Faster-RCNN model was used to label the nodules in the pulmonary nodules. The experimental results showed that the trained Mask-RCNN algorithm model can effectively complete the segmentation task of lung CT images, but there was a little jitter at the boundary. The speed of R-FCN algorithm for nodular detection was 0.172 seconds/picture, and the accuracy was 88.9%. CT scans were performed on the 56 patients based on a deep learning algorithm. The results showed that 30 cases of malignant pulmonary nodules were confirmed, and the diagnostic accuracy was 93.75%. There were 22 benign lesions, the diagnostic accuracy was 91.67%, and the overall diagnostic accuracy was 92.85%. This study effectively improved the diagnostic efficiency of CT images of pulmonary nodules, and the accuracy of CT images in the diagnosis of pulmonary nodules was analyzed and evaluated. It provided theoretical support for the follow-up diagnosis of pulmonary nodules and the treatment of lung cancer. It also significantly improved the diagnostic effect and detection efficiency of pulmonary nodules.

Rhizobium leguminosarum Glutathione Peroxidase Is Essential for Oxidative Stress Resistance and Efficient Nodulation.

Glutathione (GSH) plays a key role in regulating the cellular Redox Homeostasis, and appears to be essential for initiation and development of root nodules. Glutathione peroxidase (Gpx) catalyzes the reduction of H2O2 and organic hydroperoxides by oxidation of GSH to oxidized GSH (GSSG), which in turn is reduced by glutathione reductase (GR). However, it has not been determined whether the Rhizobium leguminosarum Gpx or GR is required during symbiotic interactions with pea. To characterize the role of glutathione-dependent enzymes in the symbiotic process, single and double mutants were made in gpxA (encoding glutathione peroxidase) and gshR (encoding glutathione reductase) genes. All the mutations did not affect the rhizobial growth, but they increased the sensitivity of R. leguminosarum strains to H2O2. Mutant in GpxA had no effect on intracellular GSH levels, but can increase the expression of the catalase genes. The gshR mutant can induce the formation of normal nodules, while the gpxA single and double mutants exhibited a nodulation phenotype coupled to more than 50% reduction in the nitrogen fixation capacity, these defects in nodulation were characterized by the formation of ineffective nodules. In addition, the gpxA and gshR double mutant was severely impaired in rhizosphere colonization and competition. Quantitative proteomics using the TMT labeling method was applied to study the differential expression of proteins in bacteroids isolated from pea root nodules. A total of 27 differentially expressed proteins were identified in these root bacteroids including twenty down-regulated and seven up-regulated proteins. By sorting the down-regulated proteins, eight are transporter proteins, seven are dehydrogenase, deoxygenase, oxidase, and hydrolase. Moreover, three down-regulating proteins are directly involved in nodule process.

Automatic Recognition of Parathyroid Nodules in Ultrasound Images Based on Fused Prior Pathological Knowledge Features

Automation diagnosis of parathyroid nodules is of crucial importance to recognize parathyroid nodules in ultrasound images. Aiming at the different nodule shapes of diverse patients, blurred boundaries, complex backgrounds and inhomogeneous intensity of ultrasound images, we propose a novel hybrid level set model to accurately segment nodules. The adaptive global term weight is determined based on the image local entropy of the region around the evolution contour and two scales are proposed for the local term to drive the evolution contour fast approaching to the boundary in order to avoid large amount of calculation and over-segmentation. We also propose membrane features and relative position features based on prior pathological knowledge to describe the inherent characteristics of parathyroid nodules different from thyroid and other nodules. We fused prior pathological knowledge features, morphology features and texture features of the segmented nodules to recognize parathyroid nodules by the support vector data description(SVDD). The experiment result indicates that the incorporation of the proposed hybrid level set segmentation method and the fused prior pathological knowledge features, morphology features and texture features improve the recognition accuracy and efficiency of parathyroid nodules, which is much higher than that only with morphology and texture features.

Shoot Extracts from Two Low Nodulation Mutants Significantly Reduce Nodule Number in Pea.

E107 and E132 are pea mutants that nodulate poorly. Because they have a shoot-controlled nodulation phenotype, we asked if their mutated genes were implicated in the autoregulation of nodulation (AON), a mechanism which consists of two systemic circuits, the positive CEP/CRA2 and the negative CLE/SUNN, coordinated via NIN and miR2111. We further characterized the mutants’ phenotype by studying nodule distribution and nodulation efficiency. E107 was similar to wild-type (WT) in its nodule distribution, but E132 had an extended nodulation zone with nodules forming distally on its lateral roots. Moreover, we tested whether their shoots produced a compound inhibitory to nodulation. We made ethyl-acetate extracts of roots and shoots of both mutants and WT, which we applied to rhizobia-inoculated WT seedlings and to pure rhizobial cultures. Whereas free-living bacteria were unaffected by any of the extracts, WT treated with shoot extracts from either inoculated mutant had fewer nodules than that of control. E107 and E132 shoot extracts led to a 50% and a 35% reduction in nodule number, respectively. We propose that E107 and E132 belong to a new sub-class of AON mutants, i.e., hypo-nodulators, and that their respective gene products are acting in the AON descending branch, upstream of TML signaling.