Ultrasound-based deep learning in the establishment of a breast lesion risk stratification system: a multicenter study.

OBJECTIVES: To establish a breast lesion risk stratification system using ultrasound images to predict breast malignancy and assess Breast Imaging Reporting and Data System (BI-RADS) categories simultaneously. METHODS: This multicenter study prospectively collected a dataset of ultrasound images for 5012 patients at thirty-two hospitals from December 2018 to December 2020. A deep learning (DL) model was developed to conduct binary categorization (benign and malignant) and BI-RADS categories (2, 3, 4a, 4b, 4c, and 5) simultaneously. The training set of 4212 patients and the internal test set of 416 patients were from thirty hospitals. The remaining two hospitals with 384 patients were used as an external test set. Three experienced radiologists performed a reader study on 324 patients randomly selected from the test sets. We compared the performance of the DL model with that of three radiologists and the consensus of the three radiologists. RESULTS: In the external test set, the DL model achieved areas under the receiver operating characteristic curve (AUCs) of 0.980 and 0.945 for the binary categorization and six-way categorizations, respectively. In the reader study set, the DL BI-RADS categories achieved a similar AUC (0.901 vs. 0.933, p = 0.0632), sensitivity (90.98% vs. 95.90%, p = 0.1094), and accuracy (83.33% vs. 79.01%, p = 0.0541), but higher specificity (78.71% vs. 68.81%, p = 0.0012) than those of the consensus of the three radiologists. CONCLUSIONS: The DL model performed well in distinguishing benign from malignant breast lesions and yielded outcomes similar to experienced radiologists. This indicates the potential applicability of the DL model in clinical diagnosis. KEY POINTS: • The DL model can achieve binary categorization for benign and malignant breast lesions and six-way BI-RADS categorizations for categories 2, 3, 4a, 4b, 4c, and 5, simultaneously. • The DL model showed acceptable agreement with radiologists for the classification of breast lesions. • The DL model performed well in distinguishing benign from malignant breast lesions and had promise in helping reduce unnecessary biopsies of BI-RADS 4a lesions.

Safety findings after intravenous administration of sulfur hexafluoride microbubbles to 463,434 examinations at 24 centers.

OBJECTIVES: We aimed to evaluate the safety of the ultrasound contrast agent sulfur hexafluoride microbubbles in a large group of patients referred for routine contrast-enhanced ultrasound (CEUS). METHODS: A retrospective assessment was made of all patients that received sulfur hexafluoride microbubbles intravenously for CEUS at 24 centers between January 2006 and April 2019. Patient demographic details, examination type, and the dose of sulfur hexafluoride microbubbles administered were recorded with specific adverse events (AEs) documentation tools at each center. All AEs were recorded as serious or non-serious. Non-serious AEs were classified by intensity as mild, moderate, or severe according to ACR criteria. The frequencies of AEs across patient subgroups were compared using the chi-square test. RESULTS: A total of 463,434 examinations were evaluated. Overall, 157 AEs (153 [0.033%] non-serious; 4 [0.001%] serious) were reported after sulfur hexafluoride microbubbles administration, giving an AE frequency of 0.034% (157/463,434). Among the non-serious AEs, 66 (0.014%) were mild, 70 (0.015%) moderate, and 17 (0.004%) severe in intensity. The liver was the most common examination site, presenting an AE frequency of 0.026%. The highest AE frequency (0.092%) was for patients undergoing CEUS for vascular disease. There were no significant gender differences in either the total number or the severity of non-serious AEs (chi-square = 2.497, p = 0.287). The onset of AEs occurred within 30 min of sulfur hexafluoride microbubbles administration in 91% of cases. CONCLUSION: The frequency of AEs to sulfur hexafluoride microbubbles is very low and severe reactions are rare, confirming that sulfur hexafluoride microbubbles are appropriate for routine CEUS applications. KEY POINT: • The frequency of AEs to sulfur hexafluoride microbubbles is very low and severe reactions are rare.

Weakly supervised video-based cardiac detection for hypertensive cardiomyopathy.

INTRODUCTION: Parameters, such as left ventricular ejection fraction, peak strain dispersion, global longitudinal strain, etc. are influential and clinically interpretable for detection of cardiac disease, while manual detection requires laborious steps and expertise. In this study, we evaluated a video-based deep learning method that merely depends on echocardiographic videos from four apical chamber views of hypertensive cardiomyopathy detection. METHODS: One hundred eighty-five hypertensive cardiomyopathy (HTCM) patients and 112 healthy normal controls (N) were enrolled in this diagnostic study. We collected 297 de-identified subjects' echo videos for training and testing of an end-to-end video-based pipeline of snippet proposal, snippet feature extraction by a three-dimensional (3-D) convolutional neural network (CNN), a weakly-supervised temporally correlated feature ensemble, and a final classification module. The snippet proposal step requires a preliminarily trained end-systole and end-diastole timing detection model to produce snippets that begin at end-diastole, and involve contraction and dilatation for a complete cardiac cycle. A domain adversarial neural network was introduced to systematically address the appearance variability of echo videos in terms of noise, blur, transducer depth, contrast, etc. to improve the generalization of deep learning algorithms. In contrast to previous image-based cardiac disease detection architectures, video-based approaches integrate spatial and temporal information better with a more powerful 3D convolutional operator. RESULTS: Our proposed model achieved accuracy (ACC) of 92%, area under receiver operating characteristic (ROC) curve (AUC) of 0.90, sensitivity(SEN) of 97%, and specificity (SPE) of 84% with respect to subjects for hypertensive cardiomyopathy detection in the test data set, and outperformed the corresponding 3D CNN (vanilla I3D: ACC (0.90), AUC (0.89), SEN (0.94), and SPE (0.84)). On the whole, the video-based methods remarkably appeared superior to the image-based methods, while few evaluation metrics of image-based methods exhibited to be more compelling (sensitivity of 93% and negative predictive value of 100% for the image-based methods (ES/ED and random)). CONCLUSION: The results supported the possibility of using end-to-end video-based deep learning method for the automated diagnosis of hypertensive cardiomyopathy in the field of echocardiography to augment and assist clinicians. TRIAL REGISTRATION: Current Controlled Trials ChiCTR1900025325, Aug, 24, 2019. Retrospectively registered.

DPDH-CapNet: A Novel Lightweight Capsule Network with Non-routing for COVID-19 Diagnosis Using X-ray Images.

COVID-19 has claimed millions of lives since its outbreak in December 2019, and the damage continues, so it is urgent to develop new technologies to aid its diagnosis. However, the state-of-the-art deep learning methods often rely on large-scale labeled data, limiting their clinical application in COVID-19 identification. Recently, capsule networks have achieved highly competitive performance for COVID-19 detection, but they require expensive routing computation or traditional matrix multiplication to deal with the capsule dimensional entanglement. A more lightweight capsule network is developed to effectively address these problems, namely DPDH-CapNet, which aims to enhance the technology of automated diagnosis for COVID-19 chest X-ray images. It adopts depthwise convolution (D), point convolution (P), and dilated convolution (D) to construct a new feature extractor, thus successfully capturing the local and global dependencies of COVID-19 pathological features. Simultaneously, it constructs the classification layer by homogeneous (H) vector capsules with an adaptive, non-iterative, and non-routing mechanism. We conduct experiments on two publicly available combined datasets, including normal, pneumonia, and COVID-19 images. With a limited number of samples, the parameters of the proposed model are reduced by 9x compared to the state-of-the-art capsule network. Moreover, our model has faster convergence speed and better generalization, and its accuracy, precision, recall, and F-measure are improved to 97.99%, 98.05%, 98.02%, and 98.03%, respectively. In addition, experimental results demonstrate that, contrary to the transfer learning method, the proposed model does not require pre-training and a large number of training samples.

Omarigliptin Prevents TNF-α-Induced Cellular Senescence in Rat Aorta Vascular Smooth Muscle Cells.

Cellular senescence is one of the most significant factors involved in aging and age-related diseases. Senescence of vascular smooth muscle cells (VSMCs) adversely affects the function of the cardiovascular system and contributes to the development of atherosclerosis, hypertension, and other cardiovascular diseases. Glucagon-like peptide-1 (GLP-1) is an important incretin hormone involved in insulin release and vascular tone. GLP-1 is quickly degraded by the enzyme dipeptidyl peptidase-4 (DPP-4). Omarigliptin is a new DPP-4 inhibitor that has demonstrated anti-inflammatory and antioxidative stress properties. In the present study, we investigated the effects of the selective DPP-4 inhibitor omarigliptin (OMG) on VSMCs exposed to insult from tumor necrosis factor-α (TNF-α), one of the main inflammatory signaling molecules involved in cellular senescence. We found that OMG could suppress TNF-α-induced expression of pro-inflammatory cytokines (interleukin-1ß (IL-1ß), IL-6, and IL-8) and inhibit oxidative stress by reducing the production of H2O2 and protein carbonyl. OMG ameliorated the increase in senescence-associated ß-galactosidase (SA-ß-gal) and telomerase activity induced by TNF-α. The plasminogen activator inhibitor-1 (PAI-1)/p53/p21 pathway is a key inducer of cellular senescence. OMG ameliorated the acetylation of p53 at lysine 382 (K382) and subsequent activation of p21 via inhibition of PAI-1. Importantly, our experiments revealed that blockage of silent information-regulator 1 (SIRT1) abolished the inhibitory effects of OMG on p53 acetylation, SA-ß-gal activity, and telomerase activity in VSMCs. These results suggest that OMG may have the potential to delay or prevent the progression of age-related cardiovascular diseases by modulating the activity of SIRT1.

Pareuzebyella sediminis gen. nov., sp. nov., a novel marine bacterium in the family Flavobacteriaceae, isolated from a tidal flat sediment.

Two marine bacterial strains, designated S2-4-21T and MT2-5-19, were isolated from two tidal flat sediments of cordgrass Spartina alterniflora and adjacent oyster culture field in Quanzhou bay, China, respectively. Both strains were Gram-staining-negative, rod-shaped, non-flagellated, non-motile, aerobic, had NaCl requirements, and contained carotenoid and flexirubin pigments. The 16S rRNA gene sequence similarity (99.8%), average nucleotide identity value (99.4%) and average amino acid identity (99.3%) between strain S2-4-21T and strain MT2-5-19 strongly supported that they belonged to a single species. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain S2-4-21T and strain MT2-5-19 formed a monophyletic branch affiliated to the family Flavobacteriaceae, sharing similarities of 94.6% with Euzebyella marina CY01T and E. saccharophila 7SM30T, and of 94.1 and 92.8% with E. algicola MEBiC 12267T and Pseudozobellia thermophile DSM 19858T, respectively. Phylogenomic analysis based on the whole genome sequences supported that the two strains formed a distinct monophyletic clade within Flavobacteriaceae members, which was phylogenetically different from the clades of Euzebyella and Pseudozobellia. The major respiratory quinone was menaquinone MK-6. The major fatty acids (>10%) consisted of C15 : 0 iso, C16 : 0, summed feature 9 (C17 : 1 iso ω9c/C16 : 0 10-methyl) and C17 : 0 iso 3-OH. The polar lipid profiles of strain S2-4-21T and strain MT2-5-19 are identical, including phosphatidylethanolamine, four unidentified aminolipids, and four unidentified lipids. The genomic size was 4.9-5.0 Mb with genomic DNA G+C content of 41.5 mol%. Based on the above characteristics, strains S2-4-21T and MT2-5-19 represented a novel species of a novel genus in the family Flavobacteriaceae. Thus, Pareuzebyella sediminis gen. nov. sp. nov. is proposed with type strain S2-4-21T (=MCCC 1K03818T=KCTC 72152T), and another strain MT2-5-19 (=KCTC 72539=MCCC 1K03874).

Ultrasound-targeted microbubble destruction promotes myocardial angiogenesis and functional improvements in rat model of diabetic cardiomyopathy.

BACKGROUND: Microvascular insufficiency plays an important role in the development of diabetic cardiomyopathy (DCM), therapeutic angiogenesis has been mainly used for the treatment of ischemic diseases. This study sought to verify the preclinical performance of SonoVue microbubbles (MB) combined ultrasound (US) treatment on myocardial angiogenesis in the rat model of DCM and investigate the optimal ultrasonic parameters. METHODS: The male Sprague-Dawley (SD) rats were induced DCM by streptozotocin through intraperitoneal injecting and fed with high-fat diet. After the DCM model was established, the rats were divided into the normal group, DCM model group, and US + MB group, while the US + MB group was divided into four subsets according to different pulse lengths (PL) (8 cycles;18 cycle;26 cycle; 36 cycle). After all interventions, all rats underwent conventional echocardiography to examine the cardiac function. The rats were sacrificed and myocardial tissue was examined by histology and morphometry evaluations to detect the myocardial protective effect of SonoVue MBs using US techniques. RESULTS: From morphologic observation and echocardiography, the DCM rats had a series of structural abnormalities of cardiac myocardium compared to the normal rats. The US-MB groups exerted cardioprotective effect in DCM rats, improved reparative neovascularization and increased cardiac perfusion, while the 26 cycle group showed significant therapeutic effects on the cardiac functions in DCM rats. CONCLUSION: This strategy using SonoVue MB and US can improve the efficacy of angiogenesis, even reverse the progress of cardiac dysfunction and pathological abnormalities, especially using the 26 cycle parameters. Under further study, this combined strategy might provide a novel approach for early intervention of DCM in diabetic patients.

Collagen Peptides Derived from Sipunculus nudus Accelerate Wound Healing.

Marine collagen peptides have high potential in promoting skin wound healing. This study aimed to investigate wound healing activity of collagen peptides derived from Sipunculus nudus (SNCP). The effects of SNCP on promoting healing were studied through a whole cortex wound model in mice. Results showed that SNCP consisted of peptides with a molecular weight less than 5 kDa accounted for 81.95%, rich in Gly and Arg. SNCP possessed outstanding capacity to induce human umbilical vein endothelial cells (HUVEC), human immortalized keratinocytes (HaCaT) and human skin fibroblasts (HSF) cells proliferation and migration in vitro. In vivo, SNCP could markedly improve the healing rate and shorten the scab removal time, possessing a scar-free healing effect. Compared with the negative control group, the expression level of tumor necrosis factor-α, interleukin-1ß and transforming growth factor-ß1 (TGF-ß1) in the SNCP group was significantly down-regulated at 7 days post-wounding (p < 0.01). Moreover, the mRNA level of mothers against decapentaplegic homolog 7 (Smad7) in SNCP group was up-regulated (p < 0.01); in contrast, type II TGF-ß receptors, collagen I and α-smooth muscle actin were significantly down-regulated at 28 days (p < 0.01). These results indicate that SNCP possessed excellent activity of accelerating wound healing and inhibiting scar formation, and its mechanism was closely related to reducing inflammation, improving collagen deposition and recombination and blockade of the TGF-ß/Smads signal pathway. Therefore, SNCP may have promising clinical applications in skin wound repair and scar inhibition.

Antimicrobial peptide AR-23 derivatives with high endosomal disrupting ability enhance poly(l-lysine)-mediated gene transfer.

BACKGROUND: pH-sensitive peptides are a relatively new strategy for conquering the poor endosomal release of cationic polymer-mediated transfection. Modification of antimicrobial peptides by exchanging positively-charged residues with negatively-charged glutamic acid residues (Glu) greatly improves its lytic activity at the endosomal pH, which could improve cationic polymer-mediated transfection. METHODS: In the present study, we investigated the effect of the number of Glu substituted for positively-charged residues on the endosomal escape activity of AR-23 and the ability of mutated AR-23 with respect to enhancing cationic polymer-mediated transfection. Three analogs were synthesized by replacing the positively-charged residues in the AR-23 sequence with Glu one-by-one. RESULTS: The pH-sensitive lysis ability of the peptides, the effect of peptides on the physicochemical characteristics, the intracellular trafficking, the transfection efficiency and the cytotoxicity of the polyplexes were determined. Increased lytic activity of peptides was observed with the increased number of Glu replacement in the AR-23 sequence at acidic pH. The number of Glu substituted for positively-charged residues of AR-23 dramatically affects its lysis ability at neutral pH. Triple-Glu substitution in the AR-23 sequence greatly improved poly(l-lysine)-mediated gene transfection efficiency at the same time as maintaining low cytotoxicity. CONCLUSIONS: The results indicate that replacement of positively-charged residues with sufficient Glu residues may be considered as a method for designing pH-sensitive peptides, which could be applied as potential enhancers for improving cationic polymer-mediated transfection.

Croceicoccus sediminis sp. nov., isolated from coastal sediment.

A Gram-stain-negative, cocci or short rod-shaped, yellow-pigmented bacterium, designated strain S2-4-2T, was isolated from coastal sediment of Spartina alterniflora in Quanzhou Bay, PR China. Growth was observed at 15-40 °C (optimum, 30 °C) and pH 6.0-8.0 (optimum, pH 7.0). Strain S2-4-2T tolerated 0-10 % NaCl (optimum, 1 %). The 16S rRNA gene of strain S2-4-2T showed highest sequence similarity to Croceicoccus pelagius Ery9T (98.2 %), followed by Croceicoccus naphthovorans PQ-2T, Croceicoccus marinus E4A9T and Croceicoccus mobilis Ery22T (97.6%, 96.3 and 96.3 %, respectively). Phylogenetic analysis based on 16S rRNA gene sequences and phylogenomic analysis based on 92 up-to-date bacterial core gene sets indicated that strain S2-4-2T forms a distinct monophyletic branch affiliated to the genus Croceicoccus. The average nucleotide identity value between strain S2-4-2T and its close relatives were estimated to be 74.8-85.7 %. The respiratory quinone was found to be Q-10. The predominant fatty acids (>10 %) were identified as summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and summed feature 3 (C16 : 1ω7c and C16 : 1ω6c). The polar lipids were identified as phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid and an unidentified phospholipid. The draft genome size of strain S2-4-2T was 3.5 Mb with a genomic G+C content of 63.0 mol%. Based on these results, strain S2-4-2T is concluded to represent a novel species within the genus Croceicoccus, for which the name Croceicoccus sediminis sp. nov. is proposed with the type strain S2-4-2T (=MCCC 1K03706T=KCTC 72146T).

Pleionea sediminis sp. nov., isolated from coastal sediment and emendation of the description of the genus Pleionea.

A Gram-stain-negative, rod-shaped and non-motile bacterium, designated strain S1-5-21T, was isolated from coastal sediment in Quanzhou Bay, PR China, and subjected to taxonomic characterization. Growth of strain S1-5-21T was observed at 15-40 °C (optimum, 30-35 °C), NaCl tolerance of 0.5-10 % NaCl (w/v; optimum, 1 %), and pH range of 5-8 (optimum, pH 7). Catalase activity and oxidase activity were found to be positive. The nearly complete 16S rRNA gene sequence of strain S1-5-21T shows maximum sequence similarity to Pleionea mediterranea MOLA115T (95.7 %), followed by Kangiella chungangensis CAU 1040T (90.4 %) and Aliikangiella marina GYP-15T (90.1 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain S1-5-21T forms a distinct monophyletic branch affiliated to the genus Pleionea. The ANI value between strain S1-5-21T and close relative P. mediterranea MOLA115T was estimated to be 70.8 %. The respiratory quinone was found to be Q-8. The predominant fatty acids (>10 %) were identified as iso-C15 : 0, summed feature 9 (iso-C17 : 1 ω9c and/or C16 : 0 10-methyl) and iso-C16 : 0. The polar lipids were identified as phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, two aminolipids, three phospholipids and five unidentified polar lipids. The draft genome size of strain S1-5-21T is 5.2 Mb with genomic G+C content of 40.1 mol%. Based on these results, strain S1-5-21T is concluded to represent a novel species within the genus Pleionea, for which the name Pleioneasediminis sp. nov. is proposed with the type strain S1-5-21T (=MCCC 1K03814T=KCTC 72149T).

A new antimicrobial peptide isoform, Pc-crustin 4 involved in antibacterial innate immune response in fresh water crayfish, Procambarus clarkii.

The main advantage of antimicrobial peptides (AMPs) used as the effectors in the innate immunity system of invertebrates is that the high specificity is not indispensable. And they play important roles in the systemic defenses against microbial invasion. In this study, a new full-length cDNA of the crustins molecule was identified in red swamp crayfish, P. clarkii (named Pc-crustin 4). The ORF of Pc-crustin 4 contained 369 bp which encoded a protein of 122 amino acids, with a 20-amino-acid signal peptide sequence. On the base of the classification method established by Smith et al., Pc-crustin 4 belonged to Type Ⅰ crustin molecule. The Pc-crustin 4 transcripts were expressed in hemocytes at relatively high level, and relatively low level in hepatopancreas, gills, and intestine in normal crayfish. After respectively challenged with S. aureus or E. ictaluri, the expression levels of Pc-crustin 4 showed up-regulation trends at different degrees in the hemocytes, hepatopancreas, gills, and intestine tissues. Besides, the results of liquid antibacterial assay showed that rPc-crustin 4 inhibited obviously the growth of S. aureus and E. ictaluri. The results of bacteria binding assay showed that rPc-crustin 4 could bind strongly to S. aureus and E. ictaluri. Finally, RNAi assay was performed to study the immunity roles of Pc-crustin 4 in crayfish in vivo. Taken together, Pc-crustin 4 is an important immunity effector molecule, which plays crucial roles in defending against bacterial infection in crayfish.

Di-n-butyl phthalate degrading endophytic bacterium Bacillus amyloliquefaciens subsp. strain JR20 isolated from garlic chive and its colonization in a leafy vegetable.

Di-n-butyl phthalate (DBP) is one of the primary PAEs (phthalate acid esters) pollutants. DBP can be absorbed by plants and threaten human health via the food chain. Some DBP-degrading bacteria have been successfully isolated from the environment (water, soil, etc.). However, only a few DBP-degrading plant endophytes have been isolated. In this study, an endophytic bacterium, Bacillus amyloliquefaciens subsp. strain JR20, which was found capable of degrading DBP, was isolated from garlic chive. We found that strain JR20 metabolized 89.74% of DBP at a 5 mg/L concentration within 4 d in liquid mineral salts medium (MSM). The optimized conditions for maximum removal of DBP were as follows: DBP concentration, 5 mg/L; pH, 7-8; temperature, 30-40 °C. The colonization of strain JR20 significantly improved the degradation rate of DBP in the roots, stems and leaves of leafy vegetables.

Three-Dimensional Echocardiography-derived strain values acquired by a novel analysis program.

OBJECTIVE: This in vitro study calculated longitudinal strain (LS) from different ultrasound systems (GE Vivid E9 and Philips IE 33) before and after myocardial infarct (MI) using a vendor-independent analysis software package (TomTec's 4D LV Analysis) to validate the variation of two ultrasound systems. METHODS: Ten freshly harvested porcine hearts were passively driven by a pulsatile pump apparatus at stroke volumes (SV) 30-70 mL. Full-volume three-dimensional echocardiography (3DE) data were acquired before and after MI using two different ultrasound systems. LS was derived from TomTec and validated against sonomicrometry data. RESULTS: Linear regression analyses showed excellent correlations between TomTec-calculated LS values and sonomicrometry data for both normal and simulated MI groups (GE: R2  = 0.72/0.68, Philip: R2  = 0.71/0.66). Bland-Altman analyses demonstrated overestimation of echo-derived strain values for all groups. Both ultrasound system-derived strain values demonstrated decreased LS after MI, and the average change in strain after infarct was roughly 30% in GE images and 25% in Philips images. CONCLUSIONS: Both GE and Philips echocardiographic systems can be analyzed with TomTec's program, and these images correlated well with sonomicrometry with acceptable variations.

A novel single WAP domain-containing protein isoform with antibacterial relevance in Litopenaeus vannamei.

Single WAP domain (SWD)-containing protein is a small protein containing a whey acidic protein (WAP) domain at the C-terminal region. SWD-containing protein exhibits structural similarity to the family of serine proteinase inhibitors. As of this writing, some SWD domain-containing proteins have been identified in crustaceans, and their functions included antibacterial and anti-proteinase activities. We identified a SWD protein isoform gene in Litopenaeus vanname (Lv-SWDi). Very high sequence similarity was found between Lv-SWDi and Lv-SWD. Results of time-course analysis for the gene expression profile showed that Lv-SWDi could produce a rapid feedback and an obvious upregulation at 12 h after Vibrio injection. Endogenous Lv-SWDi protein was obviously upregulated, and the highest expression level was reached at 24 h after Vibrio injection. The purified rLv-SWDi could directly bind to Gram-positive and Gram-negative bacteria. Results of the proteinase inhibitory assay also showed that rLv-SWDi could inhibit secretory protease activity from Bacillus subtilis. Lv-SWDi is a part of an important immunity-relevant gene and may serve important functions in defense against bacteria.

Ferritin protect shrimp Litopenaeus vannamei from WSSV infection by inhibiting virus replication.

Iron is considered as an essential element for all living organisms. Therefore, limiting iron availability may be key part of the host's innate immune response to various pathogens. Ferritin is a major iron storage protein in living cells and plays an important role in iron homeostasis. One way the host can transiently reduce iron bioavailability is by ferritin over expression. In invertebrates, ferritin was found to be up-regulated after pathogens challenge and is considered to be an important element in the innate immune system. This study was designed to investigate the involvement of ferritin in shrimp Litopenaeus vannamei defense against WSSV. We discovered that the viral load of shrimp injected with recombinant ferritin protein was lower than that of control group. The suppression of ferritin by dsRNA increased susceptibility to WSSV with 3-fold high viral copies. The present study documented that ferritin protected shrimp L. vannamei from WSSV by inhibiting virus replication. We presume that ferritin reduce iron availability, leading to inhibit the activity of ribonucleotide reductase and delay the replication of virus genome. This study provided new insights into the understanding of molecular responses and defense mechanisms in shrimp against WSSV.

Palladium/norbornene-mediated tandem C-H amination/C-I alkenylation reaction of aryl iodides with secondary cyclic O-benzoyl hydroxylamines and activated terminal olefins.

A novel palladium-catalyzed norbornene-mediated three-component reaction for the construction of ortho-alkenyl aromatic tertiary amines has been achieved, which represents a useful extension of the Catellani-type tandem ortho-selective CH amination transformations.

Platinum-catalyzed tandem cycloisomerization reaction of benzoendiynyl esters: regioselective long-range 1,5-acyl migration.

A Pt(II)-catalyzed intramolecular chemo- and regioselective pentannulation/long-range 1,5-acyl migration reaction is described. This cascade cycloisomerization protocol produces a wide variety of benzofulvene diketones in good to excellent yields with exclusively the Z configuration of the exocyclic double bond of the final product. The (18)O isotope experiment together with (13)C NMR, HRMS, and HMBC analyses confirmed an interesting long-range acyl rearrangement process in this transformation.

Synthesis of 4-alkynylquinazolines: Pd-Cu-cocatalyzed coupling of quinazoline-4-tosylates with terminal alkynes using N-heterocyclic carbenes as ligands.

A Pd-Cu-cocatalyzed coupling reaction of quinazoline-4-tosylates with terminal alkynes using N-heterocyclic carbenes (NHC) as ligands is described, providing 4-alkynylquinazolines in good to excellent yields. This transformation proceeds under mild conditions with high efficiency, which is attractive for focused compound library construction.