Self-supervised acoustic representation learning via acoustic-embedding memory unit modified space autoencoder for underwater target recognition.

Since the expensive annotation of high-quality signals obtained from passive sonars and the weak generalization ability of the single feature in the ocean, this paper proposes the self-supervised acoustic representation learning under acoustic-embedding memory unit modified space autoencoder (ASAE) and performs the underwater target recognition task. In the manner of the animal-like acoustic auditory system, the first step is to design a self-supervised representation learning method called space autoencoder (SAE) to merge Mel filter-bank (FBank) with the acoustic discrimination and gammatone filter-bank (GBank) with the anti-noise robustness into SAE spectrogram (SAE Spec). Meanwhile, due to poor high-level semantic information in SAE Spec, an acoustic-embedding memory unit (AEMU) is introduced as the strategy of adversarial enhancement. During the auxiliary task, more negative samples are joined in the improved contrastive loss function to obtain adversarial enhanced features called ASAE spectrogram (ASAE Spec). Ultimately, the comprehensive contrast experiments and ablation experiments on two underwater datasets show that ASAE Spec increases by more than 0.96% in accuracy, convergence rate, and anti-noise robustness of other mainstream acoustic features. The results prove the potential value of ASAE in practical applications.

Liver-specific Mettl3 ablation delays liver regeneration in mice.

This study investigated the role of N6-methyladenosine RNA methylation in liver regeneration following partial hepatectomy in mice. We created a liver-specific knockout mouse model by the deletion of Mettl3, a key component of the N6-methyladenosine methyltransferase complex, using the albumin-Cre system. Mettl3 liver-specific knockout mice and their wild-type littermates were subjected to 2/3 partial hepatectomy. Transcriptomic changes in liver tissue at 48 h after partial hepatectomy were detected by RNA-seq. Immunohistochemistry and immunofluorescence were used to determine protein expression levels of Ki67, hepatocyte nuclear factor 4 alpha, and cytokeratin 19. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling was also performed. Liver weight/body weight ratios after partial hepatectomy were significantly lower in Mettl3 liver-specific knockout mice than in wild-type mice at 48 h after 2/3 partial hepatectomy (3.1% ± 0.11% vs. 2.7% ± 0.03%). Compared with wild-type littermates, Mettl3 liver-specific knockout mice showed reduced bromodeoxyuridine staining and reduced Ki-67 expression at 48 h after 2/3 partial hepatectomy. RNA-seq analysis showed that Mettl3 liver-specific knockout delayed the cell cycle progression in murine liver by downregulating the expression levels of genes encoding cyclins D1, A2, B1, and B2. Loss of Mettl3-mediated N6-methyladenosine function led to attenuated liver regeneration by altering the mRNA decay of suppressor of cytokine signaling 6, thereby inhibiting the phosphorylation of signal transducer and activator of transcription 3 during early liver regeneration. These results demonstrated the importance of N6-methyladenosine mRNA modification in liver regeneration and suggest that Mettl3 targeting might facilitate liver regeneration.

Epitranscriptomics in liver disease: Basic concepts and therapeutic potential.

The development of next-generation sequencing technology and the discovery of specific antibodies targeting chemically modified nucleotides have paved the way for a new era of epitranscriptomics. Cellular RNA is known to dynamically and reversibly undergo different chemical modifications after transcription, such as N6-methyladenosine (m6A), N1-methyladenosine, N6,2'-O-dimethyladenosine, 5-methylcytosine, and 5-hydroxymethylcytidine, whose identity and location comprise the field of epitranscriptomics. Dynamic post-transcriptional modifications determine the fate of target RNAs by regulating various aspects of their processing, including RNA export, transcript processing, splicing, and degradation. The most abundant internal mRNA modification in eukaryotic cells is m6A, which exhibits essential roles in physiological processes, such as embryogenesis, carcinogenesis, and neurogenesis. m6A is deposited by the m6A methyltransferase complex (composed of METTL3/14/16, WTAP, KIAA1429, and RBM15/15B), erased by demethylases (FTO and ALKBH5), and recognised by binding proteins (e.g., YTHDF1/2/3, YTHDC1/2, IGF2BP1/2/3). The liver is the largest digestive and metabolic organ, and m6A modifications play unique roles in critical physiological hepatic functions and various liver diseases. This review focuses on the biological roles of m6A RNA methylation in lipid metabolism, viral hepatitis, non-alcoholic fatty liver disease, liver cancer, and tumour metastasis. In addition, we summarise the existing inhibitors targeting m6A regulators and discuss the potential of modulating m6A modifications as a therapeutic strategy.

Systemic and Splanchnic Lipopolysaccharide and Endothelin-1 Plasma Levels in Liver Cirrhosis before and after Transjugular Intrahepatic Portosystemic Shunt.

Lipopolysaccharide (LPS) and endothelin- (ET-) 1 may aggravate portal hypertension by increasing intrahepatic resistance and splanchnic blood flow. In the portal vein, after TIPS shunting, LPS and ET-1 were significantly decreased. Our study suggests that TIPS can benefit cirrhotic patients not only in high hemodynamics related variceal bleeding but also in intestinal bacterial translocation associated complications such as endotoxemia.

Biliary Obstruction following Transjugular Intrahepatic Portosystemic Shunt Creation in Patients with Variceal Bleeding.

This report describes an unusual complication after creation of a transjugular intrahepatic portosystemic shunt (TIPS). Biliary obstruction developed in two patients with portal hypertension accompanied by portal vein thrombosis, one patient with and the other without portal cavernous transformation. The biliary obstruction was thought to be secondary to compression of the bile duct by the stent graft placed in the TIPS. Awareness of this possible complication is important for its early diagnosis.

Transcatheter thrombolysis combined with damage control surgery for treatment of acute mesenteric venous thrombosis associated with bowel necrosis: a retrospective study.

OBJECTIVE: This study aims to evaluate the clinical outcomes of transcatheter thrombolysis in acute superior mesenteric venous thrombosis (ASMVT) associated with bowel necrosis. METHODS: A retrospective study of six patients with ASMVT treated with catheter-directed thrombectomy/thrombolysis and damage control surgery at Jinling Hospital (Nanjing, China) between 2010 and 2013 was conducted. Demographics, past medical history, risk factors, therapeutic methods and effects, mortality, and follow-up of the study population were assessed. RESULTS: Five of six patients underwent arteriovenous combined thrombolysis, while one patient underwent arterial thrombolysis. All patients required damage control surgery, and four of these patients underwent temporary abdominal closure. All patients survived and were free of recurrence. CONCLUSIONS: Transcatheter thrombectomy/thrombolysis and damage control surgery could help avoid extensive bowel resection, prevent short bowel syndrome and reduce mortality for critically ill patients with acute mesenteric venous thrombosis associated with bowel necrosis.

Multidisciplinary stepwise management strategy for acute superior mesenteric venous thrombosis: an intestinal stroke center experience.

BACKGROUD: Acute superior mesenteric venous thrombosis (ASMVT) is an uncommon but catastrophic abdominal vascular emergency with high rate of intestinal failure and mortality. The retrospective pilot study was performed to assess the effect of a multidisciplinary stepwise management strategy on survival and mesenteric recanalization in an integrated intestinal stroke center (ISC). MATERIALS AND METHODS: A modern management strategy performed by multidisciplinary specialists in ISC was evaluated among 43 ASMVT patients that were classified into central vs peripheral type, operative vs nonoperative, early vs late treated group from March 2009 to April 2013. Patients received specific medical therapy, endovascular treatment, damage-control surgery, selective second-look laparotomy, critical care management, and clinical nutrition support in a stepwise way. The demographics, etiology, imaging characteristics, treatment procedures, complications, clinical outcome, and 1-year follow-up data were analyzed and compared. Confounding factors of mortality were identified by univariate and ROC-curve analysis. A single-center experience of over 5years for this modern strategy was also reported. RESULTS: The protocol of multidisciplinary stepwise management strategy was followed in all ASMVT patients successfully. The 30-day mortality and recanalization rate were 11.63% and 90.70%. Initial damage-control surgery was carried out in 46.51% patients, with selective second-look laparotomy in 23.26% patients. Endovascular thrombolysis was performed in 83.72% patients initially or postoperatively. Bowel resection was necessary in 18 patients with the length of 100.00 (47.50, 222.50) cm. The incidence of short-bowel syndrome was 13.95%. The rate and length of bowel resection, short-bowel syndrome rate were significantly lower in nonoperative and early-treated groups (P<0.05). During the follow-up survey, 1-year survival was 83.72%, with no additional death or re-thrombosis. CONCLUSION: A multidisciplinary stepwise management strategy involving modern surgical and endovascular treatments that focus on early mesenteric recanalization and bowel viability salvage in a specialized ISC could significantly improve the clinical outcome of ASMVT patients.

D-dimer as an early marker of severity in patients with acute superior mesenteric venous thrombosis.

No early serum marker of disease severity contributes to the treatment decision-making process of acute superior mesenteric venous thrombosis (ASMVT). This study aims to assess the value of serum D-dimer level in the first 3 days after admission as a severity marker of ASMVT patients. From May 2010 to June 2014, 50 consecutive patients of ASMVT were enrolled in this observational study. The serum D-dimer level was measured on a daily basis during the first 3 days after admission as well as other laboratory-testing parameters, clinical score, and outcome variables recorded during the same period. The maximum and mean D-dimer values were analyzed and compared with other potential markers for prediction of multiple-organ dysfunction syndrome (MODS) and short-bowel syndrome (SBS). The correlation of D-dimer level with other potential severity markers and inflammation parameters were also studied. Both maximum and mean D-dimer level during the first 3 days of admission were significantly higher in patients with several clinical variables such as death within 30 days, bowel resection, sepsis, abdominal compartment syndrome, MODS, and SBS. In addition, serum D-dimer level showed precise prediction for MODS and SBS, greater than L-lactate and intestinal-type fatty acid-binding protein (I-FABP). The D-dimer level was correlated well with L-lactate, I-FABP, and APACHE II score on the first 3 days of admission. Poor correlation of D-dimer level and inflammation parameters, white blood cell count, and C-reactive protein level, was detected. D-dimer level could be an effective, early, and specific serum marker indicating the clinical evolution and outcome of ASMVT.