An improved contrastive learning network for semi-supervised multi-structure segmentation in echocardiography

Cardiac diseases have high mortality rates and are a significant threat to human health. Echocardiography is a commonly used imaging technique to diagnose cardiac diseases because of its portability, non-invasiveness and low cost. Precise segmentation of basic cardiac structures is crucial for cardiologists to efficiently diagnose cardiac diseases, but this task is challenging due to several reasons, such as: (1) low image contrast, (2) incomplete structures of cardiac, and (3) unclear border between the ventricle and the atrium in some echocardiographic images. In this paper, we applied contrastive learning strategy and proposed a semi-supervised method for echocardiographic images segmentation. This proposed method solved the above challenges effectively and made use of unlabeled data to achieve a great performance, which could help doctors improve the accuracy of CVD diagnosis and screening. We evaluated this method on a public dataset (CAMUS), achieving mean Dice Similarity Coefficient (DSC) of 0.898, 0.911, 0.916 with 1/4, 1/2 and full labeled data on two-chamber (2CH) echocardiography images, and of 0.903, 0.921, 0.928 with 1/4, 1/2 and full labeled data on four-chamber (4CH) echocardiography images. Compared with other existing methods, the proposed method had fewer parameters and better performance. The code and models are available at https://github.com/gpgzy/CL-Cardiac-segmentation

Spatial Pattern of Bacterial Community Diversity Formed in Different Groundwater Field Corresponding to Electron Donors and Acceptors Distributions at a Petroleum-Contaminated Site

The benefits of an electron-transfer mechanism for petroleum biodegrading have been widely acknowledged, but few have studied the spatial pattern of microbial community diversity in groundwater fields, and few discuss the bacterial community’s diversity in relation to electron donors-acceptors distribution, which is largely determined by groundwater flow. Eleven samples in different groundwater fields are collected at a petroleum-contaminated site, and the microbial communities are investigated using 16S rRNA gene sequences with multivariate statistics. These are mainly linked to the chemical composition analysis of electron donor indexes COD, BTEX and electron acceptor indexes DO, NO3−, Fe2+, Mn2+, and SO42−, HCO3−. The spatial pattern of the bacterial community’s diversity is characterized and the effect of the electron redox reaction on bacterial community formation in different groundwater field zones is elucidated. It is found that a considerable percentage (>65%) of the bacterial communities related to petroleum degrading suggest that petroleum biodegrading is occurring in groundwater. The communities are subject to the redox reaction in different groundwater field zones: The side plume zone and the upstream of the source zone are under aerobic redox or denitrification redox, and the corresponding bacteria are Rhodoferax, Novosphingobium, Hydrogenophaga, and Comamonas; the source zone and downstream of the source zone are under Fe3+, Mn4+, and SO42− reduction redox, and the corresponding bacteria are Rhodoferax, Treponema, Desulfosporosinus, Hydrogenophaga, and Acidovorax. These results imply that groundwater flow plays a definitive role in the bacterial community’s diversity spatial pattern formation by influencing the distribution of electron donor and acceptor

Incorporating the Soil Gas Gradient Method and Functional Genes to Assess the Natural Source Zone Depletion at a Petroleum-Hydrocarbon-Contaminated Site of a Purification Plant in Northwest China

An increasing number of studies have demonstrated that natural source zone depletion (NSZD) in the vadose zone accounts for the majority (90%~99%) of the natural attenuation of light non-aqueous phase liquid (LNAPL). Until now, 0.05 to 12 kg/a.m2 NSZD rates at tens of petroleum LNAPL source zones have been determined in the middle or late evolution stage of LNAPL release, in which limited volatile organic compounds (VOCs) and methane (CH4) were detected. NSZD rates are normally estimated by the gradient method, yet the associated functional microbial activity remains poorly investigated. Herein, the NSZD at an LNAPL-releasing site was studied using both soil gas gradient methods quantifying the O2, CO2, CH4, and VOCs concentrations and molecular biology methods quantifying the abundance of the pmoA and mcrA genes. The results showed that the methanogenesis rates were around 4 to 40 kg/a.m2. The values were greater than the rates calculated by the sum of CH4 escaping (0.3~1.2 kg/a.m2) and O2 consuming (3~13 kg/a.m2) or CO2 generating rates (2~4 kg/a.m2), suggesting that the generated CH4 was oxidized but not thoroughly to CO2. The functional gene quantification also supported the indication of this process. Therefore, the NSZD rates at the site roughly equaled the methanogenesis rates (4~40 kg/a.m2), which were greater than most of the previously studied sites with a 90th percentile value of 4 kg/a.m2. The study extended the current knowledge of the NSZD and has significant implications for LNAPL remediation management

Review on the Research Progress of Natural Source Zone Depletion in LNAPL Contaminated Sites

BACKGROUND: Human health risks and potential environmental geological hazards caused by contaminated sites have been paid much attention. Monitored natural attenuation (MNA) is recognized as a preferred remediation technique. However, for sites with non-aqueous phase liquids (NAPLs), the problem of "tailing rebound" caused by the residue of NAPLs in the source area poses a challenge to the MNA technology. In recent years, the emergence of natural source zone depletion (NSZD) enriches the connotation of MNA remediation, and it is a potential way to solve the problem of "Tailing & Rebound".OBJECTIVES: To summarize the research process and latest achievements of NSZD for light non-aqueous phase liquid (LNAPL) contaminated sites.METHODS: A comprehensive review was conducted on the literature on NSZD for LNAPL contaminated sites from the end of the 1990's. The conceptual models of vertical zoning natural elimination in LNAPL source areas have been reviewed. The key control factors on NSZD and main scientific and technological challenges for future research have been fully discussed.RESULTS: The research shows that: (1) since 2000, the research on MNA remediation has gradually shifted from groundwater pollution plume attenuation to natural depletion of vadose zone source areas; (2) The natural elimination process of aeration zones has proved to be the key biological process of NSZD, accounting for 90%-99% of the total mass loss of LNAPLs; (3) biodegradation in the volatilization process of LNAPL is the major research field of NSZD. The following research methods of NSZD are established: (1) the NSZD method can be divided into three parts: LNAPL source area plume identification, qualitative judgment and quantitative estimation; (2) The Concentration Gradient Method, CO2 Fluxes Method (including Dynamic Closed Chambers and CO2 Traps) and Thermal Gradient Method are three major methods for quantitative estimation.CONCLUSIONS: Based on the existing research progress and challenges, the key scientific problems to be solved in the application and promotion of NSZD include identifying the composition change of LNAPLs in the source area, clarifying the speed limiting factor for natural elimination in the source area, and developing appropriate monitoring methods for degassing and bubble escape

The traditional Chinese medicine formula Fufang-Zhenzhu-Tiaozhi protects myocardia from injury in diabetic minipigs with coronary heart disease

Background and purpose: Diabetes mellitus (DM) is a major risk factor for coronary heart disease (CHD). Previous research has reported that the Fufang-Zhenzhu-Tiaozhi (FTZ) formula has obvious effects on the treatment of dyslipidemia and hyperglycemia. In the present study, we intended to establish a convenient DM-CHD model in minipigs and investigated the protective effect of FTZ against myocardial injury and its mechanism. Methods: The DM-CHD model was established by a high-fat/high-sucrose/high-cholesterol diet (HFSCD) combined with balloon injury in the coronary artery. Subsequently, sixteen Wuzhishan minipigs were assigned to three groups: control group, model group, and FTZ group. The model group and FTZ group were given a HFSCD, while the control group was given a normal diet (ND). FTZ was given with meals in the FTZ group. During this time, biochemical parameters, such as total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein (HDL-C), and fasting blood glucose (FBG), were measured by using testing kits. Insulin (INS) was determined by ELISA, and the homeostasis model assessment index of insulin resistance (HOMA-IR) was calculated to evaluate insulin resistance levels. After FTZ administration, the plasma levels of lactate dehydrogenase (LDH), creatine kinase isoenzyme MB (CK-MB), and cardiac troponin I (cTnI) were measured by using ELISA kits to evaluate myocardial injury. Coronary artery stenosis was analyzed by angiographic and HE staining. Myocardial ischemia was assayed with electrocardiogram (ECG). Moreover, cytokines, including interleukin-6 (IL-6), hypersensitive C-reactive protein (hs-CRP), and tumor necrosis factor-alpha (TNF-α), were measured by ELISA kits to assess inflammation. The myocardial tissue was collected, and the pathological morphology was observed by transmission electron microscopy (TEM), HE staining, and Masson staining. Western blots were used to detect the expression of PI3K, AKT, p-AKT, p-NF-κB, and NF-κB. Results: A DM-CHD model in minipigs with glucose-lipid metabolism disorder, coronary artery incrassation and myocardial damage was successfully established through balloon injury in the coronary artery combined with HFSCD. FTZ effectively inhibited coronary artery incrassation and protected the myocardium against injury in DM-CHD minipigs. FTZ decreased proinflammatory cytokine levels and upregulated the protein expression of the PI3K/Akt pathway in the myocardium. Conclusions: A novel DM-CHD model in minipigs was successfully established through balloon injury in the coronary artery combined with HFSCD. FTZ has a protective effect against myocardial injury in DM-CHD by inhibiting inflammation and activating the PI3K/AKT signaling pathway

Sulforaphane activates CD8+ T cells antitumor response through IL-12RB2/MMP3/FasL-induced MDSCs apoptosis’

Background Extensive attention has been given to the role of myeloid-derived suppressor cells (MDSCs) in driving tumor progression and treatment failure. Preclinical studies have identified multiple agents that eliminate MDSCs. However, none have been authorized in the cliniccal ues due to the safety reasons. In the present study, we investigated the efficacy and mechanism of sulforaphane (SFN) to eliminate MDSCs in the tumor microenvironment (TME).Methods We monitored SFN effect on tumor growth and the percents or apoptosis of immune cell subsets in mice models bearing LLC or B16 cells. Flow cytometry, quantitative reverse transcription-PCR, immunohistochemistry, ELISA, immunofluorescence, imaging flow cytometry and western blot were performed to validate the role of SFN on MDSCs function in vivo and in vitro. RNA sequencing was then used to interrogate the mechanisms of how SFN regulated MDSCs function. Tumor xenograft models were established to evaluate the involvement of IL-12RB2/MMP3/FasL induced MDSCs apoptosis in vivo. We verified the effect of SFN on MDSCs and CD8+ T cells in the blood samples from a phase I clinical trial (KY-2021–0350).Results In this study, we elucidated that SFN liberated CD8+ T-cell antitumor ability by reducing MDSCs abundance, leading to repressed tumor growth. SFN treatment suppressed MDSCs accumulation in the peripheral blood and tumor sites of mice, but had no effect on the bone marrow. Mechanistically, SFN activates IL-12RB2, which stimulates the MMP3/FasL signaling cascade to trigger caspase 3 cleavage and induce apoptosis in MDSCs. Clinically, SFN treatment eliminates peripheral MDSCs and increases the percentage and activation of CD8+ T cells.Conclusions Collectively, we uncovered the role of SFN in eliminating MDSCs to emancipate CD8+ T cells through IL-12RB2/MMP3/FasL induced apoptosis, thus providing a strategy for targeting MDSCs to control tumors and improve clinical efficacy