Esterified styrene-maleic acid copolymer modified silica as mixed-mode polymer-brush stationary phases for chromatographic separation.

Styrene-maleic acid (SMA) copolymer has received much attention for its excellent solubilization characteristics. In this work, SMA copolymer brush-based chromatographic stationary phases were exploited and developed for the first time. First, SMA copolymer brush was in situ grown on the surface of spherical silica via living/controlled reversible addition-fragmentation chain transfer (RAFT) polymerization method. Subsequently, as a proof-of-concept demonstration, the copolymer was esterified by diethylene glycol mono-2-ethylhexyl ether (DGME) and 2-(2-ethylhexyloxy) ethanol (EHOE), respectively. The obtained Sil-SMA-DGME and Sil-SMA-EHOE copolymer-brush chromatographic stationary phases were characterized by transmission electron microscopy, Fourier transform infrared spectrometer, X-ray photoelectron spectroscopy, and thermogravimetric analysis, respectively. The chromatographic retention mechanism indicated that both the two packed columns exhibited hydrophilic/reverse mixed-mode retention modes. The maximum column efficiency was up to 71,000 N/m. The chromatographic separation performance evaluation indicated that the novel kind of stationary phases had excellent separation capabilities for hydrophilic, hydrophobic compounds and phospholipid standards. In addition, by combination with mass spectrometry identification, the Sil-SMA-DGME column was further exploited for separation and identification of phospholipids in human lung cancer cells. Totally, 9 classes including 186 phospholipid species were successfully identified. The results demonstrated the promising application prospects of the novel kind of SMA copolymer-brush chromatographic stationary phases.

Improving Needle Tip Tracking and Detection in Ultrasound-Based Navigation System Using Deep Learning-Enabled Approach.

Ultrasound-guided percutaneous interventions have numerous advantages over traditional techniques. Accurate needle placement in the target anatomy is crucial for successful intervention, and reliable visual information is essential to achieve this. However, previous studies have revealed several challenges, such as the variability in needle echogenicity and the common misalignment of the ultrasound beam and the needle. Advanced techniques have been developed to optimize needle visualization, including hardware-based and image-processing-based methods. This paper proposes a novel strategy of integrating ultrasound-based deep learning approaches into an optical navigation system to enhance needle visualization and improve tip positioning accuracy. Both the tracking and detection algorithms are optimized utilizing optical tracking information. The information is introduced into the tracking network to define the search patch update strategy and form a trajectory reference to correct tracking results. In the detection network, the original image is processed according to the needle insertion position and current position given by the optical localization system to locate a coarse region, and the depth-score criterion is adopted to optimize detection results. Extensive experiments demonstrate that our approach achieves promising tip tracking and detection performance with tip localization errors of 1.11 ± 0.59 mm and 1.17 ± 0.70 mm, respectively. Moreover, we establish a paired dataset consisting of ultrasound images and their corresponding spatial tip coordinates acquired from the optical tracking system and conduct real puncture experiments to verify the effectiveness of the proposed methods. Our approach significantly improves needle visualization and provides physicians with visual guidance for posture adjustment.

BAG-Net: a boundary detection and multiple attention-guided network for liver ultrasound image automatic segmentation in ultrasound guided surgery.

Objective.Automated segmentation of targets in ultrasound (US) images during US-guided liver surgery holds the potential to assist physicians in fast locating critical areas such as blood vessels and lesions. However, this remains a challenging task primarily due to the image quality issues associated with US, including blurred edges and low contrast. In addition, studies specifically targeting liver segmentation are relatively scarce possibly since studying deep abdominal organs under US is difficult. In this paper, we proposed a network named BAG-Net to address these challenges and achieve accurate segmentation of liver targets with varying morphologies, including lesions and blood vessels.Approach.The BAG-Net was designed with a boundary detection module together with a position module to locate the target, and multiple attention-guided modules combined with the depth supervision strategy to enhance detailed segmentation of the target area.Main Results.Our method was compared to other approaches and demonstrated superior performance on two liver US datasets. Specifically, the method achieved 93.9% precision, 91.2% recall, 92.4% Dice coefficient, and 86.2% IoU to segment the liver tumor. Additionally, we evaluated the capability of our network to segment tumors on the breast US dataset (BUSI), where it also achieved excellent results.Significance.Our proposed method was validated to effectively segment liver targets with diverse morphologies, providing suspicious areas for clinicians to identify lesions or other characteristics. In the clinic, the method is anticipated to improve surgical efficiency during US-guided surgery.

π-Conjugated Macrocycles Confined Dual Single-Atom Catalysts on Graphitized Bubbles for Oxygen Reduction, Evolution, and Batteries.

It is a great demand to develop high-performance electrodes for metal-air batteries to boost cathodic oxygen reduction/evolution dynamics and avoid anodic dendrites. The optimization of catalysis at electrode can be conducted by increasing effective surface exposure, active site density, and unsaturated coordination, via using metal clusters or atomic catalysts, along with conductive or defective supports. Herein, the polarized and synergistic cooperation between dual single atom sites (Fe-N4/Co-N4) are developed through electrolytical exfoliation of defect-enriched π-conjugated macrocyclic polyphthalocyanines to expose more active sites on hollow carbonized shells (HCS). Such FeCo-N4/HCS exhibits outstanding performance in oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), to achieve high-performance in an aqueous zinc battery (AZB) with a high discharge capacity (763.6 mAhg-1) after 750 cycles at 10 mA cm-2, showing stable discharge voltage and excellent durability. It also possesses high performance in a lithium-O2 battery owing to abundant defects, synergistic Fe-N4/Co-N4 active sites, reduced energy barriers, and boosted charge and mass transfer and reaction kinetics. This study provides novel perspectives to expand dual single-metal catalysts on macrocycles in the exploration of efficient, durable, and eco-friendly energy devices.

DNMT3b-mediated SPAG6 promoter hypermethylation affects lung squamous cell carcinoma development through the JAK/STAT pathway.

BACKGROUND: DNA methylation controls the transcription of genes and is involved in the development of lung cancer. Our preliminary bioinformatics prediction revealed that sperm associated antigen 6 (SPAG6) was considerably hypermethylated in lung squamous cell carcinoma (LUSC). Thus, this study aimed to probe the mechanism underlying its hypermethylation. METHODS: The effect of DNA methylation of SPAG6 on its expression in LUSC was analyzed. The contributors to SPAG6 DNA hypermethylation were sought. CCK-8, EdU, and Transwell assays were carried out to assess the malignant phenotype of LUSC cells. KEGG pathway enrichment analysis was used to screen for pathways affected by SPAG6, which were confirmed by dual-luciferase assays. Bioinformatics analysis was conducted to dissect the impact of SPAG6 on the immune response and cancer cell stemness in LUSC. RESULTS: DNA methyltransferase 3b (DNMT3b)-mediated hypermethylation of the SPAG6 promoter in LUSC led to SPAG6 downregulation. SPAG6 reverted the malignant phenotype of LUSC cells. SPAG6 regulated the JAK/STAT pathway by inhibiting the transcription of STAT1 and STAT3. The expression of SPAG6 was positively related to immune infiltration in LUSC and inversely related to the expressions of the immunosuppressive genes CTLA4 and PDCD1. SPAG6 expression was negatively correlated with cancer cell stemness in LUSC, and its expression inhibited the expressions of Nanog, ALDH1, and Sox2, markers of cancer cell stemness. CONCLUSIONS: DNMT3b-mediated SPAG6 promoter hypermethylation activates the JAK/STAT pathway to promote LUSC progression.

Bioinformatics Analysis Reveals Hub Genes That May Reduce Inflammation and Complications After Cardiopulmonary Bypass.

Cardiopulmonary bypass (CPB), though indispensable in many cardiac surgery procedures, has several undesirable consequences. The aim of this study was to identify potential genes that may reduce the inflammatory response and complications after CPB. The GSE132176 dataset was selected from the Gene Expression Omnibus (GEO) database and included 10 patients with tetralogy of Fallot and 10 patients with an atrial septal defect who underwent CPB surgery. TSV files were downloaded after GEO2R processing. Protein-protein interaction analysis of common differentially expressed genes (DEGs) was performed using the Search Tool for the Retrieval of Interacting Genes. Gene modules and hub genes were visualized in the protein-protein interaction network using Cytoscape. Enrichment analysis was performed for all important DEGs, modular genes, and hub genes. A total of 72 DEGs were screened, including two functional and one hub gene module. FOS modular genes were primarily enriched in NGF-stimulated transcription, spinal cord injury, and PID AP1 pathway. The ATF3 modular gene was mainly enriched in cytomegalovirus infection and transcriptional misregulation in cancer. Hub gene modules were primarily enriched in the PID AP1 pathway, positive regulation of pri-miRNA transcription by RNA polymerase II, and the PID ATF2 pathway. FOS, JUN, ATF3, and EGR1 were the four most important hub genes; the top three hub genes were involved in the formation of AP-1 and enriched in the AP-1 pathway. Finally, we measured the expression levels of these four genes in patients undergoing CPB via qRT-PCR, and the results were consistent with those obtained in bioinformatic analysis. FOS, JUN, ATF3, and EGR1 and the AP-1 pathway may play key roles in inflammation and complications caused by CPB.

Orbital coupling of hetero-diatomic nickel-iron site for bifunctional electrocatalysis of CO2 reduction and oxygen evolution.

While inheriting the exceptional merits of single atom catalysts, diatomic site catalysts (DASCs) utilize two adjacent atomic metal species for their complementary functionalities and synergistic actions. Herein, a DASC consisting of nickel-iron hetero-diatomic pairs anchored on nitrogen-doped graphene is synthesized. It exhibits extraordinary electrocatalytic activities and stability for both CO2 reduction reaction (CO2RR) and oxygen evolution reaction (OER). Furthermore, the rechargeable Zn-CO2 battery equipped with such bifunctional catalyst shows high Faradaic efficiency and outstanding rechargeability. The in-depth experimental and theoretical analyses reveal the orbital coupling between the catalytic iron center and the adjacent nickel atom, which leads to alteration in orbital energy level, unique electronic states, higher oxidation state of iron, and weakened binding strength to the reaction intermediates, thus boosted CO2RR and OER performance. This work provides critical insights to rational design, working mechanism, and application of hetero-DASCs.

Effect of different cardioprotective methods on extracorporeal circulation in fetal sheep: a randomized controlled trial.

BACKGROUND: Congenital heart disease is a leading cause of death in newborns and infants. The feasibility of fetal cardiac surgery is linked to extracorporeal circulation (ECC); therefore, cardioplegic solutions need to be effective and long-lasting. METHODS: Eighteen pregnant sheep were divided into an ECC-only group, St. Thomas' Hospital cardioplegic solution (STH1) group (STH group), and HTK preservation solution (Custodiol®) group (HTK group). Markers of myocardial injury including troponin I (cTnI), troponin T (cTnT) and creatine kinase myocardial band (CKMB) were measured at specific time points (T1: pre-ECC, T2: 30 min of ECC, T3: 60 min of ECC, T4: 60 min post-ECC, T5: 120 min post-ECC). Myocardial tissue was removed from the fetal sheep at T5, and apoptosis was detected by TUNEL staining. RESULTS: Changes in the serum cTnI, cTnT and CKMB concentrations were not significantly different among the three groups before and during the ECC(T1,T2,T3). At 60 min after ECC shutdown(T4), cTnI and cTnT concentrations were significantly higher in the STH group than before the start of ECC. The concentration of cTnI was higher in the STH group than in the HTK and ECC-only groups. The concentration of cTnT was higher in the STH group than in the ECC-only group. At 120 min after ECC shutdown(T5), cTnI and cTnT concentrations were significantly higher in the ECC and HTK groups than before the start of ECC, and CKMB concentration was significantly higher in STH and HTK groups. The concentrations of cTnT, cTnI and CKMB was higher in the STH group than in the HTK and ECC-only groups. The number of TUNEL-positive cells in the HTK and STH groups was higher than in the ECC-only group. The number of TUNEL-positive cells in the STH group was higher than in the HTK group. There was no statistically significant difference among the groups in the heart rate and mean arterial pressure after ECC. CONCLUSION: The HTK preservation solution was significantly better than STH1 in reducing the release of cardiomyocyte injury markers and the number of apoptotic cells in fetal sheep ECC. Fetal sheep receiving ECC-only had an advantage in all indicators, which suggests ECC-only fetal heart surgery is feasible.

Electromembrane extraction of aristolochic acids: New insights in separation of bioactive ingredients of traditional Chinese medicines.

Aristolochic acid (AA) I and AA II, which have been classified as carcinogenic to human and have been proven to be nephrotoxic, are bioactive ingredients of many traditional Chinese medicines (TCMs). Thus, development of an efficient approach for separation and determination of AA I and AA II in biological samples and herbal plants is of significance. Herein, electromembrane extraction (EME) was for the first time used to separate AA I and AA II. It is noted that also for the first time 1-decanol was discovered and used as an efficient SLM solvent for EME of acidic compounds. The proposed EME system was used to extract AA I and AA II from urine samples (recovery≥68%). The approach of EME combined with LC-MS (EME-LC/MS) was evaluated using urine samples. The linear range for AA I and AA II was 10-1000 ng mL-1 (R2≥0.9970), and the limits of detection (LOD, S/N = 3) for AA I and AA II were 2.7 and 2.9 ng mL-1, respectively. Finally, this EME-LC/MS approach was employed to discover AA I and AA II in the herbal plants. In addition, using standard addition method, AA I in Aristolochicaceae-Liao Asarum (ALA) and Radix Aristolochice (RA) were 0.23 and 2044.13 µg g-1, and AA II in ALA and RA were 0 and 338.48 µg g-1, respectively. The repeatability of EME-LC/MS at all cases for both urine samples and herbal plants was below 15% (RSD-value). We believe that EME would be a useful tool to isolate bioactive ingredients of TCMs from complex samples for different purposes.

Effect of different levels of short-term feed intake on folliculogenesis and follicular fluid and plasma concentrations of lactate dehydrogenase, glucose, and hormones in Hu sheep during the luteal phase.

This study investigated the effects of short-term food restriction or supplementation on folliculogenesis and plasma and intrafollicular metabolite and hormone concentrations. Ewes were randomly assigned to three groups: the control group received a maintenance diet (M) while the supplemented group and restricted group received 1.5×M and 0.5×M respectively on days 6-12 of their estrous cycle. Estrus was synchronized by intravaginal progestogen sponges for 12 days. On days 7-12, blood samples were taken. After slaughter, the ovarian follicles were classified and the follicular fluid was collected. Compared with restriction, supplementation shortened the estrous cycle length, decreased the number of follicles 2.5-3.5 mm and follicular fluid estradiol (E2) concentration, increased the number of follicles>3.5 mm and plasma glucose, insulin and glucagon concentrations, and augmented the volume of follicles>2.5 mm. Restricted ewes had higher intrafollicular insulin concentration, but it was similar to that of supplemented ewes. Compared with follicles≤2.5 mm, the intrafollicular glucose and E2 concentrations were increased and the testosterone, insulin, and glucagon concentrations and lactate dehydrogenase (LDH) activity were decreased in follicles>2.5 mm. Only in restricted ewes were intrafollicular LDH and testosterone concentrations in follicles≤2.5 mm not different from those in follicles≤2.5 mm. In conclusion, the mechanism by which short-term dietary restriction inhibits folliculogenesis may involve responses to intrafollicular increased E2, testosterone, and LDH levels in late-stage follicles. This may not be due to the variation of intrafollicular insulin level but rather due to decreased circulating levels of glucose, insulin, and glucagon.

[Construction and identification of mammary expressional vector for cDNA of human lactoferrin].

The aim of this study was to construct a mammary gland-specific expressional vector pBC1-hLF-Neo for Human Lactoferrin (hLF) gene and then investigate its expression in the mammary gland epithelium cells. The constructed vector contained the 6.2 kb long 5' flank regulation region including promoter, other elements and the 7.1 kb long 3' flank regulation region including transcriptional ending signal of a goat's beta-casein gene. A cassette of Neo gene was also inserted into the vector which gave a total length of 26.736 kb identified by restriction fragment analysis and partial DNA sequencing. The results revealed that the structure of the final constructed vector accords with the designed plasmid map. In order to analyze the bioactivity of the vector, we transfected the lined vector DNA into the dairy goat's mammary gland epithelium cells and C127 cells of a mouse's mammary epithelium by Lipofectamine. After selection with G418 for 8-10 days, G418-risistant clones were obtained. PCR analysis demonstrated that hLF gene cassette had been integrated into the genomic DNA of G418-risistant clones. After proliferation culture, the two kinds of transgenic cells were cultured in serum-free DMEM-F12 medium with prolactin, insulin and hydrocortisone- a medium capable of inducing recombinant hLF expression. RT-PCR, Western blotting and anti-bacteria bioactivity experiments demonstrated that the constructed mammary gland specific vector pBC1-hLF-Neo possessed the desirable bioactivity to efficiently express and could secrete hLF in both mammary gland cells and have the effect of E. coli proliferation inhibition. Paramount to everything, this study laid a firm foundation for preparing the hLF gene transgenic goat fetal-derived fibroblast cells.