Action mechanism and structural requirements of the antimicrobial peptides, gaegurins

AbstractGaegurins (GGNs) are a family of cationic, α-helical, antimicrobial peptides that were isolated from a Korean frog, Glandirana emeljanovi (formerly classified as Rana rugosa) and represent one of the structurally well-characterized groups. Among six gaegurins, gaegurin 4 (renamed herein esculentin-2EM), gaegurin 5 (brevinin-1EMa), and gaegurin 6 (brevinin-1EMb) have been investigated comprehensively in terms of structure–activity relationships. In this paper, we first suggest renaming of gaegurins according to a recently raised rule of systematic nomenclature. Then, the current understanding of gaegurins is reviewed by summarizing their structure–activity relationships. In particular competing arguments on gaegurins are synthetically inspected. Finally their action mechanism and structural requirements will be discussed

High-efficiency Bidirectional Buck-Boost Converter for Residential Energy Storage System

This paper proposes a bidirectional dc-dc converter for residential micro-grid applications. The proposed converter can operate over an input voltage range that overlaps the output voltage range. This converter uses two snubber capacitors to reduce the switch turn-off losses, a dc-blocking capacitor to reduce the input/output filter size, and a 1:1 transformer to reduce core loss. The windings of the transformer are connected in parallel and in reverse-coupled configuration to suppress magnetic flux swing in the core. Zero-voltage turn-on of the switch is achieved by operating the converter in discontinuous conduction mode. The experimental converter was designed to operate at a switching frequency of 40-210 kHz, an input voltage of 48 V, an output voltage of 36-60 V, and an output power of 50-500 W. The power conversion efficiency for boost conversion to 60 V was >= 98.3% in the entire power range. The efficiency for buck conversion to 36 V was >= 98.4% in the entire power range. The output voltage ripple at full load was <3.59 V-p.p for boost conversion (60 V) and 1.35 V-p.p for buck conversion (36 V) with the reduced input/output filter. The experimental results indicate that the proposed converter is well-suited to smart-grid energy storage systems that require high efficiency, small size, and overlapping input and output voltage ranges.11Ysciescopu

Isolated Double-Chambered Right Ventricle in a Young Adult

Double-chambered right ventricle (DCRV) is a rare congenital heart disorder in which the right ventricle is divided by an anomalous muscle bundle into a high pressure inlet portion and a low pressure outlet portion. We report a case of isolated DCRV without symptoms in adulthood, diagnosed through echocardiography, cardiac catheterization and cardiac magnetic resonance imaging

Dimeric configuration of SeqA protein bound to a pair of hemi-methylated GATC sequences

The binding of SeqA protein to hemi-methylated GATC sequences (hemi-sites) regulates chromosome initiation and the segregation of replicated chromosome in Escherichia coli. We have used atomic force microscopy to examine the architecture of SeqA and the mode of binding of one molecule of SeqA to a pair of hemi-sites in aqueous solution. SeqA has a bipartite structure composed of a large and a small lobe. Upon binding of a SeqA molecule to a pair of hemi-sites, the larger lobe becomes visibly separated into two DNA binding domains, each of which binds to one hemi-site. The two DNA binding domains are held together by association between the two multimerization domains that make up the smaller lobe. The binding of each DNA binding domain to a hemi-site leads to bending of the bound DNA inwards toward the bound protein. In this way, SeqA adopts a dimeric configuration when bound to a pair of hemi-sites. Mutational analysis of the multimerization domain indicates that, in addition to multimerization of SeqA polypeptides, this domain contributes to the ability of SeqA to bind to a pair of hemi-sites and to its cooperative behavior

Effects of PI3Kγ overexpression in the hippocampus on synaptic plasticity and spatial learning

Previous studies have shown that a family of phosphoinositide 3-kinases (PI3Ks) plays pivotal roles in the brain; in particular, we previously reported that knockout of the γ isoform of PI3K (PI3Kγ) in mice impaired synaptic plasticity and reduced behavioral flexibility. To further examine the role of PI3Kγ in synaptic plasticity and hippocampus-dependent behavioral tasks we overexpressed p110γ, the catalytic subunit of PI3Kγ, in the hippocampal CA1 region. We found that the overexpression of p110γ impairs NMDA receptor-dependent long-term depression (LTD) and hippocampus-dependent spatial learning in the Morris water maze (MWM) task. In contrast, long-term potentiation (LTP) and contextual fear memory were not affected by p110γ overexpression. These results, together with the previous knockout study, suggest that a critical level of PI3Kγ in the hippocampus is required for successful induction of LTD and normal learning

Comparison of the prevalence and histology between primary benign bladder tumors and recurrent benign lesions after transurethral resection of malignant bladder tumors

Background Benign bladder tumors are rare disease entities, and insufficient studies have assessed their epidemiological characteristics. The authors investigated the prevalence of benign bladder tumors by retrospectively investigating pathology reports of transurethral resection of bladder tumor (TURBT) procedures over the past 20 years. Methods We analyzed 1,674 pathology reports of TURBT conducted in 1,160 patients from January 1, 2000, to April 30, 2022. The prevalence of benign tumors and histological classification according to the presence of primary (group 1) and recurrent (group 2) bladder lesions were retrospectively investigated. Results The mean age of patients was 65.2±11.5 years, and 1,284 cases (79.1%) were in men. Benign bladder tumors comprised 278 cases (248 patients) accounting for about 17.1% of the total TURBT cases (278/1,624). Furthermore, 184 patients (16.0%, 184/1,147) belonged to group 1 and 78 patients (27.4%, 78/285) belonged to group 2. Among all benign lesions that underwent TURBT, cystitis was the most common (41.0%, 114/278), and this rate was higher in group 2 (64/184 [34.8%] vs. 50/94 [53.2%], p<0.001). The prevalence of non-neoplastic lesions was higher in group 1 (44/184 [23.9] vs. 11/94 [11.7%], p<0.001). There was no difference in the prevalence of noninvasive urothelial neoplasms between the two groups (22/184 [12.0%] vs. 8/94 [8.5%], p=0.86). Conclusions The probability of benign lesions in TURBT was 17.1%, among which cystitis was the most common. When TURBT was performed for recurrent lesions, the frequency of benign tumors was higher than that of primary benign bladder tumors

Isolated Double-Chambered Right Ventricle in a Young Adult

Double-chambered right ventricle (DCRV) is a rare congenital heart disorder in which the right ventricle is divided by an anomalous muscle bundle into a high pressure inlet portion and a low pressure outlet portion. We report a case of isolated DCRV without symptoms in adulthood, diagnosed through echocardiography, cardiac catheterization and cardiac magnetic resonance imaging