Understanding β-Hairpin Formation by Molecular Dynamics Simulations of Unfolding

AbstractWe have studied the mechanism of formation of a 16-residue β-hairpin from the protein GB1 using molecular dynamics simulations in an aqueous environment. The analysis of unfolding trajectories at high temperatures suggests a refolding pathway consisting of several transient intermediates. The changes in the interaction energies of residues are related with the structural changes during the unfolding of the hairpin. The electrostatic energies of the residues in the turn region are found to be responsible for the transition between the folded state and the hydrophobic core state. The van der Waals interaction energies of the residues in the hydrophobic core reflect the behavior of the radius of gyration of the core region. We have examined the opposing influences of the protein-protein (PP) energy, which favors the native state, and the protein-solvent (PS) energy, which favors unfolding, in the formation of the β-hairpin structure. It is found that the behavior of the electrostatic components of PP and PS energies reflects the structural changes associated with the loss of backbone hydrogen bonding. Relative changes in the PP and PS van der Waals interactions are related with the disruption of the hydrophobic core of a protein. The results of the simulations support the hydrophobic collapse mechanism of β-hairpin folding

Chemically etched ultrahigh-Q wedge-resonator on a silicon chip

Ultrahigh-Q optical resonators are being studied across a wide range of fields, including quantum information, nonlinear optics, cavity optomechanics and telecommunications. Here, we demonstrate a new resonator with a record Q-factor of 875 million for on-chip devices. The fabrication of our device avoids the requirement for a specialized processing step, which in microtoroid resonators8 has made it difficult to control their size and achieve millimetre- and centimetre-scale diameters. Attaining these sizes is important in applications such as microcombs and potentially also in rotation sensing. As an application of size control, stimulated Brillouin lasers incorporating our device are demonstrated. The resonators not only set a new benchmark for the Q-factor on a chip, but also provide, for the first time, full compatibility of this important device class with conventional semiconductor processing. This feature will greatly expand the range of possible ‘system on a chip’ functions enabled by ultrahigh-Q devices

ChimerDB—a knowledgebase for fusion sequences

Chromosome translocation and gene fusion are frequent events in the human genome and are often the cause of many types of tumor. ChimerDB is the database of fusion sequences encompassing bioinformatics analysis of mRNA and expressed sequence tag (EST) sequences in the GenBank, manual collection of literature data and integration with other known database such as OMIM. Our bioinformatics analysis identifies the fusion transcripts that have non-overlapping alignments at multiple genomic loci. Fusion events at exon–exon borders are selected to filter out the cloning artifacts in cDNA library preparation. The result is classified into two groups—genuine chromosome translocation and fusion between neighboring genes owing to intergenic splicing. We also integrated manually collected literature and OMIM data for chromosome translocation as an aid to assess the validity of each fusion event. The database is available at for human, mouse and rat genomes

Le rôle d’un système ESEC dans l’estimation de la surmortalité liée à la COVID-19 en Corée du Sud

Affaires mondiales Canad

Full parallax integral 3d display and image processing techniques

Purpose – Full parallax integral 3D display is one of the promising future displays that provide different perspectives according to viewing direction. In this paper, the authors review the recent integral 3D display and image processing techniques for improving the performance, such as viewing resolution, viewing angle, etc. Design/methodology/approach – Firstly, to improve the viewing resolution of 3D images in the integral imaging display with lenslet array, the authors present 3D integral imaging display with focused mode using the time-multiplexed display. Compared with the original integral imaging with focused mode, the authors use the electrical masks and the corresponding elemental image set. In this system, the authors can generate the resolution-improved 3D images with the n×n pixels from each lenslet by using n×n time-multiplexed display. Secondly, a new image processing technique related to the elemental image generation for 3D scenes is presented. With the information provided by the Kinect device, the array of elemental images for an integral imaging display is generated. Findings – From their first work, the authors improved the resolution of 3D images by using the time-multiplexing technique through the demonstration of the 24 inch integral imaging system. Authors’ method can be applied to a practical application. Next, the proposed method with the Kinect device can gain a competitive advantage over other methods for the capture of integral images of big 3D scenes. The main advantage of fusing the Kinect and the integral imaging concepts is the acquisition speed, and the small amount of handled data. Originality / Value – In this paper, the authors review their recent methods related to integral 3D display and image processing technique

Do large thyroid nodules (≥4 cm) without suspicious cytology need surgery?

BackgroundFine-needle aspiration biopsy (FNAB) is a good diagnostic tool for thyroid nodules; however, its high false-negative rate for giant nodules remains controversial. Many clinicians recommend surgical resection for nodules >4 cm owing to an increased risk of malignancy and an increased false-negative rate. This study aimed to examine the feasibility of this approach and investigate the incidence of malignancy in thyroid nodules >4 cm without suspicious cytology based on medical records in our center.MethodsThis was a retrospective analysis of 453 patients that underwent preoperative FNAB for nodules measuring >4 cm between January 2017 and August 2022 at Severance Hospital, Seoul.ResultsAmong the 453 patients, 140 nodules were benign and 119 were indeterminate. Among 259 patients, the final pathology results were divided into benign (149) and cancerous (110) groups, and the prevalence of malignancy was 38.9% in the benign group and 55.5% in the indeterminate group. Among the malignancies, follicular carcinoma and follicular variants of papillary carcinoma were observed in 83% of the cytologically benign group and 62.8% of the indeterminate group.ConclusionPreoperative FNAB had high false-negative rates and low diagnostic accuracy in patients with thyroid nodules >4 cm without suspicious cytologic features; therefore, diagnostic surgery may be considered a treatment option

Comparison of the number of live births, maternal age at childbirth, and weight of live births between Korean women and immigrant women in 2018

Purpose This study compared maternal age at childbirth, the number of live births, and the weight of live births between Korean women and immigrant women using statistical data from the Republic of Korea for the period of 2008-2018. Methods The analysis was conducted using data from the Microdata Integrated Service of Statistics Korea (https://mdis.kostat.go.kr/index.do). Results Korean women and immigrant women showed a higher age at childbirth in 2018 than in 2008. The percentage of newborns of Korean women with a birth weight of less than 2.5 kg increased slightly for 3 consecutive years from 2016 to 2018, whereas for immigrant women, this percentage increased in 2017 compared to 2016 and then decreased again in 2018. Very low birth weight (less than 1.5 kg) became more common among immigrant women from 2016 to 2018. Birth at a gestational age of fewer than 37 weeks increased both among Korean and immigrant women from 2016 to 2018. In both groups, the percentage of women who had their first child within their first 2 years of marriage decreased from 2008 to 2018. Conclusion Immigrant women had higher birth rates than Korean women, while both groups showed an increasing trend in preterm birth. Greater attention should be paid to the pregnancy and birth needs of immigrant women, and steps are needed to ensure health equity and access in order to prevent preterm births. It is also necessary to identify factors that affect preterm birth and birth of very low birth weight infants among immigrant women in the future

Long Distance Seed Dispersal by Forest Elephants

By dispersing seeds long distances, large, fruit-eating animals influence plant population spread and community dynamics. After fruit consumption, animal gut passage time and movement determine seed dispersal patterns and distances. These, in turn, are influenced by extrinsic, environmental variables and intrinsic, individual-level variables. We simulated seed dispersal by forest elephants (Loxodonta cyclotis) by integrating gut passage data from wild elephants with movement data from 96 individuals. On average, elephants dispersed seeds 5.3 km, with 89% of seeds dispersed farther than 1 km. The longest simulated seed dispersal distance was 101 km, with an average maximum dispersal distance of 40.1 km. Seed dispersal distances varied among national parks, perhaps due to unmeasured environmental differences such as habitat heterogeneity and configuration, but not with human disturbance or habitat openness. On average, male elephants dispersed seeds farther than females. Elephant behavioral traits strongly influenced dispersal distances, with bold, exploratory elephants dispersing seeds 1.1 km farther than shy, idler elephants. Protection of forest elephants, particularly males and highly mobile, exploratory individuals, is critical to maintaining long distance seed dispersal services that shape plant communities and tropical forest habitat.Additional co-authors: Tanguy Nkoghe, Médard Obiang Ebanega, Connie J. Clark, Michael J. Fay, Pete Morkel, Joseph Okouy