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Ứng dụng sinh khối năng lượng của Dunaliella salina SA 134 được nuôi trồng ở các mức độ độ mặn khác nhau để sản xuất lipid Dịch bởi AI
Scientific Reports - Tập 7 Số 1
Rajper Aftab Ahmed, Meilin He, Rajper Asma Aftab, Shiyan Zheng, Mostafa Nagi, Ramadan Bakri, Changhai Wang
Tóm tắt

Các loại nhiên liệu sinh học đang nhận được sự quan tâm lớn như một sự thay thế cho dầu diesel hóa thạch. Đối với vi tảo, mật độ tế bào hoặc sinh khối và hàm lượng lipid là những yếu tố quan trọng cho sản xuất biodiesel. Nghiên cứu này được thực hiện nhằm phát triển các điều kiện văn hóa thuận lợi cho Dunaliella salina để tối đa hóa sinh khối và tích lũy lipid. Ảnh hưởng của độ mặn (0.5 đến 2.5 M NaCl) lên quần thể tế bào, thành phần sinh hóa và sản lượng lipid của Dunaliella salina đã được xem xét trong một môi trường kiểm soát trong 21 ngày. Tăng trưởng tối đa (6.57 × 107 đến 7.17 × 107 tế bào mL−1) được quan sát ở mức độ NaCl từ 1.5 đến 2 M. Các sắc tố quang hợp và carbohydrate cũng thể hiện xu hướng tương tự như tăng trưởng. Mức carotenoid tối đa (5.16 mg L−1) được ghi nhận tại mức độ 2 M NaCl. Hầu hết các thông số lý hóa đều tăng khi độ mặn tăng, sinh khối (1231.66 ± 1.26 mg L−1) và hàm lượng lipid (248.33 mg L−1) được ghi nhận ở mức 2 M NaCl. Dựa trên cường độ huỳnh quang, các giá trị cao nhất (11.84 × 107 tế bào/ml) của lipid trung tính và lipid tổng cộng (22.28%) đã được ghi nhận ở các mức độ độ mặn tối ưu. Nghiên cứu hiện tại gợi ý rằng sinh khối cao và tích lũy lipid của Dunaliella salina SA 134 có thể đạt được ở mức độ NaCl 2 M.

#Dunaliella salina #biodiesel #lipid #sinh khối #độ mặn #sản xuất năng lượng
Characteristics of Patent Ductus Arteriosus in Congenital Rubella Syndrome
Scientific Reports - Tập 9 - Trang 1-12 - 2019
Michiko Toizumi, Cam Giang T. Do, Hideki Motomura, Tin N. Do, Hirofumi Fukunaga, Makiko Iijima, Nhan NT. Le, Hung Thanh Nguyen, Hiroyuki Moriuchi, Lay-Myint Yoshida
This study investigated the characteristics of congenital rubella syndrome (CRS)-associated cardiac complications, particularly patent ductus arteriosus (PDA). We reviewed the medical records of patients with CRS who were admitted to the Children’s Hospital 1 in Vietnam between December 2010 and December 2012, and patients with CRS who underwent PDA transcatheter occlusion therapy at the cardiology department between December 2009 and December 2015. We compared the characteristics of PDA treated with transcatheter closure between children with CRS (CRS-PDA) and those without CRS (non-CRS-PDA) who underwent PDA transcatheter closure between July 2014 and December 2015. One-hundred-and-eight children with CRS were enrolled. Cardiac defects (99%), cataracts (72%), and hearing impairment (7%) were detected. Fifty CRS-PDA and 290 non-CRS-PDA patients were examined. CRS-PDA patients had smaller median birthweight (p < 0.001), more frequent pulmonary (p < 0.001) and aortic stenosis (p < 0.001), higher main pulmonary artery pressure, and higher aortic pressure in systole/diastole (p < 0.001 for each) than did non-CRS-PDA patients. The proportion of tubular-type PDA was higher in CRS-PDA patients (16%) than in non-CRS-PDA patients (3%) (p = 0.020). Tubular-type PDA was frequently seen in patients with CRS and accompanied by pulmonary/systemic hypertension and pulmonary/aortic stenosis; in these patients, more cautious device selection is needed for transcatheter PDA closure.
Imidazole[1,5-a]pyridine derivatives as EGFR tyrosine kinase inhibitors unraveled by umbrella sampling and steered molecular dynamics simulations
Scientific Reports - Tập 14 - Trang 1-16 - 2024
Duc Toan Truong, Kiet Ho, Huynh Thi Yen Nhi, Van Ha Nguyen, Tuan Thanh Dang, Minh Tho Nguyen
Although the use of the tyrosine kinase inhibitors (TKIs) has been proved that it can save live in a cancer treatment, the currently used drugs bring in many undesirable side-effects. Therefore, the search for new drugs and an evaluation of their efficiency are intensively carried out. Recently, a series of eighteen imidazole[1,5-a]pyridine derivatives were synthetized by us, and preliminary analyses pointed out their potential to be an important platform for pharmaceutical development owing to their promising actions as anticancer agents and enzyme (kinase, HIV-protease,…) inhibitors. In the present theoretical study, we further analyzed their efficiency in using a realistic scenario of computational drug design. Our protocol has been developed to not only observe the atomistic interaction between the EGFR protein and our 18 novel compounds using both umbrella sampling and steered molecular dynamics simulations, but also determine their absolute binding free energies. Calculated properties of the 18 novel compounds were in detail compared with those of two known drugs, erlotinib and osimertinib, currently used in cancer treatment. Inspiringly the simulation results promote three imidazole[1,5-a]pyridine derivatives as promising inhibitors into a further step of clinical trials.
Associations Between Nutrition, Gut Microbiome, and Health in A Novel Nonhuman Primate Model
Scientific Reports - Tập 8 - Trang 1-16 - 2018
Jonathan B. Clayton, Gabriel A. Al-Ghalith, Ha Thang Long, Bui Van Tuan, Francis Cabana, Hu Huang, Pajau Vangay, Tonya Ward, Vo Van Minh, Nguyen Ai Tam, Nguyen Tat Dat, Dominic A. Travis, Michael P. Murtaugh, Herbert Covert, Kenneth E. Glander, Tilo Nadler, Barbara Toddes, John C. M. Sha, Randy Singer, Dan Knights, Timothy J. Johnson
Red-shanked doucs (Pygathrix nemaeus) are endangered, foregut-fermenting colobine primates which are difficult to maintain in captivity. There are critical gaps in our understanding of their natural lifestyle, including dietary habits such as consumption of leaves, unripe fruit, flowers, seeds, and other plant parts. There is also a lack of understanding of enteric adaptations, including their unique microflora. To address these knowledge gaps, we used the douc as a model to study relationships between gastrointestinal microbial community structure and lifestyle. We analyzed published fecal samples as well as detailed dietary history from doucs with four distinct lifestyles (wild, semi-wild, semi-captive, and captive) and determined gastrointestinal bacterial microbiome composition using 16S rRNA sequencing. A clear gradient of microbiome composition was revealed along an axis of natural lifestyle disruption, including significant associations with diet, biodiversity, and microbial function. We also identified potential microbial biomarkers of douc dysbiosis, including Bacteroides and Prevotella, which may be related to health. Our results suggest a gradient-like shift in captivity causes an attendant shift to severe gut dysbiosis, thereby resulting in gastrointestinal issues.
Investigation of changes in structure and thermodynamic of spruce budworm antifreeze protein under subfreezing temperature
Scientific Reports - Tập 7 - Trang 1-9 - 2017
Hung Nguyen, Ly Le
The aim of this theoretical work is to investigate of the changes in structure and thermodynamics of spruce budworm antifreeze protein (sbAFP) at low temperatures by using molecular dynamics simulation. The aqueous solution will form ice crystal network under the vaguely hexagonal shape at low temperature and fully represented the characteristics of hydrophobic interaction. Like ice crystal network, the cyclohexane region (including cyclohexane molecules) have enough of the characteristics of hydrophobic interaction. Therefore, in this research the cyclohexane region will be used as a representation of ice crystal network to investigate the interactions of sbAFP and ice crystal network at low temperature. The activity of sbAFP in subfreezing environment, therefore, can be clearly observed via the changes of the hydrophobic (cyclohexane region) and hydrophilic (water region) interactions. The obtained results from total energies, hydrogen bond lifetime correlation C(t), radial distribution function, mean square deviation and snapshots of sbAFP complexes indicated that sbAFP has some special changes in structure and interaction with water and cyclohexane regions at 278 K, as being transition temperature point of water molecules in sbAFP complex at low temperatures, which is more structured and support the experimental observation that the sbAFP complex becomes more rigid as the temperature is lowered.
The Lake Chad hydrology under current climate change
Scientific Reports - Tập 10 - Trang 1-10 - 2020
Binh Pham-Duc, Florence Sylvestre, Fabrice Papa, Frédéric Frappart, Camille Bouchez, Jean-Francois Crétaux
Lake Chad, in the Sahelian zone of west-central Africa, provides food and water to ~50 million people and supports unique ecosystems and biodiversity. In the past decades, it became a symbol of current climate change, held up by its dramatic shrinkage in the 1980s. Despites a partial recovery in response to increased Sahelian precipitation in the 1990s, Lake Chad is still facing major threats and its contemporary variability under climate change remains highly uncertain. Here, using a new multi-satellite approach, we show that Lake Chad extent has remained stable during the last two decades, despite a slight decrease of its northern pool. Moreover, since the 2000s, groundwater, which contributes to ~70% of Lake Chad’s annual water storage change, is increasing due to water supply provided by its two main tributaries. Our results indicate that in tandem with groundwater and tropical origin of water supply, over the last two decades, Lake Chad is not shrinking and recovers seasonally its surface water extent and volume. This study provides a robust regional understanding of current hydrology and changes in the Lake Chad region, giving a basis for developing future climate adaptation strategies.
Construction of CuS/Au Heterostructure through a Simple Photoreduction Route for Enhanced Electrochemical Hydrogen Evolution and Photocatalysis
Scientific Reports - Tập 6 Số 1
Mrinmoyee Basu, Roshan Nazir, Pragati Fageria, Surojit Pande
Abstract

An efficient Hydrogen evolution catalyst has been developed by decorating Au nanoparticle on the surface of CuS nanostructure following a green and environmental friendly approach. CuS nanostructure is synthesized through a simple wet-chemical route. CuS being a visible light photocatalyst is introduced to function as an efficient reducing agent. Photogenerated electron is used to reduce Au(III) on the surface of CuS to prepare CuS/Au heterostructure. The as-obtained heterostructure shows excellent performance in electrochemical H2 evolution reaction with promising durability in acidic condition, which could work as an efficient alternative for novel metals. The most efficient CuS-Au heterostructure can generate 10 mA/cm2 current density upon application of 0.179 V vs. RHE. CuS-Au heterostructure can also perform as an efficient photocatalyst for the degradation of organic pollutant. This dual nature of CuS and CuS/Au both in electrocatalysis and photocatalysis has been unveiled in this study.

Antibody–nanobody combination increases their neutralizing activity against SARS-CoV-2 and nanobody H11-H4 is effective against Alpha, Kappa and Delta variants
Scientific Reports - Tập 12 - Trang 1-15 - 2022
Hung Nguyen, Mai Suan Li
The global spread of COVID-19 is devastating health systems and economies worldwide. While the use of vaccines has yielded encouraging results, the emergence of new variants of SARS-CoV-2 shows that combating COVID-19 remains a big challenge. One of the most promising treatments is the use of not only antibodies, but also nanobodies. Recent experimental studies revealed that the combination of antibody and nanobody can significantly improve their neutralizing ability through binding to the SARS-CoV-2 spike protein, but the molecular mechanisms underlying this observation remain largely unknown. In this work, we investigated the binding affinity of the CR3022 antibody and H11-H4 nanobody to the SARS-CoV-2 receptor binding domain (RBD) using molecular modeling. Both all-atom steered molecular dynamics simulations and coarse-grained umbrella sampling showed that, consistent with the experiment, CR3022 associates with RBD more strongly than H11-H4. We predict that the combination of CR3022 and H11-H4 considerably increases their binding affinity to the spike protein. The electrostatic interaction was found to control the association strength of CR3022, but the van der Waals interaction dominates in the case of H11-H4. However, our study for a larger set of nanobodies and antibodies showed that the relative role of these interactions depends on the specific complex. Importantly, we showed Beta, Gamma, Lambda, and Mu variants reduce the H11-H4 activity while Alpha, Kappa and Delta variants increase its neutralizing ability, which is in line with experiment reporting that the nanobody elicited from the llama is very promising for fighting against the Delta variant.
Second order anisotropy contribution in perpendicular magnetic tunnel junctions
Scientific Reports - Tập 6 - Trang 1-12 - 2016
A. A. Timopheev, R. Sousa, M. Chshiev, H. T. Nguyen, B. Dieny
Hard-axis magnetoresistance loops were measured on perpendicular magnetic tunnel junction pillars of diameter ranging from 50 to 150 nm. By fitting these loops to an analytical model, the effective anisotropy fields in both free and reference layers were derived and their variations in temperature range between 340 K and 5 K were determined. It is found that a second-order anisotropy term of the form −K2cos4θ must be added to the conventional uniaxial –K1cos2θ term to explain the experimental data. This higher order contribution exists both in the free and reference layers. At T = 300 K, the estimated −K2/K1 ratios are 0.1 and 0.24 for the free and reference layers, respectively. The ratio is more than doubled at low temperatures changing the ground state of the reference layer from “easy-axis” to “easy-cone” regime. The easy-cone regime has clear signatures in the shape of the hard-axis magnetoresistance loops. The existence of this higher order anisotropy was also confirmed by ferromagnetic resonance experiments on FeCoB/MgO sheet films. It is of interfacial nature and is believed to be due to spatial fluctuations at the nanoscale of the first order anisotropy parameter at the FeCoB/MgO interface.
A novel method for single-cell data imputation using subspace regression
Scientific Reports - Tập 12 - Trang 1-13 - 2022
Duc Tran, Bang Tran, Hung Nguyen, Tin Nguyen
Recent advances in biochemistry and single-cell RNA sequencing (scRNA-seq) have allowed us to monitor the biological systems at the single-cell resolution. However, the low capture of mRNA material within individual cells often leads to inaccurate quantification of genetic material. Consequently, a significant amount of expression values are reported as missing, which are often referred to as dropouts. To overcome this challenge, we develop a novel imputation method, named single-cell Imputation via Subspace Regression (scISR), that can reliably recover the dropout values of scRNA-seq data. The scISR method first uses a hypothesis-testing technique to identify zero-valued entries that are most likely affected by dropout events and then estimates the dropout values using a subspace regression model. Our comprehensive evaluation using 25 publicly available scRNA-seq datasets and various simulation scenarios against five state-of-the-art methods demonstrates that scISR is better than other imputation methods in recovering scRNA-seq expression profiles via imputation. scISR consistently improves the quality of cluster analysis regardless of dropout rates, normalization techniques, and quantification schemes. The source code of scISR can be found on GitHub at https://github.com/duct317/scISR .
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