The Internet on the router level, is a complex network embedded in a geographical space. We provide experimental evidences suggesting that the average travel time for a message, with fixed length, increases roughly as the square root of the geographical distance. To understand this scaling law and other measurable topological properties of the Internet as a graph, we introduce and study a simple network model. The model is based on a few realistic socio-economic facts/assumptions and qualitatively reproduces the experimentally observed stylized facts.
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http://dx.doi.org/10.1038/s41598-019-46208-6 | DOI Listing |
Biotechnol Prog
January 2025
AdBIOPRO, VINNOVA Competence Centre for Advanced Bioproduction by Continuous Processing, Royal Institute of Technology (KTH), Stockholm, Sweden.
The possibility to produce recombinant adeno-associated virus (rAAV) by adherent HEK293T cells was studied in a stirred tank bioreactor (STR) culture of cell aggregates. A proof-of-concept of rAAV production was successfully demonstrated in a process where single cells were first expanded, then cell aggregates were formed by dilution into a different medium 1 day before triple plasmid transfection was conducted. An alternative approach for the STR inoculation using a seed taken from a high cell density perfusion (HCDP) culture was also investigated.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Mathematics, Khalifa University of Science and Technology, PO Box 127788, Abu Dhabi, UAE.
We propose a general approach to quasi-deform the Korteweg-De Vries (KdV) equation by deforming its Hamiltonian. The standard abelianization process based on the inherent sl(2) loop algebra leads to an infinite number of anomalous conservation laws, that yield conserved charges for definite space-time parity of the solution. Judicious choice of the deformed Hamiltonian yields an integrable system with scaled parameters as well as a hierarchy of deformed systems, some of which possibly are quasi-integrable.
View Article and Find Full Text PDFJ Biotechnol
January 2025
Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; The Research Center of Chiral Drugs, Shanghai Frontiers Science Center for TCM Chemical Biology, Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China. Electronic address:
Chiral azacyclic amine derivatives occupy a vital role of nitrogen-containing compounds, due to serve as foundational motifs in numerous pharmaceuticals and bioactive substances. Novel complementary enantioselective reductive aminases IRED9 and IRED11 were unveiled through comprehensive gene mining from Streptomyces viridochromogenes and Micromonospora echinaurantiaca, respectively, which both demonstrated enantiomeric excess (ee) values and conversion ratios of up to 99 % towards N-Boc-3-pyridinone (NBPO) and cyclopropylamine. IRED9 exhibited the highest activity at pH 8.
View Article and Find Full Text PDFSci Adv
January 2025
Center for Nano Science and Technology, Fondazione Istituto Italiano di Tecnologia, Milano, Italy.
Achieving highly tailored control over both the spatial and temporal evolution of light's orbital angular momentum (OAM) on ultrafast timescales remains a critical challenge in photonics. Here, we introduce a method to modulate the OAM of light on a femtosecond scale by engineering a space-time coupling in ultrashort pulses. By linking azimuthal position with time, we implement an azimuthally varying Fourier transformation to dynamically alter light's spatial distribution in a fixed transverse plane.
View Article and Find Full Text PDFBioorg Chem
February 2025
School of Biotechnology and Key Laboratory of Industrial Biotechnology of Education, School of Biotechnology, Jiangnan University, Wuxi 214122 China. Electronic address:
Achieving enzyme catalysis at high substrate concentrations is a substantial challenge in industrial biocatalysis, and the role of glycosylation in post-translational modifications that modulate enzyme substrate inhibition remains poorly understood. This study provides insights into the role of N-glycosylation in substrate inhibition by comparing the catalytic properties of d-lactonohydrolase (d-Lac) derived from Fusarium moniliforme expressed in prokaryotic and eukaryotic hosts. Experimental evidence indicates that recombinant d-Lac expressed in Pichia pastoris (PpLac-WT) exhibits higher hydrolysis rates at a substrate concentration of 400 g/L, with reduced substrate inhibition and enhanced stability compared to the recombinant d-Lac expressed in Escherichia coli (EcLac-WT).
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