Laboratoire d'Optique et Biosciences

This study aimed at controlling both the organization and the transparency of dense collagen scaffolds making use of the lyotropic mesogen properties of collagen. Cholesteric or plywood-like liquid crystal phases were achieved using mixtures of acetic and hydrochloric acids as solvents. The critical pH at which the switch between the two phases occurred was around pH = 3. The use of the two acids led to fibrillated collagen I scaffolds, whose visual aspect ranged from opaque to transparent. Rheological investigations showed that viscoelastic properties of the plywood-like solutions were optimized for molding due to faster recovery. They also confirmed the correlation between the elastic modulus and the diameter of collagen fibrils obtained after fibrillogenesis under ammonia vapor. Human corneal epithelial cells, grown from donor limbal explants, were cultured both on transparent plywood-like matrices and on human amniotic membranes for 14 days. The development of corneal epithelium and the preservation of epithelial stem cells were checked by optical microscopy, colony formation assay, immuno-fluorescence and quantitative polymerase chain reaction. A higher level of amplification of limbal stem cells was obtained with collagen matrices compared with amniotic membranes, showing the high biocompatibility of our scaffolds. We therefore suggest that collagen solutions presenting both plywood-like organization and transparency might be of interest for biomedical applications in ophthalmology.

, two 6-coordinate b-hemes and a [2Fe-2S] cluster. Using excitation of these components in different ratios under various excitation conditions, probing in the full visible range and under three well-defined redox conditions, we demonstrate that for all ferrous hemes of the complex photodissociation of axial ligands takes place and that they rebind in 5-7 ps, as in other 6-coordinate heme proteins, including cytoglobin, which is included as a reference in this study. By contrast, the signals are not consistent with photooxidation of the b hemes. This conclusion contrasts with a recent assessment based on a more limited data set. The binding kinetics of internal and external ligands are indicative of a rigid heme environment, consistent with the electron transfer function. We also report, for the first time, photoactivity of the very weakly absorbing iron-sulfur center. This yields the unexpected perspective of studying photochemistry, initiated by excitation of iron-sulfur clusters, in a range of protein complexes.

Based on the first order upwind scheme, the paper establishes a set of horizontal 2-D uneven sed- iment mathematical model in dike burst. Several simulated results are given to introduce the applicability of the numerical model.

Carrying digital information in traditional copper wires is becoming a major issue in electronic circuits. Optical connections such as fiber optics offers unprecedented transfer capacity, but the mismatch between the optical wavelength and the transistors size drastically reduces the coupling efficiency. By merging the abilities of photonics and electronics, surface plasmon photonics, or 'plasmonics' exhibits strong potential. Here, we propose an original approach to fully understand the nature of surface electrons in plasmonic systems, by experimentally demonstrating that surface plasmons can be modeled as a phase of surface waves. First and second order phase transitions, associated with percolation transitions, have been experimentally observed in the building process of surface plasmons in lattice of subwavelength apertures. Percolation theory provides a unified framework for surface plasmons description.

Research has shown that modifying the aspect of the virtual hand in immersive virtual reality can convey objects properties to users. Whether we can achieve the same results in augmented reality is still to be determined since the user’s real hand is visible through the headset. Although displaying a virtual hand in augmented reality is usually not recommended, it could positively impact the user effectiveness or appreciation of the application.

Pelaksanaan praktik jual beli Benih Lobster yang terjadi pada saat ini diduga belum sesuai dengan Hukum positif. Pada praktik jual beli tersebut khususnya dalam ekspor, terdapat beberapa pihak yang merasa dirugikan, seperti halnya Nelayan, dan juga Negara Republik Indonesia sendiri, karena harga yang ditetapkan oleh penjual belum sesuai dengan apa yang telah ditetapkan oleh Undang-Undang. Dalam hukum positif sendiri dalam jual beli benih lobster ada aturan dan ketetapan jenis dan ukuran dalam jual beli lobster laut. Namun sangat disayangkan beberapa nelayan saat melakukan profesi mereka tidak memperhatikan efek kedepannya, yang dimana sebagian nelayan ada yang melakukan transaksi jual beli benih lobster tidak sesuai kebijakan yang telah dibuat. Ditakutkannya pula ini akan berdampak pada tingkat ekonomi khususnya dalam jual beli biota laut, terutama untuk hewan lobster. Dikarenakan, bewan tersebut menjadi incaran para nelayan sebab harganya yang jika dijual lumayan mahal dan rasanya sendiri bila dikonsumsi sungguh nikmat sehingga permintaan pasar akan hewan tersebut terus menerus tiada henti. Oleh sebab itu, pemerintah membuat kebijakan yang telah diatur dalam Peraturan Menteri Kelautan dan Perikanan Nomor 12 Tahun 2020 tentang Pengelolaan kepiting dan lobster di wilayah NKRI.

Interaction between metal surface waves and periodic geometry of subwavelength structures is at the core of the recent but crucial renewal of interest in plasmonics. One of the most intriguing points is the observation of abnormal strong transmission through these periodic structures, which can exceed by orders of magnitude the classical transmission given by the filling factor of the plate. The actual paradigm is that this abnormal transmission arises from the periodicity, and then that such high transmission should disappear in random geometries. Here, we show that extra energy can be coupled through the subwavelength structure by adding a controlled quantity of noise to the position of the apertures. This result can be modelled in the statistical framework of stochastic resonance. The evolution of the coupled energy with respect to noise gives access to the extra energy coupled at the surface of the subwavelength array.

Cells respond to biophysical and biochemical signals. We developed a composite filament from collagen and silica particles modified to interact with collagen and/or present a laminin epitope (IKVAV) crucial for cell-matrix adhesion and signal transduction. This combines scaffolding and signaling and shows that local tuning of collagen organization enhances cell differentiation.

This paper addresses a generalization of polyominoes called ( a , b )- connected discrete figures , where a and b represent the connectivity of the foreground ( i.e. black pixels ) and background ( i.e. white pixels ), respectively. Formally, a finite set of pixels P is ( a , b )-connected if P is a -connected and P is b -connected. By adapting a combinatorial structure enumeration algorithm by J. L. Martin and employing breadth-first search ordering on the pixels of the figures, we sequentially generate all ( a , b )-connected discrete figures up to size n = 18, utilizing minimal storage space. This paper presents an extended version of the research presented at the 2022 GASCom conference.

Abstract: The rise of Antimicrobial Resistance (AMR) necessitates fast and accurate computationalapproaches to predict resistance phenotypes directly from genomic data. While Whole-GenomeSequencing (WGS) coupled with Deep Learning (DL) models is the state-of-the-art paradigm, asystematic comparative evaluation of different genomic encoding and visualization methodsremains limited, particularly in the critical context of AMR prediction for Escherichia coli. Thisstudy systematically assesses four distinct genomic representation strategies: traditional K-mercounting with ensemble tree-based classifiers, reference-based SNP profiles with ensemble learning,One-Hot Encoding with a 1D-Convolutional Neural Network (1D-CNN), and Chaos GameRepresentation (CGR) with a 2D-Convolutional Neural Network (2D-CNN), for predictingresistance to ciprofloxacin, gentamicin, and ampicillin. The results reveal a consistent and superiordiscriminatory power of the alignment-free traditional Machine Learning approach based on Kmer frequency profiles (specifically 4-mers) when coupled with gradient boosting algorithms (suchas XGBoost and LightGBM), compared to both SNP-based Machine Learning and Deep Learningarchitectures. This performance advantage was most pronounced for gentamicin and ampicillin,where complex resistance mechanisms involving mobile genetic elements are captured moreeffectively by the K-mer approach. Crucially, the study benchmarks the limitations of DeepLearning: while the One-Hot 1D-CNN model exhibited a severe calibration failure characterized by an extremely low Recall for ampicillin (F1-Score of only 0.1132), the SNP-based Machine Learningmodels maintained robust performance on the same feature set, highlighting the architecturalefficiency of gradient boosting over CNNs for tabular genomic data. Statistical analysis confirmedthe significance of these differences, with K-mer ML significantly outperforming Deep Learningacross all antibiotics (p < 0.001 for Gentamicin and Ampicillin). The amino acid 4-mer XGBoostmodel achieved an AUC of 0.9917 (95% CI: 0.9827-0.9983) for Ciprofloxacin. The studyconcludes that, for current dataset sizes and complex resistance phenotypes, the denseinformation representation of K-mers offers a more accurate and robust solution, and identifies the4-mer XGBoost and Combined K-mer LightGBM configurations as the optimal modeling strategies.Keywords: Machine learning, Deep learning, Bioinformatics, Computational Biology,Antimicrobials, Bacteria, Escherichia coli, Applied microbiology.

The dosage resulted in a mortality of 25% was considered as zero level, from the base of co-toxicity factor evaluating joint action of two insecticides. Bioassay was arranged with quadratic regression rotation composite design method to study the combined synergism of cypermethrin and quinalphos on the 2nd-instar larvae of common cutworm, Spodoptera litura. The relationship between the death probability of target insect and the dosages of the insecticides was described by a quadratic polynomial. The mathematical relationship between co-toxicity coefficient (CTC) and the dosages of the insecticides (N1,.N2) was deduced from the calculating formula of CTC. i.e. CTC a,b represent the medium lethal concentrations of cypermethrin and quinalphos, respectively. So the formula, was taken as the goal function of optimization problem. Finally, the maximum CTC and optimal mixture ratio of cypermethrin and quinalphos were obtained with the program. NLP of SAS. These results were very consistent with the ones of Sun's (1960) method.

Correction for ‘Ultrafast photochemistry of the <italic>bc</italic>₁ complex’ by Marten H. Vos <italic>et al.</italic>, <italic>Phys. Chem. Chem. Phys.</italic>, 2017, <bold>19</bold>, 6807–6813.