Explore the vast range of titles available.

Protein crystallization as opposed to well-established chromatography processes has the benefits to reduce production costs while reaching a comparable high purity. However, monitoring crystallization processes remains a challenge as the produced crystals may interfere with analytical measurements. Especially for capturing proteins from complex feedstock containing various impurities, establishing reliable process analytical technology (PAT) to monitor protein crystallization processes can be complicated. In heterogeneous mixtures, important product characteristics can be found by multivariate analysis and chemometrics, thus contributing to the development of a thorough process understanding. In this project, an analytical set-up is established combining offline analytics, on-line ultraviolet visible light (UV/Vis) spectroscopy, and in-line Raman spectroscopy to monitor a stirred-batch crystallization process with multiple phases and species being present. As an example process, the enzyme Lactobacillus kefir alcohol dehydrogenase (L k ADH) was crystallized from clarified Escherichia coli ( E. coli ) lysate on a 300 mL scale in five distinct experiments, with the experimental conditions changing in terms of the initial lysate solution preparation method and precipitant concentration. Since UV/Vis spectroscopy is sensitive to particles, a cross-flow filtration (cross-flow filtration)-based bypass enabled the on-line analysis of the liquid phase providing information on the lysate composition regarding the nucleic acid to protein ratio. A principal component analysis (PCA) of in situ Raman spectra supported the identification of spectra and wavenumber ranges associated with productspecific information and revealed that the experiments followed a comparable, spectral trend when crystals were present. Based on preprocessed Raman spectra, a partial least squares (PLS) regression model was optimized to monitor the target molecule concentration in real-time. The off-line sample analysis provided information on the crystal number and crystal geometry by automated image analysis as well as the concentration of Lk ADH and host cell proteins (HCPs) In spite of a complex lysate suspension containing scattering crystals and various impurities, it was possible to monitor the target molecule concentration in a heterogeneous, multi-phase process using spectroscopic methods. With the presented analytical set-up of off-line, particle-sensitive on-line, and in-line analyzers, a crystallization capture process can be characterized better in terms of the geometry, yield, and purity of the crystals.

To solve environmental-related issues (wastewater remediation, energy conservation and air purification) caused by rapid urbanization and industrialization, synthesis of novel and modified nanostructured photocatalyst has received increasing attention in recent years. We herein report the facile synthesis of in situ nitrogen-doped chemically anchored TiO 2 with graphene through sol–gel method. The structural analysis using X-ray diffraction showed that the crystalline nitrogen-doped graphene-titanium dioxide (N-GT) nanocomposite is mainly composed of anatase with minor brookite phase. Raman spectroscopy revealed the graphene characteristic band presence at low intensity level in addition to the main bands of anatase TiO 2 . X-ray photoelectron spectroscopy analysis disclosed the chemical bonding of TiO 2 with graphene via Ti–O-C linkage, also the substitution of nitrogen dopant in both TiO 2 lattice and into the skeleton of graphene nanoflakes. UV–Vis absorption spectroscopy analysis established that the modified material can efficiently absorb the longer wavelength range photons due to its narrowed band gap. The N 0.06 -GT material showed the highest degradation efficiency over methylene blue (MB, ∼98%) under UV and sulfamethoxazole (SMX, ∼ 90.0%) under visible light irradiation. The increased activity of the composite is credited to the synergistic effect of high surface area via greater adsorption capacity, narrowed band gap via increased photon absorption, and reduced e − /h + recombination via good electron acceptability of graphene nanoflakes and defect sites (Ti 3+ and oxygen vacancy (V o )). The ROS experiments further depict that primarily hydroxyl radicals (OH • ) and superoxide anions (O 2 •− ) are responsible for the pollutant degradation in the process redox reactions. In summary, our findings specify new insight into the fabrication of this new material whose efficiency can be further tested in applications like H 2 production, CO 2 conversion to value-added products, and in energy conservation and storage.

Eight edible and non-edible oils have been characterized using UV–Vis absorption and transmission, FTIR, and Raman spectroscopy. Oils’ molecular structure, characteristics, and type of bonds have been analyzed separately. Black seed oil and Olive oil have the maximum number of absorbance peaks in the UV–Vis range. There are absorbance peak positions in the range of 250 to 350 nm within all samples. Moreover, FTIR vibrational modes related to molecular structures have been characterized. Also, hierarchical agglomerative clustering was done using the Euclidean metric and the Ward linkage method. Cluster dendrogram trees were drawn based on the UV–Vis transmission and FTIR spectral data, which show four clusters for these eight types of oils. There are two distinct regions in the Raman spectra of edible oils. The first region is 1000–1800 cm −1 as the fingerprint region. The second one is about 2500 to 4200 cm −1 . Clustering of Raman spectral data shows two main clusters: edible vegetable and non-edible oils. Also, the first cluster has two distinctive sub-clusters, including cooking oils and medical skin care oils. It shows that the Raman spectra can effectively separate the oils in this clustering method. It means that the molecular structure, transparency, colors, densities, chemical bonding, and other features of oils can be classified by this clustering method. Therefore, spectroscopic data clustering can use for more accurate oil diagnosis and oil classification. In conclusion, the hierarchical agglomerative clustering can be used effectively as a complementary method alongside UV–Vis, FTIR, and Raman spectroscopy.

Nanotechnology can offer a series of new “green” and eco-friendly methods for developing different types of nanoparticles, among which the development of nanomaterials using plant extracts (phytosynthesis) represents one of the most promising areas of research. This present study details the use of lavender flowers (Lavandula angustifolia Mill., well-known for their use in homeopathic applications) for the biosynthesis of silver nanoparticles with enhanced antioxidant and antibacterial properties. Several qualitative and quantitative assays were carried out in order to offer an image of the extracts’ composition (the recorded total phenolics content varied between 21.0 to 40.9 mg GAE (gallic acid equivalents)/g dry weight (d.w.), while the total flavonoids content ranged between 3.57 and 16.8 mg CE (catechin equivalents)/g d.w.), alongside modern analytical methods (such as gas chromatography-mass spectrometry—GC-MS, quantifying 12 phytoconstituents present in the extracts). The formation of silver nanoparticles (AgNPs) using lavender extract was studied by UV-Vis spectroscopy, Fourier-transform infrared spectrometry (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and dynamic light scattering (DLS)/zeta potential, with the selected nanoparticles having crystallite sizes of approx. 14.55 nm (AgNP-L2) and 4.61 nm, respectively (for AgNP-L4), and hydrodynamic diameters of 392.4 nm (for AgNP-L2) and 391.6 nm (for AgNP-L4), determined by DLS. A zeta potential of around −6.4 mV was displayed for both samples while presenting as large aggregates, in which nanoparticle clusters with dimensions of around 130–200 nm can be observed. The biomedical applications of the extracts and the corresponding phytosynthesized nanoparticles were evaluated using antioxidant and antimicrobial assays. The obtained results confirmed the phytosynthesis of the silver nanoparticles using Lavandula angustifolia Mill. extracts, as well as their antioxidant and antimicrobial potential.