Single Band Research Articles

Enhancing thermometric efficiency: a wavelength excitation analysis in LiSrGdW3O12:Tb3+ for superior single band ratiometric (SBR) thermometry.

This study delves into the Single Band Ratiometric (SBR) method for luminescence thermometry, specifically employing Tb3+-doped LiSrGdW3O12 (LSGW) as a novel phosphor. The prepared samples crystallize with the tetragonal scheelite structure, with the optimal Tb3+ concentration pinpointed at 0.3Tb3+ ions. When stimulated at diverse wavelengths exhibit luminescence characterized by varying heat dependencies. By utilizing two Fluorescence Intensity Ratio (FIR) parameters for the 544 nm green emission, firstly excited at 405 nm and 488 nm, and then at 405 nm and 379 nm, the Sr relative thermal sensitivity of the luminescent thermometer peaks at 3.56% K-1 and 4.21% K-1, respectively, within the temperature range of 290-440 K. The temperature resolution (δT) of the luminescent thermometer is calculated to be δT1 = 0.68 K and δT2 = 0.75 K for T = 290 K, respectively. These outcomes underscore the applicability of Tb3+ ions for SBR thermometry, emphasizing the impact of the excitation wavelength on the thermal sensitivity. The study lays the groundwork for developing highly sensitive temperature probes by elucidating the interplay of material properties and physical processes.

Identification and analgesic activity study of analgesic protein Ⅶ-2 from Naja naja atra venom.

Acid-sensing ion channel 1a (ASIC1a) plays a critical role in physiological and pathological processes. To further elucidate the biological functions of ASICs and their relationships with disease occurrence and development, it is advantageous to investigate and develop additional regulatory factors for ASICs. In this study, cation exchange chromatography was used to separate seven chromatographic components from Naja naja atra venom. Capillary electrophoresis was employed to detect that Ⅶ peak component containing a main protein Ⅶ-2, which could bind to ASIC1a. The analgesic effects of Ⅶ-2 protein were determined using hot plate methods, and ASIC1a expression in spinal cord tissue from rats with inflammatory pain was detected using western blot. The purified Ⅶ-2 protein named Naja naja atra venom-Ⅶ-2 (NNAV-Ⅶ-2) was obtained by Sephadex G-50 gel filtration, which exhibited a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with a molecular weight of 6.7 kD. Remarkably, the NNAV-Ⅶ-2 protein demonstrated a significant analgesic effect and downregulated ASIC1a expression in the spinal cord tissue of rats with inflammatory pain. The analgesic mechanism of the NNAV-Ⅶ-2 protein may be associated with its binding to ASIC1a, consequently downregulating ASIC1a expression in neural tissues.

基于高光谱成像和卷积神经网络的欧李果实缺陷检测

In order to perform highly effective identification of external defects and increase the additional value of Cerasus Humilis fruits, this study used hyperspectral imaging technology to collect information on intact and defective Cerasus Humilis fruits. Based on the full transition spectrum, partial least squares discriminant analysis (PLS-DA) and back propagation neural networks (BPNN) were used to establish a discriminative model. The competitive adaptive reweighted sampling (CARS) was used to extract feature wavelengths, principal component analysis was used for data compression of single band images, BPNN and convolutional neural networks (CNN) were used for defect Cerasus Humilis fruits recognition of principal component images. The results showed that the overall detection accuracy of PLS-DA and BPNN models based on wavelength spectral information were 83.81% and 85.71%, respectively. BPNN was used to establish the calibration model based on the selected characteristic wavelengths by CARS, the accuracy rate was 90.47%. The classified accuracy of CNN model based on principal component images was 93.33%, which was obviously better than that of BPNN model at 83.81%. The research shows that the CNN model was successfully applied to the detection of Cerasus Humilis fruits defects using hyperspectral imaging. This study provides a theoretical basis for the development of fruit grading and sorting equipment.

Arbitrary ratio power splitter based on shape optimization for dual-band operation

Arbitrary ratio power splitters (ARPSs) are essential components in integrated photonics. However, most existing ARPSs are limited to operating within a single wavelength band. To address this limitation, in this paper, we propose a 1 × 2 ARPS capable of operating in multi-wavelength bands using the shape optimization method. Harnessing a compact footprint of 14 μm × 1.7 μm, a series of dual-band ARPSs (DBARPSs) with varying power splitting ratios (PSRs) are designed. Within the wavelength ranges of 1280–1340 nm and 1520–1580 nm, all of the DBARPSs have an excess loss of less than 0.55 dB, with PSR deviations falling within the range of −0.5 dB to 1 dB. The practical viability is confirmed through a fabricated DBARPS with a 3 dB PSR. Experimental results show that the PSR deviation is within −0.8 dB to 1 dB, while the excess loss remains below 0.54 dB within the bandwidths of 1280–1340 nm and 1520–1580 nm. Additionally, the same design methodology is extended to develop a high-performance 1310/1550 nm wavelength demultiplexer. The resulting device showcases remarkable performance, with insertion loss below 0.7 dB and extinction ratios higher than 17 dB across the specified wavelength ranges. Experimental outcomes align closely with the design objectives, underscoring the dual-band operational capability and robust generality of the approach outlined in this paper.

GENERATION OF MONOCLONAL ANTIBODIES AGAINST TRICHINELLA SPIRALIS AND DETERMINATION OF THEIR IMMUNOCHEMICAL PROPERTIES

Diagnosis of trichinellosis in humans and animals is still in the developmental stage of the most effective and sensitive test for early detection. Serological methods are the most sensitive for detecting trichinella invasion. However, there is a high risk of non-specific reactions with other parasitological diseases. To address this issue, monoclonal antibodies (mAbs) against excretory-secretory antigens (ESAg) of trichinella muscle larvae are employed. In this study, hybridomas secreting mAbs against ES-Ag of Trichinella spiralis muscle larvae were generated. Out of 79 colonies, 5 mAb producer monoclonal clones (1D5, 1E7, 3C10, 4D6, 4F7) were obtained, and further stability testing selected 3 clones (1D5, 1E7, and 4F7) that yielded 14 to 40% active subclones. Western blotting using T. spiralis ES antigens demonstrated that the mAbs recognized a single band at 75 kDa. The productivity of the clones ranged from 2.0 to 4.0 mg/ml of protein. The obtained results indicate that the high activity, specificity of mAbs, and productivity of the clones recommend these mAbs for application in diagnostic purposes.

Kinetic studies and bioremediation potential of chromate reductase-characterized Aspergillus flavus from tannery effluent

Chromium is among the major environmental pollutants endangering the health of all living things, including humans. Conventional methods for chromium detoxification are expensive, so bioremediation using fungi as potential agents for the detoxification of chromium is justified. This study aims to investigate chromium-resistant fungi capable of reducing or transforming Cr (VI) to less toxic Cr (III) from tannery effluents. The fungi were isolated from tannery wastewater and identified using 16S rRNA gene sequencing. Chromate reductase was isolated from pure fungal isolate and purified using molecular weight estimation and gel filtration chromatography. Aspergillus flavus, in an interesting turn of events, demonstrated 97% chromate reduction. The chromate reductase from Aspergillus flavus has KM of 0.015 mM and a Vmax of 0.25 mol/min. Furthermore, the enzyme's activity was constant at its peak at pH 7.0 and 50 oC, with a single band displaying a molecular weight of 44 kDa for a pure protein. The data suggest that A. flavus can be a good candidate for the detoxification of Cr (VI) in industrial effluents. The efficiency of which can be attributed to the action of chromate reductase in the A. flavus.

Subthalamic and pallidal neurons are modulated during externally cued movements in Parkinson's disease

External sensory cues can reduce freezing of gait in people with Parkinson's disease (PD), yet the role of the basal ganglia in these movements is unclear. We used microelectrode recordings to examine modulations in single unit (SU) and oscillatory local field potentials (LFP) during auditory-cued rhythmic pedaling movements of the feet. We tested five blocks of increasing cue frequencies (1 Hz, 1.5 Hz, 2 Hz, 2.5 Hz, and 3 Hz) in 24 people with PD undergoing deep brain stimulation surgery of the subthalamic nucleus (STN) or globus pallidus internus (GPi). Single unit firing and beta band LFPs (13–30 Hz) in response to movement onsets or cue onsets were examined. We found that the timing accuracy of foot pedaling decreased with faster cue frequencies. Increasing cue frequencies also attenuated firing rates in both STN and GPi neurons. Peak beta power in the GPi and STN showed different responses to the task. GPi beta power showed persistent suppression with fast cues and phasic modulation with slow cues. STN beta power showed enhanced beta synchronization following movement. STN beta power also correlated with rate of pedaling. Overall, we showed task-related responses in the GPi and STN during auditory-cued movements with differential roles in sensory and motor control. The results suggest a role for both input and output basal ganglia nuclei in auditory rhythmic pacing of gait-like movements in PD.

Antifungal, Antimycobacterial, Protease and α‒Amylase Inhibitory Activities of a Novel Serine Bifunctional Protease Inhibitor from Adenanthera pavonina L. Seeds.

Antifungal resistance poses a significant challenge to disease management, necessitating the development of novel drugs. Antimicrobial peptides offer potential solutions. This study focused on extraction and characterization of peptides from Adenanthera pavonina seeds with activity against Candida species, Mycobacterium tuberculosis, proteases, and α-amylases. Peptides were extracted in phosphate buffer and heated at 90°C for 10 min to create a peptide rich heated fraction (PRHF). After confirming antimicrobial activity and the presence of peptides, the PRHF underwent ion exchange chromatography, yielding retained and non-retained fractions. These fractions were evaluated for antimicrobial activity and cytotoxicity against murine macrophages. The least toxic and most active fraction underwent reversed-phase chromatography, resulting in ten fractions. These fractions were tested for peptides and antimicrobial activity. The most active fraction was rechromatographed on a reversed-phase column, resulting in two fractions that were assessed for antimicrobial activity. The most active fraction revealed a single band of approximately 6 kDa and was tested for inhibitory effects on proteases and α-amylases. Thermal stability experiments were conducted on the 6 kDa peptide at different temperatures followed by reassessment of antifungal activity and circular dichroism. The 6 kDa peptide inhibited yeasts, M. tuberculosis, human salivary and Tenebrio molitor larvae intestine α-amylases, and proteolytic activity from fungal extracts, and thus named ApPI. Remarkably, ApPI retained antifungal activity and conformation after heating and is primarily composed of α-helices. ApPI is a thermally stable serine protease/α-amylase inhibitor from A. pavonina seeds, offering promise as a foundational molecule for innovative therapeutic agents against fungal infections and tuberculosis.

A greener RP-HPTLC-densitometry method for the quantification of apremilast in nanoformulations and commercial tablets: Greenness assessment by analytical eco-scale, ChlorTox, and AGREE methods

The greener “high-performance thin-layer chromatography (HPTLC)” methods for apremilast (APM) analysis in pharmaceutical products and biological fluids are not currently available in the literature. Accordingly, this study involves the development and validation of a rapid, simple, economical, and greener reversed-phase HPTLC methodology for the estimation of APM in prepared nanoparticles (NPs), nanoemulsion, and marketed tablets. The estimation of APM was conducted using “RP-18 silica gel 60 F254S HPTLC plates” as the stationary phase. The combination of ethanol/water (65:35, v/v) was used as the greener mobile phase for APM analysis. The greenness of the method was predicted using three different approaches, namely Analytical Eco-Score (AES), ChlorTox, and the Analytical GREENness (AGREE) approaches. The λmax = 238 nm was used for the APM detection. By contrasting its single band at Rf = 0.61 ± 0.01 with those of pure APM, the HPTLC peaks for APM in an prepared NP formulation, nanoemulsion, and marketed tablets were identified. In the concentration range of 100–700 ng/band, the proposed analytical methodology was linear. The values of AES, ChlorTox, and AGREE were determined to be 93, 0.66 g, and 0.89, respectively, demonstrated an outstanding greener profile for the existing method. The amount of APM in the tablet, NP formulation, and nanoemulsion was found to be 98.40, 101.60, and 99.37 %, respectively. According to the findings of validation tests and pharmaceutical analysis, the suggested analytical technique could be successfully applied for the routine examination of APM in marketed tablets and laboratory generated nanoformulations.

Strategies for the High Average zT in the Electron-Doped SnTe

We propose a new strategy to achieve a high average zT in electron-doped SnTe by applying the two-band (TB) and single parabolic band (SPB) models to the electronic transport properties of Sn0.97M0.03Te ( M = Ga , In, Bi, and Sb) reported in the literature. To achieve a high average zT at temperatures from 300 to 823 K, both zT at 300 and 823 K should be high with a steadily increasing zT over the temperatures. The p-type SnTe is known to have a light valence band and a heavy valence band that are approximately 0.40 eV apart. The Bi-doped SnTe exhibits one of the highest zT among all the other doped samples at 300 K (0.09) and the highest zT at 823 K (0.9), with a steadily increasing zT in between. The TB model confirms the presence of the resonant state at 300 K which is responsible for the high zT at 300 K. The B-factor, which is related to the theoretical maximum zT, calculated by the SPB model indicates a steady increase in zT with increasing temperature. The temperature-dependent B-factor of the Bi-doped SnTe suggests that the initial position of its Fermi level at 300 K calculated by the TB model may be responsible for the temperature coefficient of the B-factor, which determines the zT at 823 K. According to the SPB model, experimental zT of 0.9 of the Bi-doped SnTe can be further improved to 1.03 (14% improvement) at 823 K upon carrier concentration optimization. To achieve a high average zT in SnTe, electron doping with a dopant that forms a resonant state and placing the Fermi level at the light valence band in the vicinity of the heavy valence band maximum are both essential.

Quasi-one-dimensional carbon-based fractal lattices

Fractal systems are now considered alternative routes for engineering physical properties on the nanoscale. In particular, stable annular quantum corrals have been demonstrated in distinct synthesis procedures and can provide interesting localized and resonant states. We here present a theoretical description of effective fractal lattices, mainly composed of annular Koch geometries based on carbon atoms, and of more complex organic molecules described by triangular Sierpinski geometries. A single band tight-binding approach is considered to derive electronic and transport properties. Fractal molecular linear chains composed of fractal Koch quantum corrals are proposed, and their electronic transport is discussed based on the complexity of the neighboring hopping. The spatial charge distributions at different energies highlight the contribution of the composing metallic and carbons atoms in the quantum corral features, serving as a guide to new functionalization applications based on the symmetry and fractal peculiarities of the proposed nanostructured lattices.

Analytical quality by design‐based thin‐layer chromatography method development and validation for assay and content uniformity testing of the anti‐neoplastic drug Axitinib in tablet formulation

AbstractThe current study aims to develop and validate an analytical quality by design approach‐based high‐performance thin‐layer chromatographic (HPTLC) method for the analysis of Axitinib tablet samples. The chromatographic conditions in the TLC method were optimized using a three‐level full factorial design. The mobile phase composition and chamber saturation time served as the independent variables for optimization. The mobile phase used for TLC separation on pre‐coated aluminum plates with silica gel 60 F254 consisted of a mixture of ethyl acetate and isopropyl alcohol in a ratio of 9:1 (v/v). Axitinib was quantified at 330 nm using the densitometric method. Axitinib peak from tablet formulation was verified against the reference standard by comparing its single band at Rf 0.44 ± 0.02. Linearity was found to exist between 100 and 600 ng/band, with a correlation coefficient (r2) of 0.9978. The percentage recovery was obtained as 98.21%–99.05%. The system was validated by determining the parameters according to the guidelines of the International Council for Harmonization of Technical Conditions for Medical Products for Human Use. The proposed TLC method can be effectively applied to routine quality control of a pharmaceutical product.

Novel oil spill indices for sentinel-2 imagery: A case study of natural seepage in Qaruh Island, Kuwait

Oil spills are a paramount and immediate challenge affecting marine ecosystems globally. Effective and timely monitoring tools, such as oil detection indices, offer a swift means to track oil spill spread across vast oceanic expanses. Moreover, these indices enhance data clarity, making it more conducive for machine learning and deep learning algorithms.This study leverages the natural seepage occurring around Qaruh Island, Kuwait as a unique context for the spectral analysis of oil spills using Sentinel-2 multispectral imagery due to repeated occurrences in the same region. This research evaluated 859 single band and 455 multichannel combinations to identify the most effective combinations in oil-water separability, employing the Jeffries-Matusita (JM) distance measure as a key metric. Bands 1, 2, 3, 8A, 11, and 12 consistently featured among the top-performing indices combinations B1−B11B1+B11;B1+B2B3+B11;B1+B2B3+B12;B1+B2B3+B8A affirming the significant effect of oil spills on visible, Near-Infrared (NIR), and Shortwave Infrared (SWIR) bands. Notably, the indices developed in this study outperformed those from prior research in terms of suitability to unsupervised classification algorithms. A significant conclusion of this study is that incorporating a higher number of bands in the analysis did not correlate with an increase in JM values, suggesting that the selection of specific, informative bands is more critical than the volume of input data. These findings underscore the indispensable role of Sentinel-2 imagery in environmental investigations and highlight the potential for focused, efficient analysis using strategic band combinations for effective oil spill detection.•This study identified optimized Sentinel-2 band combinations for oil-water separability, benefiting from naturally occurring spills around Qaruh Island.•The proposed indices outperformed the previous indices for oil spill visualization and clustering.•The new indices highlighted the critical role of specific band selection over the volume of input data for effective oil spill detection.

Achieving high quality factor and enhanced thermoelectric performance in polycrystalline SnS by Ag doping and Se alloying

The polycrystalline SnS with a similar layered crystal structure and band structure to SnSe exhibits enormous commercial thermoelectric potential due to its lower cost and environmentally friendly characteristics. However, the wider bandgap of SnS leads to low carrier concentration and inferior electrical transport performance. The two-dimensional interlayer hinders carrier transport, leading to interesting and mysterious anisotropic thermoelectric properties. Herein, we reported the optimized electron–phonon transport in anisotropic polycrystalline SnS by Ag doping and Se alloying, realizing a high quality factor B by multiple strategies of optimizing carrier concentration, modifying band structure, and introducing various defects; further potential performance is predicted by the single parabolic band model. Specifically, Ag-doped SnS not only significantly increases the carrier concentration and weighted mobility μw in both directions but also induces multi-scale precipitates proven by the Debye–Callaway model to suppress phonon transport. Moreover, additional Se alloying optimizes the electronic band structure and increases the Seebeck coefficient, further improving μW and boosting the maximum power factor to ∼3.72 μW cm−1 K−2 at 873 K in the out-of-plane direction. Consequently, the synergistic optimization of carrier and phonon transport achieved a high B of 0.7 and a maximum zTmax of ∼0.8 at 873 K in Ag0.02Sn0.98S0.99Se0.01. Additionally, the high B predicted a high zTmax∼1.5 based on optimized carrier transport characteristics, demonstrating the potential great-performance polycrystalline SnS. This work provides a promising avenue for optimizing the zT of polycrystalline SnS by transport engineering.

Influence of composition on luminescence properties of Cd1-xZnxWO4 solid solutions

A set of single-phase Cd1-xZnxWO4 (x = 0–1) solid solutions synthesized by spontaneous crystallization technique was studied by the methods of luminescence and electron paramagnetic resonance (EPR) spectroscopy. Luminescence spectra of all studied solutions are characterised by a single emission band related to the intrinsic emission of self-trapped excitons. The dependence of luminescence spectra and thermostimulated luminescence (TSL) curves on solution composition was investigated, and the origin of TSL peaks was analysed on the basis of the EPR data. It is shown that the values of optical bandgap and activation energy of luminescence thermal quenching gradually change with solution composition. Several phenomena are observed in solid solutions predominantly at intermediate concentrations of Cd and Zn cations that can be connected with the structural disorder of the solid solutions. In particular, the deviation of lattice parameters from the Vegard's law, the redshift and broadening of the emission band, the suppression of low-temperature (T < 80 K) TSL peaks related to self-trapped holes and the broadening of high-temperature (100–200 K) TSL peaks related to structural defects. The structural disorder arises due to the non-homogeneous distribution of substitutional atoms in cation lattice sites, pronounced because of the mismatch in ionic radii of substitutional cations, which reaches 28.3 % for Cd2+ and Zn2+.

Fluorescence quenching of fluorescein dye using silver nanoparticles

Fluorescence quenching is indeed a versatile and widely used technique in various scientific disciplines, including chemistry, biology, and medicine. It provides valuable information about the behaviour of small molecules in organized systems and offers insights into the properties of the microenvironments surrounding the fluorescent probe and quencher molecules. In the present work, we report the synthesis of citrate-stabilized silver nanoparticles and also investigate the effect of the prepared silver nanoparticles on the fluorescence luminous intensity of fluorescein dye with different concentrations of silver nanoparticles. The UV–visible spectrometer is used to study the absorption properties of silver nanoparticles. We have obtained a single surface plasmon resonance band, which indicates the isotropic nature of particles. The particle size was obtained from the absorption spectra, using the Mie scattering theory. The luminous intensity of fluorescein dye was found to be quenched in addition to silver nanoparticles. The morphological analysis is done using SEM.

Detecting active latitudes of Sun-like stars using asteroseismic a-coefficients

Aims. We introduce a framework to measure the asphericity of Sun-like stars using a1, a2, and a4 coefficients and constrain their latitudes of magnetic activity. Methods. We evaluated systematic errors on the inferred coefficients in function of key physical and seismic parameters (inclination of rotation axis, average rotation, height-to-noise ratio of peaks in power spectrum). The measured a-coefficients account for rotational oblateness and the effect of surface magnetic activity. We used a simple model that assumes a single latitudinal band of activity. Results. Using solar SOHO, VIRGO, and SPM data, we demonstrate the capability of the method to detect the mean active latitude and its intensity changes between 1999 and 2002 (maximum of activity) and 2006 and 2009 (minimum of activity). We further applied the method to study the solar-analogue stars 16 Cyg A and B using Kepler observations. In 16 Cyg A, we detected an equatorial band of activity exhibiting an intensity that could be comparable to that of the Sun. However, 16 Cyg B exhibits a bimodality in a4 that is challenging to explain. We suggest that this could be a manifestation of the transition between a quiet and an active phase of activity. Validating or invalidating this hypothesis may require new observations.

AutoSourceID-Classifier

Aims.Traditional star-galaxy classification techniques often rely on feature estimation from catalogs, a process susceptible to introducing inaccuracies, thereby potentially jeopardizing the classification’s reliability. Certain galaxies, especially those not manifesting as extended sources, can be misclassified when their shape parameters and flux solely drive the inference. We aim to create a robust and accurate classification network for identifying stars and galaxies directly from astronomical images.Methods.The AutoSourceID-Classifier (ASID-C) algorithm developed for this work uses 32x32 pixel single filter band source cutouts generated by the previously developed AutoSourceID-Light (ASID-L) code. By leveraging convolutional neural networks (CNN) and additional information about the source position within the full-field image, ASID-C aims to accurately classify all stars and galaxies within a survey. Subsequently, we employed a modified Platt scaling calibration for the output of the CNN, ensuring that the derived probabilities were effectively calibrated, delivering precise and reliable results.Results.We show that ASID-C, trained on MeerLICHT telescope images and using the Dark Energy Camera Legacy Survey (DECaLS) morphological classification, is a robust classifier and outperforms similar codes such as SourceExtractor. To facilitate a rigorous comparison, we also trained an eXtreme Gradient Boosting (XGBoost) model on tabular features extracted by SourceExtractor. While this XGBoost model approaches ASID-C in performance metrics, it does not offer the computational efficiency and reduced error propagation inherent in ASID-C’s direct image-based classification approach. ASID-C excels in low signal-to-noise ratio and crowded scenarios, potentially aiding in transient host identification and advancing deep-sky astronomy.

Klasifikasi Spesies Mangrove Menggunakan Drone di Nusa Lembongan, Bali

Mapping of mangroves using remote sensing technology has been widely carried out, especially in coastal areas of Indonesia. The most used remote sensing technology is satellite imagery. However, there are still some weaknesses in the use of satellite imagery for mapping mangrove, especially at the species level, including taking a long time, high costs, and low spatial resolution. One of the breakthroughs in remote sensing is drone. Drones have advantages, namely time flexibility, relatively low cost, and high spatial resolution. The purpose of this study was to determine the ability to use drones in mapping mangrove up to the species level and distribution of mangrove species in Nusa Lembongan. The method used is classification of GEOBIA (Geographic Object Based Image Analysis). Drone images were obtained with four flight missions in the northern and eastern areas of the Nusa Lembongan mangrove forest. Field data collection was carried out using a systematic random sampling method and high-resolution single band drones. The results showed that drone observations were able to identify two mangrove species in the northern research area and four mangrove species in the eastern Nusa Lembongan research area. In the northern area there are mangrove species Rhizophora apiculata and Bruguiera gymnorrhiza. In the eastern region, mangrove species Rhizophora apiculata, Avicennia alba, Sonneratia alba, and Avicennia lanata were found. The accuracy test in both research areas in the northern and eastern areas of Nusa Lembogan obtained an overall value with an average of 65% and a kappa coefficient of 0.56.

Online multimethod platform for comprehensive characterization of monoclonal antibodies in cell culture fluid from a single sample injection - Intact protein workflow

BackgroundTherapeutic monoclonal antibodies (mAbs) comprise a large structural variability with respect to charge, size and post-translational modifications. These critical quality attributes (CQAs) need to be assessed during and after the production of mAbs. This normally requires off-line purification and sample preparation as well as several chromatographic selectivities, which makes the whole process time-consuming and error-prone. To improve on this, we developed an integrated and automated multi-dimensional analytical platform for the simultaneous assessment of multiple CQAs of mAbs in cell culture fluid (CCF) from upstream processes. ResultsThe on-line system allows mAb characterization at the intact level, combining protein A affinity chromatography (ProtA) with size-exclusion, ion-exchange, and reversed-phase liquid chromatographic modes with UV and mass spectrometric detection. Multiple heart cuts of a single mAb elution band from ProtA are stored in 20-μL loops and successively sent to the multimethod options in the second dimension. ProtA loading and elution conditions and their compatibility with second-dimension LC modes were studied and optimized. Subsequently, heart-cutting and valve-switching schemes were investigated to achieve effective and reproducible analyses. The applicability of the developed workflow was demonstrated by the direct analysis (i.e. not requiring off-line sample preparation) of a therapeutic mAb in CCF, obtaining useful information on accurate molecular mass, glycosylation, and charge and size variants of the mAb product at the same time and in just over 1 h. SignificanceThe developed multidimensional platform is the first system that allows for multiple fractions from a single ProtA band to be characterized using different chromatographic selectivities in a single run allowing direct correlation between CQAs. The performance of the system is comparable to established off-line methods, fully compatible with upstream process samples, and provides a significant time-reduction of the characterization procedure.