New Approach For Characterization Research Articles

PET Imaging for Monitoring Cellular and Immunotherapy of Cancer.

Cancer immunotherapy, including checkpoint blockade and cellular therapy, has become a cornerstone in cancer treatment. However, understanding the factors driving patient response or resistance to these therapies remains challenging. The dynamic interplay between the immune system and tumors requires new approaches for characterization. Biopsies and blood tests provide valuable information, but their limitations have led to increased interest in positron emission tomography (PET)/computed tomography imaging to complement these strategies. The noninvasive nature of PET imaging makes it ideal for monitoring the dynamic tumor immune microenvironment. This review discusses various PET imaging approaches, including immune cell lineage markers, immune functional markers, immune cell metabolism, direct cell labeling, and reporter genes, highlighting their potential in targeted immunotherapies and cell-based approaches. Although PET imaging has limitations, its integration into diagnostic strategies holds promise for improving patient outcomes and accelerating drug development in cancer immunotherapy.

Synthetic Chemistry and Microelectrode Arrays: Building Stable Platforms for Point of Care Diagnostics

Molecular diagnostics typically require three main components. A molecular interaction that identifies a specific target, a device that detects, quantifies, and records that interaction, and an interface between the two. The interface is critical because it provides a means to fix molecular recognition elements to the surface of the device. For a "point-of-care" application, the interface must be stable both in terms of chemistry and time while still allowing the signal from the molecular interaction to be sensed and recorded by the device. For the use of a microelectrode array as the detection device, construction of the interface must also allow for individual molecular recognition elements to be placed by individual, addressable electrodes in the array.Because of the need for stability and synthetic flexibility, we made the choice to move away from the use of self-assembled monolayers as the interface for developing microelectrode arrays as point-of-care devices. To that end, we have employed diblock copolymers to coat the surface of microelectrode arrays, a change that has offered increased stability of the surface and enabled the use of a broad array of synthetic methods for functionalizing the electrodes in the array. In this talk, we show how the use of a diblock copolymer in conjunction with Cu(I)- and Cu(II)-mediated reactions can be used to functionalize a microelectrode array with multiple DNA-aptamers for the multiplex detection of metabolites. The resulting surface is stable for over 30 weeks (and counting), allows for the detection of multiple metabolites in the same experiment, and retains the detection sensitivity obtained with a self-assembled monolayer.One of the goals of the talk will also be to illustrate for the synthetic community the role that it can play in developing new tools for molecular diagnostics. After all, it is the surface on a microelectrode array that in the long-run defines what an array can be used for and the quality of the resulting analytical experiments. The construction of those surfaces is a synthetic chemistry challenge that moving forward will require both new synthetic methods and new approaches for characterization of the products generated from the new methods. One approach for characterization will be discussed in the context of the Cu(I)- and Cu(II)-mediated reactions employed in the current study.

A new approach for characterization of meteorological and hydrological droughts: Cumulative standardized drought index (CSDI)

Identifying drought events and their characteristics for a river watershed that provides drinking water for metropolitan centers is crucial to sustaining water resources management. In this study, Cumulative Standardized Drought Index (CSDI) is developed to examine the effect of previous dry or wet periods on the characteristics of the drought event. Meteorological and hydrological droughts of the Gordes and Tahtali watersheds, which provide a significant part of the drinking water of Izmir, Turkey, determined for 1, 3, 6 and 12 month time scale by CSDI. The peak turning points of CSDI according to time show the transition from wet to dry period, whereas the lowest turning points do the transition from dry to wet period. Cumulative sum (CUSUM), Pettitt and means square error (MSE) analyzes are used to determine whether the turning points are significant turning point. As a result of the study, the characteristics of dry events, duration, magnitude and intensity, are determined with CSDI, especially those occurring at short time scales such as 1 and 3 months. In addition, the characteristics of meteorological and hydrological droughts observed at 12 month time scale are determined with the CSDI method and the Run Theory and comparisons were made in the study. As a result of the comparison, it is found that drought events, which seem to be different drought periods, indicate a single period when the effect of the past periods is considered. It is shown that the CSDI method can be used adequately to determine the dry and wet periods and their characteristics of the watersheds.

Rapid diagnosis of malignant pleural mesothelioma and its discrimination from lung cancer and benign exudative effusions using blood serum

Malignant pleural mesothelioma (MPM), an aggressive cancer associated with exposure to fibrous minerals, can only be diagnosed in the advanced stage because its early symptoms are also connected with other respiratory diseases. Hence, understanding the molecular mechanism and the discrimination of MPM from other lung diseases at an early stage is important to apply effective treatment strategies and for the increase in survival rate. This study aims to develop a new approach for characterization and diagnosis of MPM among lung diseases from serum by Fourier transform infrared spectroscopy (FTIR) coupled with multivariate analysis. The detailed spectral characterization studies indicated the changes in lipid biosynthesis and nucleic acids levels in the malignant serum samples. Furthermore, the results showed that healthy, benign exudative effusion, lung cancer, and MPM groups were successfully separated from each other by applying principal component analysis (PCA), support vector machine (SVM), and especially linear discriminant analysis (LDA) to infrared spectra.

New Approach for Characterization and Mitigation of the Swelling Phenomenon

This article first introduces a new method of characterization of expansive clays after oedometer test results performed on intact saturated clay specimens. On the presumed expansive clays specimens, oedometer tests are preceded by the free swelling test from which the swelling pressure is measured. From current oedometer test results carried out on expansive and non-expansive clays, the ratio of compression index (Cc) by the swelling index (Cs) was determined. A threshold value of the ratio Cc/Cs was identified to distinguish between expansive clay specimens and non-expansive clay specimens. Second, a novel mitigation method of the swelling phenomena was validated by performing oedometer tests on expansive clay specimens preceding the measurement of swelling pressure. Oedometer tests performed on a 53% thickness clay specimen overlaid by a 47% thickness of sand showed a significant reduction of the swelling pressure compared to that measured on a full expansive clay specimen. The mitigation solution reduced the swelling effect by placing a compacted granular layer as an interface between the expansive clay and the foundation. This solution has been adopted and approved in forthcoming a lightweight building construction at the Faculty of Sciences of Tunis City.

Predictive potential of ACE phenotyping in extrapulmonary sarcoidosis

Elevated ACE expression in tissues (reflected by blood ACE levels) is associated with increased risk of cardiovascular diseases and is also a marker for granulomatous diseases. We developed a new approach for characterization of ACE status in the blood—ACE phenotyping and established normal values of ACE levels 50–150% of control pooled plasma. ACE phenotyping was performed in citrated plasma of 120 patients with known interstitial lung diseases. In the 1st set of 100 patients we found 22 patients with ACE levels > 150%; ACE phenotyping also objectively identified the presence of ACE inhibitors in the plasma of 15 patients. After excluding these patients and patient with ACE mutation that increases ACE shedding, 17 patients were identified as a suspicious for systemic sarcoidosis based on elevation of blood ACE (> 150% of mean). A new parameter that we have established–ACE immunoreactivity (with mAb 9B9)—allowed us to detect 22 patients with decreased values (< 80%) of this parameter, which may indicate the presence of ACE in the blood that originates from macrophages/dendritic cells of granulomas. In the remaining 20 patients, this new parameter (mAbs binding/activity ratio) was calculated using 3 mAbs (9B9, 3A5 and i1A8—having overlapping epitopes), and 8 patients were identified as having decreases in this parameter, thus increasing dramatically the sensitivity for detection of patients with systemic sarcoidosis. Whole body PET scan confirmed extrapulmonary granulomas in some patients with lower immunoreactivity towards anti-ACE mAbs. ACE phenotyping has novel potential to noninvasively detect patients with systemic sarcoidosis.

A new approach for characterization of phosphatidylcholines and lysophosphatidylcholine in human plasma.

Aim: Characterization of phosphatidylcholines (PCs) and lysophosphatidylcholine in human plasma using LC-IT-MSn. The characterization approach was based on trapping the eluted positive ions and applying low voltage for fragmentation to MS2 and further fragmentation of the most abundant two peaks to obtain MS3. This approach allowed linking the MS3 data to MS2 and precursor ion. Methodology: The fatty acid part, at sn-1 and sn-2 of the glycerol backbone, could be identified based on the favored cleavage pathway. Conclusion: The dysregulated PCs and lysophosphatidylcholines in human plasma obtained from acute coronary syndrome cases, and Type 2diabetes patients suffering no coronary syndromes were estimated and matched versus healthy volunteers. An epoxide form of 16:0-18:2 PC was confirmed, m/z 774.6.

Quantitative Visual Characterization of Contaminant Metals and Their Mobility in Fluid Catalytic Cracking Catalysts

A new approach for characterization of fluid catalytic cracking (FCC) catalysts is proposed. This approach is based on computational visual analyses of images originating from field emission scanning electron microscopy (FE-SEM) studies coupled with elemental mapping via electron dispersive x-ray spectroscopy (EDX) analyses. The concept of contaminant metal mobility is defined and systematically studied through quantification of interparticle transfer and intraparticle penetration of the most common FCC contaminant metals (nickel, vanadium, iron, and calcium). This novel methodology was employed for practical quantification of intraparticle mobility via the Peripheral Deposition Index (PDI). For analyzing and quantifying interparticle mobility, a new index was developed and coined “Interparticle Mobility Index” or IMI. With the development and practical application of these two indices, this study offers the first standardized methodology for quantification of metals mobility in FCC. This novel systematic approach for analyzing metals mobility allows for improved troubleshooting of refinery-specific case studies and for more effective research and development in contaminant metals passivation in FCC catalysts.

A new approach for characterization and prediction of natural fracture occurrence in tight oil sandstones with intense anisotropy

Natural fractures provide the main path for fluid flow in tight oil reservoirs and can control the flow direction in the subsurface. Tight sandstones commonly have intense mechanical anisotropy, which means that fracture development in such tight formations may vary widely with respect to fracture orientations. However, the prediction of the degree of fracture development for each orientation is challenging. Focusing on the tight sandstones of the Chang 4 and 5 Member in the Jiyuan oil field, Ordos Basin, China, a new approach was presented for better prediction of the tectonic fracture occurrence in different directions based on fracture characterization, controlling factor, and formation mechanism analysis. First, fracture types, characteristics, formation time, and controlling factors were determined using data from outcrops, cores, and image logs. Then, triaxial tests were conducted to measure the mechanical parameters of rock samples in different directions that assessed the mechanical anisotropy of the formation and its impact on the development of fracture networks in the basin. Next, finite element numerical simulations of the paleotectonic stress field during fracturing were performed based on the fracture formation mechanism and controlling factors (lithology, bed thickness, sedimentary microfacies, and rock anisotropy). Finally, according to the failure criteria established using the measured mechanical parameters, the failure ratio and strain energy were calculated. These criteria could be employed to predict the fracture occurrence and the degree of development of each fracture network. The simulation predictions in this work are in good agreement with observed data from outcrops, cores, and image logs.

Nonlinear characterization of silica and chalcogenide microresonators

Microresonators offer an attractive combination of high quality factors and small optical mode volume. They have emerged as a unique platform for the study of fundamental physics and for applications ranging from exquisite sensors to miniature optical combs. Characterizing the linear and nonlinear properties of a microresonator is the first step toward new applications. Here, we present a novel in situ method to measure the nonlinear refractive index and absorption coefficient in microresonators. Laser-scanned transmission spectra are fitted by a comprehensive theoretical model that includes the thermo-optic effect, Kerr effect, and back-coupling of counter-propagating modes. The effectiveness of our technique is demonstrated by evaluating the nonlinear indices and optical absorption of silica and chalcogenide (As2S3) microspheres at 1.55 μm. Significantly, our method also quantifies important parameters including the quality factor, thermal relaxation time, and back-coupling coefficient at the same time. Our findings provide a powerful new approach for characterization of microresonators and optical materials and pave the way for new opportunities in the area.

A new approach for characterization of hydrophobization mechanisms of surfactants on muscovite surface

A new approach ‘dynamic contact angle analysis’ has been used in the present investigation to characterize the hydrophobization mechanisms of single and mixed surfactants on muscovite surface. The hydrophobization of muscovite surface was achieved by anionic NaOL (sodium oleate), cationic DDA (dodecylamine) and combined DDA/NaOL surfactants. Besides dynamic contact angle analysis, AFM and flotation tests were carried out to gain detail information about the wettability of muscovite, adhesion ability of bubbles towards muscovite surface and adsorption of single and mixed DDA/NaOL surfactants on the muscovite surface. From flotation results, the highest recovery (>90%) was obtained by the mixed DDA/NaOL when they were used at a ratio of 1:3 and the concentration of 2 × 10−4 mol/L. The dynamic contact angle tests showed that the angles achieved by DDA/NaOL were bigger and the bubbles were adhered more easily, which are in agreement with the flotation results. AFM imaging indicated that, as compared to single collectors, the combined surfactants adsorbed uniformly on the muscovite surface as bulks and formed a tight adsorption multilayer. The attraction in mixed DDA/NaOL was stronger than that in single DDA with the same jump-in distance at around 15 nm and the long-range repulsion was observed in single NaOL.

Adaptive Façade: Concept, Applications, Research Questions

Adaptive building envelopes can provide improvements in the building energy efficiency and economics, through their capability to change their behaviour in real time according to indoor-outdoor parameters, by means of materials, components and systems. Therefore, adaptive façades can make a significant and viable contribution to meeting the EU's 2020 targets. Several different types of adaptive façade concepts have already been developed, and an increase in emerging, innovative solutions is expected for the near future. The objective of this paper is to contribute to these developments by presenting the findings of an analysis of the existing concepts and case studies and by proposing a new approach for characterization of these elements.

New approach for characterisation of mechanical properties of cement paste at micrometre scale

In this study, a new approach for characterisation of the mechanical behaviours of cement paste at micrometre scale is developed. The new approach includes fabrication of the specimens using focused ion beam milling and loading of the specimens using atomic force microscopy. We demonstrate that the new approach provides an effective method for measuring the mechanical properties of cement-based materials at micrometre scale with sufficient accuracy.

Development of Power Electronics Based Test Platform for Characterization and Testing of Magnetocaloric Materials

Magnetocaloric effects of various materials are getting more and more interesting for the future, as they can significantly contribute towards improving the efficiency of many energy intensive applications such as refrigeration, heating, and air conditioning. Accurate characterization of magnetocaloric effects, exhibited by various materials, is an important process for further studies and development of the suitable magnetocaloric heating and cooling solutions. The conventional test facilities have plenty of limitations, as they focus only on the thermodynamic side and use magnetic machines with moving bed of magnetocaloric material or magnet. In this work an entirely new approach for characterization of the magnetocaloric materials is presented, with the main focus on a flexible and efficient power electronic based excitation and a completely static test platform. It can generate a periodically varying magnetic field using superposition of an ac and a dc magnetic field. The scale down prototype uses a customized single phase H-bridge inverter with essential protections and an electromagnet load as actuator. The preliminary simulation and experimental results show good agreement and support the usage of the power electronic test platform for characterizing magnetocaloric materials.

Dispersion analysis of spreadable processed cheese with low content of emulsifying salts by photocentrifugation

SummaryPhotocentrifugation at 1200 g and 60 °C was used to monitor emulsion stability of spreadable processed cheese (PC) with a low content (0.7 and 1.0 g 100 g−1) of typical emulsifying salts (ES) after different manufacturing conditions. This method of dispersion analysis has been used more frequently for nonfood materials rather than for foodstuffs. The PC contained 36.5 g 100 g−1 dry matter, 40 g 100 g−1 fat in dry matter and was manufactured in a laboratory cooker at 82 or 92 °C and 1000–3000 rpm cutter speed for 5–19 min. Insufficient fat emulsification and a heterogeneous casein matrix of a PC with 0.7% was well illustrated by photocentrifugation. At 1 g 100 g−1 ES and 3000 rpm cutter speed, the effect of manufacturing time on the behaviour of the colloidal dispersion was demonstrated by the different evolutions of the corresponding transmission profiles. Sedimentation velocities were measured at a level of 20% transmission. These results showed that dispersion analysis of spreadable PC by photocentrifugation at 60 °C is a sensitive method and applicable as a new approach for characterisation of emulsion stability resulting from physicochemical changes during manufacture.

Watching Gene Regulation by Small RNA in Bacteria with Super-Resolution Imaging

Small RNAs play important roles in regulating gene expression. Here we describe a new approach for characterization and quantification of small regulatory RNAs as well as targeting mRNA at single-cell level by combining single-molecule in situ hybridization and super-resolution imaging. We apply this approach to investigate a stress-induced bacterial small RNA, which is the central regulatory effector of the glucose-phosphate stress response. The quantitative analysis and localization information allow us to establish a kinetic model to describe the sRNA-induced target mRNA degradation in the cell. More importantly, our results demonstrate very promising application of this technique in studying other bacterial small RNA systems, and potentially microRNAs in eukaryotes.

Evaluation of yarn lateral deformation

Abstract The article focuses on a new approach for characterization and evaluation of lateral yarn deformation. A small review about theoretical description and measurement possibilities will be introduced. The evaluation of yarn compression will be done by three innovative methods (lateral deformation of yarn between two parallel plates, simulation of binding point of fabric, cross-sectional analysis of real fabric). The analysis of yarn deformation will be carried out for a set of samples in combination of fiber material, yarn count and given fabric structure.

Capillary electrophoresis ribosomal RNA single-stranded conformation polymorphism: a new approach for characterization of low-diversity microbial communities

Capillary electrophoresis (CE) has been the principle system for nucleic acid analysis since the early 1990s due to its inherent advantages such as fast analysis time, high resolution and efficiency, minimal sample requirement, high detection sensitivity, and automation. In the past few decades, microbial community fingerprinting methods such as terminal restriction fragment length polymorphism and single-stranded conformation polymorphism (SSCP) have migrated to CE to utilize its advantages over conventional slab gel electrophoresis. Recently, a gel-based direct rRNA fingerprint method was demonstrated. Different from other existing microbial community characterization approaches, this novel approach is polymerase chain reaction free and capable of providing information on the relative abundance of rRNA from individual phylotypes in low-diversity samples. As a gel-based method, it has a long analysis time and relatively large reagent and sample requirements. Here, we addressed these limitations by transferring the RNA fingerprint approach to the CE platform. Analysis time significantly improved from 24 h to 60 min, and the use of a fluorescently labeled hybridization probe as the detection strategy decreased the sample requirement by ten-fold. The combination of fast analysis time, low sample requirement, and sensitive fluorescence detection makes CE-RNA-SSCP an appealing new approach for characterizing low-diversity microbial communities.

Polarized light‐scattering profile—advanced characterization of nonspherical particles with scanning flow cytometry

We instrumentally, theoretically, and experimentally demonstrate a new approach for characterization of nonspherical individual particles from light scattering. Unlike the original optical scheme of the scanning flow cytometer that measures an angle-resolved scattering corresponding in general to S₁₁ element of the light-scattering matrix, the modernized instrument allows us to measure the polarized light-scattering profile of individual particles simultaneously. Theoretically, the polarized profile is expressed by the combination of a few light-scattering matrix elements. This approach supports us with additional independent data to characterize a particle with a complex shape and an internal structure. Applicability of the new method was demonstrated from analysis of polymer bispheres. The bisphere characteristics, sizes, and refractive indices of each sphere composing the bisphere were successfully retrieved from the solution of the inverse light-scattering problem. The solution provides determination of the Eulerian angles, which describe the orientation of the bispheres relative to the direction of the incident laser beam and detecting polarizer of the optical system. Both the ordinary and polarized profiles show a perfect agreement with T-matrix simulation resulting to 50-nm precision for sizing of bispheres.

Loading velocity dependent permeability in agarose gel under compression

A new approach for characterization of agarose gel permeability under compression at different loading velocities is proposed. Uniaxial compression tests on thin agarose gel specimens in a rigid porous confinement cell immersed in a water bath are undertaken. The equilibrium response of the gel, which is assumed to be achieved under extremely low-loading velocity (of the order of tens nanometers per second) is considered to be the response of the hydrated gel scaffold. The water exudation behavior from the agarose gel was extracted from the load–displacement response under various loading velocities by subtracting the equilibrium response. It was found that the pressure on water in the gel is not a linear function of loading velocity or volume flow rate and therefore, the permeability of agarose gel was observed to vary with deformation and water flow velocity. In addition, it was inferred from the analysis that at low velocities and large strain levels the gel permeability dominates the compression behavior, and at higher velocities and small strain levels the viscosity of the hydrated matrix may contribute to the load. Finally, permeability variation in agarose gel at different loading velocities is attributed to the two states (free water and bound water) of water molecules in the gel.