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- 摘要
- 关键词
- 实验方案
- 产品
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Correlated Materials Characterization via Multimodal Chemical and Functional Imaging
摘要： Multimodal chemical imaging simultaneously offers high resolution chemical and physical information with nanoscale, and in select cases atomic resolution. By coupling modalities that collect physical and chemical information, we can address scientific problems in biological systems, battery and fuel cell research, catalysis, pharmaceuticals, photovoltaics, medicine and many others. The combined systems enable local correlation of material properties with chemical makeup, making fundamental questions in how chemistry and structure drive functionality approachable. In this review we present recent progress and offer a perspective for chemical imaging used to characterize a variety of samples by a number of platforms. Specifically, we present cases in infrared and Raman spectroscopies combined with scanning probe microscopy; optical microscopy and mass spectrometry; nonlinear optical microscopy; and finally, ion, electron and probe microscopies with mass spectrometry. We also discuss the challenges associated with the use of data originated by the combinatorial hardware, analysis, and machine learning as well as processing tools necessary for interpretation of multidimensional data acquired from multimodal studies.
关键词： raman spectroscopy,ion microscopy,nonlinear optical microscopy,mass spectrometry,electron microscopy,infrared spectroscopy,chemical imaging,scanning probe microscopy,data analytics,optical microscopy
更新于2025-09-10 09:29:36
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Coulomb explosion imaging of CH <sub/>3</sub> I and CH <sub/>2</sub> ClI photodissociation dynamics
摘要： The photodissociation dynamics of CH3I and CH2ClI at 272 nm were investigated by time-resolved Coulomb explosion imaging, with an intense non-resonant 815 nm probe pulse. Fragment ion momenta over a wide m/z range were recorded simultaneously by coupling a velocity map imaging spectrometer with a pixel imaging mass spectrometry camera. For both molecules, delay-dependent pump-probe features were assigned to ultraviolet-induced carbon-iodine bond cleavage followed by Coulomb explosion. Multi-mass imaging also allowed the sequential cleavage of both carbon-halogen bonds in CH2ClI to be investigated. Furthermore, delay-dependent relative fragment momenta of a pair of ions were directly determined using recoil-frame covariance analysis. These results are complementary to conventional velocity map imaging experiments and demonstrate the application of time-resolved Coulomb explosion imaging to photoinduced real-time molecular motion.
关键词： pixel imaging mass spectrometry,time-resolved,CH3I,velocity map imaging,photodissociation dynamics,Coulomb explosion imaging,CH2ClI
更新于2025-09-10 09:29:36
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Development and Validation of Spectrophotometric Methods for the Simultaneous Determination of Mebeverine Hydrochloride and Chlordiazepoxide in Bulk and in Dosage Form
摘要： Two accurate, precise and simple spectrophotometric methods had been developed and validated for the determination of mebeverine hydrochloride (MEB) and chlordiazepoxide (CHL). The first method was used for the determination of MEB in the range of 5-81 μg/mL and CHL in the range of 0.5-4 μg/mL, MEB was determined by second derivative spectrophotometric determination by measuring the peak amplitude at 234.8 nm (zero value of CHL) whereas CHL was determined by first derivative spectrophotometric method by measuring the peak amplitude at 280.4 nm (zero value of MEB). In the second method, three chemometric methods were evaluated for simultaneous assay of MEB and CHL. The developed methods were successfully applied to the analysis of the cited drugs in laboratory prepared mixtures and tablets with good recoveries. The validity of the proposed methods was further assessed by applying the standard addition technique. The validation was carried out following the International Conference on Harmonization (ICH) guidelines.
关键词： Mebeverine Hydrochloride,Derivative spectrometry,Chlordiazepoxide,Chemometrics techniques
更新于2025-09-10 09:29:36
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Dense restructuring of amorphous silicon network induced by non-bonded hydrogen
摘要： We con?rmed the presence of non-bonded hydrogens (NBHs) in hydrogenated amorphous silicon (a-Si:H) ?lms, using a combination of multiple techniques (Rutherford backscattering spectrometry/hydrogen forward scattering, Fourier-transform infrared spectroscopy-attenuated total re?ection, and thermal desorption spectrometry). The hydrogen e?usion pro?le of an a-Si:H ?lm with large amounts of NBHs was analyzed in detail. We report the e?ect of NBHs on band structure and electrical conductivity, and we present additional considerations for previous data on number density of silicon, optical bandgap, and vacancy size distribution [J. Non-Cryst. Solids 447, 207 (2016)]. The e?ect of NBHs on the a-Si network is explained by the “dense restructuring model”.
关键词： thermal desorption spectrometry,Rutherford backscattering spectrometry,hydrogenated amorphous silicon,non-bonded hydrogens,dense restructuring model,Fourier-transform infrared spectroscopy
更新于2025-09-09 09:28:46
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Pre-Processing MALDI/TOF Mass Spectra by Using Geena 2
摘要： Geena 2 is a tool for filtering, averaging, and aligning MALDI/TOF mass spectra, designed to assist scientists in the analysis of high volumes of data and support them for comparative studies. Three web interfaces are available with different levels of complexity. In this manuscript, we explain how to use Geena 2 with these three interfaces to perform analyses of one’s own data. Two support protocols showing how to check the example input file and how to create an input file with own data are also presented.
关键词： spectra alignment,mass spectrometry,pre-processing,MALDI/TOF
更新于2025-09-09 09:28:46
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Modeling Light Propagation through the Tissues of the Head Taking Account of Scattering Anisotropy to Optimize the Positioning of Irradiation Detectors and Sources in a Brain–Computer Interface Based on Near Infrared Spectroscopy
摘要： We describe here use of the Monte Carlo modeling method to specify the parameters of near infrared light propagation though the tissues of the head, which is needed for optimizing the operation of brain–computer interfaces. The studies used a four-layer spherical model of the head consisting of skin, bone, gray matter, and white matter. The relationship between the parameters of the radiation recorded and the distance between the source and detector were obtained.
关键词： foci of hemodynamic activity,near infrared spectrometry,brain–computer interface,Monte Carlo modeling
更新于2025-09-09 09:28:46
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BCAbox Algorithm Expands Capabilities of Raman Microscope for Single Organelles Assessment
摘要： Raman microspectroscopy is a rapidly developing technique, which has an unparalleled potential for in situ proteomics, lipidomics, and metabolomics, due to its remarkable capability to analyze the molecular composition of live cells and single cellular organelles. However, the scope of Raman spectroscopy for bio-applications is limited by a lack of software tools for express-analysis of biomolecular composition based on Raman spectra. In this study, we have developed the first software toolbox for immediate analysis of intracellular Raman spectra using a powerful biomolecular component analysis (BCA) algorithm. Our software could be easily integrated with commercial Raman spectroscopy instrumentation, and serve for precise analysis of molecular content in major cellular organelles, including nucleoli, endoplasmic reticulum, Golgi apparatus, and mitochondria of either live or fixed cells. The proposed software may be applied in broad directions of cell science, and serve for further advancement and standardization of Raman spectroscopy.
关键词： single cell assay,biomolecular analysis,Raman spectrometry,microscopy
更新于2025-09-09 09:28:46
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Programmable Flow Rate Scanner for Evaluating Detector Sensitivity Regime
摘要： In order to expedite characterization of on-line detection systems, we have developed a flow rate scanner comprising a pump, an inexpensive single-board computer, and an associated Python program. The program controls the pump, triggers the detector, acquires raw data, filters/smooths the data, calculates the first derivative of the temporal signal trend, and determines the sensitivity regime threshold in real time. The slope of the curve relating the detector response with the sample flow rate is used to determine the sensitivity regime for a given analyte and a given detector. The key part of the data analysis is on-the-fly calculation of the first derivatives using a fourth-order polynomial fit to the raw data by the Savitzky-Golay algorithm. The device has been tested by determining the flow rate profiles for an ultraviolet absorption detector and a mass spectrometer operated with electrospray ionization, atmospheric pressure chemical ionization, and a dual ion source. The sensitivity regime thresholds for various test analytes have been determined automatically and robustly in time as short as a few minutes.
关键词： prototype,mass spectrometry,flow rate,sensitivity,optimization,automation
更新于2025-09-09 09:28:46
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NOVEL MATRIX SUBLIMATION DEVICE FOR MALDI MASS SPECTROMETRY IMAGING
摘要： Sublimation is a widely used method for matrix deposition in imaging mass spectrometry experiments. Still, most of the time standard glass sublimators are used for this purpose, which do not enable optimal matrix deposition reproducibility, compromising inter-experiment comparison of the results. Here we present an in-house designed stainless steel sublimator in which the parameters that have the strongest influence over matrix deposition reproducibility can be easily monitored. Using sections of human colon biopsies we demonstrate the capabilities of this new prototype.
关键词： mass spectrometry imaging,matrix sublimation,stainless steel sublimator,reproducibility,MALDI
更新于2025-09-09 09:28:46
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A brief review on mass/optical spectrometry for imaging analysis of biological samples
摘要： Imaging analysis, especially bioimaging analysis, has been a hot research topic in recent years. There are numerous imaging analysis techniques for diverse applications of a wide spectrum of samples, with their unique advantages and disadvantages, and there are several related reviews published yearly. Among them, imaging mass spectrometry (IMS) technique for studying the distribution of molecular or ionic species at the level of tissue, cell, or subcellular, with its main feature of combining mass spectra for molecular identification and image visualization for quick and convenient analysis. The IMS does not require chemical labeling or complex sample preparation. This review, mainly focuses on the popular emerging IMS technique, including related ionization techniques in connection with their IMS applications, and some unique optical imaging techniques such as chemiluminescence imaging and dual-modal bioimaging for biological sample analysis, with 105 related recent references.
关键词： laser,multimodal bioimaging,biomedical imaging,chemiluminescence,optical spectrometry,bioimaging analysis,dual-modal bioimaging,mass spectrometry,Imaging analysis,ionization source
更新于2025-09-04 15:30:14