scholarly journals Cooling Dynamics of a Single Trapped Ion via Elastic Collisions with Small-Mass Atoms

2018 ◽  
Vol 120 (4) ◽  
Author(s):  
Shinsuke Haze ◽  
Mizuki Sasakawa ◽  
Ryoichi Saito ◽  
Ryosuke Nakai ◽  
Takashi Mukaiyama
Keyword(s):  
Small Mass ◽  
Elastic Collisions ◽  
Trapped Ion

scholarly journals Surface-Induced Dissociation of Protein Complexes Selected by Trapped Ion Mobility Spectrometry

2020 ◽  
Author(s):  
Erin Panczyk ◽  
Dalton Snyder ◽  
Mark. E. Ridgeway ◽  
Arpad Somogyi ◽  
Melvin A. Park ◽  
...  
Keyword(s):  
Ion Mobility Spectrometry ◽  
Ion Mobility ◽  
Protein Complexes ◽  
Small Mass ◽  
Resolving Power ◽  
Mass Selection ◽  
Trapped Ion ◽  
Surface Induced Dissociation ◽  
Trapped Ion Mobility Spectrometry ◽  
Ft Icr

<p><a>Native mass spectrometry, particularly in conjunction with gas-phase ion mobility spectrometry measurements, has proven useful as a structural biology tool for evaluating the stoichiometry, conformation, and topology of protein complexes. Here, we demonstrate the combination of trapped ion mobility spectrometry (TIMS) and surface-induced dissociation (SID) on a Bruker SolariX XR 15 T FT-ICR mass spectrometer for structural analysis of protein complexes. We successfully performed SID on mobility-selected protein complexes, including streptavidin tetramer and cholera toxin B with bound ligand. Additionally, TIMS-SID was employed on a mixture of peptides bradykinin desR1 and desR9 to mobility separate and identify the individual peptides. Importantly, results show that native-like conformations can be maintained throughout the TIMS analysis. The TIMS-SID spectra are analogous to SID spectra acquired using quadrupole mass selection, indicating little measurable, if any, structural rearrangement during mobility selection. Mobility parking was used on the ion or mobility of interest and 50 to 200 SID mass spectra were averaged. High quality TIMS-SID spectra were acquired over a period of 2-10 minutes, comparable to or slightly longer than SID coupled with ion mobility on various instrument platforms in our laboratory. The ultrahigh resolving power of the 15 T FT-ICR allowed for the identification and relative quantification of overlapping SID fragments with the same nominal <i>m/z</i> based on isotope patterns and shows promise as a platform to probe small mass differences, such as protein-ligand binding or post-translational modifications. These results represent the potential of TIMS-SID-MS for the analysis of both protein complexes and peptides.</a></p>

scholarly journals Surface-Induced Dissociation of Protein Complexes Selected by Trapped Ion Mobility Spectrometry

2020 ◽  
Author(s):  
Erin Panczyk ◽  
Dalton Snyder ◽  
Mark. E. Ridgeway ◽  
Arpad Somogyi ◽  
Melvin A. Park ◽  
...  
Keyword(s):  
Ion Mobility Spectrometry ◽  
Ion Mobility ◽  
Protein Complexes ◽  
Small Mass ◽  
Resolving Power ◽  
Mass Selection ◽  
Trapped Ion ◽  
Surface Induced Dissociation ◽  
Trapped Ion Mobility Spectrometry ◽  
Ft Icr

<p><a>Native mass spectrometry, particularly in conjunction with gas-phase ion mobility spectrometry measurements, has proven useful as a structural biology tool for evaluating the stoichiometry, conformation, and topology of protein complexes. Here, we demonstrate the combination of trapped ion mobility spectrometry (TIMS) and surface-induced dissociation (SID) on a Bruker SolariX XR 15 T FT-ICR mass spectrometer for structural analysis of protein complexes. We successfully performed SID on mobility-selected protein complexes, including streptavidin tetramer and cholera toxin B with bound ligand. Additionally, TIMS-SID was employed on a mixture of peptides bradykinin desR1 and desR9 to mobility separate and identify the individual peptides. Importantly, results show that native-like conformations can be maintained throughout the TIMS analysis. The TIMS-SID spectra are analogous to SID spectra acquired using quadrupole mass selection, indicating little measurable, if any, structural rearrangement during mobility selection. Mobility parking was used on the ion or mobility of interest and 50 to 200 SID mass spectra were averaged. High quality TIMS-SID spectra were acquired over a period of 2-10 minutes, comparable to or slightly longer than SID coupled with ion mobility on various instrument platforms in our laboratory. The ultrahigh resolving power of the 15 T FT-ICR allowed for the identification and relative quantification of overlapping SID fragments with the same nominal <i>m/z</i> based on isotope patterns and shows promise as a platform to probe small mass differences, such as protein-ligand binding or post-translational modifications. These results represent the potential of TIMS-SID-MS for the analysis of both protein complexes and peptides.</a></p>

Studies on Water in the Hydration Chamber of a Modified Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 544-545
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Steady State ◽  
Room Temperature ◽  
Small Mass ◽  
Equilibrium Pressure ◽  
Biological Objects ◽  
Mechanical Pump ◽  
Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

PARATHYROID HORMONE SECRETION IN DISORDERS OF CALCIUM METABOLISM STUDIED BY MEANS OF EDTA

1974 ◽  
Vol 75 (2) ◽  
pp. 286-296 ◽  
Author(s):  
J. H. Lockefeer ◽  
W. H. L. Hackeng ◽  
J. C. Birkenhäger
Keyword(s):  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Calcium Metabolism ◽  
Hormone Secretion ◽  
Parathyroid Tissue ◽  
Small Mass ◽  
Idiopathic Hypercalciuria ◽  
List Type ◽  
Immunoreactive Parathyroid Hormone ◽  
Pth Level

ABSTRACT In 22 of 28 cases of primary hyperparathyroidism (PHP) the rise in the serum immunoreactive parathyroid hormone (IRPTH or PTH) level observed in response to lowering of the serum calcium by EDTA, exceeded that obtained in 8 control subjects. In 5 of these 22 patients who were studied again after parathyroidectomy the supranormal response was abolished. Fifteen of these 22 hyper-responsive PHP patients had basal IRPTH levels not exceeding the highest level in the controls and that of other groups of patients investigated (idiopathic hypercalciuria, non-parathyroid hypercalcaemia, operated PHP). Fourteen of the 22 hyper-reactive patients with PHP did not show hypocalcaemia during the infusion of EDTA. The extent of the release of PTH elicited by EDTA in cases of PHP does not as yet allow a prediction of the amount of pathological parathyroid tissue present, although all the PHP patients showing a normal release of PTH had a relatively small mass of parathyroid tissue (up to about 1 g) subsequently removed. In 9 cases of nephrolithiasis (8 of whom had idiopathic hypercalciuria) and in 7 cases of non-parathyroid hypercalcaemia, a normal PTH release was found.

Spatial Metabolomics of the Human Kidney Using MALDI Trapped Ion Mobility Imaging Mass Spectrometry

2020 ◽  
Author(s):  
Elizabeth Neumann ◽  
Lukasz Migas ◽  
Jamie L. Allen ◽  
Richard Caprioli ◽  
Raf Van de Plas ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ion Mobility ◽  
Imaging Mass Spectrometry ◽  
Structural Complexity ◽  
Human Kidney ◽  
Resolving Power ◽  
Mobility Separation ◽  
Trapped Ion ◽  
Mobility Data ◽  
Ion Mobility Separation

<div> <div> <p>Small metabolites are essential for normal and diseased biological function but are difficult to study because of their inherent structural complexity. MALDI imaging mass spectrometry (IMS) of small metabolites is particularly challenging as MALDI matrix clusters are often isobaric with metabolite ions, requiring high resolving power instrumentation or derivatization to circumvent this issue. An alternative to this is to perform ion mobility separation before ion detection, enabling the visualization of metabolites without the interference of matrix ions. Here, we use MALDI timsTOF IMS to image small metabolites at high spatial resolution within the human kidney. Through this, we have found metabolites, such as arginic acid, acetylcarnitine, and choline that localize to the cortex, medulla, and renal pelvis, respectively. We have also demonstrated that trapped ion mobility spectrometry (TIMS) can resolve matrix peaks from metabolite signal and separate both isobaric and isomeric metabolites with different localizations within the kidney. The added ion mobility data dimension dramatically increased the peak capacity for molecular imaging experiments. Future work will involve further exploring the small metabolite profiles of human kidneys as a function of age, gender, and ethnicity.</p></div></div>

Small Mass Impact Testing of Sandwich Structures

2010 ◽  
Vol 52 (11-12) ◽  
pp. 765-770 ◽  
Author(s):  
Stefan Dietrich ◽  
Jan Kuppinger ◽  
Peter Elsner ◽  
Kay Weidenmann
Keyword(s):  
Sandwich Structures ◽  
Small Mass ◽  
Impact Testing

Realisation of a photonic link between a trapped ion and a semiconductor quantum dot

2014 ◽  
Author(s):  
Claire Le Gall ◽  
Robert Stockill ◽  
Matthias Steiner ◽  
Hendrik-Marten Meyer ◽  
Clemens Matthiesen ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Trapped Ion ◽  
Semiconductor Quantum Dot

scholarly journals Resection of primary cardiac angiosarcoma infiltrating the right atrioventricular junction and tricuspid valve: a case report

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Lubna Bakr ◽  
Hussam AlKhalaf ◽  
Ahmad Takriti
Keyword(s):  
Surgical Resection ◽  
Tricuspid Valve ◽  
Right Atrium ◽  
Large Mass ◽  
Small Mass ◽  
Malignant Tumours ◽  
Atrioventricular Junction ◽  
Cardiac Angiosarcoma ◽  
Complete Surgical Resection ◽  
The Right

Abstract Background Primary cardiac tumours are extremely rare. Most of them are benign. Sarcomas account for 95% of the malignant tumours. Prognosis of primary cardiac angiosarcoma remains poor. Complete surgical resection is oftentimes hampered when there is extensive tumour involvement into important cardiac apparatus. We report a case of cardiac angiosarcoma of the right atrium and ventricle, infiltrating the right atrioventricular junction and tricuspid valve. Case presentation Initially, a 22-year-old man presented with dyspnoea. One year later, he had recurrent pericardial effusion. Afterwards, echocardiography revealed a large mass in the right atrium, expanding from the roof of the right atrium to the tricuspid valve. The mass was causing compression on the tricuspid valve, and another mass was seen in the right ventricle. Complete resection of the tumour was impossible. The mass was resected with the biggest possible margins. The right atrium was reconstructed using heterologous pericardium. The patient’s postoperative course was uneventful. Postoperative echocardiography showed a small mass remaining in the right side of the heart. Histopathology and immunohistochemistry confirmed the diagnosis of angiosarcoma. The patient underwent adjuvant chemotherapy and radiotherapy later on. He survived for 1 year and 5 days after the surgery. After a diagnosis of lung and brain metastases, he ended up on mechanical ventilation for 48 h and died. Conclusions Surgical resection combined with postoperative chemotherapy and radiotherapy is feasible even in patients with an advanced stage of cardiac angiosarcoma when it is impossible to perform complete surgical resection.

scholarly journals Xenon-1T excess as a possible signal of a sub-GeV hidden sector dark matter

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Amin Aboubrahim ◽  
Michael Klasen ◽  
Pran Nath
Keyword(s):  
Dark Matter ◽  
Particle Physics ◽  
Small Mass ◽  
Big Bang ◽  
Mass Splitting ◽  
Recoil Energy ◽  
Dirac Fermions ◽  
Dark Sector ◽  
Dark Photon ◽  
Physics Model

Abstract We present a particle physics model to explain the observed enhancement in the Xenon-1T data at an electron recoil energy of 2.5 keV. The model is based on a U(1) extension of the Standard Model where the dark sector consists of two essentially mass degenerate Dirac fermions in the sub-GeV region with a small mass splitting interacting with a dark photon. The dark photon is unstable and decays before the big bang nucleosynthesis, which leads to the dark matter constituted of two essentially mass degenerate Dirac fermions. The Xenon-1T excess is computed via the inelastic exothermic scattering of the heavier dark fermion from a bound electron in xenon to the lighter dark fermion producing the observed excess events in the recoil electron energy. The model can be tested with further data from Xenon-1T and in future experiments such as SuperCDMS.

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