scholarly journals Simulation studies for characterizing ultrashort bunches using novel polarizable X-band transverse deflection structures

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Daniel Marx ◽  
Ralph W. Assmann ◽  
Paolo Craievich ◽  
Klaus Floettmann ◽  
Alexej Grudiev ◽  
...  
Keyword(s):  
Charge Density ◽  
Plasma Cells ◽  
Bunch Length ◽  
The Novel ◽  
Density Distributions ◽  
X Band ◽  
Length Measurements ◽  
External Injection ◽  
Dielectric Structures ◽  
Transverse Deflection

AbstractTransverse deflection structures are useful devices for characterizing the longitudinal properties of bunches in electron accelerators. With efforts to produce ever-shorter bunches for applications such as external injection into novel accelerator structures, e.g. plasma cells or dielectric structures, the applicability of deflection structures to measuring ultrashort bunches has been considered. In this paper, charge-density and bunch-length measurements of femtosecond and subfemtosecond bunches at the ARES linac at the SINBAD facility at DESY are studied with simulations and the limitations discussed in detail. The novel polarizable X-band transverse deflection structure (PolariX-TDS) will allow the streaking of bunches at all transverse angles, making a 3D charge-density reconstruction of bunches possible, in addition to the standard 1D charge-density reconstruction and bunch-length measurements. These various measurements of the charge-density distributions of bunches have been simulated, and it is shown that useful information about ultrashort bunches down to subfemtosecond lengths may be obtained using the setup planned for the ARES linac.

scholarly journals Bunch-Length Measurements in PEP-II

2006 ◽  
Author(s):  
A.S. Fisher ◽  
A. Novokhatski ◽  
J.L. Turner ◽  
U. Wienands ◽  
G. Yocky
Keyword(s):  
Bunch Length ◽  
Length Measurements

scholarly journals Maturation of Human Long-lived Plasma Cells Results in Resistance to Apoptosis by Transcriptional and Epigenetic Regulation

2021 ◽  
Author(s):  
Chester J Joyner ◽  
Ariel Ley ◽  
Doan Nguyen ◽  
Muhammad Ali ◽  
Alessia Corrado ◽  
...  
Keyword(s):  
Gene Expression ◽  
Plasma Cells ◽  
The Novel ◽  
Epigenetic Changes ◽  
Apoptosis Pathway ◽  
Apoptotic Gene ◽  
Survival Gene ◽  
Distinct Morphology ◽  
Antibody Secreting Cells

Antibody secreting cells (ASC) circulate after vaccination and migrate to the bone marrow (BM) where a subset known as long-lived plasma cells (LLPC) persist and secrete antibodies for a lifetime. The mechanisms of how circulating ASC become LLPC are not well elucidated. Here, we show that human blood ASCs have distinct morphology, transcriptomes, and epigenetics compared to BM LLPC. LLPC acquire transcriptional and epigenetic changes in the apoptosis pathway to support their survival. Upregulation of pro-survival gene expression accompanies downregulation of pro-apoptotic gene expression in LLPC. While pro-apoptotic gene loci are less accessible, pro-survival gene loci are not always accompanied by accessibility changes. Importantly, we show similar LLPC morphological and transcriptional maturation of blood ASC in response to the novel in vitro BM mimetic. In all, our study demonstrates that blood ASC in the BM microniche must undergo morphological and molecular changes to mature into apoptotic-resistant LLPC.

scholarly journals Rich p -type-doping phenomena in boron-substituted silicene systems

2020 ◽  
Vol 7 (12) ◽  
pp. 200723
Author(s):  
Hai Duong Pham ◽  
Wu-Pei Su ◽  
Thi Dieu Hien Nguyen ◽  
Ngoc Thanh Thuy Tran ◽  
Ming-Fa Lin
Keyword(s):  
Charge Transfer ◽  
Fermi Level ◽  
Charge Density ◽  
Electronic Properties ◽  
First Principles ◽  
Chemical Environment ◽  
First Principles Calculations ◽  
Density Distributions ◽  
Essential Properties ◽  
P Type

The essential properties of monolayer silicene greatly enriched by boron substitutions are thoroughly explored through first-principles calculations. Delicate analyses are conducted on the highly non-uniform Moire superlattices, atom-dominated band structures, charge density distributions and atom- and orbital-decomposed van Hove singularities. The hybridized 2 p z –3 p z and [2s, 2 p x , 2 p y ]–[3s, 3 p x , 3 p y ] bondings, with orthogonal relations, are obtained from the developed theoretical framework. The red-shifted Fermi level and the modified Dirac cones/ π bands/ σ bands are clearly identified under various concentrations and configurations of boron-guest atoms. Our results demonstrate that the charge transfer leads to the non-uniform chemical environment that creates diverse electronic properties.

scholarly journals Charge density distributions and electron scattering form factors of 25Mg, 27Al and 29Si nuclei

2019 ◽  
Vol 14 (30) ◽  
pp. 129-135
Author(s):  
Lubna Abduljabbar Mahmood
Keyword(s):  
Charge Density ◽  
Explicit Form ◽  
Electron Scattering ◽  
Ground State ◽  
Density Operator ◽  
Form Factors ◽  
Body Density ◽  
Density Distributions ◽  
Tail Part

An effective two-body density operator for point nucleon systemfolded with the tenser force correlations( TC's), is produced and usedto derive an explicit form for ground state two-body charge densitydistributions (2BCDD's) applicable for 25Mg, 27Al and 29Si nuclei. It isfound that the inclusion of the two-body TC's has the feature ofincreasing the central part of the 2BCDD's significantly and reducingthe tail part of them slightly, i.e. it tends to increase the probability oftransferring the protons from the surface of the nucleus towards itscenteral region and consequently makes the nucleus to be more rigidthan the case when there is no TC's and also leads to decrease the1/ 2r 2 of the nucleus. It is also found that the effect of the TC's and theeffect of increasing the values of  on the 2BCDD's, elasticelectron scattering form factors and r2 1/ 2 are in the same directionfor all considered nuclei.

Charge density studies on methylene blue – a potential anti-Alzheimer agent

2018 ◽  
Vol 73 (2) ◽  
pp. 99-108 ◽  
Author(s):  
Peter Luger ◽  
Birger Dittrich ◽  
Leonard Benecke ◽  
Hannes Sterzel
Keyword(s):  
Methylene Blue ◽  
Charge Density ◽  
Molecular Electrostatic Potential ◽  
Positive Charge ◽  
Atomic Charges ◽  
Charge Densities ◽  
Density Distributions ◽  
Atomic Properties ◽  
Counter Ions ◽  
Medical Interest

AbstractMotivated by the medical interest in methylene blue as potential anti-Alzheimer agent, the charge densities of three salt structures containing the methylene blue cation with nitrate (as dihydrate), chloride (as pentahydrate) and thiocyanate counter-ions were generated by application of the invariom formalism and examined. The so-obtained charge density distributions were analyzed using the QTAIM formalism to yield bond topological and atomic properties. The atomic charges on the methylene blue cation indicate a delocalized charge distribution; only a small positive charge on the sulfur atom was found. Electrostatic potentials mapped onto iso-surfaces of electron density for the cations, and for the methylene blue cations with anions, were compared. The effect of hydrogen disorder on the molecular electrostatic potential was investigated for the thiocyanate structure.

Implications for the monitoring of patients with multiple myeloma undergoing treatment with the anti-CD38 monoclonal daratumumab

2019 ◽  
Vol 57 (2) ◽  
pp. 178-181 ◽  
Author(s):  
Sally Thirkettle ◽  
Joanne Russell ◽  
Sarah Wilson ◽  
Tasneem Ganijee ◽  
Samar Kulkarni ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Healthcare Workers ◽  
Plasma Cells ◽  
Clinical Laboratory ◽  
Response To Treatment ◽  
Serological Response ◽  
The Novel ◽  
Remission Rates ◽  
Human Igg1 ◽  
Single Laboratory

Background The novel daratumumab immunotherapy is a human IgG1 kappa antibody targeted against CD38, which is almost universally expressed on myeloma plasma cells. Daratumumab has efficacy in clinical trials for the treatment of multiple myeloma; however, it complicates laboratory monitoring of the serological response to treatment, as it is detected by serum electrophoresis and/or immunofixation. Methods Laboratory reports of electrophoresis patterns serially performed in a single laboratory of six patients with relapsed multiple myeloma receiving daratumumab therapy as part a clinical trial were reviewed retrospectively. Results Post administration of daratumumab therapy, an additional band was visible by serum electrophoresis, migrating to the mid-gamma region, which was confirmed as IgG kappa by immunofixation. In five out of the six patients, this band was quantified at <2.0 g/L. For one patient, this band co-migrated with the patient’s disease paraprotein band, so both bands were quantified together. The appearance of an apparent second paraprotein band while receiving treatment for multiple myeloma can cause anxiety for patients, confusion for healthcare workers and may also underestimate complete remission rates. Conclusions The clinical laboratory must be aware of the interference of daratumumab in serum electrophoresis. Effective communication between clinicians and the laboratory is essential for the production of clinically valuable, non-misleading reports for these patients.

The effects of changing NOM composition and characteristics on coagulation performance, optimisation and control

2004 ◽  
Vol 4 (4) ◽  
pp. 95-102 ◽  
Author(s):  
E.L. Sharp ◽  
S.A. Parsons ◽  
B. Jefferson
Keyword(s):  
Charge Density ◽  
Water Source ◽  
Cationic Polyelectrolyte ◽  
Winter Period ◽  
Potential Range ◽  
The Novel ◽  
Coagulation Performance ◽  
Resin Adsorption ◽  
Autumn And Winter ◽  
And Control

A number of water utilities have been experiencing operational difficulties during specific times of the year, associated with elevated levels of organics due to heavy rainfall or snow melt. Water samples were collected from Albert treatment works (Halifax, UK) and the natural organic matter (NOM) was characterised using XAD resin adsorption techniques. The addition of a cationic polyelectrolyte was employed to determine the charge density of the fractions. Results show that NOM fraction make-up changes throughout the year, with the fulvic acid fraction (FAF) showing the greatest increase during the autumn and winter period. The charge density of the FAF fraction also increases. The coagulation conditions for traditional coagulants, such as iron, are more affected by increased levels of organics than the novel coagulant also investigated, and the zeta potential range for optimum removal is narrower. Therefore, the conditions required for zero charge during coagulation varies with both raw water source and the coagulant type.

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