Ionization Properties Research Articles

Magnetically-coupled piston pump for high-purity gas applications

Experiments based on noble elements such as gaseous or liquid argon or xenon utilize the ionization and scintillation properties of the target materials to detect radiation-induced recoils. A requirement for high light and charge yields is to reduce electronegative impurities well below the ppb (parts per billion, 1 ppb =1times 10^{-9} mol/mol) level. To achieve this, the target material is continuously circulated in the gas phase through a purifier and returned to the detector. Additionally, the low backgrounds necessary dictate low-Rn-emanation rates from all components that contact the gas. Since commercial pumps often introduce electronegative impurities from lubricants on internal components or through small air leaks, and are not designed to meet the radiopurity requirements, custom-built pumps are an advantageous alternative. A new pump has been developed in Muenster in cooperation with the nEXO group at Stanford University and the nEXO/XENON group at Rensselaer Polytechnic Institute based on a magnetically-coupled piston in a hermetically sealed low-Rn-emanating vessel. This pump delivers high performance for noble gases, reaching more than 210 standard liters per minute (slpm) with argon and more than 170 slpm with xenon while maintaining a compression of up to 1.9 bar, demonstrating its capability for noble gas detectors and other applications requiring high standards of gas purity.

Analysis of the xylenol isomers by femtosecond laser time of flight mass spectrometry

Xylenol is a phenolic chemical substance having two methyl groups and one hydroxyl group attached to a benzene ring and has six isomers. 2,4-xylenol is the only isomer of the xylenol molecule that is in the liquid phase while the remaining isomers are all in crystal form at room temperature. In the scope of this study, we have experimentally investigated ionization and dissociation properties of xylenol isomers. All experiments were carried out by using a time of flight mass spectrometry (TOF-MS) system coupled with a femtosecond laser system. The laser pulse power-dependent multiphoton ionization of xylenol isomers was investigated by using IR (800 nm) femtosecond laser pulses having a pulse width of ∼90 fs in duration and laser intensities changing from 2.6 × 1013 to 2.6 × 1014 W/cm2. Theoretically, molecular orbitals (LUMO+1, LUMO, HOMO, HOMO–1), vertical and adiabatic ionization energies were calculated using density functional theory (DFT) with B3LYP functional and 6–311++G(d,p) basis set by following geometry optimization and performing conformational analysis.

Application of Molecular Mass Spectrometry for The Structural Characterization of a DNA-Protein Cross-Links

<p>To date, many different analytical methods have been used to investigate the cross-linking reaction mechanism and to obtain the chemical structure of DNA-Protein Cross-links (DPCs). Direct MS analysis of DPCs is challenging because of the ionization properties of DNA and the protein. However, peptide sequencing and mass spectrometry (MS) as analytical techniques are playing increasingly important roles for the structure determination of DPCs model. In our previous study, a novel approach was presented for purification, detection and quantification of DPCs by newly developed inductively coupled plasma mass spectrometry (ICPMS/MS), which allows sub-ppb detection of S and P, key heteroelements in DNA and proteins.</p><p>In this study, we enhanced our previously developed method and it was complemented by the use of molecular MS to allow complete characterization of a DNA-protein cross-link. First, a small molecule model is utilized to identify the adduct structure that will likely occur in an intact DNA-protein cross-link. We investigate the thermal stability of DNA-protein cross-links, both in an intact DPC and a small molecule adduct to determine feasibility of digestion/thermal degradationof DNA without the cross-link information being lost. Thermal degradation was conducted to reduce the cross-linked DNA into a single nucleoside. The remaining protein-nucleoside adduct then was proteolytically digested, generating a peptide-nucleoside adduct. The absence of the phosphate moiety allows for facile structural characterization <em>via</em> electrospray ionization mass spectrometry (ESI-MS). Additional calculations were done for peptide matching allowing us to determine the cross-link location in the protein, made possible <em>via</em> MS/MS analysis. Additionally, we show that steric effects play an important role in DPC formation.</p>

Screening of semifluorinated n‐alkanes by gas chromatography coupled to dielectric barrier discharge ionization mass spectrometry

The potential of an atmospheric pressure ionization source based on a dielectric barrier discharge in helium for the hyphenation of gas chromatography and mass spectrometry (GC/DBDI-MS) has been demonstrated only recently and for a limited range of compounds. Due to its 'soft' ionization properties and the possibility to choose from a variety of atmospheric pressure ionization MS instruments, GC/DBDI-MS has the potential to be an interesting alternative to 'classic' GC/MS techniques. The hyphenation of GC with DBDI-MS at atmospheric pressure is used for the determination of semifluorinated n-alkanes in ski wax samples. Different to perfluorinated n-alkanes, which are typically detected as [M-F+O]- and [M-F]- , semifluorinated n-alkanes can be detected both in positive mode as [M-3H+nO]+ and [M-H+nO]+ (n=0, 1, 2, and 3) ions, as well as in negative mode as a fragment ion representing the fluorinated part of the respective semifluorinated n-alkane. The method allowed the sensitive detection of semifluorinated n-alkanes with achievable limits of detection (LODs) in the single digit pg range injected on column. To examine the applicability of the GC/DBDI-MS method, semifluorinated n-alkanes were determined in fluorinated ski waxes. Results were confirmed by complimentary GC/electron ionization MS measurements. The unique SFA ionization patterns serve for complementary unambiguous identification of semifluorinated n-alkane species in positive mode and screening of contained n-alkanes fluorinated chain lengths in negative mode.

Dynamic stabilization of Na atom in an intense pulsed laser field**Project supported by the National Natural Science Foundation of China (Grant Nos. 11465016, 11664035, and 11764038).

We investigate theoretically the ionization properties of the valence electron for the alkali metal atom Na in an intense pulsed laser field by solving numerically the time-dependent Schrödinger equation with an accurate l-dependent model potential. By calculating the variations of the ionization probabilities with laser peak intensity for wavelengths ranging from 200 nm to 600 nm, our results present a dynamic stabilization trend for the Na atom initially in its ground state (3s) and the excited states (3p and 4s) exposed to an intense pulsed laser field. Especially a clear “window” of dynamic stabilization at lower laser intensities and longer wavelengths for the initial state 4s (the second excited state) is found. By analyzing the time-dependent population distributions of the valence electron in the bound states with the different values of principal quantum number n and orbital quantum number l, we can attribute the dynamic stabilization to the periodic population in the low-excited states since the valence electron oscillates rapidly between the lowly excited states and the continuum states.

3-Amino-1-phenyl-2-pyrazoline-5-ketone as a heterobifunctional chromogenic reagent to derivatize reducing glycans for subsequent online LC/MS analysis

Sensitive analysis of glycans by liquid chromatography/mass spectrometry is significantly hampered by the lack of chromogenic or fluorescent groups on the glycan structures, as well as, their poor ionization properties. In the present, a heterobifunctional chromogenic reagent 3-amino-1-phenyl-2-pyrazoline-5-ketone (PAP) bearing amino and active methylene groups, which readily reacts with reducing glycans, was used for detection of the pre-column-labeled glycans via high-performance liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESI-MS). The PAP derivatives with active methylene and amino groups were obtained via reductive amination in acidic medium and condensation of an active PAP methylene group with the reducing end of glycans in alkaline medium, respectively, and the PAP derivatives could be further functionalized, e.g., via glycan microarray preparation. The conditions for the two reaction modes were optimized, the HPLC separation method of PAP derivatives was investigated, and the PAP derivatives of some glycans derived from biological samples were obtained and analyzed by ESI-MS and LC-MS. Using this new reagent, reducing glycans can be selectively derivatized by different reaction mechanisms, having great importance for functional glycomics studies.

Ionization and Dynamic Properties of Single and Multiple Histidine Residues on a Transmembrane Helical Backbone

Ionization and Dynamic Properties of Single and Multiple Histidine Residues on a Transmembrane Helical Backbone

Impact ionization and transport properties of hexagonal boron nitride in a constant-voltage measurement

The electrical evaluation of the crystallinity of hexagonal boron nitride (h-BN) is still limited to the measurement of dielectric breakdown strength, in spite of its importance as the substrate for 2-dimensional van der Waals heterostructure devices. In this study, physical phenomena for degradation and failure in exfoliated single-crystal h-BN films were investigated using the constant-voltage stress test. At low electrical fields, the current gradually reduced and saturated with time, while the current increased at electrical fields higher than ~8 MV/cm and finally resulted in the catastrophic dielectric breakdown. These transient behaviors may be due to carrier trapping to the defect sites in h-BN because trapped carriers lower or enhance the electrical fields in h-BN depending on their polarities. The key finding is the current enhancement with time at the high electrical field, suggesting the accumulation of electrons generated by the impact ionization process. Therefore, a theoretical model including the electron generation rate by impact ionization process was developed. The experimental data support the expected degradation mechanism of h-BN. Moreover, the impact ionization coefficient was successfully extracted, which is comparable to that of SiO2, even though the fundamental band gap for h-BN is smaller than that for SiO2. Therefore, the dominant impact ionization in h-BN could be band-to-band excitation, not defect-assisted impact ionization.

Ionised gas structure of 100 kpc in an over-dense region of the galaxy group COSMOS-Gr30 at z ~ 0.7

We report the discovery of a 104 kpc2 gaseous structure detected in [O ii]λλ3727, 3729 in an over-dense region of the COSMOS-Gr30 galaxy group at z ~ 0.725 with deep MUSE Guaranteed Time Observations. We estimate the total amount of diffuse ionised gas to be of the order of (~5 ± 3) × 1010 M⊙ and explore its physical properties to understand its origin and the source(s) of the ionisation. The MUSE data allow the identification of a dozen group members that are embedded in this structure through emission and absorption lines. We extracted spectra from small apertures defined for both the diffuse ionised gas and the galaxies. We investigated the kinematics and ionisation properties of the various galaxies and extended gas regions through line diagnostics (R23, O32, and [O iii]/Hβ) that are available within the MUSE wavelength range. We compared these diagnostics to photo-ionisation models and shock models. The structure is divided into two kinematically distinct sub-structures. The most extended sub-structure of ionised gas is likely rotating around a massive galaxy and displays filamentary patterns that link some galaxies. The second sub-structure links another massive galaxy that hosts an active galactic nucleus (AGN) to a low-mass galaxy, but it also extends orthogonally to the AGN host disc over ~ 35 kpc. This extent is likely ionised by the AGN itself. The location of small diffuse regions in the R23 vs. O32 diagram is compatible with photo-ionisation. However, the location of three of these regions in this diagram (low O32, high R23) can also be explained by shocks, which is supported by their high velocity dispersions. One edge-on galaxy shares the same properties and may be a source of shocks. Regardless of the hypothesis, the extended gas seems to be non-primordial. We favour a scenario where the gas has been extracted from galaxies by tidal forces and AGN triggered by interactions between at least the two sub-structures.

Graphene oxide membrane as an efficient extraction and ionization substrate for spray-mass spectrometric analysis of malachite green and its metabolite in fish samples

A graphene oxide (GO) nanosheet-modified N+-nylon membrane (GOM) has been prepared and used as an extraction and spray-ionization substrate for robust mass spectrometric detection of malachite green (MG), a highly toxic disinfectant in liquid samples and fish meat. The GOM is prepared by self-deposition of GO thin film onto an N+-nylon membrane, which has been used for efficient extraction of MG in aquaculture water samples or homogenized fish meat samples. Having a dissociation constant of 2.17 × 10−9 M−1, the GOM allows extraction of approximately 98% of 100 nM MG. Coupling of the GOM-spray with an ion-trap mass spectrometer allows quantitation of MG in aquaculture freshwater and seawater samples down to nanomolar levels. Furthermore, the system possesses high selectivity and sensitivity for the quantitation of MG and its metabolite (leucomalachite green) in fish meat samples. With easy extraction and efficient spray ionization properties of GOM, this membrane spray-mass spectrometry technique is relatively simple and fast in comparison to the traditional LC-MS/MS methods for the quantitation of MG and its metabolite in aquaculture products.

The inherent matrix properties of lichen metabolites in matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

Light-absorbing secondary metabolites from lichens were recently reported to exhibit promising Laser Desorption Ionization (LDI) properties, enabling their direct detection from crude lichen extracts. In addition, many of them display close structural homologies to commercial Matrix-Assisted Laser Desorption Ionization (MALDI) matrices, which is incentive for the evaluation of their matrical properties. The current study systematically evaluated the matrix effects of several structural classes of lichen metabolites: monoaromatic compounds, quinone derivatives, dibenzofuran-related molecules and the shikimate-derived vulpinic acid. Their matrical properties were tested against a wide range of structurally diverse analytes including alkaloids, coumarins, flavonoids and peptides. Triplicate automatic positive-ion mode MALDI analyses were carried out and ionization efficiencies were compared with those of structurally related reference matrices (i.e. DHB, HCCA, dithranol and usnic acid) in terms of (i) analyte absolute intensities and (ii) Matrix Suppressing Effect (MSE) scores. Monoaromatic lichen metabolites revealed matrical properties similar to those of DHB when obtained under comparable experimental conditions. Likewise, anthraquinone metabolites triggered ionization of tested analytes in a similar way to the structurally related dithranol. Finally, dibenzofuran derivatives displayed a broad ionization profile, reminiscent of that of (+)-usnic acid. Lichen metabolites exhibit interesting MALDI matrix properties, especially for medium and low molecular weight analytes. For many of the tested molecules, matrix ion formation was very limited. This proof-of-concept study paves the way for follow-up investigations to assess the matrix properties of lichen metabolites against a wider array of analytes as well as adapting experimental settings to individually optimize the performance of successfully tested candidates.

Mrk 71/NGC 2366: The Nearest Green Pea Analog

Abstract We present the remarkable discovery that the dwarf irregular galaxy NGC 2366 is an excellent analog of the Green Pea (GP) galaxies, which are characterized by extremely high ionization parameters. The similarities are driven predominantly by the giant H ii region Markarian 71 (Mrk 71). We compare the system with GPs in terms of morphology, excitation properties, specific star-formation rate, kinematics, absorption of low-ionization species, reddening, and chemical abundance, and find consistencies throughout. Since extreme GPs are associated with both candidate and confirmed Lyman continuum (LyC) emitters, Mrk 71/NGC 2366 is thus also a good candidate for LyC escape. The spatially resolved data for this object show a superbubble blowout generated by mechanical feedback from one of its two super star clusters (SSCs), Knot B, while the extreme ionization properties are driven by the ≲1 Myr-old, enshrouded SSC Knot A, which has ∼10 times higher ionizing luminosity. Very massive stars (>100 M ⊙) may be present in this remarkable object. Ionization-parameter mapping indicates that the blowout region is optically thin in the LyC, and the general properties also suggest LyC escape in the line of sight. Mrk 71/NGC 2366 does differ from GPs in that it is one to two orders of magnitude less luminous. The presence of this faint GP analog and candidate LyC emitter (LCE) so close to us suggests that LCEs may be numerous and commonplace, and therefore could significantly contribute to the cosmic ionizing budget. Mrk 71/NGC 2366 offers an unprecedentedly detailed look at the viscera of a candidate LCE, and could clarify the mechanisms of LyC escape.

ДОСЛІДЖЕННЯ ЗВ'ЯЗКІВ ВЛАСТИВОСТЕЙ ЗОНИ ІОНІЗАЦІЇ ТА ПРИСКОРЕННЯ З МАГНІТНИМ ПОЛЕМ У ПРИСКОРЮВАЛЬНОМУ КАНАЛІ СТАЦІОНАРНОГО ПЛАЗМОВОГО ДВИГУНА

Paper represents results of an analysis of electric and magnetic fields distributions in the acceleration channel in stationary plasma thruster, performed to find relationships between properties of ionization and acceleration zone (IAZ) and parameters of magnetic field. There were found: connections between IAZ boundaries and maximum value of the radial component of magnetic induction Br, connections between IAZ length and magnitude of the maximum longitudinal gradient of Br. A directly proportional dependence of the electric field strength on the maximum longitudinal gradient Br was found. Deviation of lines with constant electric potential from magnetic force lines is revealed. The analysis of the relations is carried out over the entire width of the accelerating channel. Results of verification of the detected relations are given.

Modulation of ionization and structural properties of weak polyelectrolytes due to 1D, 2D, and 3D confinement

ABSTRACTWhat is the impact of reducing the space available to molecules onto their properties is a fundamental question for capillary systems, molecular biology and transport, protein and material sciences. Possibly influenced by space restriction, ionization degree has rarely been studied for confined polyelectrolytes; Monte Carlo titrations and coarse‐grained models are thus used to investigate structural and ionization changes induced on a single polyelectrolyte chain by confinement into slit (1D), cylindrical (2D), or spherical (3D) cavities. Four polyelectrolyte models differing in chain stiffness and the possible formation of charged hydrogen bonds (cHbonds) are studied. Low pH effective ionization constants (pKa) of confined chains are lower than for the free species if cHbonds can be formed. This is especially evident for 3D‐confined stiff chains, a finding rationalized by the impact of global compression onto chain conformations. If no cHbonds are allowed, chain ionization is largely unaffected by 1D or 2D confinement, while it is depressed by 3D. Chain confinement Helmholtz energy (ΔAconf) was computed as a function of both pH and confining width (W) to gauge the impact of ionization‐induced stiffening onto ΔAconf versus W behavior, the partition coefficient governing absorption, and the average number of cHbond formed. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1088–1102

Free or confined arc model relevant to the quench hazard of large superconducting coils

This arc model was motivated by the need to model arcs during the failure of a large superconducting magnet following an unmitigated quench. During a quench, resistive heating raises the conductor and insulator temperature. Electrical and mechanical properties change and inline and bypass arcs can form. The arcs are sustained by the massive (gigaJoule) stored magnetic energy. As windings are bypassed by shorts, the inline arc current and hence, arc diameter, increases. Cable-in-conduit conductors limit the maximum arc column diameter and when limited, the arc properties change rapidly as the arc changes from a free arc to a confined arc. For arc current 10–100kA we calculate the arc column electrical properties and temperature, by solving a set of equations describing the arc physics. The equations describe the arc column heating, gas ionisation, heat loss and electrical properties. By constraining the maximum arc column diameter in the solution, the transition between free and confined arc can be calculated.

Eventual limits of the current EU official method for evaluating milk adulteration of water buffalo dairy products and potential proteomic solutions.

The European reference method (ERM) recognises the fraudulent addition of bovine (B) milk in water buffalo (WB) milk/dairy products based on concomitant isoelectric focusing (IEF) detection of B γ2- and γ3-CN fragments after corresponding plasminolysis. We here used proteomics to characterise false positive results occurring in the ERM as being due to WB β-CN(f100-209), which is also formed after plasminolysis of genuine WB milk/dairy products and comigrates in IEF with B γ2-CN. These ERM limitations were overcome by a dedicated proteomic procedure based on loading of B/WB milk/cheese CN extracts on a hydroxyapatite column, in situ trypsinolysis and elution of B β-CN(f1-25)4P and WB β-CN(f1-28)4P proteotypic peptides. Based on their similar ionisation properties and resolution in MALDI-TOF-MS, these phosphopeptides were identified as suitable markers for detection of B material in WB milk/dairy products to a detection limit of 0.8% v/v. This proteomic procedure is here proposed as integrative/alternative to the ERM.

Application of a Quantitative LC-MS Multiattribute Method for Monitoring Site-Specific Glycan Heterogeneity on a Monoclonal Antibody Containing Two N-Linked Glycosylation Sites.

A significant challenge of traditional glycan mapping techniques is that they do not provide site-specific glycosylation information. Therefore, for proteins containing multiple glycosylation sites, the individual glycan species present at a particular site cannot be differentiated from those species present at the other glycosylation sites on the molecule. Quantification of glycoform has previously been demonstrated using a multiattribute method (MAM), which can quantify multiple post-translational modifications including deamidation, oxidation, glycosylation variants, and fragmentation ( Rogers, R. S.; Nightlinger, N. S.; Livingston, B.; Campbell, P.; Bailey, R.; Balland, A. MAbs 2015 , 7 , 881 - 890 ; ref 1). In this paper we describe the application of an MAM based method for site specific quantification of N-linked glycan heterogeneity present on an IgG1 mAb molecule containing two distinct N-linked glycosylation sites: one present on the heavy chain (HC) variable region (Fab) and the other present on the conserved HC constant region (Fc). MAM is a peptide mapping method utilizing mass spectrometry to detect and quantify specific peptides of interest. The ionization properties of the glycopeptides with different classes of glycan structural variants, including high mannose, sialylated, and terminal galactosylated species were studied in detail. Our results demonstrate that MAM quantification of individual glycan species from both the Fab and Fc N-Linked glycosylation sites is consistent with quantification using the traditional hydrophilic interaction liquid chromatography (HILIC) analysis of enzymatically released and fluorescently labeled glycans. Furthermore, no significant impact from the glycoform on the ionization properties of the glycopeptide is observed. Our work demonstrates that the MAM method is a suitable approach for providing quantitative, site-specific glycan information for profiling of N-linked glycans on immunoglobulins.

Direct aqueous measurement of 25-hydroxyvitamin D levels in a cellular environment by LC-MS/MS using the novel chemical derivatization reagent MDBP.

Vitamin D measurements in biological fluids by mass spectrometry are challenging at very low concentration levels. As a result, chemical derivatization is often employed to enhance the ionization properties of low abundant vitamin D compounds. Cookson-type reagents such as 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) or similar derivatives work well but require careful, water-free experimental conditions, as traces of water inactivate the reagent and inhibit or stop the derivatization reactions, thus making quantitative measurements in aqueous samples impossible. We describe a novel electrospray liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for determining 25-hydroxyvitamin D3 (25(OH)D3) directly in aqueous cellular systems using a new derivatization reagent, the ionic liquid 12-(maleimidyl)dodecyl-tri-n-butylphosphonium bromide (MDBP). The proof-of-concept for the MDBP assay was demonstrated by measuring the levels of 25(OH)D3 in four different human cell types, namely T cells, helper T cells, B cells, and macrophages. In addition to the ability to determine the levels of 25(OH)D3 directly in aqueous samples, the cellular integrity was maintained in our application. We show the time-dependent uptake of 25(OH)D3 into the investigated cells to demonstrate the applicability of the new label. Furthermore, the MDBP derivatization technique may be equally useful in imaging mass spectrometry, where it could be used for response enhancements of spatially localized vitamin D metabolites on wet tissue surfaces, without destroying the integrity of the tissue surface. Graphical Abstract MDBP labelling of 25-hydroxyvitamin D in the extracellular space.

How side chains affect conformation and electrical properties of poly(acrylic acid) in solution?

To better understand the effect of side chains on the chain conformation and electrical properties of polyelectrolytes, dielectric measurements were carried out on solutions of poly(acrylic acid) (PAA), poly(acrylic acid)-graft-dodecyl (PAA-g-dodecyl), and poly(acrylic acid)-graft-poly(ethylene oxide) (PAA-g-PEO) over a wide concentration range. Double dielectric relaxations with counterion distribution were observed for these polymers and a refined double-layer polarization model was proposed to analyze these, by which valuable information about conformations and interfacial electrokinetic properties was obtained. The transitional concentrations for the overlapping and entanglement of chains were identified from results for the dielectric increment and relaxation time. The concentration dependences of the ratio of effective charges were estimated from conductivity data. It was shown that effective charges on PAA were greatly influenced by PEO or dodecyl side chains, which caused steric hindrance of counterion binding and further dissociation of carboxylic groups or bound counterions. Moreover, a mutual superposition and offsetting effect of PEO and dodecyl side chains was observed. An enhancement in the interpenetration of counterion atmospheres as a result of side chains was also found. In addition, the rate constant ratio and the distance of counterion fluctuations perpendicular to the chains were estimated. It was demonstrated that the effects of side chains on the effective charges or ionization properties of GCP play an important role in their conformation, counterion distribution, and fluctuation.

UNRAVELLING THE COMPLEX STRUCTURE OF AGN-DRIVEN OUTFLOWS. II. PHOTOIONIZATION AND ENERGETICS

ABSTRACT Outflows have been shown to be prevalent in galaxies hosting luminous active galactic nuclei (AGNs); they present a physically plausible way to couple the AGN energy output with the interstellar medium of their hosts. Despite their prevalence, accurate characterization of these outflows has been challenging. In the second of a series of papers, we use Gemini Multi-Object Spectrograph integral field unit (IFU) data of six local (z < 0.1) and moderate-luminosity Type 2 AGNs to study the ionization properties and energetics of AGN-driven outflows. We find strong evidence connecting the extreme kinematics of the ionized gas to the AGN photoionization. The kinematic component related to the AGN-driven outflow is clearly separated from other kinematic components, such as virial motions or rotation, on the velocity and velocity dispersion diagram. Our spatially resolved kinematic analysis reveals that 30 to 90% of the total mass and kinetic energy of the outflow is contained within the central kpc of the galaxy. The spatially integrated mass and kinetic energy of the gas entrained in the outflow correlate well with the AGN bolometric luminosity and results in energy conversion efficiencies between 0.01% and 1%. Intriguingly, we detect ubiquitous signs of ongoing circumnuclear star formation. Their small size, the centrally contained mass and energy, and the universally detected circumnuclear star formation cast doubts on the potency of these AGN-driven outflows as agents of galaxy-scale negative feedback.