Performance evaluation of a hybrid linear ion trap/orbitrap mass spectrometer

Design and performance of a novel hybrid mass spectrometer is described. It couples a linear ion trap mass spectrometer to an orbitrap mass analyzer via an rf-only trapping quadrupole with a curved axis. The latter injects pulsed ion beams into a rapidly changing electric field in the orbitrap wherein they are trapped at high kinetic energies around an inner electrode. Image current detection is subsequently performed after a stable electrostatic field is achieved. Fourier transformation of the acquired transient allows wide mass range detection with high resolving power, mass accuracy, and dynamic range. The entire instrument operates in LC/MS mode (1 spectrum/s) with nominal mass resolving power of 60,000 and uses automatic gain control to provide high-accuracy mass measurements, within 2 ppm using internal standards and within 5 ppm with external calibration. The maximum resolving power exceeds 100,000 (fwhm). Rapid, automated data-dependent capabilities enable real-time acquisition of up to three high-mass accuracy MS/MS spectra per second.     

Social desirability: Its relevance to the measurement of hopelessness and suicidal behavior.

Replies to J. S. Nevid's (see record 1983-11675-001) comments on an article by the present authors (see record 1982-01443-001) examining the relationship between social desirability (SD), hopelessness, and reports of suicidal ideation/behavior. Further data on the relationship of SD, hopelessness, and prediction of future suicidal behavior collected from an inpatient psychiatric population (N?=?44) are analyzed. Results are similar to those obtained in the original study, thus strengthening confidence in those results. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reasons for staying alive when you are thinking of killing yourself: The Reasons for Living Inventory.

65 adults generated 72 distinct reasons for not committing suicide; these were reduced to 48 by factor analyses performed on 2 additional samples, and the items were arranged into the Reasons for Living Inventory (RFL), which requires a rating of how important each reason would be for living if suicide were contemplated. In addition, factor analyses indicated 6 primary reasons for living: Survival and Coping Beliefs, Responsibility to Family, Child-Related Concerns, Fear of Suicide, Fear of Social Disapproval, and Moral Objections. The RFL was then given to 2 additional samples, 197 Seattle shoppers (mean age 36 yrs) and 175 psychiatric inpatients (mean age 31 yrs). Both samples were divided into several suicidal (ideators and parasuicides) and nonsuicidal groups. Separate multivariate ANOVAs indicated that the RFL differentiated suicidal from nonsuicidal Ss in both samples. In the shopping-center sample, the Fear of Suicide scale further differentiated between previous ideators and previous parasuicides. In the clinical sample, the Child-Related Concerns scales differentiated between current suicide ideators and current parasuicides. In both samples, the Survival and Coping, the Responsibility to Family, and the Child-Related Concerns scales were most useful in differentiating the groups. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of physical attractiveness on therapists' initial judgments of a person's self-concept.

Videotapes and audiotapes were made of interviews with attractive and unattractive males and females. Ratings of attractiveness were derived from peer judgments of photographs of 83 undergraduates; the 2 most attractive males, 2 least attractive males and a similar number of females were selected as stimulus persons. 13 male and 3 female graduate students in clinical psychology rated the person they had heard (seen) as to self-concept. As hypothesized, physically attractive persons of both sexes were rated as having better self-concepts than unattractive persons. Further, the self-concept ratings of attractive females increased significantly from the audiotape to the videotape conditions, whereas the ratings of all the other stimulus persons remained the same. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Complementary variational principles with fractional derivatives

Complementary variational principles for a class of fractional boundary value problems are formulated. They are used for the error estimates of solutions for a general mechanical problems, first Painlevé equation also given in the form with fractional derivatives and in the task of image regularization.     

Experimental Investigation of Microstructure and Phase Transitions in Ag-Cu-Zn Brazing Alloys

Microstructure and phase transitions of selected brazing alloys from the Ag-Cu-Zn ternary system were investigated. Four ternary alloys with silver content in the compositional range from 25 to 60 wt.% were studied using x-ray diffraction (XRD) and scanning electron microscopy coupled with the energy-dispersive spectroscopy (SEM–EDS). Phase transitions of the investigated alloys were measured using differential scanning calorimetry (DSC). Experimentally obtained results were compared with the results of a thermodynamic calculation of the phase equilibria according to the CALPHAD method. The experiments confirmed the optimized thermodynamic parameters for the calculations from the thermodynamic assessment in literature. Phase compositions, liquidus and solidus temperatures were confirmed by the EDS and DTA methods. Additionally, the calculated solidification paths and predicted phase transformations were in agreement with the SEM images.     

Discovery of New Classes of Compounds that Reactivate Acetylcholinesterase Inhibited by Organophosphates

Acetylcholinesterase (AChE) that has been covalently inhibited by organophosphate compounds (OPCs), such as nerve agents and pesticides, has traditionally been reactivated by using nucleophilic oximes. There is, however, a clearly recognized need for new classes of compounds with the ability to reactivate inhibited AChE with improved in vivo efficacy. Here we describe our discovery of new functional groups—Mannich phenols and general bases—that are capable of reactivating OPC‐inhibited AChE more efficiently than standard oximes and we describe the cooperative mechanism by which these functionalities are delivered to the active site. These discoveries, supported by preliminary in vivo results and crystallographic data, significantly broaden the available approaches for reactivation of AChE.