Secondary ionization of chemical warfare agent simulants: atmospheric pressure ion mobility time-of-flight mass spectrometry

For the first time, the use of a traditional ionization source for ion mobility spectrometry (radioactive nickel ((63)Ni) beta emission ionization) and three alternative ionization sources (electrospray ionization (ESI), secondary electrospray ionization (SESI), and electrical discharge (corona) ionization (CI)) were employed with an atmospheric pressure ion mobility orthogonal reflector time-of-flight mass spectrometer (IM(tof)MS) to detect chemical warfare agent (CWA) simulants from both aqueous- and gas-phase samples. For liquid-phase samples, ESI was used as the sample introduction and ionization method. For the secondary ionization (SESI, CI, and traditional (63)Ni ionization) of vapor-phase samples, two modes of sample volatilization (heated capillary and thermal desorption chamber) were investigated. Simulant reference materials, which closely mimic the characteristic chemical structures of CWA as defined and described by Schedule 1, 2, or 3 of the Chemical Warfare Convention treaty verification, were used in this study. A mixture of four G/V-type nerve simulants (dimethyl methylphosphonate, pinacolyl methylphosphonate, diethyl phosphoramidate, and 2-(butylamino)ethanethiol) and one S-type vesicant simulant (2-chloroethyl ethyl sulfide) were found in each case (sample ionization and introduction methods) to be clearly resolved using the IM(tof)MS method. In many cases, reduced mobility constants (K(o)) were determined for the first time. Ion mobility drift times, flight times, relative signal intensities, and fragmentation product signatures for each of the CWA simulants are reported for each of the methods investigated.     

Inverse Probleme in der Elektrotechnik

Ohne Zusammenfassung     

Towards an optimised lab procedure for long-term oxidative ageing of asphalt mix specimen

Ageing of bitumen leads to increased stiffness and brittleness. Thus, bituminous bound pavements become more prone to failure by low-temperature and fatigue cracking. Therefore, the ageing behaviour of bitumen has a crucial impact on durability, as well as recyclability of pavements. To assess ageing of bitumen, the rolling thin film oven test and pressure ageing vessel are standardised methods for short-term and long-term ageing in the lab. For lab-ageing of hot mix asphalt (HMA), various methods have been developed in the last decades. This paper presents a study on the potential of employing a highly oxidant gas for simulating the long-term oxidative ageing of asphalt mix specimens in the lab. Based on the results, an optimised lab-ageing procedure (Viennese Ageing Procedure – VAPro) for compacted HMA specimens to assess mix performance of long-term lab-aged specimens is developed. Thus, it is possible to optimise mix design not only for short-term performance but to take into account effects of oxidative ageing during its in-service life. VAPro is based on a triaxial cell with forced flow of a gaseous oxidant agent through the specimen. The oxidant agent is enriched in ozone and nitric oxides to increase the rate of oxidation. It is shown by stiffness tests of unaged and lab-aged specimens, as well as by Dynamic Shear Rheometer tests of recovered binder from aged specimens that asphalt mixes can be long-term aged at moderate temperatures (+60°C) and within 4 days and a flow rate of 1 l/min by applying VAPro. Thus, an ageing procedure is at hand that can simulate long-term ageing at conditions that are representative of conditions that occur in the field within an efficient amount of time.     

Is there a diagnostic role for bone scanning of patients with a high pretest probability for metastatic renal cell carcinoma?

A 66-year-old woman was admitted to our hospital complaining of abdominal pain and jaundice. Upper gastrointestinal series and computed tomography revealed pancreatic cancer. Pancreatectomy could not be performed because of portal invasion and multiple liver metastasis. Cholecystectomy, choledochojejunostomy and gastrojejunostomy were performed. The patient was treated with methotrexate (MTX) 100 mg/m2 i.v. followed one hour later with 5-fluorouracil (5-FU) 700 mg/m2. Leucovorin rescue of 10 mg po was given 24 hours after MTX administration. Treatment was repeated every 14 days. As a result, the size of a primary tumor of the pancreas was reduced (42%) on computed tomography, and the CEA level decreased to 27.8 ng/ml from 84 ng/ml. No side effects were observed. The patient continued to receive chemotherapy at our outpatient clinic for 20 months. She died of exacerbation of carcinomatous peritonitis 23 months after initial admission. Therefore, we conclude that MTX/5-FU sequential therapy seems beneficial to manage advanced pancreatic carcinoma from the viewpoint of antineoplastic activity as well as quality of life.     

New multiparty authentication services and key agreement protocols

Many modern computing environments involve dynamic peer groups. Distributed simulation, multiuser games, conferencing applications, and replicated servers are just a few examples. Given the openness of today's networks, communication among peers (group members) must be secure and, at the same time, efficient. This paper studies the problem of authenticated key agreement in dynamic peer groups with the emphasis on efficient and provably secure key authentication, key confirmation, and integrity. It begins by considering two-party authenticated key agreement and extends the results to group Diffie-Hellman (1976) key agreement. In the process, some new security properties (unique to groups) are encountered and discussed     

Conjointanalyse-basierte Produkt(linien)gestaltung unter Berücksichtigung von Konkurrenzreaktionen Conjoint-based product (line) design considering competitive reactions

Ausgangspunkt unserer Untersuchungen zur Conjointanalyse-basierten wettbewerbsorientierten Produktgestaltung bilden segmentspezifische konditionale MNL-Modelle. Bisher auf diesem Gebiet entwickelte Ans?tze, die sich mit der Bestimmung von Marktgleichgewichten befassen, beschr?nken sich ausschlie?lich auf den Single-Produkt-Fall (z.B. Choi u. DeSarbo, 1993; Green u. Krieger, 1997). Unser Beitrag setzt sich ebenfalls mit dem Single-Produkt-Fall (d.h. ein Produkt je Anbieter) auseinander, behandelt darüber hinaus erstmals aber auch den Wettbewerb mit Produktlinien. Gegenstand der Untersuchungen sind insbesondere die Existenz und Eindeutigkeit simultaner Positions-Preis- Gleichgewichte, die Existenz ineffizienter Marktgleichgewichte sowie der Differenzierungsgrad zwischen Konkurrenzprodukten.     

Gender dysphoria, gender reorientation, and the clinical management of transsexualism.

Conducted 2 studies of gender dysphoria and postoperative adjustment by transsexuals. Study 1 examined the relation of gender reorientation (approximation of the status of the opposite biological sex) to psychological adjustment in gender dysphorics. Three S groups (75 heterosexual males, mean age 36.7 yrs; 85 homosexual males, mean age 29.8 yrs; and 103 biological females, mean age 27.4 yrs) were studied in multiple regression analyses, with psychological symptoms as criteria and measures of 3 roughly sequential components of gender reorientation (role changes, document changes, and physical changes), age, and education as predictors. Psychological complaints correlated negatively with the earliest phase of reorientation for females and with the later phases for males. Age and education bore little relation to current symptoms. Results suggest that psychological improvement accompanies gender reorientation in both male and female gender dysphorics; the greatest degree of improvement is seen earlier in the process for females. Ss in Study 2 were postoperative transsexuals (32 homosexual males, mean age 33.2 yrs; 9 heterosexual males, mean age 47.7 yrs; and 38 biological females, mean age 32.6 yrs) at least 1 yr after surgery. Follow-up rate was 77.5% for all Ss meeting the 1-yr criterion. Satisfaction with surgery was high, and psychosocial adjustment was acceptable for the majority. Results of both studies support the rationale for clinical intervention in aid of gender reorientation in selected cases. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Referate

Ohne Zusammenfassung     

Analysis of recovery from behavioral asymmetries induced by unilateral removal of vibrissae in the rat.

Unilateral removal of vibrissae in rats induces an asymmetry in the side of the face used to scan the wall while traversing the edge of an open field (thigmotactic scanning). This behavioral asymmetry recovers over time. The time course of asymmetry and recovery was systematically analyzed by testing groups of rats deprived of vibrissae for different periods of time. The preferential use of the hemiface with intact vibrissae persisted up to 3 days after vibrissae removal. It was expressed maximally during the first minute of testing. This phase was followed by a rapid return to symmetry by Day 6. Recovery to symmetry involved both a decrease in duration of scanning with the vibrissae-intact side and an increase with the vibrissae-clipped side of the face, with the total duration remaining constant throughout the states of asymmetry and recovery. The time course of behavioral recovery corresponds to the time course of neural plasticity in the basal ganglia that accompanies hemivibrissotomy, a result suggesting a functional link between the two phenomena. (PsycINFO Database Record (c) 2010 APA, all rights reserved)