Reliability loss of boiling water reactors (BWRs) has often been reported due to intergranular stress corrosion cracking (IGSCC) on stainless steel of major components and piping of primary cooling systems [1]. In order to mitigate IGSCC, water chemistry, which is one of the major factors determining IGSCC [2,3], should be improved. Corrosive conditions of BWR primary cooling systems are caused by oxidants as a result of water radiolysis. The latest information has shown that corrosive conditions in BWRs are caused mainly by hydrogen peroxide (H2O2) [2]. In order to understand all of the phenomena associated with corrosion behaviour, application of in-situ measurements is one of the key technologies. However, corrosion behaviour itself is determined in a complex fashion by many water chemistry and material parameters.

OBJECTIVES The aims of this study were to evaluate whether the use of CT facilitates agreement among endodontists in selecting treatments for root-filled maxillary molars with apical periodontitis and to assess the efficacy of CT in choosing a treatment for such teeth. METHODS 39 root-filled maxillary molars from 34 patients with suspected apical periodontitis were independently evaluated by 4 endodontists and 1 postgraduate student (decision-makers). Treatment decisions were made based on intra-oral radiographs and a fictive clinical history. After 1-3 months, the same decision-makers repeated the examination of the same teeth but with additional information from a CT examination. Agreement between decision-makers with or without the availability of the CT results was measured with Cohen's kappa coefficient. Differences in selected treatments with or without accessibility to the CT results were plotted for the same endodontists using descriptive statistics. RESULTS The agreement in assessments among endodontists was slight or fair before the CT results were available (range: 0.081-0.535). No increase was observed after reviewing the CT results (range: 0.116-0.379). After the use of CT, the treatment plan was changed 38-76% of the time by all decision-makers, and the changes affected 57.8% of the cases in the study. CONCLUSIONS The endodontists in this study exhibited a low degree of agreement when choosing a treatment for root-filled maxillary molars with apical periodontitis. A CT examination of the investigated teeth did not result in a significantly higher degree of agreement, and CT frequently contributed to a shift in the selected therapy.

The aim of the present study was testing the hypothesis that the adoption of nickel-titanium rotary instrumentation (NTRI) will improve the technical quality of root-fillings. The investigation was carried out within a mandatory continuing education program (CEP) for general dental practitioners (GDPs). The study was conducted amongst GDPs employed by the Public Dental Health Service in the County of Stockholm. Identical questionnaires were distributed before the CEP (Pre-Q) and 9 to 12 months after the course (Post-Q). The CEP consisted of two parts: lectures and hands-on training. From each GDP, radiographs of two cases completed before the course and two cases treated 9-12 months after the course were randomly selected. Primarily molars were selected for evaluation. The radiographs were individually evaluated by two endodontists. Teeth treated before and after training were presented in random order. Adoption rate of NTRI increased from 35% to 75%. Cases from 124 GDPs were included in the final analysis. The rate of good quality root-fillings increased from 27% to 49% (p<.001). A significantly increased radiographic quality was found between GDPs adopting NTRI and those who did not. The GDPs produced root-fillings of very poor quality before as well as after the training period. However, the rate decreased from 29% to 12% amongst adopters and from 46% to 28% amongst non-adopters. Dentists considering canal preparation and root-filling as "easy" produced more frequently good quality root-fillings than the others (p<0.05). In conclusion, the results of the present study were in favour of the idea that a shift to NTRI increases the technical quality of root-fillings produced by GDPs. However, adopters still produce root-fillings of very poor quality. This important issue needs to be addressed in future studies.

Rationale. We have previously shown that the muscarinic acetylcholine M4 receptor is involved in the regulation of operant self-administration of alcohol in mice. However, it is not clear by which mechanisms the M4 receptor modulates alcohol drinking behaviour. Underlying traits such as anxiety, novelty seeking, and cognitive ability have previously …

Rationale. Glucagon-like-peptide-1 (GLP-1) is a gut- and neuro-peptide with an important role in the regulation of food intake and glucose metabolism. GLP-1 receptors (GLP-1R) are expressed in the brain reinforcement system and may be involved in the regulation of reward related behaviors. Indeed, GLP-1R activation results in …

Objective. The aim of this study was to study the long-term effect on root filling quality after the introduction of nickel titanium rotary instrumentation (NTRI) within a public dental health organization.Study design. After an education package, including hands-on training and/or lectures, the root filling quality was evaluated at the organizational level. All general dental practitioners (GDPs) employed at primary evaluation (n = 120) and after 4 years (n = 174) were included.Results. The improved root filling quality had been maintained 4 years later. The frequency of excellent root fillings was slightly higher at the long-term follow-up (52%) compared with the short-term follow-up (45%; P = .038). A nonsignificant decrease in very poor-quality root fillings was registered.Conclusions. A technology shift among GDPs to NTRI will increase the rate of good-quality root fillings. However, the shift per se will not eliminate the problem of substandard clinical performance. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;112:814-819)

New stress corrosion studies are presented from initiation tests and crack growth measurements on Alloy 600 in primary PWR environment. The effects of hydrogen, lithium and boron have been studied. Initiation tests have been performed at a high hydrogen content of 70 cc/kg. A longer initiation time was measured compared to intermediate levels but shorter than for low hydrogen concentration of 5 ml/kg. Initiation tests at a Li content of 6 ppm have also been performed. The time to initiation was longer than for 3.5 ppm and about the same as for 2.2 ppm. In addition crack growth measurements using different Li/B contents to simulate a reactor cycle and study any variations with the different composition has been performed. The results show a weak influence of the primary environment. A correlation with the boron concentration was noticed and for high boron contents also a weak dependence on the lithium concentration. The results show that the beginning of cycle conditions usually used for PWSCC studies creates conservative crack growth rates.

Despite the generally held view that alcohol is an unspecific pharmacological agent, recent molecular pharmacology studies demonstrated that alcohol has only a few known primary targets. These are the NMDA, GABA(A), glycine, 5-hydroxytryptamine 3 (serotonin) and nicotinic ACh receptors as well as L-type Ca2+ channels and G-protein-activated inwardly rectifying K+ channels. Following this first hit of alcohol on specific targets in the brain, a second wave of indirect effects on a variety of neurotransmitter/neuropeptide systems is initiated that leads subsequently to the typical acute behavioural effects of alcohol, ranging from disinhibition to sedation and even hypnosis, with increasing concentrations of alcohol. Besides these acute pharmacodynamic aspects of alcohol, we discuss the neurochemical substrates that are involved in the initiation and maintenance phase of an alcohol drinking behaviour. Finally, addictive behaviour towards alcohol as measured by alcohol-seeking and relapse behaviour is reviewed in the context of specific neurotransmitter/neuropeptide systems and their signalling pathways. The activity of the mesolimbic dopaminergic system plays a crucial role during the initiation phase of alcohol consumption. Following long-term, chronic alcohol consumption virtually all brain neurotransmission seems to be affected, making it difficult to define which of the systems contributes the most to the transition from controlled to compulsive alcohol use. However, compulsive alcohol drinking is characterized by a decrease in the function of the reward neurocircuitry and a recruitment of antireward/stress mechanisms comes into place, with a hypertrophic corticotropin-releasing factor system and a hyperfunctional glutamatergic system being the most important ones.

AIM:To test the hypothesis that an increased utilization of nickel-titanium rotary instrumentation (NTRI) by general dental practitioners will lead to an increased frequency of good quality root fillings. A second aim was to determine whether the educational format would exert influence on the quality.METHODOLOGY:Dentists were assigned at random to three intervention groups: a 4-h lecture (L-group, n = 40); a 4-h lecture plus a full day hands-on course (LH-group, n = 40); or a control group receiving no instruction (n = 68). The control group received education later on in the study. Radiographs of two root filled molar teeth per dentist were selected at random before the start of the education program and after a 6-month clinical learning period. Using length, seal and shape of root-fillings a 5-level variable was created.RESULTS:The rate of good quality root fillings increased after the introduction of NTRI. Calculated over all types of roots the frequency of excellent (score 1) root fillings increased from 31% to 51% (P = 0.006) in the L-group and from 27% to 47% (P = 0.016) in the LH-group. The frequency of low quality root-fillings (score 5) dropped in the L-group from 22% to 16% (P = 0.29) and in the LH-group from 13% to 9% (P = 0.48). No statistically significant difference was seen among the controls.CONCLUSIONS:When NTRI technology replaced manual stainless steel techniques the rate of good quality root fillings increased. A significant drop in the rate of low quality root fillings was not found.

The present investigation recorded the 2-year clinical and radiographic outcome of one- and two visit endodontic treatment and studied the significance of the bacteriologic sampling results on the outcome. A randomization procedure allocated 53 teeth to one-visit treatment and 48 teeth to two-visit treatment. At the end of the study period, 32 teeth (65%) in the one-visit group and 30 teeth (75%) in the two-visit group were classified as healed. The statistical analysis of the healing results did not show any significant difference between the groups (p=0.75). Forty-nine (80%) of the 61 teeth that were obturated after a negative micobiologic sample were classified as healed. Teeth sealed after positive samples healed in 44%. The present study gave evidence that similar healing results might be obtained through one- and two-visit antimicrobial treatment.

Aim To study the influence of two educational programmes on the adoption of nickel-titanium rotary instrumentation (NTRI) amongst general dental practitioners in a short-term as well as a long-term perspective.Methodology All dentists employed in the Gothenburg Dental service (n = 148) were enrolled in the study. The clinics in the organization were randomly assigned to one of two educational programmes. In the first programme a 4-h lecture on root canal instrumentation was given. In the second programme the lecture course was supplemented by a 6-h hands-on training session. The short-term effect was measured by a questionnaire distributed 6 months after completed education. The long-term effect was evaluated 4 years later.Results The overall utilization rate of NTRI increased from 4% to 73%. However, lectures in combination with hands-on training resulted in a better short-term acceptance rate (94%) than if teaching was given only in lecture-format (53%) (P = 0.000). As a consequence, all staff were offered hands-on training. The long-term adoption rate was 88%. Reasons for accepting the new technology usually were found within the 'relative advantage' category. Common reasons for dentists not to adopt NTRI were that they could not get started or that they found no advantage over the old technology.Conclusions The short-term adoption of a new technology might be influenced by the design of an introductory educational programme. For clinical procedures, such as root canal instrumentation, the inclusion of hands-on training sessions seems to be important to reach a high acceptance rate.