Two Fast GC-MS Methods for the Measurement of Nicotine, Propylene Glycol, Vegetable Glycol, Ethylmaltol, Diacetyl, and Acetylpropionyl in Refill Liquids for E-Cigarettes.

The use of e-cigarettes (ECs) has become increasingly popular worldwide, even though scientific results have not established their safety. Diacetyl (DA) and acetylpropionyl (AP), which can be present in ECs, are linked with lung diseases. Ethyl maltol (EM)-the most commonly used flavoring agent-can be present in toxic concentrations. Until now, there is no methodology for the determination of nicotine, propylene glycol (PG), vegetable glycerin (VG), EM, DA, and acetylpropionyl in e-liquids that can be used as a quality control procedure. Herein, gas chromatography coupled with mass spectrometry (GC-MS) was applied for the development of analytical methodologies for these substances. Two GC-MS methodologies were developed and fully validated, fulfilling the standards for the integration in a routine quality control procedure by manufacturers. As proof of applicability, the methodology was applied for the analysis of several e-liquids. Differences were observed between the labeled and the experimental levels of PG, VG, and nicotine. Three samples contained EM at higher concentrations compared to the other samples, while only one contained DA. These validated methodologies can be used for the quality control analysis of EC liquid samples regarding nicotine, PG, and VG amounts, as well as for the measurement of the EM.

[External fixator of the elbow]. / Fixateur externe am Ellenbogen.

AIM OF SURGERY: The placement of an external elbow fixator can be statically carried out as temporary stabilization or as a hinged movement fixator. As a hinged movement fixator a functional follow-up treatment is possible due to control of the joint guidance and reduction of the compromising forces on the osteoligamentous structures. INDICATIONS: As a temporary stabilization of the elbow, the external fixator is used as a damage control method. As a movement fixator it is used as an additional protection and movement control after complex osteoligamentous interventions and persisting tendency to dislocation of the joint and also as a standalone procedure. In some cases, the procedure is also used in distraction arthrolysis of stiff elbows and as a salvage procedure in patients with relevant comorbidities as part of fracture treatment. CONTRAINDICATIONS: Inexperience in relation to the procedure as well as a local acute infection at the level of the intended pin locations should specifically be mentioned as contraindications. In addition, compliance and patient understanding of the procedure are essential for the success of treatment. SURGICAL TECHNIQUE: Soft tissue preparation for pin placement should be preferred over percutaneous incisions to enable a safe bone exposure. Knowledge of the course of neurovascular structures (particularly the radial nerve) is essential. When placing a hinge, knowledge of the position and detection of the idealized center of rotation is of fundamental importance. POSTOPERATIVE MANAGEMENT: The type of postoperative management required essentially depends on the underlying injury. When placing a hinged fixator, the aim is to enable movement as early as possible. Nevertheless, blocking of the hinged fixator may be useful for a short period of time. Adequate pin care over the duration of the treatment is essential in order to prevent complications. RESULTS: Good functional results have been reported for the treatment of unstable elbows after primary and secondary placement of a hinged external fixator. Good functional scores and improvement in the range of motion were also recorded in the context of an arthrolysis (additive for open arthrolysis or distraction arthrolysis); however, in contrast a significant number of complications associated with this surgery are likely to emerge. As a definitive salvage procedure, satisfactory results were obtained in a small case series of a selected older patient group with relevant comorbidities.

Evaluation of the Compliance of Orthodontists to Infection Control Procedures in Turkey.

OBJECTIVE: Orthodontists do not perform surgical procedures, nevertheless they are obliged to practice appropriate sterilization techniques to prevent cross-infection. This is also important from an ethical and legal point of view. The aim of the present study is to evaluate the compliance of orthodontists to infection control procedures in Turkey. METHODS: A questionnaire with 36 items was delivered by e-mail to a total of 1152 orthodontists/residents between October 2014 and March 2015 by the Turkish Orthodontic Society. Various data from surveys were analyzed using the IBM SPSS statistics 22 software. RESULTS: The questionnaire was completed by 130 (11.28%) respondents. 95.4% of the orthodontists were immunized against hepatitis B. The usage rates of type B autoclave, non-type B autoclave, and dry-heat sterilizer were 40%, 17.7%, and 16.9%, respectively. A total of 24.6% of the orthodontists used disinfectant solutions for the sterilization of hand instruments and pliers; the rate of using disinfectants for the sterilization of dental handpieces was found to be higher (56.9%). CONCLUSION: The infection control procedures in the field of orthodontics must be improved in Turkey. Training on compliance with the infection control principles should be included in education programs, and these programs should be repeated on a regular basis.

Longitudinal monitoring of reconstructed activity concentration on a clinical time-of-flight PET/CT scanner.

Positron emission tomography (PET) images are potential quantitative biomarkers. Understanding long-term (months/years) biomarker variability is important for establishing confidence intervals on studies using such biomarkers over these time frames. PET biomarkers are derived from activity concentration ([Formula: see text]) extracted from PET images. Over 30 months, we measured the stability of decay-normalized counts ([Formula: see text]) and [Formula: see text] by scanning the same 4.5-cm-diameter Ge-68 cylinder weekly, the same Na-22 point source daily, and a refilled 20-cm F-18 cylinder phantom monthly on a clinical TOF-PET/CT scanner. Longitudinal and adjacent-measurement variability was characterized. We found no drift in [Formula: see text] or [Formula: see text] for properly calibrated images over 24 months. During this time, [Formula: see text] ranged [Formula: see text] to 6% for count-matched Ge-68 and F-18 images, with coefficient of variation (COV) across time of 2.3% (Ge-68, 81 scans) and 3.2% (F-18, 24 scans). At typical patient image count levels the Ge-68 [Formula: see text] ([Formula: see text]) COV across time was 6.9% (9.6%). Changes in [Formula: see text] between adjacent F-18 scans ([Formula: see text]) ranged between [Formula: see text], with corresponding date-matched changes in Ge-68 [Formula: see text] ranging [Formula: see text]. We recommend (1) tracking trends in [Formula: see text] with image [Formula: see text] as a check of quantitative data corrections/calibrations and (2) tracking both mean and COV of [Formula: see text] (single time point measures) to hundredths precision using standardized uptake values.

A novel quantitative evaluation method for quality control results.

BACKGROUND: Quality control (QC) procedures using stable control materials are important for preventing systematic errors (SEs). While the current QC methods assess QC results semi-quantitatively, we designed a novel quantitative QC procedure (QQCP). METHODS: QC results were expressed as Z-scores to analyze results quantitatively. The decision values were accumulated up to 30, with three decision values per run, and were compared to rejection criteria at each run. The probability for false rejection (Pfr) and error detection (Ped) for the QQCP and Westgard multirule methods were estimated using simulated QC data with SEs ranging from 0 to 3 standard deviations (SDs). RESULTS: The Pfr of the QQCP was 3.4% at the 10th run. When 2 QC materials with the same SEs (0.5 SD and 1.0 SD) were used, the Peds were 36.1% and 95.7% at run 10, respectively. When the SE of each material was greater than 1.5 SDs, the Ped reached 100% at run 10. The QQCP could detect more than 99% of errors in the 6th, 4th, 3rd, and 2nd runs for 2 QC results with 1.5, 2.0, 2.5, and 3.0 SD SEs, respectively. CONCLUSION: The QQCP exhibited a Ped value up to 3.3-fold higher than the Westgard method. Implementation of the QQCP would satisfy the high quality goals derived from biological variations.

Evaluating the presence versus absence of the reinforcer during extinction.

The purpose of this study was to assess the effects of extinction when the reinforcer was present versus absent. These effects were examined with 2 human operant procedures (i.e., a computer program and a mechanical apparatus) with college students as participants. Discriminable properties of the apparatus appeared to influence responding during extinction. In general, responding during extinction was less likely with the mechanical apparatus when the reinforcer was absent and more likely with the computer program.

Spinal epidural hematoma after pain control procedure.

Spinal epidural hematoma is a rare complication associated with pain control procedures such as facet block, acupuncture, epidural injection, etc. Although it is an uncommon cause of acute myelopathy, and it may require surgical evacuation. We report four patients with epidural hematoma developed after pain control procedures. Two procedures were facet joint blocks and the others were epidural blocks. Pain was the predominant initial symptom in these patients while two patients presented with post-procedural neurological deficits. Surgical evacuation of the hematoma was performed in two patients while in remaining two patients, surgery was initially recommended but not performed since symptoms were progressively improved. Three patients showed near complete recovery except for one patient who recovered with residual deficits. Although, spinal epidural hematoma is a rare condition, it can lead to serious complications like spinal cord compression. Therefore, it is important to be cautious while performing spinal pain control procedure to avoid such complications. Surgical treatment is an effective option to resolve the spinal epidural hematoma.

Human responding on random-interval schedules of response-cost punishment: the role of reduced reinforcement density.

An experiment with adult humans investigated the effects of response-contingent money loss (response-cost punishment) on monetary-reinforced responding. A yoked-control procedure was used to separate the effects on responding of the response-cost contingency from the effects of reduced reinforcement density. Eight adults pressed buttons for money on a three-component multiple reinforcement schedule. During baseline, responding in all components produced money gains according to a random-interval 20-s schedule. During punishment conditions, responding during the punishment component conjointly produced money losses according to a random-interval schedule. The value of the response-cost schedule was manipulated across conditions to systematically evaluate the effects on responding of response-cost frequency. Participants were assigned to one of two yoked-control conditions. For participants in the Yoked Punishment group, during punishment conditions money losses were delivered in the yoked component response independently at the same intervals that money losses were produced in the punishment component. For participants in the Yoked Reinforcement group, responding in the yoked component produced the same net earnings as produced in the punishment component. In 6 of 8 participants, contingent response cost selectively decreased response rates in the punishment component and the magnitude of the decrease was directly related to the punishment schedule value. Under punishment conditions, for participants in the Yoked Punishment group response rates in the yoked component also decreased, but the decrease was less than that observed in the punishment component, whereas for participants in the Yoked Reinforcement group response rates in the yoked component remained similar to rates in the no-punishment component. These results provide further evidence that contingent response cost functions similarly to noxious punishers in that it appears to suppress responding apart from its effects on reinforcement density.

Spinal Epidural Hematoma after Pain Control Procedure

Spinal epidural hematoma is a rare complication associated with pain control procedures such as facet block, acupuncture, epidural injection, etc. Although it is an uncommon cause of acute myelopathy, and it may require surgical evacuation. We report four patients with epidural hematoma developed after pain control procedures. Two procedures were facet joint blocks and the others were epidural blocks. Pain was the predominant initial symptom in these patients while two patients presented with post-procedural neurological deficits. Surgical evacuation of the hematoma was performed in two patients while in remaining two patients, surgery was initially recommended but not performed since symptoms were progressively improved. Three patients showed near complete recovery except for one patient who recovered with residual deficits. Although, spinal epidural hematoma is a rare condition, it can lead to serious complications like spinal cord compression. Therefore, it is important to be cautious while performing spinal pain control procedure to avoid such complications. Surgical treatment is an effective option to resolve the spinal epidural hematoma.

[Epidemiologic characteristics and prevention of viral nosocomial infections]. / Particularités épidémiologiques et prévention des infections nosocomiales virales.

OBJECTIVES: To describe epidemiological features of viral nosocomial infections (VNI) and their prevention principles. EPIDEMIOLOGY: Many factors lead to underestimate VNI: difficulty to distinguish between community-acquired and nosocomial infections for seasonal viral diseases, incubation time leading to symptoms after patient discharge, difficulty for diagnosis. Population at high risks of VNI are the children, the elderly and the immunocompromized patients. The risk of severe diseases is high in this last population. The main reservoir of virus is infected symptomatic or asymptomatic individuals. Asymptomatic carriers, especially health care workers, are a major source of transmission. Main routes of transmission are the fecal-oral route, the respiratory route, cutaneous or mucous contact and blood and body fluids exposure. A review of the main virus involved in VNI is presented. PREVENTION: Preventive measures, such as strict adherence to standard precautions and, in some instances, to isolation procedures, are critical to control VNI. In a major outbreak situation, it may be necessary to consider cohort isolation. Specific control measures rely on immunization, antiviral drug prophylaxis (varicella-zooster, herpes, influenza, exposure to blood) and clinical and biological screening of organ, blood, tissue and cell donors.