Learning curves of robotic technology in an orthopedic teaching hospital.

BACKGROUND: In recent years there has been an increasing implementation of robotic technology in arthroplasty. Due to the unclear data situation the aim of this study was to analyze the learning curve for robotic technology in residency training. METHODS: After its introduction, the first 351 consecutive robotic knee replacements were prospectively included in the study. Surgical times, preoperative and postoperative radiographs, intraoperatively recorded alignment data and complications were analyzed. Satisfaction, revision, and referral rates were determined in a 90-day follow-up survey. Data from the last 350 navigated total knee arthroplasties were analyzed as a historical control group. RESULTS: A learning curve of between 3 and 53 procedures was identified, depending on the surgeon, with further reductions in time measured even after 1 year of use. The operative times of the navigated technique were achieved by all surgeons. With respect to precision (alignment outliers) and patient satisfaction rate, no learning curve was evident. Comparison between tutorial and non-tutorial surgery showed a 16-min increase in operating time, but no significant differences in precision, complications, and patient satisfaction rate. CONCLUSION: The study showed that there was a learning curve in terms of duration of surgery but not in terms of precision, complications, and patient satisfaction. Robotic tutorial surgery requires more time but provides the same outcome compared to experienced surgeons. Thus, the robotic surgical technique appears to be an excellent training tool in knee arthroplasty.

A web-survey assessed attitudes toward evidence-based practice among psychotherapists in Austria.

Evidence-based practice (EBP) means integrating the best available scientific evidence with clinical experience and patient values. Although perceived as important by many psychotherapists, there still seems to be reluctance to use empirically supported therapies in clinical practice. We aimed to assess the attitudes of psychotherapists in Austria toward EBP in psychotherapy as well as factors influencing the implementation of EBP. We conducted an online survey. To investigate attitudes toward EBP, we used two subscales ("Limitations" and "Balance") of a translated and validated short version of the Evidence-Based Practice Attitude Scale-36 (EBPAS-36). Participants provided perceived barriers and facilitators as answers to open-ended questions. We analyzed the responses mainly using descriptive statistics. Open answers were analyzed using a thematic analysis. In total, 238 psychotherapists completed our survey (mean age 51.0 years, standard deviation [SD] = 9.9, 76.9% female). Psychotherapists scored on average 2.62 (SD = 0.89) on the reversed EBPAS-36 subscale "Limitations," indicating that the majority do not perceive EBP as limiting their practice as psychotherapists. They scored 1.43 (SD = 0.69) on the reversed EBPAS-36 subscale "Balance," indicating that psychotherapists on average put a higher value on the art of psychotherapy than on evidence-based approaches. Organizational factors such as lack of time and access to research studies as well as negative attitudes toward research and a lack of skills and knowledge kept respondents from implementing EBP. Our study highlights that EBP is still not very popular within the psychotherapy community in Austria. The academization of psychotherapy training might change this in the future.

The Influence of Methylphenidate on Hyperactivity and Attention Deficits in Children With ADHD: A Virtual Classroom Test.

Objective: This study compares the performance in a continuous performance test within a virtual reality classroom (CPT-VRC) between medicated children with ADHD, unmedicated children with ADHD, and healthy children. Method:N = 94 children with ADHD (n = 26 of them received methylphenidate and n = 68 were unmedicated) and n = 34 healthy children performed the CPT-VRC. Omission errors, reaction time/variability, commission errors, and body movements were assessed. Furthermore, ADHD questionnaires were administered and compared with the CPT-VRC measures. Results: The unmedicated ADHD group exhibited more omission errors and showed slower reaction times than the healthy group. Reaction time variability was higher in the unmedicated ADHD group compared with both the healthy and the medicated ADHD group. Omission errors and reaction time variability were associated with inattentiveness ratings of experimenters. Head movements were correlated with hyperactivity ratings of parents and experimenters. Conclusion: Virtual reality is a promising technology to assess ADHD symptoms in an ecologically valid environment.

Clinical Impact of Ventilation Duration in Patients with Stroke Undergoing Interventional Treatment under General Anesthesia: The Shorter the Better?

BACKGROUND AND PURPOSE: Whether general anesthesia for neurothrombectomy in patients with ischemic stroke has a negative impact on clinical outcome is currently under discussion. We investigated the impact of early extubation and ventilation duration in a cohort that underwent thrombectomy under general anesthesia. MATERIALS AND METHODS: We analyzed 103 consecutive patients from a prospective stroke registry. They met the following criteria: CTA-proved large-vessel occlusion in the anterior circulation, ASPECTS above 6 on presenting cranial CT, revascularization by thrombectomy with the patient under general anesthesia within 6 hours after onset of symptoms, and available functional outcome (mRS) 90 days after onset. RESULTS: The mean ventilation time was 128.07 ± 265.51 hours (median, 18.5 hours; range, 1-1244.7 hours). Prolonged ventilation was associated with pneumonia during hospitalization and unfavorable functional outcome (mRS ≥3) and death at follow-up (Mann-Whitney U test; P ≤ .001). According to receiver operating characteristic analysis, a cutoff after 24 hours predicted unfavorable functional outcome with a sensitivity and specificity of 60% and 78%, respectively. Our results imply that delayed extubation was not associated with a less favorable clinical outcome compared with immediate extubation after the procedure. CONCLUSIONS: Short ventilation times are associated with a lower pneumonia rate and more favorable clinical outcome. Cautious interpretation of our data implies that whether patients are extubated immediately after the procedure is irrelevant for clinical outcome as long as ventilation does not exceed 24 hours.

[No improved survival rate in severely injured patients by prehospital intubation : A retrospective data analysis and matched-pair analysis]. / Kein verbessertes Überleben bei schwerstverletzten Patienten durch die präklinische Intubation : Eine retrospektive Datenanalyse mit Matched-pair-Analyse.

BACKGROUND: Training programs for the treatment of trauma patients generally recommend establishing a secure airway if the patient presents with a Glasgow coma scale (GCS) score of less than 9; however, the evidence for its effectiveness is rather sparse. This study analyzed the effect of preclinical intubation on mortality of patients with a GCS <9 in an emergency medical situation. METHODS: This retrospective analysis included patients who were primarily admitted to a German level 1 trauma center between 2002 and 2012 with an injury severity score (ISS) ≥ 16, a GCS < 9 and primary transport from the site of the accident. Data were collected from the trauma registry of the German Society for Trauma Surgery and from hospital records. A total of 455 patients were included and a matched-pair analysis of 62 patients was conducted. RESULTS: Both analytical methods showed no significant reduction in mortality rate after prehospital intubation. In the retrospective analysis intubated patients presented with a significantly lower systolic blood pressure on admission, received a higher amount of fluid volume at all phases of treatment and arrived at the hospital after a prolonged rescue time. In the matched-pair analysis, intubated patients also received a higher amount of fluid volume and showed better peripheral oxygen saturation on admission. No further differences between the groups could be found. CONCLUSION: It appears that preclinical intubation in trauma patients with a GCS < 9 does not result in a better outcome. The preclinical intubation resulted in a reduced systolic blood pressure on arrival at hospital, a prolonged preclinical rescue time and a greater amount of infused fluid volume.

Cost-efficient delay generator for fast terahertz imaging.

We present a fast and low-cost delay generator for terahertz (THz) waves that transfers a rotational motion of a transparent dielectric cube into an effective THz delay. The device is easily implemented in the THz beam path and allows for coherent sampling over 40 ps with a scan rate of hundreds of hertz. Furthermore, we show that our approach is particularly suitable for fast THz imaging.

Terahertz plastic compound lenses.

We present terahertz (THz) lenses made of highly refracting polymeric compounds which provide a better focusing performance and an increased functionality in comparison to conventional THz lenses. Using mixtures consisting of polypropylene (PP) and alumina as well as PP and zinc sulfide allows a significant increase of the refractive index while simultaneously keeping a low extinction and dispersion. With these new material combinations, lenses with an increased focusing capability are realized. This is evaluated by focal plane measurements using a fiber coupled THz time-domain spectrometer.

Sonographic discrimination of corticobasal degeneration vs progressive supranuclear palsy.

OBJECTIVE: To study the use of brain parenchyma sonography (BPS) in discriminating between patients with corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP). METHODS: Thirteen patients with PSP and eight with CBD were studied with BPS according to a standardized protocol. RESULTS: Seven (88%) of the eight CBD patients showed marked hyperechogenicity of the substantia nigra (SN) but none of eleven PSP patients (Mann-Whitney U test, p < 0.001). This finding indicated CBD with a positive predictive value of 100%. Marked dilatation of the third ventricle (width > 10 mm) was found in 10 (83%) of 12 PSP patients, but in none of the CBD patients (p < 0.005). BPS measurements of ventricle widths closely matched MRI measurements (Pearson correlation, r = 0.90, p < 0.001). The presence of at least one of the BPS findings 1) marked SN hyperechogenicity and 2) third-ventricle width < 10 mm indicated CBD with a sensitivity of 100%, a specificity of 83%, and a positive predictive value of 80%. Other BPS findings such as echogenicity of lentiform and caudate nuclei and widths of the frontal horns did not discriminate between CBD and PSP. One PSP patient could not be assessed because of insufficient acoustic temporal bone windows. CONCLUSIONS: Substantia nigra hyperechogenicity, reported earlier as characteristic brain parenchyma sonography finding in idiopathic Parkinson disease, is also typical for corticobasal degeneration.

[Use of botulinum toxin the the treatment of muscle pain]. / Der Einsatz von Botulinumtoxin in der Therapie von Muskelschmerzen.

The analgesic effects of botulinum toxin (BTX) have been discussed controversially due to substantial placebo effects and flaws in the study designs used. Additionally, pathophysiological concepts of pain and the specific analgesic mechanisms of BTX remain largely unclear. Apart from pain reduction through the well-documented effects of BTX at the neuromuscular endplate, additional analgesic mechanisms, including other synaptic and local effects, have been suggested. Currently, BTX can be recommended for pain treatment in dystonia and spasticity. In myofascial pain syndromes, pain relief by BTX injections has been reported, but definite proof according to evidence-based medicinal criteria is still lacking. In fibromyalgia, there seems to be no analgesic effect. The role of BTX in pain therapy is likely to increase in the future.

Brain parenchyma sonography discriminates Parkinson's disease and atypical parkinsonian syndromes.

OBJECTIVE: To study the use of brain parenchyma sonography (BPS) in discriminating between patients with idiopathic PD (IPD) and atypical parkinsonian syndromes (APS). METHODS: Twenty-five patients with APS, 9 with progressive supranuclear palsy (PSP) and 16 with multiple-system atrophy (MSA), and 25 age-matched patients with IPD were prospectively studied with BPS according to a standardized protocol. RESULTS: Twenty-four of the 25 (96%) IPD patients exhibited hyperechogenicity of the substantia nigra (SN) but only 2 of 23 (9%) APS patients (Mann-Whitney U test, p < 0.001). In those two APS patients, SN hyperechogenicity was moderate only, whereas the remaining 21 APS patients had normal SN echogenicity. The specificity of SN hyperechogenicity in detection of clinically diagnosed IPD patients was 96%, and the sensitivity was 91%. If SN hyperechogenicity was marked, APS could be excluded because of a positive predictive value of 100% for IPD. Nucleus lentiformis hyperechogenicity was found in 17 of 22 (77%) APS patients but in only 5 of 22 (23%) IPD patients (Mann-Whitney U test, p < 0.001). Nucleus caudatus and thalamus echogenicity and widths of the third ventricle and of the frontal horns of the lateral ventricles did not discriminate between IPD and APS. Two patients with PSP could not be assessed because of an insufficient bone window. CONCLUSIONS: BPS is a novel and noninvasive method to differentiate highly specifically between IPD and APS. Therefore, BPS might become a standard investigation in parkinsonian disorders.

Rapid and sensitive determination of radiocesium (Cs-135, Cs-137) in the presence of excess barium by electrothermal vaporization-inductively coupled plasma-mass spectrometry (ETV-ICP-MS) with potassium thiocyanate as modifier.

An electrothermal vaporization-inductively coupled plasma-mass spectrometric (ETV-ICP-MS) method based on selective volatilization of cesium with KSCN as modifier has been developed for determination of radiocesium, i.e. 135Cs and 137Cs, in the presence of isobaric barium. A 10,000 times excess of barium, which was volatilized at a temperature of 1,100 degrees C, resulted only in a 1% signal increase in the signal of mass 135 amu. The recommended concentration of KSCN is 0.3 mM, and pretreatment and volatilization temperatures are 400 degrees C and 1,100 degrees C, respectively. A ramp time of 1 s is recommeded for the volatilization step. The achieved limit of detection for 135Cs is 0.2 pg/mL (10 microBq/mL) and 4 fg (0.2 microBq) absolute for a sample volume of 20 microL. This means a limit of detection for 137Cs of 0.2 pg/mL (0.6 Bq/mL) and of 4 fg (0.01 Bq) absolute. Signal variations of 135Cs and 137Cs, respectively, in spiked samples with various matrices were investigated.

Velocity not acceleration of self-motion mediates vestibular-visual interaction.

We investigated the influence of vestibular stimulation with different angular accelerations and velocities on the perception of visual motion direction. Constant accelerations resulting in different angular velocities and constant angular velocities obtained at different accelerations were combined in twenty healthy subjects. Random-dot kinematograms with coherently moving pixels and randomly moving pixels were used as visual stimuli during whole-body rotations. The smallest percentage of coherently moving pixels leading to a clear perception of motion direction was taken as the perception threshold. Perception thresholds significantly increased with increasing angular velocity. Increased acceleration, however, had no significant effect on the perception thresholds. We conclude that the achieved angular velocity, and not acceleration, is the predominant factor in the processing of vestibular-visual interaction.

Platinum concentrations in Danish air samples determined by instrumental neutron activation analysis.

Platinum, gold and calcium concentrations of 20 samples of airborne dust collected at two sampling sites between 1995 and 1997 in the city of Copenhagen, which suffers from heavy traffic, were determined by instrumental neutron activation analysis (INAA). INAA of platinum using the 199Au daughter of 199Pt was performed. Two interferences on the INAA of platinum were removed by calculations. The spectral interference on 199Au from the 47Sc daughter of 47Ca was removed by separating the 157-161 keV doublet peak into its components by calculating the counts due to 47Sc from the counts of the parent 47Ca. The contribution of 197Au to 199Au by two neutron absorption was corrected for using the ratio 198Au/199Au in a pure Au standard. From the INAA results, high platinum concentrations are present in air in the range 0.25-2.74 ng m-3 and gold concentrations in the range 0.10-1.96 ng m-3.

The effects of job insecurity on employee safety outcomes: cross-sectional and longitudinal explorations.

Job insecurity research has focused primarily on attitudinal (e.g., job satisfaction), behavioral (e.g., employee turnover), and health outcomes. Moreover, research in the area of workplace safety has largely focused on ergonomic factors and personnel selection and training as primary antecedents of safety. Two cross-sectional structural equational modeling analyses and 1 longitudinal regression analysis of 237 food-processing plant employees unite these 2 disparate areas of research by exploring the relatively uncharted relationship between job insecurity and safety outcomes. Results indicate that employees who report high perceptions of job insecurity exhibit decreased safety motivation and compliance, which in turn are related to higher levels of workplace injuries and accidents.

A new class of drugs for BNCT? Borylated derivatives of ferrocenium compounds in animal experiments.

A new class of drugs, borylated derivatives of ferrocenium compounds, which show a comparatively facile synthesis is investigated on their boron neutron capture accumulation. Investigations focused on the fast and effective testing of 12 ferrocene derivatives with tetracoordinated boron atoms, which should accumulate in rodent tumors. The macroscopic studies on time-dependent boron distributions and boron concentrations in mice were carried out by inductively coupled plasma-atomic emission spectrometry, inductively coupled plasma-mass spectrometry, and quantitative neutron capture radiography. The determination of boron concentrations after injection of 2b showed high boron contents in spleen, liver, kidneys, less in lung and muscle, and poor in integral blood, blood plasma, tumor, and brain. It is interesting to note that 2b penetrates the blood-brain barrier which may be advantageous in the treatment of astrocytomas and glioblastomas.

Fructose- and sorbitol-reduced diet improves mood and gastrointestinal disturbances in fructose malabsorbers.

BACKGROUND: Fructose malabsorption is characterized by the inability to absorb fructose efficiently. As a consequence fructose reaches the colon where it is broken down by bacteria to short fatty acids, CO2 and H2. Bloating, cramps, osmotic diarrhea and other symptoms of irritable bowel syndrome are the consequences and can be seen in about 50% of fructose malabsorbers. We have previously shown that fructose malabsorption is associated with early signs of mental depression and low serum tryptophan concentrations. It was therefore of interest whether a fructose-reduced diet could not only improve gastrointestinal complaints but also depressive signs seen in fructose malabsorbers. METHODS: Fifty-three adults (12 males, 41 females), who were identified as fructose malabsorbers according to their breath-H2 concentrations, filled out a Beck's depression inventory-questionnaire, and a questionnaire with arbitrary scales for measurement of meteorism, stool frequency and quality of life for a 4-week period before dietary intervention and 4 weeks after dietary change as for fructose- and sorbitol-reduced diet. RESULTS: Depression scores were reduced by 65.2% after 4 weeks of diet (P < 0.0001), and there was a significant reduction of meteorism (P < 0.0001) and stool frequency (P < 0.01). Improvement of signs of depression and of meteorism was more pronounced in females than in males. CONCLUSION: Fructose- and sorbitol-reduced diet in subjects with fructose malabsorption does not only reduce gastrointestinal symptoms but also improves mood and early signs of depression.

Pavlovian conditioning of taste aversion using a motion sickness paradigm.

OBJECTIVE: Pavlovian conditioning of taste aversion has rarely been investigated in healthy humans using motion sickness as the unconditioned stimulus (US). METHODS: Ninety subjects were pretested for susceptibility to illusory motion (vection) in a rotating drum. Thirty-two subjects susceptible to pseudomotion were assigned randomly to two groups and received either water 1 hour before rotation and a novel taste (elderberry juice, conditioned stimulus, [CS]) immediately before rotation in a rotating chair (conditioning group), or the sequence of water and juice was reversed (control group). During the test session 1 week later, all subjects were exposed to water 1 hour before and juice immediately before rotation. The amount of liquids ingested, nausea ratings, rotation tolerance, and blood levels of hormones (ACTH, ADH, PP) were evaluated. RESULTS: Subjects in the conditioning group developed taste aversion toward the novel taste, but not subjects in the control group. Postrotation nausea rating was affected marginally by conditioning, but rotation tolerance was not changed by conditioning. ACTH and ADH but not PP levels increased with rotation, but were unaffected by conditioning. CONCLUSIONS: Pavlovian conditioning of behavioral, but not of endocrine, indicators was effective in susceptible subjects using a rotating chair as US and a single CS-US pairing.

Empowerment and continuous improvement in the United States, Mexico, Poland, and India: predicting fit on the basis of the dimensions of power distance and individualism.

Although variations in national cultures predominate as explanation for the belief that universal approaches to management do not exist, there have been few reports of systematic studies. Data from employees of a single firm with operations in the United States, Mexico, Poland, and India were used to test the fit of empowerment and continuous improvement practices with national culture. Using the theoretical constructs of individualism-collectivism and power distance, the authors predicted that the practices would be more congruent in some cultures than in others and that value congruence would result in job satisfaction. Using structural equations modeling, the authors found that empowerment was negatively associated with satisfaction in India but positively associated in the other 3 samples. Continuous improvement was positively associated with satisfaction in all samples. Substantive, theoretical, and methodological implications are discussed.

Does computerizing paper-and-pencil job attitude scales make a difference? New IRT analyses offer insight.

The measurement equivalence of 2 scales of the Job Descriptive Index (JDI; P. C. Smith, L. M. Kendall, & C. L. Hulin, 1969), the Supervisor Satisfaction scale and the Coworker Satisfaction scale, was examined across computerized and paper-and-pencil administrations. In this study, employees in 2 organizations (N = 1,777) were administered paper-and-pencil versions of the scales, and employees in a third organization (N = 509) were administered a computerized version. A newly developed item response theory (IRT) technique for examining differential test functioning (N. S. Raju, W. J. van der Linden, & P. F. Fleer, 1995) was used to examine measurement equivalence across media. Results support the measurement equivalence of the JDI Supervisor and Coworker scales across administration media. The implications of these findings for both practitioners and organizational researchers are discussed.