593 research outputs found
Improving Sustainable Performance of SMEs
"This thesis aims to design and develop a comprehensive SME model and measuring tool and to close the narrowing gap of research concerned with performance optimization in SMEs. This study focuses on the positions of 27 individual SMEs concerning specific issues against their societal, economic and physical context.
Distinction of disorder, classical and quantum vibrational contributions to atomic mean-square amplitudes in dielectric pentachloronitrobenzene
The solid-state molecular disorder of pentachloronitrobenzene (PCNB) and its
role in causing anomalous dielectric properties are investigated. Normal
coordinate analysis (NCA) of atomic mean-square displacement parameters (ADPs)
is employed to distinguish disorder contributions from classical and
quantum-mechanical vibrational contributions. The analysis relies on
multitemperature (5-295 K) single-crystal neutron-diffraction data. Vibrational
frequencies extracted from the temperature dependence of the ADPs are in good
agreement with THz spectroscopic data. Aspects of the static disorder revealed
by this work, primarily tilting and displacement of the molecules, are compared
with corresponding results from previous, much more in-depth and time-consuming
Monte Carlo simulations; their salient findings are reproduced by this work,
demonstrating that the faster NCA approach provides reliable constraints for
the interpretation of diffuse scattering. The dielectric properties of PCNB can
thus be rationalized by an interpretation of the temperature-dependent ADPs in
terms of thermal motion and molecular disorder. The use of atomic displacement
parameters in the NCA approach is nonetheless hostage to reliable neutron data.
The success of this study demonstrates that state-of-the-art single-crystal
Laue neutron diffraction affords sufficiently fast the accurate data for this
type of study. In general terms, the validation of this work opens up the field
for numerous studies of solid-state molecular disorder in organic materials.Comment: Now published in Physical Review
First-principles calculations of the structural, electronic, vibrational and magnetic properties of C_{60} and C_{48}N_{12}: a comparative study
In this work, we perform first-principles calculations of the structural,
electronic, vibrational and magnetic properties of a novel azafullerene. Full geometrical optimization shows that is characterized by several distinguishing features: only
one nitrogen atom per pentagon, two nitrogen atoms preferentially sitting in
one hexagon, symmetry, 6 unique nitrogen-carbon and 9 unique
carbon-carbon bond lengths. The highest occupied molecular orbital of is a doubly degenerate level of symmetry and its
lowest unoccupied molecular orbital is a nondegenerate level of
symmetry. Vibrational frequency analysis predicts that has in total 116 vibrational modes: 58 infrared-active and 58
Raman-active modes. is also characterized by 8
and 2 NMR spectral signals. Compared to , shows an enhanced third-order optical
nonlinearities which implies potential applications in optical limiting and
photonics.Comment: a long version of our manuscript submitted to J.Chem.Phy
Effectiveness of a procalcitonin algorithm to guide antibiotic therapy in respiratory tract infections outside of study conditions: a post-study survey
All published evidence on procalcitonin (PCT)-guided antibiotic therapy was obtained in trials where physicians knew that they were being monitored, possibly resulting in higher adherence to the PCT algorithm. This study investigates the effectiveness of PCT guidance in an observational quality control survey. We monitored antibiotic therapy and algorithm adherence in consecutive patients with respiratory tract infections admitted to the Kantonsspital Aarau, Switzerland, between May 2008 and February 2009. The results were compared to the site-specific results of the former ProHOSP study. Overall and more pronounced for patients with community-acquired pneumonia, the median duration of antibiotic treatment in this survey was shorter than the ProHOSP control patients (6 vs. 7days, P = 0.048 and 7 vs. 9days, P < 0.001). In 72.5% of patients, antibiotics were administered according to the prespecified PCT algorithm. No significant differences concerning adverse medical outcome could be detected. This study mirrors the use of PCT-guided antibiotic therapy in clinical practice, outside of trial conditions. If algorithm adherence is reinforced, antibiotic exposure can be markedly reduced with subsequent reduction of antibiotic-associated side effects and antibiotic resistance. The integration of the PCT algorithm into daily practice requires ongoing reinforcement and involves a learning process of the prescribing physician
THE PREVALENCE OF PALPABLE FINGER JOINT NODULES IN DIFFUSE IDIOPATHIC SKELETAL HYPEROSTOSIS (DISH). A CONTROLLED STUDY
The presence of clinically palpable finger joint nodules a(Heberden's and Bouchard's nodes) was documented in 123 consecutive cases with diffuse idiopathic skeletal hyperostosis (DISH) of the thoracic spine and 191 matched DISH negative controls. The prevalence of palpable finger joint nodules was almost twice as frequent in cases with spinal DISH compared to controls (46% versus 31%, X2 = 7.67, P<0.01; multivariate adjusted odds ratio OR = 1.84; 95% CI: 1.14-2.98). This increase was most marked at the proximal interphalangeal joint, in males and in patients up to the age of 65 years. In addition and independent of other variables such as hyperostotic features, age and sex, the prevalence of palpable finger joint nodules was about twice as high in probands with a history of physically heavy work compared to those without (43% ver sus 26%, X = 9.18, P<0.005; multivariate adjusted odds ratio OR = 2.10; 95% CI: 1.26-3.52). From these results we con clude that DISH should be considered as an independent risk factor in the development of finger joint nodule
DIFFUSE IDIOPATHIC SKELETAL HYPEROSTOSIS (DISH) OF THE SPINE: A CAUSE OF BACK PAIN? A CONTROLLED STUDY
This is the first controlled study of the frequency of back pain in a European caucasian population with diffuse idiopathic skeletal hyperostosis (DISH). Elderly patients admitted to hospital for reasons other than back pain were assessed for the presence of spinal DISH using the routine lateral chest radiograph films. A total of 106 probands (82 males, 24 females) with a mean age of 70 years fulfilled the criteria for DISH as defined previously. One hundred and seventyeight patients (117 males, 61 females) not meeting these criteria were used as controls. The prevalence of back pain was assessed by a blinded interviewer using a structured questionnaire. Our primary hymthesis was that spinal DISH positive probands had not had back pain more often than controls. The controlled study showed no statistically significant difference in pain frequency between spinal DISH positive probands and controls at any spinal level. We conclude that back pain does not occur more often in radiographically defined DISH positive probands than in controls. The radiological finding of spinal DISH, as far as it does not lead to stenosis of the spinal canal or dysphagia, thus seems to be a finding without clinical relevanc
Risk Factors Promoting Hypertensive Crises: Evidence From a Longitudinal Study
Background Current knowledge about risk factors promoting hypertensive crisis originates from retrospective data. Therefore, potential risk factors of hypertensive crisis were assessed in a prospective longitudinal study. Methods Eighty-nine patients of the medical outpatient unit at the University Hospital of Bern (Bern, Switzerland) with previously diagnosed hypertension participated in this study. At baseline, 33 potential risk factors were assessed. All patients were followed-up for the outcome of hypertensive crisis. Cox regression models were used to detect relationships between risk factors and hypertensive crisis (defined as acute rise of systolic blood pressure (BP) ≥200mmHg and/or diastolic BP ≥120mmHg). Results The mean duration of follow-up was 1.6 ± 0.3 years (range 1.0-2.4 years). Four patients (4.5%) were lost to follow-up. Thirteen patients (15.3%) experienced hypertensive crisis during follow-up. Several potential risk factors were significantly associated with hypertensive crisis: female sex, higher grades of obesity, the presence of a hypertensive or coronary heart disease, the presence of a somatoform disorder, a higher number of antihypertensive drugs, and nonadherence to medication. As measured by the hazard ratio, nonadherence was the most important factor associated with hypertensive crisis (hazard ratio 5.88, 95% confidence interval 1.59-21.77, P < 0.01). Conclusions This study identified several potential risk factors of hypertensive crisis. Results of this study are consistent with the hypothesis that improvement of medical adherence in antihypertensive therapy would help to prevent hypertensive crises. However, larger studies are needed to assess potential confounding, other risk factors and the possibility of interaction between predictor
Electronic, vibrational and magnetic properties of a novel C_{48}N_{12} aza-fullerene
We study the structural, electronic, vibrational and magnetic properties of a
novel aza-fullerene using density functional theory
and restricted Hartree-Fock theory. Optimized geometries and total energy of
this fullerene have been calculated. We find that for the total ground state energy is about -67617 eV, the HOMO-LUMO gap is
about 1.9 eV, five strong IR spectral lines are located at the vibrational
frequencies, 461.5 , 568.4 , 579.3 , 1236.1 , 1338.9 , the Raman scattering
activities and depolarization ratios are zero, and 10 NMR spectral signals are
predicted. Calculations of diamagnetic shielding factor, static dipole
polarizabilities and hyperpolarizabilities of are
performed and discussed.Comment: published in Chem.Phys.Let
The effects of excluding patients from the analysis in randomised controlled trials: meta-epidemiological study
Objective To examine whether excluding patients from the analysis of randomised trials are associated with biased estimates of treatment effects and higher heterogeneity between trials
DIFFUSE IDIOPATHIC SKELETAL HYPEROSTOSIS (DISH) OF THE SHOULDER: A CAUSE OF SHOULDER PAIN?
Shoulder pain is a common complaint and shoulder hyperostosis a frequent radiological condition. However, little is known about the association between the clinical and radiological findings. To evaluate the clinical relevance of shoulder hyperostosis we performed a controlled, blind study of 99 hospitalized probands with and without thoracospinal hyperostosis on lateral chest X-rays. The study included grading of the shoulder hyperostosis on the basis of three bilateral standard radiographs, assessing shoulder pain in a standardized way by an interviewer and recording extraskeletal causes of shoulder pain. The prevalence of shoulder hyperostosis was doubled in probands with thoracospinal hyperostosis compared to controls (X2= 5.90, F>0.025, n = 99). Shoulder hyperostosis, irrespective of thoracospinal hyperostosis, predisposed to shoulder pain (40% versus 18%, x2 = 4.06, F>0.05, n = 74). Shoulder hyperostosis in combination with thoracospinal hyperostosis (shoulder DISH) predisposed to shoulder pain to an even greater extent (46% versus 12%, x2 = 6.64, P>0.01, n = 47). We conclude that shoulder hyperostosis is a radiological finding of potential clinical relevanc
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