13,688 research outputs found
Degeneration of the intervertebral disc with new approaches for treating low back pain.
This review paper discusses the process of disc degeneration and the current understanding of cellular degradation in patients who present with low back pain. The role of surgical treatment for low back pain is analysed with emphasis on the proven value of spinal fusion. The interesting and novel developments of stem cell research in the treatment of low back pain are presented with special emphasis on the importance of the cartilaginous end plate and the role of IL-1 in future treatment modalities
Quasinormal mode theory of elastic Purcell factors and Fano resonances of optomechanical beams
We introduce a quasinormal mode theory of mechanical open-cavity modes for
optomechanical resonators, and demonstrate the importance of using a
generalized (complex) effective mode volume and the phase of the quasinormal
mode. We first generalize and fix the normal mode theories of the elastic
Purcell factor, and then show a striking example of coupled quasinormal modes
yielding a pronounced Fano resonance. Our theory is exemplified and confirmed
by full three-dimensional calculations on optomechanical beams, but the general
findings apply to a wide range of mechanical cavity modes. This quasinormal
mechanical mode formalism, when also coupled with a quasinormal theory of
optical cavities, offers a unified framework for describing a wide range of
optomechanical structures where dissipation is an inherent part of the
resonator modes.Comment: 11 pages, 7 figure
The In-Hospital Suicide: A Psychological Autopsy of a System Involving Borderline Dynamics
This manuscript reviews principles of hospital management in the care of severe borderline patients with concomitant affective syndromes. The case presented highlights a process of experiential learning in a novice clinician (a beginning psychiatric resident) and illustrates several critical areas of concern with these patients. The following four facets of clinical management are discussed: 1) Failed attempts to understand borderline dynamics and subsequent countertransference reactions; 2) Staff resistance to consistent, honest and open acknowledgement of suicide potential; 3) Special risks when borderline dynamics are combined with affective syndromes; and 4) Possible suicide preventive measures and their relative effectiveness
Reproducibility of Left Ventricular Dyssynchrony Indices by Three-Dimensional Speckle-Tracking Echocardiography: The Impact of Sub-optimal Image Quality
Background: 3D speckle-tracking echocardiography (3D-STE) is a novel method to quantify left ventricular (LV) mechanical dyssynchrony. 3D-STE is influenced by image quality, but studies on the magnitude of its effect on 3D-STE derived LV systolic dyssynchrony indices (SDIs) and their test-retest reproducibility are limited.
Methods: 3D-STE was performed in two groups, each comprising 18 healthy volunteers with good echocardiographic windows. In study 1, optimal and inferior-quality images, by intentionally poor echocardiographic technique, were acquired. In study 2, sub-optimal quality images were acquired by impairing ultrasound propagation using neoprene rubber sheets (thickness 2, 3, and 4 mm) mimicking mildly, moderately, and severely impaired images, respectively. Measures (normalized to cardiac cycle duration) were volume- and strain-based SDIs defined as the standard deviation of time to minimum segmental values, and volume- and strain-derived dispersion indices. For both studies test-retest reproducibility was assessed.
Results: Test-retest reproducibility was better for most indices when restricting the analysis to good quality images; nevertheless, only volume-, circumferential strain-, and principal tangential strain-derived LV dyssynchrony indices achieved fair to good reliability. There was no evidence of systematic bias due to sub-optimal quality image. Volume-, circumferential strain-, and principal tangential strain-derived SDIs correlated closely. Radial strain- and longitudinal strain-SDI correlated moderately or weakly with volume-SDI, respectively.
Conclusions: Sub-optimal image quality compromised the reliability of 3D-STE derived dyssynchrony indices but did not introduce systematic bias in healthy individuals. Even with optimal quality images, only 3D-STE indices based on volume, circumferential strain and principal tangential strain showed acceptable test-retest reliability
Optimal Configuration of Regional Water Supply Systems (WASOPT2)
Any water supply system can be conceptualized as consisting of three componenets--source development facilities (including treatment), transmission facilities, and a distribution network. The scope of this report is limited to the first two--the source related facilities upstream from the distribution network. In the mathematical modeling of regional rural systems, the number of variables, and hence the size of the model, increases rapidly as the number of system componenets and their alternative designs increase. Regardless of the method of solution, manual preparation of large models is cumbersome and is vulnerable to human error both in the computations of the matrix coefficients as well as in the format requirements. This research is aimed at developing a flexible matrix generator for the general rural water supply problem and alternative solution methods that can be used for especially large problems. The Mixed Integer Programming (MIP) method is particularly expensive to use for large problems and is not practical if the number of variables approaches a hundred or so, while the laternative solution methods can handle hundreds of variables. A real-world application problem is solved using the MIP and the three alternative methods developed during this research. These include the continuous, the nonlinear discrete, and the objective bounding methods. The solutions are compared and conclusions drawn as to the conditions under which the different methods are recommended
Clinical access to Bedaquiline Programme for the treatment of drug-resistant tuberculosis
KMWhile clinical disease caused by drug-sensitive Mycobacterium tuberculosis (MTB) can usually be treated successfully, clinical disease caused by drug-insensitive MTB is associated with a poorer prognosis. In December 2012, a new drug, bedaquiline, was approved by the US Food and Drug Administration. This article documents the process whereby the National Department of Health, Right to Care and Médecins Sans Frontières obtained access to this medication for South Africans who might benefit from subsequent implementation of the Clinical Access to Bedaquiline Programme
Different chemical behaviors and antioxidant activity of three novel schiff bases containing hydroxyl groups. X-ray structure of CH2{cyclo-C6H10-NH=CH-(2-O-naphth)}2.H2O
The antioxidant activities of three new Schiff base compounds, 1–3, were studied through their direct scavenging ability to eliminate free radicals using DPPH and ABTS methods and also through their indirect antioxidant activity as measured using the ferric thiocyanate (FTC) method. The number of OH groups in the compounds and their positions play a role in the activity. The crystal structure of CH2{cycloC6H10NHCH-(2-O-naphth)}2.H2O (1), has been determined and proves the existence of intramolecular hydrogen-bonds and hydrogen-bonded water molecules and reveals the keto-amine (NH⋯O) tautomer of this compound. One cyclo-hexyl ring was found to be disordered, and was resolved in two orientations. Hydrogen atoms of the NHCH groups were located in difference maps and were refined freely. Compounds 2 and 3 exhibit the enol-imine form. The UV–vis spectra of the three compounds have been studied in organic solvents of different polarity, and in basic and acidic media, and were found helpful in understanding the tautomeric forms in these compounds; the polarity was modified by adding (CF3COOH) or [(C2H5)3N] to the solvent. All three compounds have been characterized by elemental analysis, UV–vis, FTIR, NMR and MS
Daily Management of Antimicrobial Prescribing Leading to Reduction of Clostridium difficile Infections in Elderly Patients
Fatigue and Sleep Disturbance in Arabic Cancer Patients after Completion of Therapy:Prevalence, Correlates, and Association with Quality of Life
Background
Fatigue and sleep disturbance are 2 of the most common and distressing cancer symptoms that negatively affect quality of life.
Objective
The aim of this study was to assess the prevalence of, and factors contributing to, fatigue and sleep disturbance in Arabic-speaking cancer patients in Oman after completion of their cancer treatment.
Methods
A cross-sectional and descriptive correlational design was used. Data were collected using the Pittsburgh Sleep Quality Index where a score of >5 indicated as poorer sleep, the Functional Assessment of Cancer Therapy–Fatigue a score of ≤34 indicating clinically significant fatigue, and the Functional Assessment of Cancer Therapy–General.
Results
Of the 369 patients who participated, 77.5% (n = 286) reported clinically significant fatigue, and 78% (n = 288) reported poor sleep. Fatigue (P < .05) was significantly associated with age, cancer site, months since diagnosis, type of treatment received, and comorbidity. Those experiencing fatigue and poor sleep had the lowest quality of life among the cancer patients studied.
Conclusion
Fatigue and sleep disturbance are significant problems for the Arabic patients diagnosed with cancer. Both fatigue and sleep disturbance should be routinely assessed in the case of such patients.
Implications for Practice
Routine assessments of fatigue and sleep disturbance are recommended so that appropriate interventions and treatment management plans can be introduced to reduce fatigue and improve sleep quality among patients with cancer
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