Tunable fibre-coupled multiphoton microscopy with a negative curvature fibre

Negative curvature fibre (NCF) guides light in its core by inhibiting the coupling of core and cladding modes. In this work, an NCF was designed and fabricated to transmit ultrashort optical pulses for multiphoton microscopy with low group velocity dispersion (GVD) at 800 nm. Its attenuation was measured to be <0.3 dB m(-1) over the range 600-850 nm and the GVD was -180 ± 70 fs(2)  m(-1) at 800 nm. Using an average fibre output power of ∼20 mW and pulse repetition rate of 80 MHz, the NCF enabled pulses with a duration of <200 fs to be transmitted through a length of 1.5 m of fibre over a tuning range of 180 nm without the need for dispersion compensation. In a 4 m fibre, temporal and spectral pulse widths were maintained to within 10% of low power values up to the maximum fibre output power achievable with the laser system used of 278 mW at 700 nm, 808 mW at 800 nm and 420 mW at 860 nm. When coupled to a multiphoton microscope, it enabled imaging of ex vivo tissue using excitation wavelengths from 740 nm to 860 nm without any need for adjustments to the set-up

Coronary heart disease risks associated with high levels of HDL cholesterol.

BackgroundThe association between high-density lipoprotein cholesterol (HDL-C) and coronary heart disease (CHD) events is not well described in individuals with very high levels of HDL-C (&gt;80 mg/dL).Methods and resultsUsing pooled data from 6 community-based cohorts we examined CHD and total mortality risks across a broad range of HDL-C, including values in excess of 80 mg/dL. We used Cox proportional hazards models with penalized splines to assess multivariable, adjusted, sex-stratified associations of HDL-C with the hazard for CHD events and total mortality, using HDL-C 45 mg/dL and 55 mg/dL as the referent in men and women, respectively. Analyses included 11 515 men and 12 925 women yielding 307 245 person-years of follow-up. In men, the association between HDL-C and CHD events was inverse and linear across most HDL-C values; however at HDL-C values &gt;90 mg/dL there was a plateau effect in the pattern of association. In women, the association between HDL-C and CHD events was inverse and linear across lower values of HDL-C, however at HDL-C values &gt;75 mg/dL there were no further reductions in the hazard ratio point estimates for CHD. In unadjusted models there were increased total mortality risks in men with very high HDL-C, however mortality risks observed in participants with very high HDL-C were attenuated after adjustment for traditional risk factors.ConclusionsWe did not observe further reductions in CHD risk with HDL-C values higher than 90 mg/dL in men and 75 mg/dL in women

Anomalous nonadditive dispersion interactions in systems of three one-dimensional wires

10 pages, 8 figures, 1 tableFinancial support was provided by the U. K. Engineering and Physical Sciences Research Council (EPSRC). Part of the computations have been performed using the K computer at Advanced Institute for Computational Science, RIKEN. R.M. is grateful for financial support from KAKENHI Grants No. 23104714, No. 22104011, and No. 25600156, and from the Tokuyama Science Foundation

Fibre-coupled multiphoton microscope with adaptive motion compensation

To address the challenge of sample motion during in vivo imaging, we present a fibre-coupled multiphoton microscope with active axial motion compensation. The position of the sample surface is measured using optical coherence tomography and fed back to a piezo actuator that adjusts the axial location of the objective to compensate for sample motion. We characterise the system’s performance and demonstrate that it can compensate for axial sample velocities up to 700 µm/s. Finally we illustrate the impact of motion compensation when imaging multiphoton excited autofluorescence in ex vivo mouse skin

Perioperative statin therapy reduces mortality in normolipidemic patients undergoing cardiac surgery

ObjectiveStatins might have pleiotropic effects, independent of their ability to reduce lipid levels. Recent data have suggested that statins improve early survival and cardiovascular outcomes after coronary artery bypass graft surgery. The effectiveness of statin therapy in normolipidemic cardiac surgery patients is as yet unclear.MethodsWe evaluated 3056 consecutive patients who had undergone cardiac surgery between April 2004 and April 2009. Perioperative statin therapy was defined as continued treatment both before (≥ 6 months) and after the index surgery (included as a discharge medication). Hyperlipidemia (HL) was defined as a total cholesterol level greater than 200 mg/dL within 6 months before surgery. Four groups were analyzed: (1) statin-untreated normolipidemic (NL−, n = 1052); (2) statin-treated normolipidemic (NL+, n = 206); (3) statin-untreated hyperlipidemic (HL−, n = 638); and (4) statin-treated hyperlipidemic (HL+, n = 1160) patients. Adjusted hazard ratios accounted for the known preoperative cardiac risk factors. Mortality was ascertained by retrospective database review and the Social Security Death Index.ResultsThe mean follow-up was 2.2 years. The crude rate of 30-day mortality was 3.0% (32/1052), 0% (0/206), 8.0% (51/638), and 0.7% (8/1160) for the NL−, NL+, HL−, and HL+ groups, respectively. The overall all-cause crude mortality rate was 9.6% (101/1052), 3.9% (8/206), 17.2% (110/638), and 6.5% (75/1160) for the NL−, NL+, HL−, and HL+ groups, respectively. Statin therapy for NL patients undergoing cardiac surgery independently reduced the overall all-cause mortality (adjusted hazard ratio, 0.34; 95% confidence interval, 0.16–0.71; P = .004).ConclusionsPerioperative statin therapy was associated with reduced mid-term mortality for patients undergoing cardiac surgery, irrespective of their baseline lipid status. This clinical evidence suggests that the beneficial effects of statins might extend beyond their lipid-lowering ability

Developing a virtual reality environment for petrous bone surgery: a state-of-the-art review

The increasing power of computers has led to the development of sophisticated systems that aim to immerse the user in a virtual environment. The benefits of this type of approach to the training of physicians and surgeons are immediately apparent. Unfortunately the implementation of “virtual reality” (VR) surgical simulators has been restricted by both cost and technical limitations. The few successful systems use standardized scenarios, often derived from typical clinical data, to allow the rehearsal of procedures. In reality we would choose a system that allows us not only to practice typical cases but also to enter our own patient data and use it to define the virtual environment. In effect we want to re-write the scenario every time we use the environment and to ensure that its behavior exactly duplicates the behavior of the real tissue. If this can be achieved then VR systems can be used not only to train surgeons but also to rehearse individual procedures where variations in anatomy or pathology present specific surgical problems. The European Union has recently funded a multinational 3-year project (IERAPSI, Integrated Environment for Rehearsal and Planning of Surgical Interventions) to produce a virtual reality system for surgical training and for rehearsing individual procedures. Building the IERAPSI system will bring together a wide range of experts and combine the latest technologies to produce a true, patient specific virtual reality surgical simulator for petrous/temporal bone procedures. This article presents a review of the “state of the art” technologies currently available to construct a system of this type and an overview of the functionality and specifications such a system requires

The Impact of Depression, Anxiety and Personality Disorders on the Outcome of Patients with Functional Limb Weakness – Individual Patient Data Meta-Analysis

Objective: Psychiatric comorbidities such as depression, anxiety, and personality disorders are common in patients with functional limb weakness/paresis (FND-par). The impact of these conditions on the prognosis of FND-par has not been systematically reviewed. The aim of this study was to identify a potential prognostic effect of comorbid depression, anxiety, and/or personality disorder on prognosis in patients with FND-par. Methods: A systematic review was performed to identify studies that reported measures of baseline depression, anxiety, and/or personality disorder, and physical disability. An individual patient data meta-analysis was subsequently performed. Results: Eight studies comprising 348 individuals were included (7 prospective cohorts; 1 case-control study). There was heterogeneity in sample size, follow-up duration, and treatment modality. Depression and anxiety were present in 51.4% and 53.0% of FND-par patients, respectively. In individuals whose FND-par improved, there was no significant difference between those with versus without depression (52.6% vs 47.4%, p = 0.69) or those with versus without anxiety (50.3% vs 49.7%, p = 0.38). Meta-analysis showed no clear impact of baseline depression or anxiety per se [pooled OR for depression 0.85 (95%CI 0.50–1.45; p = 0.40) and anxiety 0.84 (95%CI 0.51–1.38; p = 0.91)]; and of depression or anxiety severity [pooled OR for depression 1.23 (95%CI 0.63–2.39; p = 0.91) and anxiety 1.40 (95%CI 0.70–2.78; p = 0.58)] on FND-par outcome. Insufficient data were available to assess the impact of personality disorders. Conclusion: We found no evidence that depression or anxiety influenced outcome in FND-par. Large-scale, prospective studies in FND-par, and other FND subtypes, are needed to fully contextualize the impact of concurrent mental health concerns on outcomes.</p

Distribution of health care expenditures for HIV-infected patients

BACKGROUND: Health care expenditures for persons infected with human immunodeficiency virus (HIV) in the United State determined on the basis of actual health care use have not been reported in the era of highly active antiretroviral therapy. METHODS: Patients receiving primary care at the University of Alabama at Birmingham HIV clinic were included in the study. All encounters (except emergency room visits) that occurred within the University of Alabama at Birmingham Hospital System from 1 March 2000 to 1 March 2001 were analyzed. Medication expenditures were determined on the basis of 2001 average wholesale price. Hospitalization expenditures were determined on the basis of 2001 Medicare diagnostic related group reimbursement rates. Clinic expenditures were determined on the basis of 2001 Medicare current procedural terminology reimbursement rates. RESULTS: Among the 635 patients, total annual expenditures for patients with CD4+ cell counts \u3c50 cells/microL (36,533 dollars per patient) were 2.6-times greater than total annual expenditures for patients with CD4+ cell counts \u3e or =350 cells/microL (13,885 dollars per patient), primarily because of increased expenditures for nonantiretroviral medication and hospitalization. Expenditures for highly active antiretroviral therapy were relatively constant at approximately 10,500 dollars per patient per year across CD4+ cell count strata. Outpatient expenditures were 1558 dollars per patient per year; however, the clinic and physician component of these expenditures represented only 359 dollars per patient per year, or 2% of annual expenses. Health care expenditures for patients with HIV infection increased substantially for those with more-advanced disease and were driven predominantly by medication costs (which accounted for 71%-84% of annual expenses). CONCLUSIONS: Physician reimbursements, even with 100% billing and collections, are inadequate to support the activities of most clinics providing HIV care. These findings have important implications for the continued support of HIV treatment programs in the United States