Generation of Super-Gaussian modes in Nd:YAG lasers with a graded-phase mirror

A dielectric graded-phase mirror was developed to change the intensity distribution of the fundamental mode in an Nd:YAG laser resonator to a top-hat profile. A super-Gaussian mode of the sixth order was generated by means of a graded-phase mirror with a simple ring-shaped phase step on a spherical reflector. The depth of the ring on the mirror was 90 nm. The graded-phase mirror was manufactured with an ordinary vapor deposition technique using an appropriate mask. Laser experiments with CW and repetitively pulsed diode-laser pumping were performed and compared. Slope efficiencies up to 19% were achieved. The experimental results are in excellent agreement with the theory.     

Diastolic dysfunction and altered energetics in the alphaMHC403/+ mouse model of familial hypertrophic cardiomyopathy

An arginine to glutamine missense mutation at position 403 of the beta-cardiac myosin heavy chain causes familial hypertrophic cardiomyopathy. Here we study mice which have this same missense mutation (alphaMHC403/+) using an isolated, isovolumic heart preparation where cardiac performance is measured simultaneously with cardiac energetics using 31P nuclear magnetic resonance spectroscopy. We observed three major alterations in the physiology and bioenergetics of the alphaMHC403/+ mouse hearts. First, while there was no evidence of systolic dysfunction, diastolic function was impaired during inotropic stimulation. Diastolic dysfunction was manifest as both a decreased rate of left ventricular relaxation and an increase in end-diastolic pressure. Second, under baseline conditions alphaMHC403/+ hearts had lower phosphocreatine and increased inorganic phosphate contents resulting in a decrease in the calculated value for the free energy released from ATP hydrolysis. Third, hearts from alphaMHC403/+ hearts that were studied unpaced responded to increased perfusate calcium by decreasing heart rate approximately twice as much as wild types. We conclude that hearts from alphaMHC403/+ mice demonstrate work load-dependent diastolic dysfunction resembling the human form of familial hypertrophic cardiomyopathy. Changes in high-energy phosphate content suggest that an energy-requiring process may contribute to the observed diastolic dysfunction.     

The impact of true partnership between a university Level I trauma center and a community Level II trauma center on patient transfer practices

OBJECTIVE: To examine the effect of a clinical and administrative partnership with an academic urban Level I trauma center on the patient transfer practices at a suburban/rural Level II center. METHODS: Data for 2 years before affiliation (PRE) abstracted from inpatient charts and the trauma registry were compared with that for 2 years after (POST). The following data were collected: number of, reason for, and destination and demographics of transfers. Chi(2) test and t test analyses were used; p < 0.05 defined significance; data are mean +/- SEM. RESULTS: Transfer rate increased from 4% PRE to 6.9% (p = 0.001) POST with no significant difference in age, Glasgow Coma Scale score, Injury Severity Score, or Revised Trauma Score. Repatriation occurred in 12.8% POST (none PRE). The current Level I facility accepted 1.8% of all transfers PRE and 36.4% POST (p = 0.0001). PRE/POST rates by reason are as follows: pediatric, 14.6%/9.0% (p = 0.04); intensive care unit, 0.4%/1.7% (p = 0.13); complex orthopedic, 100%/0% (p = 0.005); vascular, 50%/0% (p = 0.008); spinal cord injury, 100%/100%; and ophthalmologic, 0%/100% (p = 0.005). CONCLUSIONS: In this experience of Level I/II partnership (1) transfer patterns were altered, (2) select patient cohort transfers decreased (pediatric, complex orthopedic, vascular), whereas others increased (aortic work-up), and (3) repatriation rates were low.     

Effect of changing strain paths on

The effect of changing strain paths on forming limits of aluminum alloy 2008-T4 has been investigated by determining forming limit diagrams (FLDs) after prestraining. Sheets were pre- strained to several levels in uniaxial, biaxial, and plane-strain tension parallel and perpendicular to the prior rolling direction (RD). Abrupt changes in the strain path can be used to increase the forming limits. Prestraining in biaxial tension generally lowers the forming limits for the entire FLD, whereas prestraining in uniaxial tension raises the limits on the right-hand side of the FLD without much effect on the left-hand side. Prestraining in plane-strain tension raises both sides away from the minimum. Finally, it was found that after prestraining, the amount of the additional plane-strain deformation possible depends on the effective strain during prestrain.     

Intra-arterial regional anaesthesia for hand surgery with alkalinized 0.5% lignocaine

Intra-arterial regional anaesthesia (IARA) for hand surgery is an old, forgotten technique. One of the causes of low popularity may be a scalding sensation in the hand during intra-arterial injection of lignocaine, which may be caused by low pH of lignocaine's solution. In this randomized, double-blind study, normal (pH 5.2-5.3) or alkalinized (pH 7.2-7.3) preservative-free 0.5% lignocaine 1.5 mg kg-1 was injected into the radial arteries of forty adult patients to produce anaesthesia for ambulatory hand surgery. Scalding sensation in the hand during intra-arterial injection (VAS) was less pronounced with alkalinized lignocaine (P = 0.04). The time of onset and regression of analgesia was similar in both groups. Four patients in group 1 (normal lignocaine) and six patients in group 2 (alkalinized lignocaine) needed supplemental analgesia at the start of surgery (NS). Cannulation time, operating conditions, motor blockade, surgical-, and tourniquet pain scores (VAS) and patient's acceptance were similar. Three patients (two in group 1 and one in group 2) had minor systemic adverse effects after tourniquet release (NS). Nine patients in group 1 and seven in group 2 developed minor bruises after cannulation (NS). No other sequelae of intra-arterial injections were observed. We conclude that alkalinized 0.5% lignocaine was less painful on injection than normal lignocaine and should be preferred for intra-arterial anaesthesia for hand surgery.     

A four-point-bending-test for the stability assessment of glass frit bonded molded microsensors

For increasingly miniaturized micromechanical sensors the silicon package is thinned and therefore more sensitive to thermomechanical stresses caused by the production stages. We present a four-point-bending-test that enables the investigation of reliability relevant loading like warping. The initiation of crack growth at the glass frit bonding frame is observed by an infrared camera and critical fracture mechanical parameters are determined for different tensile and shear mode contributions. Based on this crucial fracture mechanical data the stability of silicon packages can be assessed.     

The potential of the teaching hospital for the development of prepaid group practices

This paper deals with the development of a hospital based prepaid group practice at Long Island Jewish-Hillside Medical Center. The paper provides an historical perspective of the factors leading to the decision to develop such a Medical Group practice, the difficulties encountered in obtaining conceptual approval from the Medical Center's Board of Trustees and its medical staff, the negotiations between the Medical Center and Blue Cross-Blue Shield of Greater New York as the insurance company which agreed to market the program and to subsidize it in its developmental stage, factors relating to the contractual negotiations between the Medical Center and Blue Cross, the key elements of the negotiated contract from the standpoint of the prepaid group, and the nature of the subsidies provided to ensure a healthy fiscal beginning. The paper highlights the methods used in achieving the desired goals and the development of the Group, sets forth the resistance which other, similar hospitals might anticipate in undertaking such a venture of their own, and highlights the nature and the degree of commitment necessary to bring such a program into being.