Design and fabrication of monolithic optical spot size transformers(MOSTs) for highly efficient fiber-chip coupling

A novel type of monolithic optical spot size transformer realized in the InP/InGaAsP material system combines many desirable features like high fiber-chip coupling efficiency, large spot size transformation, high tolerances for fiber alignment, simple fabrication, and straightforward integrability with other devices. The spot size transformation is accomplished by two waveguide sections tapered in the vertical and lateral directions, respectively. We discuss design issues, describe the fabrication process, give experimental results, and present the monolithic integration of the spot size transformers with a current controlled directional coupler switch     

Up-regulation of hypoxia-inducible factor-1alpha is not sufficient for hypoxic/anoxic p53 induction

Oxygen-deprived regions of a solid tumor can induce tumor suppressor p53 expression and hence select for p53-mutant tumor cells with diminished apoptotic potential. It has been proposed that the hypoxia-inducible factor-1 (HIF-1) alpha subunit binds to p53 and protects it from proteasomal degradation. However, we found that hypoxic conditions that strongly induce HIF-1-dependent endogenous gene expression as well as HIF-1alpha protein neither induce p53-dependent gene expression nor p53 protein. The iron chelator deferoxamine induced both HIF-1alpha and p53, but p53 up-regulation could still be detected in HIF-1alpha-deficient cells, suggesting that mechanisms other than HIF-1alpha activation contribute to oxygen-regulated p53 induction.     

Results of proximal tibial osteotomy. The effects of tibiofemoral angle, stance-phase flexion-extension, and medial-plateau force

Forty-eight knees were evaluated after proximal tibial osteotomy, performed for varus deformity to determine the desired amount of correction of the deformity, the effect of osteotomy on knee motion during gait and one medial-plateau force during standing, and the relationships between these factors and the result. Correction of the tibiofemoral angle to 5 degrees of genu valgum or more produced the best and most lasting results. Stance-phase flexion-extension increased the rotation decreased in knees with good results while the other gait parameters were not significantly changed. Medial-plateau force was decreased by successful tibial osteotomy. The knees with the best and most lasting results had 7 degrees of stance-phase flexion-extension or more during walking and either a valgus tibiofemoral angle of 5 degrees or more or a medial-plateau force of 50 per cent of body weight or less.     

Secreting paragangliomas of the organ of Zuckerkandl. A report on two cases (author's transl)

The authors describe two cases of secreting paragangliomas of the organ of Zuckerkandl, beinging the number of known cases to 78. They underline the interest of arteriographic and phlebographic explorations which define more accurately the origin and spread of these tumours.     

Outbreak of serogroup C meningococcal disease associated with campus bar patronage

Between February 1991 and April 1992, eight undergraduates at a US residential university and one at a nearby 2-year college contracted serogroup C meningococcal disease. A case-control investigation with 20 controls per case, oropharyngeal carriage surveys, and multilocus enzyme electrophoresis (MEE) of serogroup C isolates were used to identify factors contributing to the outbreak. All eight sterile-site isolates from cases were closely related by MEE and were similar (though not identical) to the strain associated with the 1991-1992 epidemic of meningococcal disease in eastern Canada. Disease was associated with cigarette smoking (p = 0.012), recent patronage of campus-area bars (p = 0.034), estimated amount of time spent in campus-area bars (p = 0.0003), and, especially, recent patronage of one specific bar, bar A (p = 0.0006; odds ratio = 23.1, 95% confidence interval 3.0-571.5). In carriage surveys, 1,528 throat cultures taken from (primarily student) noncases yielded only five (0.3%) strains that were identical by MEE to those from cases. Two of these were found among 22 cultures obtained from bar A employees in spring 1992. Some cases in this outbreak may have followed transmission of the epidemic strain in bar A. Campus bar environments may facilitate the spread of meningococcal disease among teenagers and young adults.     

Bacillary angiomatosis and bacillary peliosis in patients infected with human immunodeficiency virus: clinical characteristics in a case-control study

Clinical characteristics associated with bacillary angiomatosis and bacillary peliosis (BAP) in patients with human immunodeficiency virus (HIV) infection were evaluated in a case-control study; 42 case-patients and 84 controls were matched by clinical care institution. Case-patients presented with fever (temperature, > 37.8 degrees C; 93%), a median CD4 lymphocyte count of 21/mm3, cutaneous or subcutaneous vascular lesions (55%), lymphadenopathy (21%), and/or abdominal symptoms (24%). Many case-patients experienced long delays between medical evaluation and diagnosis of BAP (median, 4 weeks; range, 1 day to 24 months). Case-patients were more likely than controls to have fever, lymphadenopathy, hepatomegaly, splenomegaly, a low CD4 lymphocyte count, anemia, or an elevated serum level of alkaline phosphatase (AP) (P < .001). In multivariate analysis, a CD4 lymphocyte count of < 200/mm3 (matched odds ratio [OR], 9.9; P < .09), anemia reflected by a hematocrit value of < 0.36 (OR, 19.7; P < .04), and an elevated AP level of > or = 2.6 mukat/L (OR, 23.9; P < .05) remained associated with disease after therapy with zidovudine was controlled for. BAP should be considered an AIDS-defining opportunistic infection and should be included in the differential diagnosis for febrile, HIV-infected patients with cutaneous or osteolytic lesions, lymphadenopathy, abdominal symptoms, anemia, or an elevated serum level of AP.     

Cognitive sequence knowledge: What is learned?

In 4 experiments, participants performed running-arithmetic tasks. These tasks involved a sequential ordering of individual operations and a structure of subgoals that defined how calculations fit together in purpose. Consistent transitions between adjacent steps facilitated performance only when subgoal structures were relatively simple. When subgoal structures were more complex, consistent mapping of operations to serial locations produced a slight benefit. Consistently of subgoal structure produced a substantial benefit in both speed and accuracy, and some knowledge of subgoal structure integrated with knowledge of the sequence of operations. Apparently, a task's subgoal structure imposes demands that either facilitate or obscure benefits of sequence consistencies. The benefits are attributed to increase deficiency in using working memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Disposable microscope objective lenses for fluorescence correlation spectroscopy using latex microspheres

We explore the combination of a latex microsphere with a low NA lens to form a high performance optical system, and enable the detection of single molecules by fluorescence correlation spectroscopy (FCS). Viable FCS experiments at concentrations 1-1000 nM with different objectives costing less than $40 are demonstrated. This offers a simple and low-cost alternative to the conventional complex microscope objectives.     

Assessment of the surface state behaviour of Al71Cu10Fe9Cr10 and Al3Mg2 complex metallic alloys in sliding contacts

Electrochemical measurements and friction measurements during continuous and intermittent unidirectional sliding tests are used to monitor and to evaluate the surface characteristics of two types of metallic materials characterized by a huge unit cell, namely Al₇₁Cu₁₀Fe₉Cr₁₀ and Al₃Mg₂. The modification of the surface characteristics results from the periodic mechanical removal of a surface film during sliding, and the subsequent (electro)chemical re-growth of a surface film in-between successive sliding contacts. Al₇₁Cu₁₀Fe₉Cr₁₀ and Al₃Mg₂ materials were tested in a phosphate buffer solution pH 7 at 25 °C to compare their depassivation and subsequent repassivation behaviour. The Al₃Mg₂ material was also tested in a 0.1 M KOH solution pH 13 and 25 °C to reveal the role of constituting metallic elements on the surface film formation. The effect of film formation and removal on the coefficient of friction recorded during unidirectional sliding is discussed.