A fiber-based crosspoint switch using high-refractive indexinterlay materials

A switch principle is described which relies on the coupling between two polished fiber coupler blocks through a high-index interlay waveguide whose refractive index is higher than the effective mode index of the fibers. Switching is effected by the input radiation coupling through the interlay waveguide into the second fiber (cross-coupled state) or recoupling into the first fiber (straight-through state). The half-coupler blocks were constructed with a nominal radius of curvature of 25 cm and the top surfaces polished close to the edge of the fiber core. Accurate glass and polymer ribbon spacers were used to separate the two blocks by from 5-20 μm and align them in parallel. The interstice was filled with a film of transparent high-index oil to form a slab waveguide     

Can the clinical examination diagnose left-sided heart failure in adults?

We systematically reviewed the literature to ascertain how well clinicians determine the probability and type of left-sided heart failure in their patients. Left-sided heart failure is characterized by decreased left ventricular ejection fraction or increased filling pressure. The type of heart failure determines optimal treatment. Systolic dysfunction exists when ejection fraction is reduced. Diastolic dysfunction is presumed to be present when filling pressure is increased with a normal ejection fraction and without another explanatory diagnosis. Many findings are associated with heart failure, and wide variation exists in clinicians' ability to detect these findings. The best findings for detecting increased filling pressure are jugular venous distention and radiographic redistribution. The best findings for detecting systolic dysfunction are abnormal apical impulse, radiographic cardiomegaly, and q waves or left bundle branch block on an electrocardiogram. Diastolic dysfunction is especially difficult to diagnose, but is associated with an elevated blood pressure during heart failure.     

Development of the human external ear

PURPOSE: To present own results of extracapsular cataract extraction with the use of the envelope technique. MATERIAL: 200 patients (110 male, 87 female and 3 children) aged from 7 to 86 years operated in the Department of Ophthalmology in Bydgoszcz from December 1992 to May 1996, including patients with congenital, senile, presenile cataract or with diabetes. RESULTS: In 187 patients (93.5%) final distance visual acuity was 0.7-1.0. Visual acuity less than 0.7 wasn't related with surgical procedure itself. In 8 patients corneal edema, lasting for a few days, was observed postoperatively. After treatment with systemic steroids all the symptoms resolved-not effecting final visual acuity. CONCLUSION: Cataract extraction with the use of an envelope technique allows for stable IOL placement in the lens capsule and decreases postoperative corneal reaction to minimum.     

Atenolol use and clinical outcomes after thrombolysis for acute myocardial infarction: the GUSTO-I experience. Global Utilization of Streptokinase and TPA (alteplase) for Occluded Coronary Arteries

OBJECTIVES: We assessed the use and effects of acute intravenous and later oral atenolol treatment in a prospectively planned post hoc analysis of the GUSTO-I dataset. BACKGROUND: Early intravenous beta blockade is generally recommended after myocardial infarction, especially for patients with tachycardia and/or hypertension and those without heart failure. METHODS: Besides one of four thrombolytic strategies, patients without hypotension, bradycardia or signs of heart failure were to receive atenolol 5 mg intravenously as soon as possible, another 5 mg intravenously 10 min later and 50 to 100 mg orally daily during hospitalization. We compared the 30-day mortality of patients given no atenolol (n=10,073), any atenolol (n=30,771), any intravenous atenolol (n=18,200), only oral atenolol (n=12,545) and both intravenous and oral drug (n=16,406), after controlling for baseline differences and for early deaths (before oral atenolol could be given). RESULTS: Patients given any atenolol had a lower baseline risk than those not given atenolol. Adjusted 30-day mortality was significantly lower in atenolol-treated patients, but patients treated with intravenous and oral atenolol treatment vs. oral treatment alone were more likely to die (odds ratio, 1.3; 95% confidence interval, 1.0 to 1.5; p=0.02). Subgroups had similar rates of stroke, intracranial hemorrhage and reinfarction, but intravenous atenolol use was associated with more heart failure, shock, recurrent ischemia and pacemaker use than oral atenolol use. CONCLUSIONS: Although atenolol appears to improve outcomes after thrombolysis for myocardial infarction, early intravenous atenolol seems of limited value. The best approach for most patients may be to begin oral atenolol once stable.     

Evaluation and treatment of posterior cruciate ligament injuries

Twenty-eight low median nerve injuries and 23 low ulnar nerve injuries were repaired using intraneural fascicular dissection and electrical fascicular orientation. Eleven freshly lacerated nerves were seen within 48 hours after injury; 40 nerve lacerations were chronic. Fascicular orientation between sensory and motor fascicles at the proximal nerve end could be accurately differentiated in 47 nerves (92%) independent of whether it was acute or chronic. At the distal nerve end in fresh lacerations, the motor fascicles could be determined conclusively by muscle contraction with sequential electrical stimulation of the fascicles. In chronic nerve lacerations, the distal fascicles could be estimated anatomically after internal neurolysis. After fascicular orientation, nerves were repaired with end-to-end group fascicular suture or interfascicular sural nerve grafting. Twenty-four nerves repaired with end-to-end suture and 13 nerves repaired with nerve grafting were monitored more than 25 months. Satisfactory sensory results (i.e., S3+ or S4 functions) were obtained in 29 nerves (78%) and M4 or M5 motor functions were achieved in 29 nerves (78%). There were no patients who needed additional tendon transfers to reconstruct thumb opposition or to correct claw finger deformity. These results suggest that low median or ulnar nerve lacerations, whether acute or chronic, partial or complete, may be successfully repaired with the aid of electrical fascicular orientation with or without intraneural fascicular dissection.     

Sequencing of the alpha-synuclein gene in a large series of cases of familial Parkinson''s disease fails to reveal any further mutations. The European Consortium on Genetic Susceptibility in Parkinson''s Disease (GSPD)

PURPOSE: Tumor hypoxia may be an important factor predicting relapse following radiation therapy. This study was designed to determine the relationship between the oxygenation parameters measured using a polarographic oxygen electrode, prior to and during treatment in patients with cervix cancer, and to assess these results with regard to patient survival. MATERIALS AND METHODS: Forty-three patients had pretreatment oxygen assays performed and measurements repeated following external beam radiation to a median dose of 50 Gy (range 26-52 Gy). Stage distribution showed 15 patients in Stage IB, 17 in Stage II, and 11 in Stage III. The median tumor size was 5 cm (range 3-10 cm). RESULTS: The median proportion of pO2 values <5 mm Hg (the HP5) was 41% following radiation, and the median pO2 was 12 mm Hg. These results were not significantly different from the pretreatment HP5 or pO2 of 37% and 12 mm Hg, respectively. Disease-free survival at 2 years was 50% in patients with posttreatment HP5 < or =50%, compared to 60% when posttreatment HP5 was >50% (p = 0.35). CONCLUSIONS: Unlike pretreatment results, tumour oxygenation measured following external radiation does not appear to be a useful predictive assay in patients with cervical cancer.     

Chirp and system performance of integrated laser modulators

Time-resolved chirp measurements and laser-threshold measurements are used to understand the chirp performance of integrated laser electroabsorption modulators. The different effects of the intrinsic modulator chirp component and chirp caused by optical feedback, from reflection at the output facet into the laser, are observed. A figure of merit is introduced to assess the chirp performance, which shows good correlation with dispersion penalty measurements. The effect of reflection-induced chirp is considerably reduced by operating the modulator with negative chirp. An optimized device is reported, which delivers purely negative chirp with reasonable optical power     

Polarisation-independent 20 Gbit/s soliton data transmission over12500 km using amplitude and phase modulation soliton transmissioncontrol

Polarisation-independent error-free 20 Gbit/s soliton data transmission over 12500 km with flat system Q dependence on distance, has been demonstrated using static filtering and a semiconductor polarisation-independent amplitude and phase modulator for soliton transmission control