Nonlinearity-insensitive standard-fibre transmission based onoptical-phase conjugation in a semiconductor-laser amplifier

Experimental results are presented confirming that optical-phase conjugation in a semiconductor-laser amplifier has the potential to compensate for the interplay of chromatic dispersion and nonlinear self-phase modulation, thereby enabling high-capacity high-power transmission over standard singlemode fibres     

Taste and smell complaints in HIV-infected patients

OBJECTIVES: To define the scope of taste and smell (chemosensory) complaints amongst HIV-infected persons in the study population; to evaluate the clinical factors associated with chemosensory complaints; and to determine the impact of chemosensory complaints on quality of life. DESIGN: Cross-sectional survey. SETTING: Tertiary care university medical center clinic. PARTICIPANTS: A total of 207 HIV-infected patients. MAIN OUTCOME MEASURES: Chemosensory complaint score from taste and smell questionnaire and quality of life scores from the Medical Outcomes Study HIV Health Survey (MOS-HIV). RESULTS: A total of 144 patients (70%) reported chemosensory complaints, 91 (44%) reported both taste and smell complaints, 47 (23%) reported only taste complaints, and six (3%) reported only smell complaints. Many patients complained that drugs interfered with their sense of taste, or that medications tasted bad. Higher chemosensory complaint scores were associated with a greater number of medications taken, tobacco use, and hay fever. Patients with chemosensory complaints had significantly lower scores in all domains of the MOS-HIV than those without complaints. Quality of life as measured by the MOS-HIV was lower in patients with chemosensory complaints even after controlling for number of AIDS diagnoses, number of medications, CD4 cell count, and HIV-1 viral load. CONCLUSIONS: Chemosensory complaints were common in the patient population and were associated with a poor quality of life. Medications played an important role in chemosensory complaints. Measures to optimize taste and smell function may improve quality of life and medication adherence, and prevent complications such as inadequate oral intake, malnutrition, weight loss, and ultimately wasting.     

The carrier lifetime of heat-treated silicon crystals

Carrier lifetime measurements were performed on crucible-grown, float-zoned, and swirl-free float-zoned silicon single crystals after annealing up to about 1000°C. In dislocation-free, crucible-grown silicon one pronounced maximum of the carrier lifetime can be found after annealing at 450°C . This gettering effect is correlated to the appearence of numerous IR-absorption bands at 80 K. The absorption coefficients of these bands depend on the oxygen concentration of the crystals and on the annealing duration. A differing number of maxima of the carrier lifetime after annealing at various temperatures can be found in dislocation-free, float-zoned silicon. These maxima are correlated to still remaining lattice defects in the crystals such as vacancy clusters of A-and B-type. Models are presented to explain the experimental findings.     

Recombinant human acid alpha-glucosidase: high level production in mouse milk, biochemical characteristics, correction of enzyme deficiency in GSDII KO mice

Glycogen storage disease type II (GSDII) is caused by lysosomal acid alpha-glucosidase deficiency. Patients have a rapidly fatal or slowly progressive impairment of muscle function. Enzyme replacement therapy is under investigation. For large-scale, cost-effective production of recombinant human acid alpha-glucosidase in the milk of transgenic animals, we have fused the human acid alpha-glucosidase gene to 6.3 kb of the bovine alphaS1-casein gene promoter and have tested the performance of this transgene in mice. The highest production level reached was 2 mg/ml. The major fraction of the purified recombinant enzyme has a molecular mass of 110 kDa and resembles the natural acid alpha-glucosidase precursor from human urine and the recombinant precursor secreted by CHO cells, with respect to pH optimum, Km, Vmax, N-terminal amino acid sequence and glycosylation pattern. The therapeutic potential of the recombinant enzyme produced in milk is demonstrated in vitro and in vivo. The precursor is taken up in a mannose 6-phosphate receptor-dependent manner by cultured fibroblasts, is converted to mature enzyme of 76 kDa and depletes the glycogen deposit in fibroblasts of patients. When injected intravenously, the milk enzyme corrects the acid alpha-glucosidase deficiency in heart and skeletal muscle of GSDII knockout mice.     

Medication use patterns among demented, cognitively impaired and cognitively intact community-dwelling elderly people

OBJECTIVE: The present study was conducted in order to describe human hypothalamo-pituitary adrenal (HPA) axis adaptation in a model of repeated physical stress (endurance training) that causes a moderate increase in cortisol levels. SUBJECTS: We performed the same stimulation tests (adrenal stimulation with ACTH or pituitary stimulation with combined CRH/LVP) in a population of 8 endurance-trained athletes in two distinct situations: resting (baseline cortisol values) and 2 h after the end of strenuous exercise (increased cortisol values) to evaluate the HPA axis sensitivity to endogenous sustained increases in cortisol concentrations. MEASUREMENTS: During these tests, saliva and plasma cortisol (Fs and Fp, respectively) were assessed and compared. RESULT: Cortisol values in both plasma and saliva at the end of 2 h of exercise were significantly higher than in rested controls: Fs 11.5 +/- 1.3 vs 6.5 +/- 0.8 nmol.l-1 and Fp 428 +/- 36 vs 279 +/- 27 nmol.l-1 (post exercise vs post rest sessions, respectively, P < 0.001 for both). After either hormone test (CRH/LVP or ACTH), cortisol levels in plasma and saliva increased similarly when rest was compared to post exercise. Saliva variations (delta %) under exogenous hormone stimulation were dramatically greater than plasma variations. For example, under ACTH stimulation, the relative increments in cortisol were on control day: delta Fs 980 +/- 139 vs delta Fp 218 +/- 43% (saliva vs plasma, respectively, P < 0.05) and on exercise day: delta Fs 605 +/- 89 vs delta Fp 102 +/- 14% (saliva vs plasma, respectively, P < 0.05). CONCLUSIONS: In endurance-trained athletes, displaying a moderate but sustained endogenous cortisol increase: (1) ACTH responses following pituitary stimulation are not blunted, (2) cortisol responses following maximal adrenal stimulation are not blunted. Our results favour the hypothesis of a decreased pituitary sensitivity to cortisol negative feedback whereas the hypothesis of a major decreased adrenal sensitivity to ACTH was discarded. The greater ability of saliva assays to detect a cortisol increase strongly supports its use in the study of HPA physiology, whether under basal or dynamic conditions.     

Die elektrische Leitfähigkeit metallkeramischer Werkstoffe der Systeme ZrO2-Mo und Al2O3-Fe zwischen 20 und 1700°C

Berechnung der elektrischen Leitfähigkeit metallkeramischer Werkstoffe. Erklärung der sprunghaften Leitfähigkeitsänderung mit einem Polyedermodell. Messung der elektrischen Leitfähigkeit an gesinterten Metallkeramiken aus elektronenleitendem Zirkonoxid und Molybdän, stabilisiertem, ionenleitendem Zirkonoxid und Molybdän sowie aus Aluminiumoxid und Eisen. Einfluß der Ausgangskorngröße der oxidischen Komponente auf die elektrische Leitfähigkeit.