Hyperdoping silicon with selenium: solid vs. liquid phase epitaxy.

Chalcogen-hyperdoped silicon shows potential applications in silicon-based infrared photodetectors and intermediate band solar cells. Due to the low solid solubility limits of chalcogen elements in silicon, these materials were previously realized by femtosecond or nanosecond laser annealing of implanted silicon or bare silicon in certain background gases. The high energy density deposited on the silicon surface leads to a liquid phase and the fast recrystallization velocity allows trapping of chalcogen into the silicon matrix. However, this method encounters the problem of surface segregation. In this paper, we propose a solid phase processing by flash-lamp annealing in the millisecond range, which is in between the conventional rapid thermal annealing and pulsed laser annealing. Flash lamp annealed selenium-implanted silicon shows a substitutional fraction of ~ 70% with an implanted concentration up to 2.3%. The resistivity is lower and the carrier mobility is higher than those of nanosecond pulsed laser annealed samples. Our results show that flash-lamp annealing is superior to laser annealing in preventing surface segregation and in allowing scalability.

Bioconjugation of the estrogen receptor hERα to a quantum dot dye for a controlled immobilization on a SiO2 surface.

We investigated the immobilization of the estrogen receptor hER(α) on silanized SiO(2) surfaces for biosensor applications. The conjugation of the estrogen receptor hER(α) to the quantum dot dye QD655 was achieved. In order to obtain an optimal immobilization of the estrogen receptor hER(α) on the functionalized SiO(2) surface, the bioconjugate hER(α)-QD655 (Rcpt-qd655) solution was prepared with a higher molar ratio of 10-15 between the QDs and the receptors. A blue laser with an excitation wavelength of 405 nm was used for photoluminescence spectroscopy (PL) investigations to monitor the bioconjugate Rcpt-qd655 immobilization on the silanized SiO(2) surfaces with three different functional groups, namely NH(2), -COO(-), and -SH. Several wash processes were applied to remove the excess receptors from the surface after the immobilization. A Fourier transform infrared spectroscopy (FTIR) was used to control the biofilm background after each wash of the receptor-coated surface which allows the optimization of the immobilization protocol. In order to test its stability a quartz crystal microbalance (QCM) was employed and the receptor density was calculated. Finally the optimal biolayer (silane film+hER(α) receptor) was tested for measurements of 17ß-estradiol (E2) with a concentration of 1 µM in waterish solution. The measurement concept outlined in [L. Rebohle et al., Vacuum 83 (2009) 24-28] was applied. The whole system was investigated by PL, which exhibits two color signals, namely from the receptor and the detected E2 molecules.

Superconducting state in a gallium-doped germanium layer at low temperatures.

We demonstrate that the third elemental group-IV semiconductor, germanium, exhibits superconductivity at ambient pressure. Using advanced doping and annealing techniques of state-of-the-art semiconductor processing, we have fabricated a highly Ga-doped Ge (GeratioGa) layer in near-intrinsic Ge. Depending on the detailed annealing conditions, we demonstrate that superconductivity can be generated and tailored in the doped semiconducting Ge host at temperatures as high as 0.5 K. Critical-field measurements reveal the quasi-two-dimensional character of superconductivity in the approximately 60 nm thick GeratioGa layer. The Cooper-pair density in GeratioGa appears to be exceptionally low.

Spraying spin coating silanization at room temperature of a SiO2 surface for silicon-based integrated light emitters.

A new silanization method for SiO(2) surfaces has been developed for Si-based light emitters which are intended to serve as light sources in smart biosensors relying on fluorescence analysis. This method uses a special silanization chamber and is based on spraying and spin coating (SSC) in nitrogen atmosphere at room temperature for 10 min. It avoids processes like sonication and the use of certain chemicals being harmful to integrated light emitters. The surface of a SiO(2) layer serving as a passivation layer for the light emitters was hydrolyzed to silanols using an in situ-hybridization chamber and catalyzed with MES (2-(N-morpholino)ethanesulfone acid hydrate) buffer solution. Subsequently, the substrates were silanized with the SSC method using two coupling agents as (3-Aminopropyl)trimethoxysilane (APMS), and N'-(3-(trimethoxysilyl)-propyl)-diethylenetriamine (triamino-APMS). The structure of the SiO(2) surface, the APMS and the triamino-APMS layers was controlled and characterized by Infrared spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The results show a covalent binding of the silane coupling agents on the surface. Atomic force microscopy was used to investigate the roughness of the surface. The silanized samples exhibit smooth and densely covered surfaces. Finally, the suitability of the SSC method was verified on real light emitters.

[Cystic fibrosis in adults--clinical aspects]. / Mukowiscydoza u doroslych--obraz kliniczny.

Nineteen patients with cystic fibrosis were seen in the I Department of Tuberculosis and Lung Diseases during 3.5 years. There were 12 (63%) female, and 7 male, aged from 16 to 35 years (mean 23.2). Most patients were diagnosed in childhood, but 4 were diagnosed in their early adulthood. The diagnosis was confirmed by positive chloride sweat test in all cases. Molecular DNA analyses were performed in 16 cases. In 9 (56%) cases two mutations in the CFTR gene were identified. In 5 cases one mutation was identified. All patients had bronchiectases confirmed by CT. Spirometry showed lung function impairment with predominantly obstructive pattern. Mean VC was 2.57l, mean FEVI was 1.66l. In 7 (37%) cases FEVI was lower then 30% of predictive value. Hypoxemia was found in 11 (58%) cases and hypercapnia in 3 (16%) cases. Sputum cultures were positive for mucoid P. aeruginosa in 12 (63%) cases, for Staph. aureus in 16 (84%) cases. Persistent colonisation with nontuberculous mycobacteria was found in 2 (10.5%) cases. Aspergillus fumigatus was identified in sputum cultures in 2 subjects who had also positive precipitation test. Diabetes mellitus was diagnosed in 2 cases. Meconium ileus equivalent was seen in 1 case. Pneumothorax was seen in 1 case. One patient died in the endstage of the illness.

[Use of methotrexate for treatment of corticosteroid-dependent asthma]. / Zastosowanie metotreksatu w leczeniu kortykozaleznej astmy oskrzelowej.

We evaluated the effects of methotrexate treatment in 20 subjects (10 men, 10 women) suffering from corticosteroid-dependent asthma. All patients had been treated with 15 mg of prednisone or more per day for at least 3 years before including in the study. Methotrexate (15 mg once weekly) had been given for 9.7 months on average. Oral steroid intake was reduced by 50% in 8 patients and it was possible to discontinue oral corticosteroids in further 6 patients without deterioration of spirometric parameters at the end of the study. Side effects of methotrexate therapy were observed in 40% of patients, and required the discontinuation of treatment in 6 subjects.

[Deaths from asthma, bronchitis and pulmonary heart disease in Warsaw in the years 1993-1994]. / Zgony na astme przewlekle zapalenie oskrzeli i serce plucne w Warszawie w latach 1993-1994.

By the regular checking the death certificates in the municipal offices in 7 districts of Warsaw, the morality rate from asthma has been established as 2.98/100.000, from chronic bronchitis as 8.71/100.000 and from pulmonary heart disease as 6.27/100.000. During one year of this survey only 15 deaths (4.7%) from these diseases were below age of 50.67% of patients died in hospitals and 22 (7%) died suddenly (at home). In general, deaths reported as the results of COLD were only 1.59% of the total number of deaths in Warsaw (21.530). 6.9% of all death certificates were without clinical diagnosis (Number 798 of ICD)-described as "natural death", "death before doctor's arrival" or "noncriminal death". Authors discuss the problem of over- and under-diagnosis of asthma as the cause of death, the historical background of asthma mortality and also put the question of the righteousness of regard the pulmonary heart disease as the primary cause of death.