Electrospinning hollow and core/sheath nanofibers using hydrodynamic fluid focusing

Hollow poly (vinylpyrrolidone) (PVP) + TiO₂ and polypyrrole (core)/PVP (sheath) nanofibers were successfully electrospun using hydrodynamic fluid focusing. Utilizing a two-dimensional fluid focusing technique previously applied to aqueous solutions, intersecting microchannels cast in (poly)dimethylsiloxane were utilized to dynamically center core fluids in immiscible sheath fluids prior to electrospinning at the channel outlet. Advantages of using microfluidic channel networks for the electrospinning of composite nanofibers include spatiotemporal control over input reagents, ease of fabrication and the ability to focus the core stream into sheath layer without the need of complex co-annular nozzles.     

Acute-stage para- and tetraplegia

A quarter of a century ago, in October 1964, the first spinal cord injury center in Switzerland was opened at Geneva University Hospital. At that time all para- and tetraplegics were classified as "high-risk" patients. Early mortality, covering the initial four weeks following trauma, was still around 15%. The available resources for diagnostic assessment were limited to clinical examination and neuroradiological assessment (subsequently improved by the introduction of tomography and gas myelography). A great many patients suffered a deteriorated neurological level due to inadequate, multiple transfers between hospitals. Most patients who are paralyzed following a road-traffic accident show severe polytrauma. Their chances of survival and functional recovery have greatly improved in recent years due to efficient emergency transport by helicopter, admission to an intensive care unit (respiratory therapy, prophylactic anticoagulation, gastrointestinal cytoprotection, prevention of pressure sores, etc.) and a comprehensive medico-surgical team approach (orthopedic surgeons, neurosurgeons, ICU specialists, internists, etc.). Evaluation of the spine and spinal cord by NMR and CT scan allows precise assessment of the extent of CNS damage and provides additional guide-lines regarding efficient surgical reposition and spinal fusion. Ongoing experimental research in neurophysiology and neurobiochemistry of the brain and spinal cord is presently yielding some interesting results which hold out new hopes for functional recovery in some specific types of incomplete spinal cord trauma.     

Double contrast examination of the stomach. Definition, technic and indications

Double contrast examination constitutes an important element in radiological gastric examination. The author examines the history of the term "double contrast" and defines the designation of "double contrast examination". The exclusive use of the double contrast method reduces the diagnostic value of gastric X-ray examinations. Thus a method is suggested that will avoid the disadvantages of exclusive double contrast examination while adequately including double contrast in the gastric examination. This is done by using various methods - according to the problem posed - in order to achieve the double contrast.     

Syncillin in bacterial skin diseases

A multicentric open clinical trial was carried out by 8 practising specialists in dermatology or paediatrics in patients with bacterial skin diseases who were subjected to a systemic therapy with Syncillin (=Azidocillin). The Syncillin presentation for adults and schoolchildren was tablets of 750 mg each, and sachets of 125 mg or 250 mg for infants. The duration of treatment was 10 days. The parameters analyzed were bacteriological findings and the clinical course of disease. 71 (=74%) of the 96 patients included in this study were considered as cured, 21 (=22%) as improved and 4 patients (=4%) as unchanged. Bacterial identification was still positive in 10 cases after the termination of treatment. However, this did not preclude the assessments of "cured' (3 cases) or "improved' (7 cases). The tolerance of the preparation was considered as "very good' or "good' in 91 and as "poor' in 5 patients. The most common side effects were nausea and diarrhoea. Exanthema was observed in 2 cases. None of these side effects, however, made a discontinuation of medication necessary. The era of rational and well-directed chemotherapy enables good therapeutic approach also to bacterial skin diseases.     

Academic trajectories of newcomer immigrant youth.

Immigration to the United States presents both challenges and opportunities that affect students' academic achievement. Using a 5-year longitudinal, mixed-methods approach, we identified varying academic trajectories of newcomer immigrant students from Central America, China, the Dominican Republic, Haiti, and Mexico. Latent class growth curve analysis revealed that although some newcomer students performed at high or improving levels over time, others showed diminishing performance. Multinomial logistic regressions identified significant group differences in academic trajectories, particularly between the high-achieving youth and the other groups. In keeping with ecological–developmental and stage–environment fit theories, School Characteristics (school segregation rate, school poverty rate, and student perceptions of school violence), Family Characteristics (maternal education, parental employment, and household structure), and Individual Characteristics (academic English proficiency, academic engagement, psychological symptoms, gender, and 2 age-related risk factors, number of school transitions and being overaged for grade placement) were associated with different trajectories of academic performance. A series of case studies triangulate many of the quantitative findings as well as illuminate patterns that were not detected in the quantitative data. Thus, the mixed-methods approach sheds light on the cumulative developmental challenges that immigrant students face as they adjust to their new educational settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Molecular cloning, sequencing, and expression of the 36 kDa protein present in pars planitis. Sequence homology with yeast nucleopore complex protein

PURPOSE: Patients with active pars planitis have increased levels of a 36 kDa protein (p-36) in their circulation. The current studies were undertaken to determine the primary structure of this protein. METHODS: A degenerate oligonucleotide probe based on the amino terminal sequence of p-36 was used to identify a clone from a human spleen cDNA library. The cDNA insert was subcloned into the EcoR1 site of pUC-19, and both strands were sequenced. Southern blot analysis was used to study the genomic hybridization pattern. p-36 cDNA was subcloned in a pSG5 expression vector, and the construct was used to transfect COS-7 cells. RESULTS: The cDNA sequence contained an open reading frame of 966 base pairs encoding a protein of 322 amino acids, an untranslated region of 322 base pairs, and 2693 base pairs at the 5' and 3' ends, respectively. The deduced amino acid sequence showed 96.8% identity with the carboxy-terminal region of a yeast nucleopore complex protein, nup 100. Southern blot analysis of human genomic DNA revealed a simple hybridization pattern. Transfection of p-36 cDNA in COS-7 cells resulted in the presence of p-36 mRNA and expression of protein. CONCLUSIONS: The 36 kDa protein (p-36) detected at increased levels in the blood of patients with active pars planitis was cloned from a human spleen cDNA library. Its deduced amino acid sequence is homologous with the carboxy-terminal region of a nucleopore complex protein. Thus, we refer to this protein as nup36.     

Photon counting in the 1540-nm wavelength region with a germaniumavalanche photodiode

Unexpected results have been obtained in measurements of dark-count rate and quantum efficiency (QE) for a germanium avalanche photodiode operating in the photon counting regime at 1540-nm wavelength. A liquid-nitrogen cooled Ge single-photon avalanche diode (SPAD) exhibited both a low dark-count rate and a QE of the order of 1%, which is at least one order of magnitude higher than the values reported for such a device. The data offer hope for future diodes that might match such performance. Reasons for the device's extraordinarily good performance, a performance level not matched by the other 17 APDs in the collection investigated, are not understood. Such high quantum efficiency germanium devices could be used in one-bit-per-photon communication systems operating in the 1540-nm telecommunications window