Voltammetric study of the influence of EDTA on the silver electrodeposition and morphological and structural characterization of silver films

The electrodeposition of silver onto platinum from an alkaline electrolyte containing EDTA (ethylenediaminetetraacetic acid) was investigated. Voltammetric studies indicated that the reduction process is influenced thermodynamically and kinetically by the EDTA concentration. Moreover, hydrodynamic studies showed that silver deposition involved different silver complexes, depending on the EDTA concentration. Scanning electron microscopy analysis showed that the presence of EDTA in the plating bath was beneficial, since the silver films coated the substrate completely, regardless of the EDTA concentration. Furthermore, the silver films were uniform, without cracks and with fine granularity, while in the absence of EDTA the granularity was rough. Energy dispersive X-ray spectroscopy showed that carbon was not incorporated into the silver films. X-ray diffraction analysis of the Ag deposits obtained at various EDTA concentrations indicated the occurrence of polycrystalline silver and that the main orientation was (1 1 1), as found in the silver film obtained from a cyanide bath.     

Factors leading to long-term hospitalization after laparoscopic appendectomy.

BACKGROUND: Randomized studies demonstrate that laparoscopic appendectomy yields better results compared with open techniques. We sought to identify factors that determine an extended hospital stay among patients undergoing laparoscopic appendectomy. METHODS: This was a prospective study including 669 patients undergoing laparoscopic appendectomy. We analyzed variables that can predict the length of hospital stay. RESULTS: Of 669 patients undergoing laparoscopic appendectomy, 141 stayed in the hospital for > or = 5 days (Group 1), and 97 stayed in the hospital for < or = 1 day after surgery (Group 2). The univariate analysis demonstrated that fever (P<0.0001), nausea and vomiting (P=0.060), leukocytosis (P<0.0001), gangrened or perforated intraoperative appearance of the appendix (P<0.0001), and appendix position behind the ileocecal junction (P<0.001) were related to a longer hospital stay. The multivariate analysis through logistical regression showed that the factors independently and significantly associated with an extended hospital stay were presurgical fever, appendix position behind the ileocecal junction, and intraoperative gangrened or perforated appearance of the appendix. CONCLUSION: Fever, appearance, and position of the appendix are factors related to an extended hospital stay.     

Genotyping of Chlamydia trachomatis in Urine Specimens Will Facilitate Large Epidemiological Studies

The serovars of Chlamydia trachomatis-positive urine specimens (n = 81; as detected by PCR and ligase chain reaction) were successfully analyzed in 94&#x00025; of cases by omp1 PCR-based RFLP analysis. The use of urine specimens and this simple and sensitive typing method will greatly facilitate epidemiological studies of C. trachomatis serovar distribution in asymptomatic C. trachomatis infections in both females and males.     

Somatosensory findings in patients with spinal cord injury and central dysaesthesia pain.

OBJECTIVE: To determine whether central pain in patients with spinal cord injury is only dependent on the lesioning of spinothalamic pathways. METHODS: In sixteen patients with spinal cord injury and central dysaesthesia pain, somatosensory abnormalities in painful denervated skin areas were compared with somatosensory findings in normal skin areas as well as in non-painful denervated skin areas. RESULTS: The threshold values for detection of thermal (heat, cold, heat pain, or cold pain) and tactile stimulation were significantly changed in denervated skin areas although there were no significant differences in the threshold values between painful and non-painful denervated skin areas. The reductions of sensations of touch, vibration, joint position, and two point discrimination in painful and non-painful denervated skin areas were not significantly different. Allodynia (pain caused by non-noxious stimulation) and wind up-like pain (pain caused by repeatedly pricking the skin) were significantly more common in painful than non-painful denervated skin areas. CONCLUSIONS: Because pain and thermal sensory perception are primarily mediated to the brain via spinothalamic pathways, whereas the sensations of touch, vibration and joint position are primarily mediated by dorsal column-medial lemniscal pathways, the results indicate that central pain is not only dependent on the lesioning of either dorsal column-medial lemniscal pathways or spinothalamic pathways. The findings of abnormal evoked pain (allodynia and wind up-like pain) may be consistent with the experimental findings of hyperexcitability in nociceptive spinothalamic tract neurons, that may be involved in the pathogenesis of central pain.