Transfer of low nanoliter volumes between microplates using focused acoustics—automation considerations

Acoustic droplet ejection (ADE) gently and precisely aliquots nanoliter and picoliter liquid volumes without any physical contact with the solution being transferred. The technology is very automation-friendly, as it is compatible with conventional microplates. Focused energy from an acoustic transducer induces droplet ejection into an inverted standard microplate. The commercial system transfers low-nanoliter volumes of dimethyl sulfoxide–dissolved compound libraries and thereby enables cell-based assays to be performed in 1536-well plates.     

Neuroblastoma in Europe: differences in the pattern of disease in the UK. SENSE. Study group for the Evaluation of Neuroblastoma Screening in Europe

BACKGROUND: Neuroblastoma is a major contributor to childhood cancer mortality, but its prognosis varies with age and stage of disease, and some tumours regress spontaneously. Urinary screening programmes or clinical examination may detect the disease before symptoms appear, but the benefit of early diagnosis is uncertain. We examined the incidence, pattern, and presentation of neuroblastoma in four European countries. METHOD: Population-based incidence rates were derived for France, Austria, Germany, and the UK. Age, sex, and stage distribution were analysed by Mantel-Haenszel techniques and Poisson regression. The proportion of incidental diagnoses (cases without symptoms found at routine health checks or during investigation of other disorders) and mortality rates were also compared. FINDINGS: Between 1987 and 1991, 1672 cases of neuroblastoma were diagnosed in children under 15 years old (France, 624; Austria, 69; Germany, 493; UK, 486). Age-standardised annual incidence was significantly lower in the UK (10.1/million) than in France (12.5) and Germany (11.4). In the UK a deficit of low-stage disease in infants was accompanied by an excess of stage IV in older children. The UK had significantly fewer incidental diagnoses (8%) than Austria (27%) and Germany (34%). UK mortality rates were significantly higher than German or French rates. INTERPRETATION: In the UK, neuroblastoma diagnosis is delayed, possibly because of a less rigorous system of health checks for children. Although some overdiagnosis occurs in mainland Europe, our data suggest that in the UK some low-stage cases, undetected in infancy, may later present as advanced disease. This finding has implications for screening programmes and organisation of routine surveillance of infant health in the UK.     

Effect of stretch on passive transport in toad urinary bladder

In order to gain further information about the effect of stretch on the urinary bladder of the toad, transepithelial movement of radioactive sucrose, chloride, and urea was measured across bladder sacs during acute changes in the internal volume. Short-circuit current (SCC) and total tissue conductance (Kt) were also measured in each experiment. It was found that sudden large increases or smaller graded increases in volume resulted in a consistent fall in the tracer permeability (P*) of all three isotopes. However, this fall was due entirely to the larger area term in the calculation of P* rather than any real change in isotope movement. When total diffusion (TD) of each isotope was calculated by a method that eliminated the changes in surface area, it was apparent that stretch produced no significant effects on the transepithelial movement of any of these three molecules. Large stretch also resulted in parallel increases in SCC and Kt in most bladders. We conclude from these observations that the intercellular pathway for sucrose and chloride and the transcellular pathway for urea are unaltered by degrees of stretch that enhance SCC and sodium transport. By inference, the observed increases in Kt appear to represent changes in specific active pathway conductance (Ka), and may relate importantly to the changes in sodium transport.     

Optimal method of urgent decompression of the collecting system for obstruction and infection due to ureteral calculi

PURPOSE: We compare the efficacy of percutaneous nephrostomy with retrograde ureteral catheterization for renal drainage in cases of obstruction and infection associated with ureteral calculi. MATERIALS AND METHODS: We randomized 42 consecutive patients presenting with obstructing ureteral calculi and clinical signs of infection (temperature greater than 38 C and/or white blood count greater than 17,000/mm.3) to drainage with percutaneous nephrostomy or retrograde ureteral catheterization. Preoperative patient and stone characteristics, procedural parameters, clinical outcomes and costs were assessed for each group. RESULTS: Urine cultures obtained at drainage were positive in 62.9% of percutaneous nephrostomy and 19.1% of retrograde ureteral catheterization patients. There was no significant difference in the time to treatment between the 2 groups. Procedural and fluoroscopy times were significantly shorter in the retrograde ureteral catheterization (32.7 and 5.1 minutes, respectively) compared with the percutaneous nephrostomy (49.2 and 7.7 minutes, respectively) group. One treatment failure occurred in the percutaneous nephrostomy group, which was successfully salvaged with retrograde ureteral catheterization. Time to normal temperature was 2.3 days in the percutaneous nephrostomy and 2.6 in the retrograde ureteral catheterization group, and time to normal white blood count was 2 days in the percutaneous nephrostomy and 1.7 days in the retrograde ureteral catheterization group (p not significant). Length of stay was 4.5 days in the percutaneous nephrostomy group compared with 3.2 days in the retrograde ureteral catheterization group (p not significant). Cost analysis revealed that retrograde ureteral catheterization was twice as costly as percutaneous nephrostomy. CONCLUSIONS: Retrograde ureteral catheterization and percutaneous nephrostomy effectively relieve obstruction and infection due to ureteral calculi. Neither modality demonstrated superiority in promoting a more rapid recovery after drainage. Percutaneous nephrostomy is less costly than retrograde ureteral catheterization. The decision of which mode of drainage to use may be based on logistical factors, surgeon preference and stone characteristics.     

Mapping the impact of papers on various status groups in excellencemapping.net: a new release of the excellence mapping tool based on citation and reader scores

Scientometrics - In over five years, Bornmann, Stefaner, de Moya Anegon, and Mutz (2014b) and Bornmann, Stefaner, de Moya Anegón, and Mutz (2014c, 2015) have published several releases of the...     

Shock-induced and self-propagating high-temperature synthesis reactions in two powder mixtures: 5:3 Atomic ratio Ti/Si and 1:1 Atomic ratio Ni/Si

The conditions for initiation and propagation of the reaction forming the intermetallic compounds Ti₅Si₃ and NiSi from mixtures of elemental powders of varying porosity have been investigated using shock waves of different pressure and at atmospheric pressure using hot wire ignition in air and in an argon atmosphere. In each case, the reaction either went to completion or the powder remained essentially unreacted. The conditions for the initiation of the reaction in Ti/Si are sensitive to the presence of air. Two regimes of porosity and shock pressure are found for the Ti/Si mixture which cause complete reaction. A low-energy regime with a high initial porosity (producing a low shock pressure) with 0.1 torr of residual air triggers the reaction, while no reaction is observed with a 128 pct higher shock energy and a lower initial porosity (producing a higher shock pressure) when the residual air is replaced with argon. Hot wire ignition of porous Ti/Si powder at room temperature initiates a self-propagating high-temperature synthesis (SHS) reaction more easily in air than in an argon atmosphere, while the Ni/Si powder must be heated to allow the SHS reaction to propagate in high- or low-porosity mixtures in air. These observations are compared to published work on self-sustaining reactions in multilayer films. Reasons for the difference in behavior of the two powder mixtures are discussed. This paper is based on a presentation made in the symposium “Reaction Synthesis of Materials” presented during the TMS Annual Meeting, New Orleans, LA, February 17–21, 1991, under the auspices of the TMS Powder Metallurgy Committee.     

Unravelling the relation between natural microbiota and biogenic amines in Brazilian dry-cured loin: a chemometric approach

Exploratory data analysis was used to evaluate the influence of NaCl concentration on the relation between endogenous microbiota (mesophilic aerobic bacteria, psychrotrophic bacteria, lactic acid bacteria, Enterobacteriaceae and Staphylococcus spp.) and biogenic amines (BAs) (histamine, tyramine, putrescine, cadaverine and spermidine) content in Brazilian dry-cured loin (BDL). Using hierarchical cluster analysis (HCA), initial data analysis led to samples separation into a higher and a lower NaCl cluster. The analysis of variance showed that the microbial counts did not differ between the clusters (p > 0.05). However, the higher NaCl cluster showed a lower level of BAs. Further, principal component analysis (PCA) demonstrated a negative correlation between the microbial counts and BAs content in the lower NaCl cluster, thus indicating the possibility of the higher BA’s content in the lower NaCl cluster being a result of a stress–response mechanism. On the other hand, in the higher NaCl cluster, the salt concentration had an inhibitory property in BA’s formation except for histamine. The collective results point to a NaCl threshold to minimise the production of BAs in BDL. The findings of the present exploratory study highlight the possibility of intervention for BA minimization without the need for designed starter cultures or preservation treatments.