54 research outputs found
Assessment of Methods Used in 1D Models for Computing Bed-Load Transport in a Large River: The Danube River in Slovakia
Comprehensive measurements of bedload sediment transport through a section of the Danube River, located approximately 70km downstream from Bratislava, Slovakia, are used to assess the accuracy of bedload formulae implemented in 1D modelling. Depending on water discharge and water level, significant variations in the distribution of bedload across the section were observed. It appeared that, whatever the water discharge, the bed shear stress tau is always close to the estimated critical bed shear stress for the initiation of sediment transport . The discussion focusses on the methods used in 1D models for estimating bedload transport. Though usually done, the evaluation of bedload transport using the mean cross-sectional bed shear stress yields unsatisfactory results. It is necessary to use an additional model to distribute the bed shear stress across the section and calculate bedload locally. Bedload predictors also need to be accurate for tau close to tau. From that point of view, bedload formulae based on an exponential decrease of bedload transport close to tau appear to be more appropriate than models based on excess bed shear stress. A discussion on the bedload formula capability to reproduce grain sorting is also provided
Formation and physicochemical properties of crystalline and amorphous salts with different stoichiometries formed between ciprofloxacin and succinic acid
YesMulti-ionizable compounds, such as dicarboxylic
acids, offer the possibility of forming salts of drugs with
multiple stoichiometries. Attempts to crystallize ciprofloxacin,
a poorly water-soluble, amphoteric molecule with succinic acid
(S) resulted in isolation of ciprofloxacin hemisuccinate (1:1)
trihydrate (CHS-I) and ciprofloxacin succinate (2:1) tetrahydrate
(CS-I). Anhydrous ciprofloxacin hemisuccinate (CHS-II)
and anhydrous ciprofloxacin succinate (CS-II) were also
obtained. It was also possible to obtain stoichiometrically
equivalent amorphous salt forms, CHS-III and CS-III, by spray
drying and milling, respectively, of the drug and acid. Anhydrous CHS and CS had melting points at ∼215 and ∼228 °C, while
the glass transition temperatures of CHS-III and CS-III were ∼101 and ∼79 °C, respectively. Dynamic solubility studies revealed
the metastable nature of CS-I in aqueous media, resulting in a transformation of CS-I to a mix of CHS-I and ciprofloxacin 1:3.7
hydrate, consistent with the phase diagram. CS-III was observed to dissolve noncongruently leading to high and sustainable drug
solution concentrations in water at 25 and 37 °C, with the ciprofloxacin concentration of 58.8 ± 1.18 mg/mL after 1 h of the
experiment at 37 °C. This work shows that crystalline salts with multiple stoichiometries and amorphous salts have diverse
pharmaceutically relevant properties, including molecular, solid state, and solubility characteristics.Solid State Pharmaceutical Cluster (SSPC), supported by Science Foundation Ireland under grant number 07/SRC/ B1158
Molecular taxonomy of bambusicolous fungi: Tetraplosphaeriaceae, a new pleosporalean family with Tetraploa-like anamorphs
A new pleosporalean family Tetraplosphaeriaceae is established to
accommodate five new genera; 1) Tetraplosphaeria with small ascomata
and anamorphs belonging to Tetraploa s. str., 2)
Triplosphaeria characterised by hemispherical ascomata with rim-like
side walls and anamorphs similar to Tetraploa but with three conidial
setose appendages, 3) Polyplosphaeria with large ascomata surrounded
by brown hyphae and anamorphs producing globose conidia with several setose
appendages, 4) Pseudotetraploa, an anamorphic genus, having
obpyriform conidia with pseudosepta and four to eight setose appendages, and
5) Quadricrura, an anamorphic genus, having globose conidia with one
or two long setose appendages at the apex and four to five short setose
appendages at the base. Fifteen new taxa in these genera mostly collected from
bamboo are described and illustrated. They are linked by their Tetraploa
s. l. anamorphs. To infer phylogenetic placement in the
Pleosporales, analyses based on a combined dataset of small- and
large-subunit nuclear ribosomal DNA (SSU+LSU nrDNA) was carried out.
Tetraplosphaeriaceae, however, is basal to the main pleosporalean
clade and therefore its relationship with other existing families was not
completely resolved. To evaluate the validity of each taxon and to clarify the
phylogenetic relationships within this family, further analyses using
sequences from ITS-5.8S nrDNA (ITS), transcription elongation factor 1-α
(TEF), and β-tubulin (BT), were also conducted. Monophyly of the family
and that of each genus were strongly supported by analyses based on a combined
dataset of the three regions (ITS+TEF+BT). Our results also suggest that
Tetraplosphaeria (anamorph: Tetraploa s. str.) is an
ancestral lineage within this family. Taxonomic placement of the bambusicolous
fungi in Astrosphaeriella, Kalmusia, Katumotoa, Massarina,
Ophiosphaerella, Phaeosphaeria, Roussoella, Roussoellopsis, and
Versicolorisporium, are also discussed based on the SSU+LSU
phylogeny
Natural history of KBG syndrome in a large European cohort
KBG syndrome (KBGS) is characterized by distinctive facial gestalt, short stature and variable clinical findings. With ageing, some features become more recognizable, allowing a differential diagnosis. We aimed to better characterize natural history of KBGS. In the context of a European collaborative study, we collected the largest cohort of KBGS patients (49). A combined array- based Comparative Genomic Hybridization and next generation sequencing (NGS) approach investigated both genomic Copy Number Variants and SNVs. Intellectual disability (ID) (82%) ranged from mild to moderate with severe ID identified in two patients. Epilepsy was present in 26.5%. Short stature was consistent over time, while occipitofrontal circumference (median value: -0.88 SD at birth) normalized over years. Cerebral anomalies, were identified in 56% of patients and thus represented the second most relevant clinical feature reinforcing clinical suspicion in the paediatric age when short stature and vertebral/dental anomalies are vague. Macrodontia, oligodontia and dental agenesis (53%) were almost as frequent as skeletal anomalies, such as brachydactyly, short fifth finger, fifth finger clinodactyly, pectus excavatum/carinatum, delayed bone age. In 28.5% of individuals, prenatal ultrasound anomalies were reported. Except for three splicing variants, leading to a premature termination, variants were almost all frameshift. Our results, broadening the spectrum of KBGS phenotype progression, provide useful tools to facilitate differential diagnosis and improve clinical management. We suggest to consider a wider range of dental anomalies before excluding diagnosis and to perform a careful odontoiatric/ear-nose-throat (ENT) evaluation in order to look for even submucosal palate cleft given the high percentage of palate abnormalities. NGS approaches, following evidence of antenatal ultrasound anomalies, should include ANKRD11.</p
Electrode Movement Prevention - an Animal Model
Electrode migration is the most common complication of spinal cord stimulation (SCS). The problem of longitudinal migration has already been solved, but lateral migration remains the most common current complication. The present article describes new electrodes fixation opportunities for the reduction of lateral migration in SCS. The pig was chosen as an animal model to illustrate a new protocol of electrode fixation for the control of lateral and longitudinal migration. The displacement of the electrode was measured using two different optical methods: the digital image stereo-correlation and the digital image processing methods. Fixation with two anchors has always considerably reduced electrode displacement and when fixation is done with two anchors and a loop then lateral migration is reduced by 62.5 % and longitudinal migration is reduced by 94.1 %. It was shown that the results are significantly different at the a=0.001 significance level. Based on a statistical evaluation it is possible to state that the differences between experimental results obtained for three different protocols of lead fixation are statistically significant and we can recommend the new fixation method for common practice
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