Assessment of vibration amplitude and transmembrane pressure on vibratory shear enhanced membrane filtration for treating dairy wastewater

In this study, statistical analysis was performed to investigate the influence of operational parameters based on experimental results. The research aimed to know whether a long-term discontinuous module vibration operation is possible without adversely affecting filtration efficiency. Polymer membranes were compared by surface characteristics with contact angle measurements and selected for further membrane filtration experiments for dairy wastewater treatment. The effect of the main operational parameters, membrane module vibration amplitude (Avibr.) and transmembrane pressure (TMP), was investigated using a vibratory shear enhanced processing (VSEP) module with ultrafiltration (UF) and nanofiltration (NF) membranes. Components of the permeates, including chemical oxygen demand (COD), were measured, and membrane rejections were calculated to compare with threshold limit values. The results suggest that proper combination of Avibr. and TMP could mitigate membrane fouling. However, discontinuous module vibration resulted in more clogged membrane with lower fluxes, but slightly higher rejections. We conclude that investigating the significance of operational parameters is necessary for a wider, more energy and environment-friendly application in wastewater treatment.

Effect of aspirin in vascular surgery in patients from a randomized clinical trial (POISE-2)

BACKGROUND

In the POISE-2 (PeriOperative ISchemic Evaluation 2) trial, perioperative aspirin did not reduce cardiovascular events, but increased major bleeding. There remains uncertainty regarding the effect of perioperative aspirin in patients undergoing vascular surgery. The aim of this substudy was to determine whether there is a subgroup effect of initiating or continuing aspirin in patients undergoing vascular surgery.

METHODS

POISE-2 was a blinded, randomized trial of patients having non-cardiac surgery. Patients were assigned to perioperative aspirin or placebo. The primary outcome was a composite of death or myocardial infarction at 30 days. Secondary outcomes included: vascular occlusive complications (a composite of amputation and peripheral arterial thrombosis) and major or life-threatening bleeding.

RESULTS

Of 10 010 patients in POISE-2, 603 underwent vascular surgery, 319 in the continuation and 284 in the initiation stratum. Some 272 patients had vascular surgery for occlusive disease and 265 had aneurysm surgery. The primary outcome occurred in 13·7 per cent of patients having aneurysm repair allocated to aspirin and 9·0 per cent who had placebo (hazard ratio (HR) 1·48, 95 per cent c.i. 0·71 to 3·09). Among patients who had surgery for occlusive vascular disease, 15·8 per cent allocated to aspirin and 13·6 per cent on placebo had the primary outcome (HR 1·16, 0·62 to 2·17). There was no interaction with the primary outcome for type of surgery (P = 0·294) or aspirin stratum (P = 0·623). There was no interaction for vascular occlusive complications (P = 0·413) or bleeding (P = 0·900) for vascular compared with non-vascular surgery.

CONCLUSION

This study suggests that the overall POISE-2 results apply to vascular surgery. Perioperative withdrawal of chronic aspirin therapy did not increase cardiovascular or vascular occlusive complications. Registration number: NCT01082874 ( http://www.clinicaltrials.gov).

Characterization of a leaf rust-resistant wheat-Thinopyrum ponticum partial amphiploid BE-1, using sequential multicolor GISH and FISH

In situ hybridization (multicolor GISH and FISH) was used to characterize the genomic composition of the wheat-Thinopyrum ponticum partial amphiploid BE-1. The amphiploid is a high-protein line having resistance to leaf rust (Puccinia recondita f. sp. tritici) and powdery mildew (Blumeria graminis f. sp. tritici) and has in total 56 chromosomes per cell. Multicolor GISH using J, A and D genomic probes showed 16 chromosomes originating from Thinopyrum ponticum and 14 A genome, 14 B genome and 12 D genome chromosomes. Six of the Th. ponticum chromosomes carried segments different from the J genome in their centromeric regions. It was demonstrated that these alien chromosome segments did not originate from the A, B or D genomes of wheat, so the translocation chromosomes were considered to be J(s) type chromosomes carrying segments similar to the S genome near the centromeres. Rearrangements between the A and D genomes of wheat were detected. FISH using Afa family, pSc119.2 and pTa71 probes allowed the identification of all the wheat chromosomes present and the determination of the chromosomes involved in the translocations. The 4A and 7A chromosomes were identified as being involved in intergenomic translocations. The replaced wheat chromosome was identified as 7D. The localization of these repetitive DNA clones on the Th. ponticum chromosomes of the amphiploid was described in the present study. On the basis of their multicolor FISH patterns, the alien chromosomes could be arranged in eight pairs and could also be differentiated unequivocally from each other.

Investigation of field outbreaks of turkey haemorrhagic enteritis in Hungary

Epidemiological, pathological, serological and virological investigations are reported on turkey haemorrhagic enteritis virus (THEV) infection in Hungarian turkey flocks. The pathogenesis of infection in experimentally infected turkeys and chickens, as well as the usefulness of polymerase chain reaction (PCR)/sequencing method for epidemiological investigation and for the differentiation of vaccine and field strains of THEV was also studied. Since the first recognition of the disease in Hungary in the late 1970s, until recently the disease has been diagnosed sporadically in its mild form. In the last few years (2000-2005), however, the number of outbreaks and the severity of the disease increased (9-23 affected flocks/year). Most of the outbreaks occurred at the age of 6 to 8 weeks and was complicated with Escherichia coli infection. The antibody levels to THEV in turkey flocks gradually declined till 5-7 weeks of age, and then they increased sharply due to natural infection with THEV. The immune response to vaccination (at 5 weeks of age) showed no significant antibody level increase one week postvaccination, but four weeks later the antibody level reached high values and then remained at this high level. The agar gel immunodiffusion (AGID) test to detect turkey adenovirus A (TAdV-A) antigen and PCR methods for THEV-specific DNA gave similarly positive results if spleens with pathognomonic lesions were tested; however, PCR proved to be more sensitive in cases with less characteristic pathological lesions. Nucleotide sequence alignment of PCR products amplified from Hungarian field strains and the Domermuth vaccine strain and that of the published THEV hexon sequences in GenBank database revealed slight differences between the sequences.

Application of main component fraction collection method for purification of compound libraries

In order to support high-throughput library purification, a novel UV triggered fraction collection method was developed in which a maximum-seeking-algorithm-driven, six-port valve collects the largest chromatographic peak. This straightforward strategy achieves the one sample-one fraction approach, thus resulting in a simpler and less error prone workup procedure. The effectiveness of this main component fraction collection method will be illustrated here by the results of the purification of compound libraries (altogether 6086 compounds, having an averaged success rate of 79.4%). Advanced applications, where the desired component differs from the main component, will also be discussed.

UV-Triggered Main-Component Fraction Collection Method and Its Application for High-Throughput Chromatographic Purification of Combinatorial Libraries

A maximum-seeking, algorithm-driven fraction collection method was developed to support high-throughput chromatographic purification, which provides new possibilities for off-line high-performance liquid chromatography mass spectroscopy (HPLC/MS) quality control experiments. The method is based on manipulation of a six-port valve that is installed downstream from the UV detector and equipped with a fraction collector loop. The detector signal is monitored by a programmable microcontroller that controls the state of the fraction collector valve. After detecting a chromatographic peak, the appropriate fraction is stored in the collector loop. The height of the next peak is compared to the previous one (using a maximum-seeking algorithm) and, depending on the result, the collected fraction is or is not exchanged with the new one. At the end of the run, the stored UV main component is pumped into the external fraction vial. This configuration was used for chromatographic purification of large compound libraries (the results of the purification of 5324 compounds are reported here), as well as for high-throughput off-line HPLC quality control experiments, where the collected main component fractions of an analytical-scale separation were subjected to further mass spectrometric molecular weight verification.

Clinical signs and mortality caused by Ornithobacterium rhinotracheale in turkey flocks

Upper respiratory tract disease (manifesting itself in rhinitis, tracheitis and conjunctivitis) and mortality associated with Ornithobacterium rhinotracheale infection were observed in four flocks of 2- to 3-week-old turkeys. In a 15- to 16-week-old turkey flock bilateral catarrhal-croupous pneumonia was found in the dead birds. In a further 5-week-old flock and in three 16- to 20-week-old turkey flocks mortality was preceded by nervous signs (motor disturbances, recumbency, abnormal carriage of the head) and was found to be associated with fibrinopurulent inflammation of the cranial bones and meningitis. The bacterium O. rhinotracheale was isolated from the affected organs in the different disease conditions. The isolated strains did not differ markedly in cultural, morphological and biochemical properties. This is the first report of a turkey disease manifesting itself in nervous signs associated with O. rhinotracheale infection.

Using operative outcome to assess technical skill

BACKGROUND

This study examined whether an operative product and time to completion could serve as measures of technical skill.

METHODS

Nine final-year (PGY5) and 11 penultimate-year (PGY4) general surgery residents participated in a 6-station bench model examination. Time to completion was recorded. Twelve faculty surgeons (2 per station) evaluated the quality of the final product using a 5-point scale.

RESULTS

The mean interrater reliability was 0. 59 for product quality. Interstation reliability was 0.59 for analysis of the final product and 0.72 for time to completion. There was 63% and 78% agreement between attendings' ratings and product quality and time scores respectively. PGY5s' mean product quality score was 4.14 +/- 0.26, compared with 3.82 +/- 0.33 for PGY4s (P < 0.05). PGY5s' mean time was 110 +/- 19 minutes compared with PGY4s' 132 +/- 15 (P < 0.05).

CONCLUSIONS

Analysis of the operative end product and time to completion offer efficient alternatives to on-line examiner scoring for bench model examinations of technical competence.

Impact of red cell salvage on transfusion requirements during elective abdominal aortic aneurysm repair

Elective abdominal aortic aneurysm (AAA) surgery may result in substantial blood loss. Concerns regarding the safety, availability, and acceptability of homologous blood have led to initiatives toward reducing transfusion requirements at the time of aneurysm repair. This study was designed to determine if the routine use of intraoperative red cell salvage and autotransfusion resulted in a reduction in homologous transfusion at our institution. A retrospective review of elective AAA repairs in the years 1987, 1992, and 1997 was carried out. Demographic data, operative details, blood loss, hemoglobin levels, red cell salvage and return volumes, and transfusion requirements were recorded and compared across the study years. From this study we conclude that routine use of red cell salvage and autotransfusion is an effective means for reducing transfusion requirements in elective AAA repair.

Comparing the psychometric properties of checklists and global rating scales for assessing performance on an OSCE-format examination

PURPOSE

To compare the psychometric properties of checklists, global rating scales preceded by a checklist, and global rating scales alone in assessing surgery residents' performances on an OSCE-like technical skills examination.

METHOD

In 1996, 53 general surgery residents with one to six years of postgraduate training participated in a performance-based examination of technical skills consisting of eight 15-minute stations (bench-model simulations of operative procedures in general surgery). Two qualified surgeons marked at each station, one using a task-specific checklist (C) and a subsequent global rating scale (Gc), the other using a global rating scale only (G).

RESULTS

Interstation reliabilities measured by Cronbach's alpha were .79 for C, .89 for Gc, and .85 for G. A series of multiple regressions predicting level of training from test scores revealed an R2 of .584 for C alone, which increased to .711 when Gc was entered after (p < .001), and increased to .704 when G was entered after C (p < .001). However, R2 for Gc alone was .711, and for G alone was .704, neither of which changed when C was entered into the prediction (p > .10). The R2 for Gc and G predicting level of training (.725) was not significantly greater than that of either Gc or G alone. A very similar pattern of results was seen when C, Gc, and G were used to predict independent evaluations of the operative outcomes.

CONCLUSIONS

Global rating scales scored by experts showed higher inter-station reliability, better construct validity, and better concurrent validity than did checklists. Further, the presence of the checklists did not improve the reliability or validity of the global rating scale over that of the global rating scale alone. These results suggest that global rating scales administered by experts are a more appropriate summative measure when assessing candidates on performance-based examinations.