Specific Pretreatment Research Articles

Inoculum pre-treatment affects the fermentative activity of hydrogen-producing communities in the presence of 5-hydroxymethylfurfural

To enhance the productivity of mixed microbial cultures for fermentative bio-hydrogen production, chemical-physical pre-treatments of the original seed are needed to suppress the activity of hydrogen (H2)-consuming microbes. This approach might influence negatively the composition and diversity of the hydrogen-producing community with consequences on the functional stability of the H2-producing systems in case of perturbations. In this study, we aimed at investigating the effect of different types of pre-treatment on the performance of hydrogen production systems in the presence of an inhibitor, such as 5-hydroxymethylfurfural (HMF). The efficiency and the microbial community structure of batch reactors amended with HMF and inoculated with non-pretreated and pretreated (acid, heat shock, and aeration) anaerobic sludge were evaluated and compared with control systems. The type of pre-treatments influenced the microbial community assembly and activity in inhibited systems, with significant effect on the performance. Cumulative H2 production tests showed that the pre-aerated systems (control and HMF inhibited) were the most efficient, while the difference of the lag phase of the pre-acidified control and HMF-added test was negligible. Analyses of the structure of the enriched microbial community in the systems through PCR-denaturing gradient gel electrophoresis (DGGE) followed by band sequencing revealed that the differences in performance were mostly related to shifts in the metabolic pathways rather than in the predominant species. In conclusion, the findings suggest that the use of specific inoculum pre-treatment could contribute to regulate the metabolic activity of the fermentative H2-producing bacteria in order to enhance the bio-energy production.

Risk and management of venous thromboembolisms in bevacizumab-treated metastatic colorectal cancer patients

Bevacizumab may potentiate the risk of venous thromboembolisms (VTEs) in cancer patients, who are already predisposed to pro-thrombotic states. We aimed to characterize the incidence of VTEs in a population-based cohort of metastatic colorectal cancer (mCRC) patients treated with bevacizumab, describe patient and treatment factors associated with VTEs, and examine how VTEs are managed. Patients diagnosed with mCRC from 2006 to 2009 and offered bevacizumab were included. Descriptive statistics were used to describe VTE occurrences and management. Univariate and multivariate regression models were constructed to explore associations between clinical factors and VTEs. We identified 541 mCRC patients: 27 never started bevacizumab and 15 were lost to follow-up. Of the 499 evaluable patients, median age was 61, 59.3% were men, 88.1% had ECOG 0/1, and 5.2% reported previous VTEs. Mean number of bevacizumab doses was 13.3 cycles. After receiving bevacizumab, 81 patients developed 93 cases of VTEs, with 9 patients experiencing >1 event. Individuals who experienced VTEs were more likely to have had pre-existing cardiovascular disease (OR 2.259, p = 0.0245), resection of primary cancer (OR 3.262, p = 0.0269), pre-chemotherapy platelet count ≥350,000/μL (OR 2.295, p = 0.0293), and received >12 bevacizumab cycles (OR 2.172, p = 0.0158). Use of bevacizumab varied after occurrence of VTE where it was discontinued in 34.4%, continued in 34.4%, and temporarily held in 1.1%. VTE risk can be high, especially in patients with specific pre-treatment risk factors as well as in those who received more bevacizumab, suggesting a potential dose-related effect. Management of bevacizumab-related VTEs was variable.

CrN/AlN and CrN/AlN/Al2O3 coatings deposited by pulsed cathodic arc for aluminum die casting applications

Abstract In aluminum die casting applications corrosion and wear resistance have significant influence on tool life and product quality. Multilayer coatings based on transition metal nitrides such as CrN and AlN deposited via physical vapor deposition (PVD) have shown great advantage as protective coatings on tools and components subject to high loads in tribological conditions. Al2O3 coatings offer high potential to be used as protective coatings on die casting applications due to their high hardness, high chemical inertness and thermal stability. However, the deposition of Al2O3 onto steel substrate demands the use of a bond coat such as CrN/AlN in order to improve its adhesion on the substrate. The present work deals with the investigation of a specific pretreatment process of the substrate material AISI H11 hot work steel, consisting of quenching and tempering, plasma nitriding and pressure blasting, as well as the investigation of CrN/AlN and CrN/AlN/Al2O3 coatings deposited using pulsed cathodic arc evaporation (CAE). The chemical composition, morphology and structure were analyzed by means of energy-dispersive X-ray spectroscopy (EDS), electron probe micro-analysis (EPMA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD), respectively. Mechanical properties were determined by means of nanoindentation. The coating adhesion was studied using the Rockwell (HRC) indentation method and scratch test. The wear and corrosion resistance of the coated substrates were investigated using a rotating immersion test in the aluminum based alloy A333.1 (EN AC-46000) at T = 680 °C for t = 2 h and t = 6 h and EDS linescans. The material is an aluminum based alloy with a high silicon content, which is used for aluminum die casting applications such as engine blocks or die casting core inserts. The results revealed that a high adhesion of the CrN/AlN and CrN/AlN/Al2O3 coatings to the steel substrate was achieved. The CrN/AlN/Al2O3 showed a reduced wettability affinity to the aluminum melt and a high wear resistance. Furthermore, the Al2O3 top layer prevented corrosion from liquid metal between the aluminum based melt and the hot work steel substrate. Based on these results the CrN/AlN/Al2O3 coating is a promising candidate to be applied on aluminum die casting tools.

A Highly Flexible, Automated System Providing Reliable Sample Preparation in Element- and Structure-Specific Measurements

Life science areas require specific sample pretreatment to increase the concentration of the analytes and/or to convert the analytes into an appropriate form for the detection and separation systems. Various workstations are commercially available, allowing for automated biological sample pretreatment. Nevertheless, due to the required temperature, pressure, and volume conditions in typical element and structure-specific measurements, automated platforms are not suitable for analytical processes. Thus, the purpose of the presented investigation was the design, realization, and evaluation of an automated system ensuring high-precision sample preparation for a variety of analytical measurements. The developed system has to enable system adaption and high performance flexibility. Furthermore, the system has to be capable of dealing with the wide range of required vessels simultaneously, allowing for less cost and time-consuming process steps. However, the system's functionality has been confirmed in various validation sequences. Using element-specific measurements, the automated system was up to 25% more precise compared to the manual procedure and as precise as the manual procedure using structure-specific measurements.

Direct determination of Ti content in sunscreens with laser-induced breakdown spectroscopy: Line selection method for high TiO2 nanoparticle concentration

Sunscreen represents a large variety of creams which, in the analytical point of view, exhibit a similar matrix. Such matrix corresponds to a semi-solid emulsion of mixture of oil and water. The formulation of a cream can include metal and nonmetal elements in different contents in order to realize specific pharmaceutical or cosmetic functions designed for the product. The complex matrix of these materials makes their analysis challenging for classical elemental analytical techniques with specific and complicated sample pretreatment procedures needed for reliable quantification. In this work we demonstrate and assess direct determination, without any pretreatment, of elemental content, especially for metallic element such as titanium, in a sunscreen using laser-induced breakdown spectroscopy (LIBS). The used configuration corresponds to that of indirect ablation of a thin film of cream applied on the surface of a pure aluminum target. We especially focused, in this work, on the case of high concentration of TiO2 nanoparticle in cream. Such choice was justified first by the fact that such concentration level is usually found in commercial sunscreens. On the other hand, titanium presents a large number of lines, neutral as well as singly ionized, in the spectral range from the near UV to the near IR. It provides therefore an ideal case to study line selection method to manage the effect of self-absorption, which becomes unavoidable at high concentration level, and to optimize measurement precision. Through such study, we try to deduce a quantifiable and generalizable line selection method for high performance LIBS measurements. More specifically, calibration curves were first established using 6 laboratory-prepared samples. The quadratic term of the curves was then studied as a function of the intensity of the used lines and their type (neutral or ion, resonant or non-resonant). The prediction performance of the lines was assessed with 2 validation samples with relatively low Ti content for one and higher Ti content for the second. The titanium content of 4 unknown samples was finally determined using a set of different selected lines.

Macrophage migration inhibitory factor confers resistance to senescence through CD74-dependent AMPK-FOXO3a signaling in mesenchymal stem cells

IntroductionMesenchymal stem cells (MSCs)-based therapies have had positive outcomes in animal models of cardiovascular diseases. However, the number and function of MSCs decline with age, reducing their ability to contribute to endogenous injury repair. The potential of stem cells to restore damaged tissue in older individuals can be improved by specific pretreatment aimed at delaying senescence and improving their regenerative properties. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that modulates age-related signaling pathways, and hence is a good candidate for rejuvenative function.MethodsBone marrow-derived mesenchymal stem cells (BM-MSCs) were isolated from young (6-month-old) or aged (24-month-old) male donor rats. Cell proliferation was measured using the CCK8 cell proliferation assay; secretion of VEGF, bFGF, HGF, and IGF was assessed by RT-qPCR and ELISA. Apoptosis was induced by hypoxia and serum deprivation (hypoxia/SD) for up to 6 hr, and examined by flow cytometry. Expression levels of AMP-activated protein kinase (AMPK) and forkhead box class O 3a (FOXO3a) were detected by Western blotting. CD74 expression was assayed using RT-qPCR, Western blotting, and immunofluorescence.ResultsIn this study, we found that MSCs isolated from the bone marrow of aged rats displayed reduced proliferative capacity, impaired ability to mediate paracrine signaling, and lower resistance to hypoxia/serum deprivation-induced apoptosis, when compared to younger MSCs. Interestingly, pretreatment of aged MSCs with MIF enhanced their growth, paracrine function and survival. We detected enhanced secretion of VEGF, bFGF, HGF, and IGF from MIF-treated MSCs using ELISA. Finally, we show that hypoxia/serum deprivation-induced apoptosis is inhibited in aged MSCs following MIF exposure. Next, we found that the mechanism underlying the rejuvenating function of MIF involves increased CD74-dependent phosphorylation of AMPK and FOXO3a. Furthermore, this effect was abolished when CD74, AMPK, or FOXO3a expression was silenced using small-interfering RNAs(siRNA).ConclusionsMIF can rejuvenate MSCs from a state of age-induced senescence by interacting with CD74 and subsequently activating AMPK-FOXO3a signaling pathways. Pretreatment of MSCs with MIF may have important therapeutic implications in restoration or rejuvenation of endogenous bone marrow-MSCs in aged individuals.

Isolation of a significant fraction of non-phototroph diversity from a desert Biological Soil Crust.

Biological Soil Crusts (BSCs) are organosedimentary assemblages comprised of microbes and minerals in topsoil of terrestrial environments. BSCs strongly impact soil quality in dryland ecosystems (e.g., soil structure and nutrient yields) due to pioneer species such as Microcoleus vaginatus; phototrophs that produce filaments that bind the soil together, and support an array of heterotrophic microorganisms. These microorganisms in turn contribute to soil stability and biogeochemistry of BSCs. Non-cyanobacterial populations of BSCs are less well known than cyanobacterial populations. Therefore, we attempted to isolate a broad range of numerically significant and phylogenetically representative BSC aerobic heterotrophs. Combining simple pre-treatments (hydration of BSCs under dark and light) and isolation strategies (media with varying nutrient availability and protection from oxidative stress) we recovered 402 bacterial and one fungal isolate in axenic culture, which comprised 116 phylotypes (at 97% 16S rRNA gene sequence homology), 115 bacterial and one fungal. Each medium enriched a mostly distinct subset of phylotypes, and cultivated phylotypes varied due to the BSC pre-treatment. The fraction of the total phylotype diversity isolated, weighted by relative abundance in the community, was determined by the overlap between isolate sequences and OTUs reconstructed from metagenome or metatranscriptome reads. Together, more than 8% of relative abundance of OTUs in the metagenome was represented by our isolates, a cultivation efficiency much larger than typically expected from most soils. We conclude that simple cultivation procedures combined with specific pre-treatment of samples afford a significant reduction in the culturability gap, enabling physiological and metabolic assays that rely on ecologically relevant axenic cultures.

Enzymatic saccharification and bioethanol production from Cynara cardunculus pretreated by steam explosion

The correct choice of the specific lignocellulosic biomass pretreatment allows obtaining high biomass conversions for biorefinery implementations and cellulosic bioethanol production from renewable resources. Cynara cardunculus (cardoon) pretreated by steam explosion (SE) was involved in second-generation bioethanol production using separate hydrolysis and fermentation (SHF) or simultaneous saccharification and fermentation (SSF) processes. Steam explosion pretreatment led to partial solubilisation of hemicelluloses and increased the accessibility of residual polysaccharides towards enzymatic hydrolysis revealing 64% of sugars yield against 11% from untreated plant material. Alkaline extraction after SE pretreatment of cardoon (CSEOH) promoted partial removal of degraded lignin, tannins, extractives and hemicelluloses thus allowing to double glucose concentration upon saccharification step. Bioethanol fermentation in SSF mode was faster than SHF process providing the best results: ethanol concentration 18.7gL−1, fermentation efficiency of 66.6% and a yield of 26.6g ethanol/100g CSEOH or 10.1g ethanol/100g untreated cardoon.

Catalytic role of surface pre-treatment of noble-metal-like tungsten carbide powder on electroless deposition of nickel

In this paper, tungsten carbide (WC) powder without noble-metal activation pretreatment has been coated with a thick layer of nickel (Ni) particles by ultrasonic-assisted electroless plating process at room temperature. The surface morphologies and composition of original WC powder, pretreated WC powder, Ni-coated WC powder prepared in different electroless nickel plating (ENP) baths and worn WC–Ni composite powder were analyzed by field emission scanning electron microscopy (FE-SEM) and energy dispersion spectrometry (EDS). The results suggest that the initial WC powder, whether or not pretreatment, are both able to initiate ENP successfully. WC itself is considered to have noble-metal-like catalytic performance to induce ENP under the system of sodium hypophosphite as reducing agent. The surface defects created by specific chemical activation pretreatment not only effectively enhance the catalytic ability, but also improve binding force of WC substrate and Ni coating. Moreover, the composition of ENP bath is a key factor which can regulate the growth rate and adsorption rate of Ni particles to maximize the catalytic activity of WC powder.

Development of a lectin binding assay to differentiate between recombinant and endogenous proteins in pharmacokinetic studies of protein-biopharmaceuticals

Human glycoproteins, expressed in hamster cell lines, show similar glycosylation patterns to naturally occurring human molecules except for a minute difference in the linkage of terminal sialic acid: both cell types lack α2,6-galactosyl-sialyltransferase, abundantly expressed in human hepatocytes and responsible for the α2,6-sialylation of circulating glycoproteins. This minute difference, which is currently not known to have any physiological relevance, was the basis for the selective measurement of recombinant glycoproteins in the presence of their endogenous counterparts. The assay is based on using the lectin Sambucus nigra agglutinin (SNA), selectively binding to α2,6-sialylated N-glycans. Using von Willebrand factor (VWF), factor IX (FIX), and factor VIIa (FVIIa), it was demonstrated that (i) the plasma-derived proteins, but not the corresponding recombinant proteins, specifically bind to SNA and (ii) this binding can be used to deplete the plasma-derived proteins. The feasibility of this approach was confirmed in spike-recovery studies for all three recombinant coagulation proteins in human plasma and for recombinant VWF (rVWF) in macaque plasma. Analysis of plasma samples from macaques after administration of recombinant and a plasma-derived VWF demonstrated the suitability and robustness of this approach. Data showed that rVWF could be selectively measured without changing the ELISAs and furthermore revealed the limitations of baseline adjustment using a single measurement of the predose concentration only. The SNA gel-based depletion procedure can easily be integrated in existing procedures as a specific sample pre-treatment step. While ELISA-based methods were used to measure the recombinant coagulation proteins in the supernatants obtained by depletion, this procedure is applicable for all biochemical analyses.

Quasi 3D dosimetry (EPID, conventional 2D/3D detector matrices)

Patient specific pretreatment measurement for IMRT and VMAT QA should preferably give information with a high resolution in 3D. The ability to distinguish complex treatment plans, i.e. treatment plans with a difference between measured and calculated dose distributions that exceeds a specified tolerance, puts high demands on the dosimetry system used for the pretreatment measurements and the results of the measurement evaluation needs a clinical interpretation. There are a number of commercial dosimetry systems designed for pretreatment IMRT QA measurements. 2D arrays such as MapCHECK® (Sun Nuclear), MatriXXEvolution (IBA Dosimetry) and OCTAVIOUS® 1500 (PTW), 3D phantoms such as OCTAVIUS® 4D (PTW), ArcCHECK® (Sun Nuclear) and Delta4 (ScandiDos) and software for EPID dosimetry and 3D reconstruction of the dose in the patient geometry such as EPIDoseTM (Sun Nuclear) and Dosimetry CheckTM (Math Resolutions) are available. None of those dosimetry systems can measure the 3D dose distribution with a high resolution (full 3D dose distribution). Those systems can be called quasi 3D dosimetry systems. To be able to estimate the delivered dose in full 3D the user is dependent on a calculation algorithm in the software of the dosimetry system. All the vendors of the dosimetry systems mentioned above provide calculation algorithms to reconstruct a full 3D dose in the patient geometry. This enables analyzes of the difference between measured and calculated dose distributions in DVHs of the structures of clinical interest which facilitates the clinical interpretation and is a promising tool to be used for pretreatment IMRT QA measurements. However, independent validation studies on the accuracy of those algorithms are scarce. Pretreatment IMRT QA using the quasi 3D dosimetry systems mentioned above rely on both measurement uncertainty and accuracy of calculation algorithms. In this article, these quasi 3D dosimetry systems and their use in patient specific pretreatment IMRT/VMAT QA will be discussed.

A study on the correlation between plan complexity and gamma index analysis in patient specific quality assurance of volumetric modulated arc therapy

AimTo evaluate the new Octavius 4D system for patient specific quality assurance and to study the correlation between plan complexity and gamma index analysis in patient specific quality assurance of VMAT using the Octavius 4D system. BackgroundMcNiven (2010) proposed a study to evaluate the utility of a complexity metric, the Modulation Complexity Score, to evaluate the relationship of the metric with deliverability in IMRT. Materials and methodsEvaluation of the Octavius 4D system was carried out by gamma evaluation of user defined MLC created patterns and AAPM TG 119 benchmark plans. The relationship between plan complexity expressed as Modulation Complexity Score (MCS) and the gamma index analysis was established by a planar and volumetric gamma analysis of 106 clinically approved VMAT patient plans of different sites. ResultsAverage volumetric 3D global gamma evaluation (3mm/3%) results for the evaluation plans was 97.41% for 6MV X-rays and 98.30% for 15MV X-rays. Average MCS values for the head and neck, pelvic and thoracic plans were 0.2224, 0.3615 and 0.1874. Average volumetric 3D global gamma analysis (3mm/3%) results for the head and neck, pelvic and thoracic VMAT plans were 95.45%, 97.51% and 96.98%, respectively. Out of 90 correlation analyses between the MCS and gamma passing rate, only 3 had the r value greater than 0.5. ConclusionsThe Octavius 4D system is a suitable device for patient specific pretreatment QA. Global and local gamma analysis results showed a weak correlation with the MCS.

TH-C-BRE-01: IGART: Fast On-Line Planning for IGART

Cone beam CT IGRT provides on-line anatomical data of the patient at the treatment couch while new hybrid MRI radiotherapy systems promise to provide this data during the actual radiation delivery itself. To exploit these data, and account for tissue rotations, deformations and tumor regression during radiation therapy delivery, fast, on-line IMRT (re)planning is required.On-line IMRT re-planning needs to re-generate a similar patient specific dose distribution as done in the pre-treatment planning but then for the new state of the anatomy. For this the pre-treatment information has to be propagated to the actual treatment. A fast dose engine is required, which may be, in the case of MRI based IGRT, Monte Carlo based in order to account for the magnetic field induced dose effects. Then robust re-planning methods or class solutions should be available that account efficiently for both rigid and non-rigid anatomical changes while preserving the patient specific pre-treatment dose considerations. Preferably this is all fully automatic, but also fast interactive re-planning is an option, especially in hypo-fractionated (boost) radiotherapy. Learning Objectives: Preservation of pre-treatment prescriptions in the on-line IMRT re-planning Fast re-planning techniques and speed limitations for dose engines Pros and cons of interactive versus automatic re-planning.

Pretreatment Patient Specific Quality Assurance and Gamma Index Variation Study in Gantry Dependent EPID Positions for IMRT Prostate Treatments

Pretreatment quality assurance (QA) is a major concern in complex radiation therapy treatment plans like intensity modulated radiation therapy (IMRT). Present study considers the variations in gamma index for gantry dependent pretreatment verification and commonly practiced zero gantry angle verifications for ten prostate IMRT plans using two commercial medical linear accelerators (Varian 2300 CD, Varian Clinac iX). Two verification plans (the one with all fields at the actual treatment angles and one with all fields merged to 0 degree gantry angles) for all the patients were generated to obtain dose fluence mapping using amorphous silicon electronic portal imaging device (EPID). The gamma index was found depend on gantry angles but the difference between zero and the nonzero treatment angles is in the confidence level for clinical acceptance. The acceptance criteria of gamma method were always satisfied in both cases for two machines and are stable enough to execute the patient specific pretreatment quality assurance at 0 degree gantry angle for prostate IMRTs, where limited number of gantry angles are used.

Serum interleukin-6 levels in murine models of Candida albicans infection

Two Balb/C mouse models of Candida infection were used to detect serum interleukin-6 (IL-6) responses. The first model used systemic infection by Candida albicans ATCC 10231 strain infected through the lateral tail vein of mice without any specific pretreatment. The median Candida burdens of the kidneys were 1.5 × 106 CFU/ml 24 h postinoculation (p.i.) and 1.2 × 107 CFU/ml 72 h p.i., while median serum IL-6 levels were 479.3 pg/ml and 934.5 pg/ml, respectively. The Candida burden showed significant correlation with serum IL-6 24 h p.i. (R2 = 0.6358; P = 0.0082) but not 72 h p.i.The second model was a mouse vaginitis model applying intravaginal inoculation of mice pretreated with subcutaneous estradiol-valerate (10 mg/ml) 3 days before infection. Candida cell count in vaginal lavage fluid was 2.8 × 106 CFU/ml 24 h p.i. and 1.4 × 108 CFU/ml 72 h p.i. Serum IL-6 response was detected in 4 of 15 mice 24 h p.i. and 9 of 15 mice 72 h p.i. Even the responders had low IL-6 serum levels (mean values 29.9 pg/ml and 60.1 pg/ml, respectively) not correlating with Candida cell count in vaginal lavage fluid.In conclusion, serum IL-6 had strong relationship with systemic C. albicans infection while the local C. albicans infection of the vagina led to partial, prolonged and limited serum IL-6 response.

Downregulation of Rad51 participates in OTA-induced DNA double-strand breaks in GES-1 cells in vitro

Ochratoxin A (OTA), a mycotoxin produced by ubiquitous Aspergilli, is carcinogenic, teratogenic, and nephrotoxic in both humans and animals. Our previous study found that OTA induced DNA double-strand breaks (DSBs) and resulted in G2 phase arrest in human gastric epithelium immortalized (GES-1) cells. DSBs can cause genomic instability, mutations, and neoplastic transformations, and improper repair of DSBs may lead to the development of cancer. Rad51 is a key protein in the homologous recombination (HR) pathway of DSBs repair. The roles of Rad51 in the repair of DNA damage vary in response to different types of cytotoxic agents. The effect of OTA on Rad51 expression and its putative role in the OTA-induced DSBs in GES-1 cells are still not clear enough. The aim of the current study is to elucidate the role of Rad51 in OTA-induced DSBs in GES-1 cells. The results showed that OTA treatment decreased Rad51 expression in a dose- and time-dependent manner. Specific downregulation of Rad51 by siRNA induced DSBs and G2 phase arrest. Rad51 overexpression by transfection with a Rad51-expressing plasmid partly rescued the DSBs and G2 phase arrest in OTA-treated cells. The findings indicate that downregulation of Rad51 contributes to OTA-induced DNA damage in GES-1 cells. Knockdown of p53 with siRNA for 48h effectively reversed the downregulation of Rad51, and decreased the OTA-induced DSBs in GES-1 cells. In addition, the downregulation of Rad51 induced by OTA could be significantly attenuated with specific ERK inhibitor PD98059 or specific p38 MAPK inhibitor SB203580 pre-treatment in GES-1 cells. Thus, the results suggest that downregulation of Rad51 participates in OTA-induced DNA double-strand breaks in GES-1 cells in vitro. And p53, ERK and p38 signaling pathways are all involved in the process.

Patient Specific Pre-Treatment QA Verification Using an EPID Approach

A software program [MU-EPID], has been developed to perform patient specific pre-treatment quality assurance (QA) verification for intensity modulated radiation therapy (IMRT) using fluence maps measured with an electronic portal imaging device (EPID). The software converts the EPID acquired images of each IMRT beam, to fluence maps that are equivalent to those calculated by the treatment planning system (TPS). The software has the capability to process Varian, Elekta and Siemens EPID DICOM images. In the present investigation, several IMRT plans for different treatment sites were used to validate the software using the Varian a-Si 1000 EPID with the Pinnacle TPS. A total of 20 IMRT plans of different treatment sites were analyzed. Isodose distributions, dose profiles, dose volume histograms (DVH's) and gamma analysis comparisons were performed to evaluate the accuracy of our method. A gamma index analysis of the isocenter coronal plane was done for each plan and showed an average of 97.44% of gamma passing rate using a 3% and 3 mm gamma criterion. Isodose, DVH and dose profile comparisons were conducted between the original calculated plan and the measured reconstructed plan from the EPID images processed through the MU-EPID software. The results suggest that MU-EPID can be used clinically for patient specific IMRT QA, providing a comprehensive 3D dosimetric evaluation through DVH comparison as well as an option for a 2D gamma analysis.

Technological Advances in the Hemostasis Laboratory

Automation is conventionally defined as the use of machines, control systems, and information technologies to optimize productivity. Although automation is now commonplace in several areas of diagnostic testing, especially in clinical chemistry and immunochemistry, the concept of extending this process to hemostasis testing has only recently been advanced. The leading drawbacks are still represented by the almost unique biological matrix because citrated plasma can only be used for clotting assays and few other notable exceptions, and by the highly specific pretreatment of samples, which is particularly distinct to other test systems. Despite these important limitations, a certain degree of automation is also now embracing hemostasis testing. The more relevant developments include the growing integration of routine hemostasis analyzers with track line systems and workcells, the development of specific instrumentation tools to enhance reliability of testing (i.e., signal detection with different technologies to increase test panels, plasma indices for preanalytical check of interfering substances, failure patterns sensors for identifying insufficient volume, clots or bubbles, cap-piercing for enhancing operator safety, automatic reflex testing, automatic redilution of samples, and laser barcode readers), preanalytical features (e.g., positive identification, automatic systems for tube(s) labeling, transillumination devices), and postphlebotomy tools (pneumatic tube systems for reducing turnaround time, sample transport boxes for ensuring stability of specimens, monitoring systems for identifying unsuitable conditions of transport). Regardless of these important innovations, coagulation/hemostasis testing still requires specific technical and clinical expertise, not only in terms of measurement procedures but also for interpreting and then appropriately utilizing the derived information. Thus, additional and special caution has to be used when designing projects of automation that include coagulation/hemostasis testing because peculiar and particular requirements must be taken into account.

High-Throughput Screening and Confirmation of 22 Banned Veterinary Drugs in Feedstuffs Using LC-MS/MS and High-Resolution Orbitrap Mass Spectrometry

A new analytical strategy based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with accurate mass high-resolution Orbitrap mass spectrometry (HR-Orbitrap MS) was performed for high-throughput screening, confirmation, and quantification of 22 banned or unauthorized veterinary drugs in feedstuffs according to Bulletin 235 of the Ministry of Agriculture, China. Feed samples were extracted with acidified acetonitrile, followed by cleanup using solid-phase extraction cartridge. The extracts were first screened by LC-MS/MS in a single selected reaction monitoring mode. The suspected positive samples were subjected to a specific pretreatment for confirmation and quantification of analyte of interest with LC-MS/MS and HR-Orbitrap MS. Mean recoveries for all target analytes (except for carbofuran and chlordimeform, which were about 35 and 45%, respectively) ranged from 52.2 to 90.4%, and the relative standard deviations were <15% except for 20% for carbofuran. The decision limits (CCαs) for target analytes in formulated feed were between 2.6 and 23 μg/kg, and the detection capabilities (CCβs) were between 4.2 and 34 μg/kg. The method was successfully applied to screening of real samples obtained from local feed markets and confirmation of the suspected target analytes. It provides a high-throughput, sensitive, and reliable screening, identification, and quantification of banned veterinary drugs in routine monitoring programs of feedstuffs.

EP-1515: Advantages of patient specific VMAT pre-treatment quality assurancewith cylindrical geometry

EP-1515: Advantages of patient specific VMAT pre-treatment quality assurancewith cylindrical geometry