Nitric oxide production mediates oligogalacturonide-triggered immunity and resistance to Botrytis cinerea in Arabidopsis thaliana

Nitric oxide (NO) regulates a wide range of plant processes from development to environmental adaptation. In this study, we investigated the production and/or function of NO in Arabidopsis thaliana leaf discs and plants elicited by oligogalacturonides (OGs) and challenged with Botrytis cinerea. We provided evidence that OGs triggered a fast and long lasting NO production which was Ca(2+) dependent and involved nitrate reductase (NR). Accordingly, OGs triggered an increase of both NR activity and transcript accumulation. NO production was also sensitive to the mammalian NO synthase inhibitor L-NAME. Intriguingly, we showed that L-NAME affected NO production by interfering with NR activity, thus questioning the mechanisms of how this compound impairs NO synthesis in plants. We further demonstrated that NO modulates RBOHD-mediated reactive oxygen species (ROS) production and participates in the regulation of OG-responsive genes such as anionic peroxidase (PER4) and a β-1,3-glucanase. Mutant plants impaired in PER4 and β-1,3-glucanase, as well as Col-0 plants treated with the NO scavenger cPTIO, were more susceptible to B. cinerea. Taken together, our investigation deciphers part of the mechanisms linking NO production, NO-induced effects and basal resistance to B. cinerea.

A process to enhance the specific surface area and capacitance of hydrothermally reduced graphene oxide

The impact of post-synthesis processing in reduced graphene oxide materials for supercapacitor electrodes has been analyzed. A comparative study of vacuum, freeze and critical point drying was carried out for hydrothermally reduced graphene oxide demonstrating that the optimization of the specific surface area and preservation of the porous network are critical to maximize its supercapacitance performance. As described below, using a supercritical fluid as the drying medium, unprecedented values of the specific surface area (364 m² g^-1) and supercapacitance (441 F g^-1) for this class of materials have been achieved.

Life cycle, techno-economic and dynamic simulation assessment of bioelectrochemical systems: A case of formic acid synthesis

A novel framework, integrating dynamic simulation (DS), life cycle assessment (LCA) and techno-economic assessment (TEA) of a bioelectrochemical system (BES), has been developed to study for the first time wastewater treatment by removal of chemical oxygen demand (COD) by oxidation in anode and thereby harvesting electron and proton for carbon dioxide reduction reaction or reuse to produce products in cathode. Increases in initial COD and applied potential increase COD removal and production (in this case formic acid) rates. DS correlations are used in LCA and TEA for holistic performance analyses. The cost of production of HCOOH is €0.015-0.005 g^-1 for its production rate of 0.094-0.26 kg yr^-1 and a COD removal rate of 0.038-0.106 kg yr^-1. The life cycle (LC) benefits by avoiding fossil-based formic acid production (93%) and electricity for wastewater treatment (12%) outweigh LC costs of operation and assemblage of BES (-5%), giving a net 61MJkg^-1 HCOOH saving.

Poly(3-hydroxybutyrate) production in an integrated electromicrobial setup: Investigation under stress-inducing conditions

Poly(3-hydroxybutyrate) (PHB), a biodegradable polymer, can be produced by different microorganisms. The PHB belongs to the family of polyhydroxyalkanoate (PHA) that mostly accumulates as a granule in the cytoplasm of microorganisms to store carbon and energy. In this study, we established an integrated one-pot electromicrobial setup in which carbon dioxide is reduced to formate electrochemically, followed by sequential microbial conversion into PHB, using the two model strains, Methylobacterium extorquens AM1 and Cupriavidus necator H16. This setup allows to investigate the influence of different stress conditions, such as coexisting electrolysis, relatively high salinity, nutrient limitation, and starvation, on the production of PHB. The overall PHB production efficiency was analyzed in reasonably short reaction cycles typically as short as 8 h. As a result, the PHB formation was detected with C. necator H16 as a biocatalyst only when the electrolysis was operated in the same solution. The specificity of the source of PHB production is discussed, such as salinity, electricity, concurrent hydrogen production, and the possible involvement of reactive oxygen species (ROS).

Coal fly ash supported CoFe2O4 nanocomposites: Synergetic Fenton-like and photocatalytic degradation of methylene blue

Rapid industrialization is causing a serious threat for the environment. Therefore, this research was aimed in developing ceramic cobalt ferrite (CoFe₂O₄) nanocomposite photocatalyst coated with coal fly ash (CFA-CoFe₂O₄) using facile hydrothermal synthesis route and their applications against methylene blue. The pristine cobalt ferrite photocatalyst was also prepared, characterized, and applied for efficiency comparison. Prepared photocatalyst were characterized by X-ray diffraction (XRD), fourier transformed infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS). Optical response of catalysts was check using photoluminescence spectroscopy (PL). pH drift method was used for the surface charge characteristics of the material under acidic and basic conditions of solution pH. The photocatalytic degradation potential of all the materials were determined under ultra-violet irradiations. The influencing reaction parameters like pH, catalyst dose, oxidant dose, dye concentration, and irradiation time, were sequentially optimized to obtain best suited conditions. The 99% degradation of 10 ppm methylene blue was achieved within 60 min of reaction time under pH = 5 and 7, catalyst dose = 10 and 12 mg/100 mL, oxidant = 12 mM and 5 mM for cobalt ferrite and CFA-CoFe₂O₄ photocatalysts, respectively. Afterwards, the radical scavenging experiments were conducted to find out the effective radical scavengers (˙OH, h⁺, and e^-) in photocatalytic degradation process. The kinetic study of the process was done by applying 1st order, 2nd order, and BMG models. Statistical assessment of interaction effect among experimental variables was achieved using response surface methodology (RSM).

Electrocatalytic Reduction of Carbon Dioxide with a Well-Defined PN3 -Ru Pincer Complex

A well-defined PN³ -Ru pincer complex (5) bearing a redox-active bipyridine ligand with an aminophosphine arm has been established as an effective and stable molecular electrocatalyst for CO₂ reduction to CO and HCOOH with negligible formation of H₂ in a H₂ O/MeCN mixture.

Copper-Indium Binary Catalyst on a Gas Diffusion Electrode for High-Performance CO2 Electrochemical Reduction with Record CO Production Efficiency

Cu-In metallic hybrid is a promising non-noble catalyst for selective electrochemical CO₂ reduction (eCO₂R) to CO, but the lack of direct assembly with a gas diffusion electrode (GDE) limits the further development of eCO₂R to CO with both high Faradaic efficiency (FE) and high current density. In this study, an in situ electrochemical spontaneous precipitation (ESP) method was applied for the first time to prepare GDE-combined Cu-In electrocatalysts. The optimum Cu-In catalyst consists of a nanoscale "core-shell" structure of polycrystalline Cu_xO covered by the amorphous In(OH)₃ interface. Higher than 90% FE of CO production has been achieved. With the synergy of a GDE flow cell and 1 M KOH catholyte, a current density of ∼200 mA cm^-2 was reached at -1.17 V (reversible hydrogen electrode), which enabled a CO yield efficiency record of 3.05 mg min^-1(CO₂/15 mL min^-1 with a 2 cm² electrode). The ratios between CO and H₂ produced can be effectively modulated via fine-tuning ESP conditions demonstrating possibility of generating CO or syngas with tuneable ratios. The present study provides a simple approach for constructing novel catalytic interfaces with dual active centers for eCO₂R and other emerging electrochemical catalysis research.

Impact of motion compensation and partial volume correction for 18F-NaF PET/CT imaging of coronary plaque

Recent studies have suggested that ¹⁸F-NaF-PET enables visualization and quantification of plaque micro-calcification in the coronary tree. However, PET imaging of plaque calcification in the coronary arteries is challenging because of the respiratory and cardiac motion as well as partial volume effects. The objective of this work is to implement an image reconstruction framework, which incorporates compensation for respiratory as well as cardiac motion (MoCo) and partial volume correction (PVC), for cardiac ¹⁸F-NaF PET imaging in PET/CT. We evaluated the effect of MoCo and PVC on the quantification of vulnerable plaques in the coronary arteries. Realistic simulations (Biograph TPTV, Biograph mCT) and phantom acquisitions (Biograph mCT) were used for these evaluations. Different uptake values in the calcified plaques were evaluated in the simulations, while three 'plaque-type' lesions of 36, 31 and 18 mm³ were included in the phantom experiments. After validation, the MoCo and PVC methods were applied in four pilot NaF-PET patient studies. In all cases, the MoCo-based image reconstruction was performed using the STIR software. The PVC was obtained from a local projection (LP) method, previously evaluated in preclinical and clinical PET. The results obtained show a significant increase of the measured lesion-to-background ratios (LBR) in the MoCo  +  PVC images. These ratios were further enhanced when using directly the tissue-activities from the LP method, making this approach more suitable for the quantitative evaluation of coronary plaques. When using the LP method on the MoCo images, LBR increased between 200% and 1119% in the simulated data, between 212% and 614% in the phantom experiments and between 46% and 373% in the plaques with positive uptake observed in the pilot patients. In conclusion, we have built and validated a STIR framework incorporating MoCo and PVC for ¹⁸F-NaF PET imaging of coronary plaques. First results indicate an improved quantification of plaque-type lesions.

Tuberculous mastitis

OBJECTIVE

To find out the different clinical presentations of breast tuberculosis and its treatment outcome.

DESIGN

An observational study.

PLACE AND DURATION OF STUDY

Surgical ward 3 of Jinnah Postgraduate Medical Centre, Karachi from June 2001 to November 2003.

SUBJECTS AND METHODS

Fifty consecutive female patients above 13 years presenting with breast lump, multiple sinuses, axillary lymphadenopathy, and cold abscess were included in the study. Medical records of the patients presented were reviewed and analyzed. Data was collected regarding the patient's name, age and marital and lactational status. Clinical Examinations and investigations were carried out by triple assessment i.e. clinical, radiological and histological / cytological evaluation.

RESULTS

The commonest presentation was a solitary breast lump in 30 (60%) patients, breast lump with axillary lymphadenopathy in 13 (26%). Four (8%) patients presented with generalized breast swelling (edema) with ipsilateral axillary lymphadenopathy. Two (4%) presented with breast abscess and axillary lymphadenopathy and one (2%) with axillary sinus and breast lump. Upper outer quadrant was most frequently involved in 29 (58%) of patients. Thirty-two (64%) cases were secondary to tuberculosis in other sites, mostly (40%) from tuberculous axillary lymphadenitis. Forty-eight (96%) patients responded well to one year antituberculous treatment with complete disappearance of the lumps except 2 patients who had shrinkage of lump size only, underwent excision of lump.

CONCLUSION

Solitary lump and enlarged lymph nodes are the commonest presentation of mammary tuberculosis. Early diagnosis and treatment is necessary to prevent disfigurement of breast. Antituberculous therapy is the treatment of choice. Surgery should be reserved for unresponsive lumps.

Annealing temperature effects on photoelectrochemical performance of bismuth vanadate thin film photoelectrodes

The effects of annealing treatment between 400 °C and 540 °C on crystallization behavior, grain size, electrochemical (EC) and photoelectrochemical (PEC) oxygen evolution reaction (OER) performances of bismuth vanadate (BiVO₄) thin films are investigated in this work. The results show that higher temperature leads to larger grain size, improved crystallinity, and better crystal orientation for the BiVO₄ thin film electrodes. Under air-mass 1.5 global (AM 1.5) solar light illumination, the BiVO₄ thin film prepared at a higher annealing temperature (500–540 °C) shows better PEC OER performance. Also, the OER photocurrent density increased from 0.25 mA cm⁻² to 1.27 mA cm⁻² and that of the oxidation of sulfite, a hole scavenger, increased from 1.39 to 2.53 mA cm⁻² for the samples prepared from 400 °C to 540 °C. Open-circuit photovoltage decay (OCPVD) measurement indicates that BiVO₄ samples prepared at the higher annealing temperature have less charge recombination and longer electron lifetime. However, the BiVO₄ samples prepared at lower annealing temperature have better EC performance in the absence of light illumination and more electrochemically active surface sites, which are negatively related to electrochemical double-layer capacitance (C_dl). C_dl was 0.0074 mF cm⁻² at 400 °C and it decreased to 0.0006 mF cm⁻² at 540 °C. The OER and sulfide oxidation are carefully compared and these show that the efficiency of charge transport in the bulk (η_bulk) and on the surface (η_surface) of the BiVO₄ thin film electrode are improved with the increase in the annealing temperature. The mechanism behind the light-condition-dependent role of the annealing treatment is also discussed.

The effects of annealing treatment on crystallization behavior, grain size, electrochemical (EC) and photoelectrochemical (PEC) oxygen evolution reaction (OER) performances of bismuth vanadate (BiVO₄) thin films are investigated in this work.

Enhancement of mechanical and corrosion resistance properties of electrodeposited Ni-P-TiC composite coatings

In the present study, the effect of concentration of titanium carbide (TiC) particles on the structural, mechanical, and electrochemical properties of Ni–P composite coatings was investigated. Various amounts of TiC particles (0, 0.5, 1.0, 1.5, and 2.0 g L⁻¹) were co-electrodeposited in the Ni–P matrix under optimized conditions and then characterized by employing various techniques. The structural analysis of prepared coatings indicates uniform, compact, and nodular structured coatings without any noticeable defects. Vickers microhardness and nanoindentation results demonstrate the increase in the hardness with an increasing amount of TiC particles attaining its terminal value (593HV₁₀₀) at the concentration of 1.5 g L⁻¹. Further increase in the concentration of TiC particles results in a decrease in hardness, which can be ascribed to their accumulation in the Ni–P matrix. The electrochemical results indicate the improvement in corrosion protection efficiency of coatings with an increasing amount of TiC particles reaching to ~ 92% at 2.0 g L⁻¹, which can be ascribed to a reduction in the active area of the Ni–P matrix by the presence of inactive ceramic particles. The favorable structural, mechanical, and corrosion protection characteristics of Ni–P–TiC composite coatings suggest their potential applications in many industrial applications.

A simple UV-ozone surface treatment to enhance photocatalytic performance of TiO2 loaded polymer nanofiber membranes

UV-ozone treated electrospun nanofiber membranes for increased photocatalytic activity.

Frequency of infection in cholelithiasis

OBJECTIVE

To determine the frequency of infection in cholelithiasis and find common infecting organisms with their antibiotic sensitivity.

DESIGN

A descriptive study.

PLACE AND DURATION

This study was conducted in Surgical Unit - I, Jinnah Postgraduate Medical Centre (JPMC), Karachi, Pakistan, from April 2001 to March 2002.

PATIENTS AND METHODS

First 100 cases of cholelithiasis, selected and operated by open or laparoscopic cholecystectomy were included in this study. Patients with acute cholecystitis, history of jaundice, stones and / or dilated common bile duct were excluded from the study. Ultrasound was the main tool for pre-operative diagnosis. During cholecystectomy, bile was aspirated and specimens were sent to laboratory for microbiological examination. The results were recorded on a proforma.

RESULTS

Out of 100, 36 patients had positive bile culture. The most common organism was E. coli (17 patients) followed by Klebsiella (9), Pseudomonas (6), Staphylococcus aureus (2), Salmonella (1) and Bacteroids fragalis (1) patient. In this study, most of the biliary organisms were highly sensitive to the 2nd generation cephalosporins and quinolones.

CONCLUSION

From the bacteriological assessment, it seems that both endogenous and exogenous contamination were the causes of wound sepsis. It was also found that the infection of bile did not increase the risk of postoperative wound infection when prophylactic perioperative antibiotics were used.

Heterosis and correlation in interspecific and intraspecific hybrids of cotton

Interspecific and intraspecific hybrids show varying degrees of heterosis for yield and yield components. Yield-component traits have complex genetic relationships with each other. To determine the relationship of yield-component traits and fiber traits with seed cotton yield, six lines (Bt. CIM-599, CIM-573, MNH-786, CIM-554, BH-167, and GIZA-7) and three test lines (MNH-886, V4, and CIM-557) were crossed in a line x tester mating design. Heterosis was observed for seed cotton yield, fiber traits, and for other yield-component traits. Heterosis in interspecific hybrids for seed cotton yield was more prominent than in intraspecific hybrids. The interspecific hybrid Giza-7 x MNH-886 had the highest heterosis (114.77), while among intraspecific hybrids, CIM-554 x CIM-557 had the highest heterosis (61.29) for seed cotton yield. A major trait contributing to seed cotton yield was bolls/plant followed by boll weight. Correlation studies revealed that bolls/plant, boll weight, lint weight/boll, lint index, seed index, lint/seed, staple length, and staple strength were significantly and positively associated with seed cotton yield. Selection based on boll weight, boll number, lint weight/boll, and lint index will be helpful for improving cotton seed yield.

UK and Ireland survey of MPharm student and staff experiences of mental health curricula, with a focus on Mental Health First Aid

Background

One in four people experience a mental health problem every year and improving mental health care is an international priority. In the course of their work, pharmacists frequently encounter people with mental health problems. The experience of mental health teaching, including Mental Health First Aid (MHFA) training, in undergraduate pharmacy (MPharm) students in the UK and Ireland is not well documented. Students’ viewpoints, contextualised with curricular overviews provided by staff, were analysed to understand their experience.

Methods

An anonymous, online questionnaire was distributed to MPharm students and staff in the UK and Ireland. Students were asked closed questions regarding their course and exposure to MHFA, which were analysed using descriptive statistics. Open questions were included to enable explanations and these data were used to contextualise the quantitative findings. One member of staff from each university was invited to answer a modified staff version of the questionnaire, to provide a curriculum overview and staff perspective.

Results

232 students and 13 staff, from 22 universities, responded. Three-quarters of students did not agree with the statement that ‘mental health was embedded throughout the MPharm’. Most students (80.6%) stated that they were taught neuropharmacology whilst 44.8% stated that their course included communicating with people about their mental health. One-third (33.2%) of students stated that their degree ‘adequately prepared them to help people with their mental health’. Twenty-six students (11.6%) had completed MHFA training of which 89% would endorse inclusion of this within the MPharm. Of those who had not completed the training, 81% expressed a desire to do so. Those who completed MHFA training self-reported greater preparedness than those who did not, but student numbers were small.

Conclusions

Mental health teaching for pharmacy undergraduates is more focussed on theoretical aspects rather than applied skills. MHFA was viewed by students as one way to enhance skill application. The association of the increased self-reported preparedness of those who completed MHFA could be confounded by a positive environmental cultural. MPharm programmes need sufficient focus on real-world skills such as communication and crisis response, to complement the fundamental science.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40545-021-00364-1.

Cervical cancer screening program in a Muslim country: three-year experience at the Aga Khan University Medical Center, Karachi

A systematic cervical cancer screening program was initiated in January 1987 at The Aga Khan University Medical Center, Karachi, Pakistan. The 8,784 cervical smears obtained in 3 subsequent years from 8,412 consecutive women attending the gynecology and antenatal clinics were reviewed. "Positive" smears were found in 111 (1.3%) patients; 107 (1.27%) smears showed squamous epithelial dysplasia and 4 smears showed adenocarcinoma. The highest incidence of abnormal smears was found in the 45-54 years age group. Colposcopy and biopsy was performed on all patients with "positive" smears except on those with atypical or mildly dysplastic ones, in whom only the persistence of the abnormality on repeated smears was considered an indication for tissue evaluation. The histopathologic diagnosis of these biopsy specimens revealed cervical intra-epithelial neoplasia in 60 patients and invasive cervical cancer in 6 patients.

Outcome of stapled haemorrhoidectomy versus Milligan Morgan's haemorrhoidectomy

OBJECTIVE

To compare the postoperative outcome of stapled haemorrhoidectomy and conventional Milligan Morgan's open haemorrhoidectomy.

STUDY DESIGN

Comparative study.

PLACE AND DURATION OF STUDY

Surgical Unit 1, Ward-3, Department of Surgery, Jinnah Postgraduate Medical Centre, Karachi, from March to September 2006.

METHODOLOGY

Sixty patients of late 2nd, 3rd and 4th degree haemorrhoids were selected for admission from the outpatient department after taking informed consent. Patients with concomitant anal disease (e.g. fissure, abscess, fistula, ano-rectal cancer etc.) were excluded. Two groups of thirty each were made, one for Milligan-Morgan open haemorrhoidectomy and another for stapled haemorrhoidectomy, in which excision of a ring of mucosa proximal to the haemorrhoid(s) was done thus, interrupting the blood supply but maintaining continuity of the rectal mucosa. The operative time was measured in minutes. Postoperative pain was assessed through VAS. Bleeding was measured as no, mild, profuse. Other post-operative complications during hospital stay like urinary retention, anal stenosis etc. were noted. Student t-test, chi-square test and repeated measured analysis of variance were applied to compare the variables.

RESULTS

The mean age was 40.7+/-11.6 years. A majority (53.3%) of patients (combined % in both groups) had third degree haemorrhoid. The mean length of operative time was found statistically insignificant between open and stapled groups (19.6+/-5.9 vs. 22.4+/-7.2 minutes, p=0.974). However, the mean length of postoperative hospital stay was significantly less in the stapled than open haemorrhoidectomy group (3.37+/-2.2 vs. 2.03+/-0.81 days, p=0.003. Mean postoperative pain (observed by VAS) in the stapled group was significantly less than the open haemorrhoidectomy group (4.43+/-1.25 vs. 7.37+/-0.72). The proportion of postoperative bleeding, infection, anal tag, urinary retention, tenderness on digital rectal examination and wound discharge was higher in open than stapled haemorrhoidectomy group, but statistically insignificant (p < 0.05).

CONCLUSION

There was a significant difference between Milligan Morgan's and stapled haemorrhoidectomy for postoperative pain and hospital stay. However the mean length of operative time was insignificantly different.

Toxicity profile and objective response of paclitaxel in metastatic breast cancer

OBJECTIVE

To evaluate the efficacy and toxicity of 1-hour weekly Paclitaxel in metastatic breast cancer along with evaluation of overall survival.

DESIGN

A phase II interventional trial.

PLACE AND DURATION OF STUDY

Oncology Department, Combined Military Hospital, Rawalpindi, between August 2001 to July 2003.

PATIENTS AND METHODS

Thirty-six patients were enrolled in the study. All patients with histologically confirmed and bi-dimensionally measurable metastatic breast cancer who had received previously either chemotherapy or hormone therapy were included in the study. Paclitaxel was administered in 1-hour weekly infusion in a dose of 100 mg/m2 for 12 doses.

RESULTS

All patients had received previous chemotherapy with either CAF or CMF. Twenty-five patients had also received hormone therapy, 61% had two or more metastatic sites involved, and lung was the common site of involvement. Complete response was observed in 4 (11.1%) patients, partial response in 14 (38.8%) patients, with an overall response rate of 50.0%. Clinical benefit was 94.4% and median overall survival was 11 months. Treatment was well-tolerated with no grade 3 or 4 toxicity. Common side effects were arthralgias, myalgias and neutropenia.

CONCLUSION

Treatment with 1-hour weekly infusion of Paclitaxel is a well-tolerated chemotherapy with a substantial degree of efficacy in patients with metastatic breast cancer.

Dosimetric effect of limited aperture multileaf collimator on VMAT plan quality: A study of prostate and head-and-neck cancers

AIM

The aim of study was to evaluate the dosimetric effect of collimator-rotation on VMAT plan quality, when using limited aperture multileaf collimator of Elekta Beam Modulator™ providing a maximum aperture of 21 cm × 16 cm.

BACKGROUND

The increased use of VMAT technique to deliver IMRT from conventional to very specialized treatments present a challenge in plan optimization. In this study VMAT plans were optimized for prostate and head and neck cancers using Elekta Beam-Modulator^TM, whereas previous studies were reported for conventional Linac aperture.

MATERIALS AND METHODS

VMAT plans for nine of each prostate and head-and-neck cancer patients were produced using the 6 MV photon beam for Elekta-SynergyS^® Linac using Pinnacle³ treatment planning system. Single arc, dual arc and two combined independent-single arcs were optimized for collimator angles (C) 0°, 90° and 0°-90° (0°-90°; i.e. the first-arc was assigned C0° and second-arc was assigned C90°). A treatment plan comparison was performed among C0°, C90° and C(0°-90°) for single-arc dual-arc and two independent-single-arcs VMAT techniques to evaluate the influence of extreme collimator rotations (C0° and 90°) on VMAT plan quality. Plan evaluation criteria included the target coverage, conformity index, homogeneity index and doses to organs at risk. A 'two-sided student t-test' (p ≤ 0.05) was used to determine if there was a significant difference in dose volume indices of plans.

RESULTS

For both prostate and head-and-neck, plan quality at collimator angles C0° and C(0°-90°) was clinically acceptable for all VMAT-techniques, except SA for head-and-neck. Poorer target coverage, higher normal tissue doses and significant p-values were observed for collimator angle 90° when compared with C0° and C(0°-90°).

CONCLUSIONS

A collimator rotation of 0° provided significantly better target coverage and sparing of organs-at-risk than a collimator rotation of 90° for all VMAT techniques.