Advancements in Perovskite-Based Cathode Materials for Solid Oxide Fuel Cells: A Comprehensive Review

The high-temperature solid oxide fuel cells (SOFCs) are the most efficient and green conversion technology for electricity generation from hydrogen-based fuel as compared to conventional thermal power plants. Many efforts have been made to reduce the high operating temperature (>800 °C) to intermediate/low operating temperature (400 °C Collapse

Key Words

• Ruddlesden-Popper phase
• Solid oxide fuel cell
• double perovskite
• electrochemical activity
• polarization resistance
• thermal expansion coefficient

Collapse

MESH Headings Collapse

Grants Collapse

Affiliation(s)

Ayesha Samreen Department of Physics, University of Peshawar, Peshawar, 25120, Pakistan
Muhammad Sudais Ali Department of Physics, University of Peshawar, Peshawar, 25120, Pakistan
Muhammad Huzaifa Department of Physics, University of Peshawar, Peshawar, 25120, Pakistan
Nasir Ali Research Center for Sensing Materials and Devices, Zhejiang Labs, Yuhang District, Nanhu, China
Bilal Hassan Department of Physics, University of Peshawar, Peshawar, 25120, Pakistan
Fazl Ullah Department of Physics, University of Peshawar, Peshawar, 25120, Pakistan
Shahid Ali Department of Physics, University of Peshawar, Peshawar, 25120, Pakistan
Nor Anisa Arifin Materials Engineering and Testing Group, TNB Research Sdn Bhd, No.1, Kawasan Institusi Penyelidikan, Jln Ayer Hitam, 43000, Kajang, Selangor, Malaysia

Collapse

An appraisal of the performance of AI tools for chronic stroke lesion segmentation

Automated demarcation of stoke lesions from monospectral magnetic resonance imaging scans is extremely useful for diverse research and clinical applications, including lesion-symptom mapping to explain deficits and predict recovery. There is a significant surge of interest in the development of supervised artificial intelligence (AI) methods for that purpose, including deep learning, with a performance comparable to trained experts. Such AI-based methods, however, require copious amounts of data. Thanks to the availability of large datasets, the development of AI-based methods for lesion segmentation has immensely accelerated in the last decade. One of these datasets is the Anatomical Tracings of Lesions After Stroke (ATLAS) dataset which includes T1-weighted images from hundreds of chronic stroke survivors with their manually traced lesions. This systematic review offers an appraisal of the impact of the ATLAS dataset in promoting the development of AI-based segmentation of stroke lesions. An examination of all published studies, that used the ATLAS dataset to both train and test their methods, highlighted an overall moderate performance (median Dice index = 59.40%) and a huge variability across studies in terms of data preprocessing, data augmentation, AI architecture, and the mode of operation (two-dimensional versus three-dimensional methods). Perhaps most importantly, almost all AI tools were borrowed from existing AI architectures in computer vision, as 90% of all selected studies relied on conventional convolutional neural network-based architectures. Overall, current research has not led to the development of robust AI architectures than can handle spatially heterogenous lesion patterns. This review also highlights the difficulty of gauging the performance of AI tools in the presence of uncertainties in the definition of the ground truth.

Restricting family life - an examination of citizens' views on state interventions and parental freedom in eight European countries

This paper examines the public views - a total of 10,348 persons - on restrictions of personal autonomy of others to protect the interest of children. We use representative country samples of the adult populations of Austria, England, Estonia, Finland, Germany, Ireland, Norway, and Spain, and ask them to consider an experimental vignette with three different parental conditions: substance abuse, mental health problems, and learning difficulties. The findings display that most people would restrict parental freedom to protect the child, and a stricter restriction when the parent struggles with substance abuse compared to mental health compared to learning difficulties. There are some country differences, and when examining the role of institutional context of child protective system, a correlation is detected with significant differences between population views in a right-oriented system versus a well-being system and maltreatment system. In light of the ongoing European debates about child protection and how controversial and contested this area of the welfare state seem to be, it is interesting to learn (also) from this study that people, across countries, individual differences, child protection systems, overall are supportive of state intervention and support in a situation with a child at potential risk.

Knowledge distillation driven instance segmentation for grading prostate cancer

Prostate cancer (PCa) is one of the deadliest cancers in men, and identifying cancerous tissue patterns at an early stage can assist clinicians in timely treating the PCa spread. Many researchers have developed deep learning systems for mass-screening PCa. These systems, however, are commonly trained with well-annotated datasets in order to produce accurate results. Obtaining such data for training is often time and resource-demanding in clinical settings and can result in compromised screening performance. To address these limitations, we present a novel knowledge distillation-based instance segmentation scheme that allows conventional semantic segmentation models to perform instance-aware segmentation to extract stroma, benign, and the cancerous prostate tissues from the whole slide images (WSI) with incremental few-shot training. The extracted tissues are then used to compute majority and minority Gleason scores, which, afterward, are used in grading the PCa as per the clinical standards. The proposed scheme has been thoroughly tested on two datasets, containing around 10,516 and 11,000 WSI scans, respectively. Across both datasets, the proposed scheme outperforms state-of-the-art methods by 2.01% and 4.45%, respectively, in terms of the mean IoU score for identifying prostate tissues, and 10.73% and 11.42% in terms of F1 score for grading PCa according to the clinical standards. Furthermore, the applicability of the proposed scheme is tested under a blind experiment with a panel of expert pathologists, where it achieved a statistically significant Pearson correlation of 0.9192 and 0.8984 with the clinicians' grading.

Incidence and sociodemographic, living environment and maternal health associations with stillbirth in a tertiary healthcare setting in Kano, Northern Nigeria

Background

Almost two million stillbirths occur annually, most occurring in low- and middle-income countries. Nigeria is reported to have one of the highest stillbirth rates on the African continent. The aim was to identify sociodemographic, living environment, and health status factors associated with stillbirth and determine the associations between pregnancy and birth factors and stillbirth in the Murtala Mohammed Specialist Hospital, Kano, Nigeria.

Methods

A three-month single-site prospective observational feasibility study. Demographic and clinical data were collected. We fitted bivariable and multivariable models for stillbirth (yes/no) and three-category livebirth/macerated stillbirth/non-macerated stillbirth outcomes to explore their association with demographic and clinical factors.

Findings

1,998 neonates and 1,926 mothers were enrolled. Higher odds of stillbirth were associated with low-levels of maternal education, a further distance to travel to the hospital, living in a shack, maternal hypertension, previous stillbirth, birthing complications, increased duration of labour, antepartum haemorrhage, prolonged or obstructed labour, vaginal breech delivery, emergency caesarean-section, and signs of trauma to the neonate following birth.

Interpretation

This work has obtained data on some factors influencing stillbirth. This in turn will facilitate the development of improved public health interventions to reduce preventable deaths and to progress maternal health within this site.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04971-x.

Transmissive Polarizer Metasurfaces: From Microwave to Optical Regimes

Metasurfaces, a special class of metamaterials, have recently become a rapidly growing field, particularly for thin polarization converters. They can be fabricated using a simple fabrication process due to their smaller planar profile, both in the microwave and optical regimes. In this paper, the recent progress in MSs for linear polarization (LP) to circular polarization (CP) conversion in transmission mode is reviewed. Starting from history, modeling and the theory of MSs, uncontrollable single and multiple bands and LP-to-CP conversions, are discussed and analyzed. Moreover, detailed reconfigurable MS-based LP-to-CP converters are presented. Further, key findings on the state-of-the-arts are discussed and tabulated to give readers a quick overview. Finally, a conclusion is drawn by providing opinions on future developments in this growing research field.

Deep learning based joint segmentation and characterization of multi-class retinal fluid lesions on OCT scans for clinical use in anti-VEGF therapy

BACKGROUND

In anti-vascular endothelial growth factor (anti-VEGF) therapy, an accurate estimation of multi-class retinal fluid (MRF) is required for the activity prescription and intravitreal dose. This study proposes an end-to-end deep learning-based retinal fluids segmentation network (RFS-Net) to segment and recognize three MRF lesion manifestations, namely, intraretinal fluid (IRF), subretinal fluid (SRF), and pigment epithelial detachment (PED), from multi-vendor optical coherence tomography (OCT) imagery. The proposed image analysis tool will optimize anti-VEGF therapy and contribute to reducing the inter- and intra-observer variability.

METHOD

The proposed RFS-Net architecture integrates the atrous spatial pyramid pooling (ASPP), residual, and inception modules in the encoder path to learn better features and conserve more global information for precise segmentation and characterization of MRF lesions. The RFS-Net model is trained and validated using OCT scans from multiple vendors (Topcon, Cirrus, Spectralis), collected from three publicly available datasets. The first dataset consisted of OCT volumes obtained from 112 subjects (a total of 11,334 B-scans) is used for both training and evaluation purposes. Moreover, the remaining two datasets are only used for evaluation purposes to check the trained RFS-Net's generalizability on unseen OCT scans. The two evaluation datasets contain a total of 1572 OCT B-scans from 1255 subjects. The performance of the proposed RFS-Net model is assessed through various evaluation metrics.

RESULTS

The proposed RFS-Net model achieved the mean F₁ scores of 0.762, 0.796, and 0.805 for segmenting IRF, SRF, and PED. Moreover, with the automated segmentation of the three retinal manifestations, the RFS-Net brings a considerable gain in efficiency compared to the tedious and demanding manual segmentation procedure of the MRF.

CONCLUSIONS

Our proposed RFS-Net is a potential diagnostic tool for the automatic segmentation of MRF (IRF, SRF, and PED) lesions. It is expected to strengthen the inter-observer agreement, and standardization of dosimetry is envisaged as a result.

NLRP3 is involved in long bone edification and the maturation of osteogenic cells

Overexpression of the nucleotide-binding leucine-rich repeat protein 3 (NLRP3) inflammasome in chronic auto-immune diseases leads to skeletal anomalies, with severe osteopenia due to the activation of osteoclasts. Reproducing this phenotype in Nlrp3 knock-in mice has provided insights into the role of NLRP3 in bone metabolism. We studied the role of NLRP3 in physiological bone development using a complete Nlrp3 knock-out mouse model. We found impaired skeletal development in Nlrp3-/- mice, resulting in a shorter stature than that of Nlrp3+/+  mice. These growth defects were associated with altered femur bone growth, characterized by a deficient growth plate and an osteopenic profile of the trabeculae. No differences in osteoclast recruitment or activity were observed. Instead, Nlrp3-/- femurs showed a less mineralized matrix in the trabeculae than those of Nlrp3+/+  mice, as well as less bone sialoprotein (BSP) expressing hypertrophic chondrocytes. In vitro, primary osteoblasts lacking NLRP3 expression showed defective mineralization, together with the downregulation of BSP expression. Finally, follow-up by micro-CT highlighted the role of NLPR3 in bone growth, occurring early in living mice, as the osteopenic phenotype diminishes over time. Overall, our data suggest that NLRP3 is involved in bone edification via the regulation of hypertrophic chondrocyte maturation and osteoblast activity. Furthermore, the defect appeared to be transitory, as the skeleton recovered with aging.

Effect of lingual-based flap design on postoperative pain of impacted mandibular third molar surgery: Split-mouth randomized clinical trial

Background

The extraction of third molars is one of the most common procedures in oral and maxillofacial surgery clinic. Surgical extraction involves the manipulation of both soft and hard tissues, so the patient usually experiences pain, swelling, and trismus in the immediate post-operative period. Several studies have been conducted using different types of surgical flaps to provide access with the least possible damage of soft tissues. Designing and implementing an optimum flap, which provides easier technique, better visibility, minimal post-operative complications, and best healing, is an aspired goal of every oral surgeon. This study aimed to compare lingual-based four-cornered flap with conventional triangular flap, and to evaluate its effect on post-operative pain after surgical extraction of impacted lower third molars.

Material and Methods

Seventeen patients (age ranged from 19 to 26 years) with bilateral, symmetrical impacted lower third molars (n=34) were included in the study. This was a randomized clinical trial with a split-mouth design. The impacted molars were assigned randomly, by coin flipping, to two groups: Case side with lingual-based four-cornered flap (Group A), and control side with conventional triangular flap (Group B). Away from the incision, the prognosis, surgical intervention, and postoperative procedures were exactly the same for the two groups. Postsurgical pain was assessed for 5 days using visual analogue scale (VAS) and by recording patients need for analgesics on a daily basis. Patients were also evaluated via a self-reporting questionnaire, i.e. Postoperative Symptoms Severity (PoSSe) scale, administered on the seventh postoperative day.

Results

Pain scores recorded in Group A were found to be significantly lower as compared to pain scores in Group B in the 5 postoperative days (P<0.05). Total analgesic intake in Group B was significantly higher (P<0.05). PoSSe scores were lower in Group A, however, this difference was insignificant (P>0.05).

Conclusions

According to the data of the current study and within its limits, it appeared that lingual-based four-cornered flap design was superior to the conventional triangular flap regarding the postsurgical discomfort and pain.

Key words:Impaction, third molar surgery, flap design, pain, PoSSe scale, split-mouth, RCT.

Effect of oviposition by Bactrocera dorsalis on the antioxidant activity of orange juice

Among fruits and fruit products, oranges and orange juice are the most widely consumed worldwide. However, the effects of pest infestation of oranges on the quality of orange juice are not yet known. To evaluate the effect of the oriental fruit fly Bactrocera dorsalis on the antioxidant activity of orange juice, we measured changes in the vitamin C (Vc) concentration, total phenol content, and antioxidant activity of orange juice after the introduction of fruit fly eggs. Ten days after the eggs were introduced (larvae removed), the concentration of Vc in orange juice was 18.65 µg/mL, which was 9.16 µg/mL lower than that measured in healthy orange juice. In addition, the total phenol content decreased by 46.519 mg Gallic Acid Equivalents (GAE)/g to 9.748 mg GAE/g. Furthermore, the free-radical scavenging activity decreased from 22.297% to 5.393%. Correlation analysis indicated significant correlations between Vc concentration, total phenol content, and antioxidant activity of orange juice after B. dorsalis infestation. The decrease in Vc concentration, total phenol content and free-radical scavenging activity indicated that B. dorsalis changed the quality of orange juice by affecting the antioxidant activity of the juice after the oranges were infested.

A comprehensive study capturing vision loss burden in Pakistan (1990-2025): Findings from the Global Burden of Disease (GBD) 2017 study

This study aims to provide estimates, trends and projections of vision loss burden in Pakistan from 1990 to 2025. Global Burden of Diseases, Injuries, and Risk Factors Study (GBD 2017) was used to observe the vision loss burden in terms of prevalence and Years Lived with Disability (YLDs). As of 2017, out of 207.7 million people in Pakistan, an estimated 1.12 million (95% Uncertainty Interval [UI] 1.07–1.19) were blind (Visual Acuity [VA] <3/60), 1.09 million [0.93–1.24] people had severe vision loss (3/60≤VA<6/60) and 6.79 million [6.00–7.74] people had moderate vision loss (6/60≤VA<6/18). Presbyopia was found to be the most common ocular condition that affected an estimated 12.64 million [11.94–13.41] people (crude prevalence 6.08% [5.75–6.45]; 61% female). In terms of age-standardized YLDs rate, Pakistan is ranked fourth among other South Asian countries and twenty-first among other 42 low-middle income countries (classified by World Bank), with 552.98 YLDs [392.98–752.95] per 100,000. Compared with 1990, all-age YLDs count of blindness and vision impairment increased by 55% in 2017, which is the tenth highest increase among major health loss causes (such as dietary iron deficiency, headache disorders, low back pain etc.) in Pakistan. Moreover, our statistics show an increase in vision loss burden by 2025 for which Pakistan needs to make more efforts to encounter the growing burden of eye diseases.

Neutrophil-to-lymphocyte ratio as a predictor of survival in patients with triple-negative breast cancer

PURPOSE

Peripheral blood lymphopenia and elevated neutrophil-to-lymphocyte ratio (NLR) have been associated with poor outcomes in various malignancies. However, existing literature has largely focused on baseline parameters. The aim of this study is to assess the impact of radiation therapy (RT) and chemotherapy on absolute lymphocyte counts (ALC) and NLR in relation to survival outcomes in patients with triple-negative breast cancer (TNBC).

METHODS

A retrospective analysis was performed on 126 patients with TNBC treated at Washington University between 2005 and 2010. Cox proportional hazard model with time-varying covariates was applied to estimate the effect of time-varying ALC and NLR separately on overall survival (OS) and disease-free survival (DFS).

RESULTS

All patients received RT and 112 patients received either neoadjuvant chemotherapy or adjuvant chemotherapy, or both. Patients deceased had lower ALC and higher NLR compared to patients alive throughout the treatment course, even 1 year after treatment completion (ALC, 1 vs. 1.3, P = 0.03 and NLR, 3.9 vs. 2.6, P = 0.03). High ALC was associated with superior OS on both continuous and binary scales (cutoff of 1 K/ul) (HR 0.14; 95% CI 0.05-0.34; P < 0.001 and HR 0.28; 95% CI 0.13-0.61; P = 0.01, respectively). Additionally, high NLR was weakly associated with inferior OS on continuous scales (HR 1.1; 95% CI 1.06-1.15; P < 0.001).

CONCLUSIONS

Post-treatment lymphopenia and NLR elevation can persist until 1 year after treatment completion. Both portend shorter survival for patients with TNBC. Our data support the use of ALC and NLR to identify high risk patients who may benefit from clinical trials rather than standard of care therapy.

Effects of White Mulberry (Morus alba) Heartwood Extract Against Reticulitermes flavipes (Blattodea: Rhinotermitidae)

Heartwood extract from white mulberry (Morus alba L.) (Rosales: Moraceae) were investigated for antitermitic activity against Reticulitermes flavipes (Kollar) (Blattodea: Rhinotermitidae) in laboratory experiments. An ethanol:toluene (2:1) solvent system was used to remove extract from heartwood shavings. A concentration-dependent feeding response and mortality were observed for termites exposed to a concentration series range of 1.25 to 10 mg/ml of extract based on their dry weight. Results showed that maximum termite mortality occurred at 10 mg/ml. Based on the concentration series data, LC50 was calculated at 1.71 mg/ml. In filter paper feeding and repellency assays, extract significantly decreased the total number of gut protozoa compared with untreated and solvent controls. After feeding on filter paper treated at 10 mg/ml for 2 wk, protozoan populations were reduced by >55%. In choice and no-choice tests with mulberry heartwood, greater wood loss from termite feeding was found on solvent extracted blocks compared with nonextracted. Complete (100%) mortality was observed after feeding on nonextracted blocks compared with extracted blocks. Heartwood extract from white mulberry imparted resistance to vacuum pressure treated, nondurable southern pine and cottonwood. At every concentration tested, 100% mortality was observed after feeding on extract-treated southern pine or cottonwood. GC-MS analysis of extract showed high levels of the phenol compound, resorcinol. Results indicated that heartwood extract from white mulberry have antitermitic properties and might be potentially valuable in the development of environmentally benign termiticides.

Outcomes of High Risk Patients with Febrile Neutropenia at a Tertiary Care Center

Fever during chemotherapy-induced neutropenia continues to be a major cause of morbidity and mortality in cancer patients. Mortality depends on the duration and degree of neutropenia, bacteremia, sepsis, performance status, comorbidities and other parameters. The highest mortality rates in cancer patients hospitalized with febrile neutropenia (FN) are observed in those with documented infection. The objectives of the study were to present available tools for risk assessment, to review pathogens causing infections in adult FN patients and to assess outcomes.

Blood biomarker analysis to differentiate between pseudo-progression and true disease progression in post-treatment glioblastoma

e13501

Background: Current standard treatment for patients with glioblastoma (GBM) includes glucocorticoid therapy, temozolomide (TMZ), and radiation (RT) which may result in lymphotoxic and immunosuppressive effects. MRI use is currently unreliable in differentiating true from pseudo-progression pathology. Recent studies have suggested that total lymphocyte count (TLC) and CD4 cell count are associated with clinical outcomes. Our objective was to investigate whether TLC or CD4 may help to differentiate treatment effect (pesudoprogression) from tumor progression. Methods: Patients were eligible for this retrospective study if they had 1) GBM diagnosed between February 2010 and July 2015, 2) series of cell counts and clinical follow-ups monitored at Washington University, and 3) tumor progression documented by MRI and pathology. The data were analyzed using descriptive statistics, chi-square tests, Kaplan-Meier survival curves, and progression-free survival. Results: A total of 728 charts were reviewed, of which 45adults met eligibility criteria. The median age and KPS scores were 58 years and 80, respectively. MGMT was detected in 33% of patients and 69% of patients had undergone a gross total resection. Median TLC at baseline was 1700 cells/mm3 (range 400-3100). After the completion of RT/TMZ, TLC dropped 41% to a median of 1000 cells/mm3 (range 200-2900). Median TLC was 1000 cells/mm3 (range 300-2900) at the first MRI documented progression. Patients underwent surgery for this MRI documented progression. Pathology revealed that 62% of patients had true tumor progression, 33% had mixed treatment effect and residual tumor, and 4% had necrosis. The median time from diagnosis to progression was 15 months. There were no statistically significant differences in overall survival or progression free survival found in patients with higher vs lower TLC at baseline, completion of RT/TMZ, and time of progression. Conclusions: These preliminary results do not indicate that TLC level in GBM patients can differentiate between true disease progression and pseudo-progression. A larger sample size that includes patients with CD4 data is needed to confirm these results.

The association between neutrophil to lymphocyte ratio and overall survival in patients with triple-negative breast cancer

e12591

Background: Recent reports have suggested that an elevated neutrophil to lymphocyte ratio (NLR) is associated with poor outcomes in various malignancies. Furthermore, radiation therapy (RT) alone or in combination with chemotherapy often results in reduced absolute lymphocyte counts (ALC), which has been postulated to impair host immune surveillance and anti-tumor responses. We sought to better understand whether an elevated NLR results in impaired OS in patients with triple-negative breast cancer. Methods: Our retrospective analysis was performed on a database of patients with biopsy proven triple-negative breast cancer treated at Washington University in St. Louis between 2002 and 2010. Patients who received radiation therapy and had adequate follow up in terms of clinical documentations and laboratory data were included. NLR and ALC were collected at baseline, post-adjuvant chemotherapy, prior to RT, end of RT, 2 months post RT, 1 year post RT, and completion of all planned treatments. Results: Total of 155 patients were included. We used a cutoff value of 3.0 to classify high NLR. Wilcoxon rank-sum test was used to compare NLR at each time point between deceased and alive patients. High NLR post chemotherapy is associated with worse OS (HR 1.127, 95% CI = 1.016-1.249; p<0.05). In addition, NLRs from end of RT, 2 months post and 1 year post RT are associated with worse OS: (HR 1.109, 95% CI = 1.059–1.161; p < 0.001); (HR 1.074, 95% CI = 1.041–1.109; p < 0.001); (HR 1.069, 95% CI = 1.048–1.091; p < 0.001) respectively. Conclusions: High NLR post-chemotherapy and RT are associated with worse OS in patients with triple-negative breast cancer.Further studies are warranted to establish NLR as a prognostic marker and an addition to risk prediction models. [Table: see text]

Structure tensor based automated detection of macular edema and central serous retinopathy using optical coherence tomography images

Macular edema (ME) and central serous retinopathy (CSR) are two macular diseases that affect the central vision of a person if they are left untreated. Optical coherence tomography (OCT) imaging is the latest eye examination technique that shows a cross-sectional region of the retinal layers and that can be used to detect many retinal disorders in an early stage. Many researchers have done clinical studies on ME and CSR and reported significant findings in macular OCT scans. However, this paper proposes an automated method for the classification of ME and CSR from OCT images using a support vector machine (SVM) classifier. Five distinct features (three based on the thickness profiles of the sub-retinal layers and two based on cyst fluids within the sub-retinal layers) are extracted from 30 labeled images (10 ME, 10 CSR, and 10 healthy), and SVM is trained on these. We applied our proposed algorithm on 90 time-domain OCT (TD-OCT) images (30 ME, 30 CSR, 30 healthy) of 73 patients. Our algorithm correctly classified 88 out of 90 subjects with accuracy, sensitivity, and specificity of 97.77%, 100%, and 93.33%, respectively.

Automated segmentation of subretinal layers for the detection of macular edema

Macular edema (ME) is considered as one of the major indications of proliferative diabetic retinopathy and it is commonly caused due to diabetes. ME causes retinal swelling due to the accumulation of protein deposits within subretinal layers. Optical coherence tomography (OCT) imaging provides an early detection of ME by showing the cross-sectional view of macular pathology. Many researchers have worked on automated identification of macular edema from fundus images, but this paper proposes a fully automated method for extracting and analyzing subretinal layers from OCT images using coherent tensors. These subretinal layers are then used to predict ME from candidate images using a support vector machine (SVM) classifier. A total of 71 OCT images of 64 patients are collected locally in which 15 persons have ME and 49 persons are healthy. Our proposed system has an overall accuracy of 97.78% in correctly classifying ME patients and healthy persons. We have also tested our proposed implementation on spectral domain OCT (SD-OCT) images of the Duke dataset consisting of 109 images from 10 patients and it correctly classified all healthy and ME images in the dataset.

The impact of HLA class I and EBV latency-II antigen-specific CD8(+) T cells on the pathogenesis of EBV(+) Hodgkin lymphoma

In 40% of cases of classical Hodgkin lymphoma (cHL), Epstein–Barr virus (EBV) latency‐II antigens [EBV nuclear antigen 1 (EBNA1)/latent membrane protein (LMP)1/LMP2A] are present (EBV⁺cHL) in the malignant cells and antigen presentation is intact. Previous studies have shown consistently that HLA‐A*02 is protective in EBV⁺cHL, yet its role in disease pathogenesis is unknown. To explore the basis for this observation, gene expression was assessed in 33 cHL nodes. Interestingly, CD8 and LMP2A expression were correlated strongly and, for a given LMP2A level, CD8 was elevated markedly in HLA‐A*02^–versus HLA‐A*02⁺ EBV⁺cHL patients, suggesting that LMP2A‐specific CD8⁺ T cell anti‐tumoral immunity may be relatively ineffective in HLA‐A*02^– EBV⁺cHL. To ascertain the impact of HLA class I on EBV latency antigen‐specific immunodominance, we used a stepwise functional T cell approach. In newly diagnosed EBV⁺cHL, the magnitude of ex‐vivo LMP1/2A‐specific CD8⁺ T cell responses was elevated in HLA‐A*02⁺ patients. Furthermore, in a controlled in‐vitro assay, LMP2A‐specific CD8⁺ T cells from healthy HLA‐A*02 heterozygotes expanded to a greater extent with HLA‐A*02‐restricted compared to non‐HLA‐A*02‐restricted cell lines. In an extensive analysis of HLA class I‐restricted immunity, immunodominant EBNA3A/3B/3C‐specific CD8⁺ T cell responses were stimulated by numerous HLA class I molecules, whereas the subdominant LMP1/2A‐specific responses were confined largely to HLA‐A*02. Our results demonstrate that HLA‐A*02 mediates a modest, but none the less stronger, EBV‐specific CD8⁺ T cell response than non‐HLA‐A*02 alleles, an effect confined to EBV latency‐II antigens. Thus, the protective effect of HLA‐A*02 against EBV⁺cHL is not a surrogate association, but reflects the impact of HLA class I on EBV latency‐II antigen‐specific CD8⁺ T cell hierarchies.

Assessment of metal artefact reduction around dental titanium implants in cone beam CT

OBJECTIVES

The aim of this study was to investigate if the metal artefact reduction (MAR) tool used in the software of the ORTHOPANTOMOGRAPH(®) OP300 (Instrumentarium Dental, Tuusula, Finland) can improve the gray value levels in post-operative implant scans.

METHODS

20 potential implant sites were selected from 5 edentulous human dry mandibles. Each mandible was scanned by a CBCT scanner, and images were produced under three different conditions: implant sites drilled but no implants inserted, implants inserted without application of MAR and implants inserted with application of MAR. Using Geomagic(®) Studio 2012 (Geomagic, Morrisville, NC) and 3Diagnosys(®) v. 5.3.1 (3Diemme(®) SRL, Cantù, Italy) software, three scans of each mandible were superimposed. The mean gray value of identical regions of bone around the implants was derived for each condition. The differences between gray value measurements at implant sites derived from different conditions were assessed.

RESULTS

A significant difference was found between mean gray values from the scans with no implants inserted and with implants inserted (with and without MAR) (p = 0.012). No significant difference was revealed for gray values measured from scans with and without MAR (p = 0.975).

CONCLUSIONS

The MAR tool in the software of the ORTHOPANTOMOGRAPH OP300 CBCT scanner does not significantly correct the voxel gray values affected by the metal artefact in the vicinity of an implant in human dry mandibles.

Influence of object location in different FOVs on trabecular bone microstructure measurements of human mandible: a cone beam CT study

The aim of this study was to assess the influence of different object locations in different fields of view (FOVs) of two cone beam CT (CBCT) systems on trabecular bone microstructure measurements of a human mandible. A block of dry human mandible was scanned at five different locations (centre, left, right, anterior and posterior) using five different FOVs of two CBCT systems (NewTom™ 5G; QR Verona, Verona, Italy and Accuitomo 170; Morita, Kyoto, Japan). Image analysis software (CTAn software v. 1.1; SkyScan, Kontich, Belgium) was used to assess the trabecular bone microstructural parameters (thickness, Tb.Th; spacing, Tb.Sp; number, Tb.N; bone volume density, BV/TV). All measurements were taken twice by one trained observer. Tb.Th, Tb.Sp and Tb.N varied significantly across different FOVs in the NewTom 5G (p < 0.001) and the Accuitomo 170 (p < 0.001). For location, a significant difference was observed only when measuring BV/TV (p = 0.03) using the NewTom 5G. The trabecular bone microstructural measurements obtained from CBCT systems are influenced by the size of FOVs. Not all trabecular bone parameters measured using different CBCT systems are affected when varying the object location within the FOVs.

The effect of scan parameters on cone beam CT trabecular bone microstructural measurements of the human mandible

The objective of this study was to investigate the effect of different cone beam CT scan parameters on trabecular bone microstructure measurements. A human mandibular cadaver was scanned using a cone beam CT (3D Accuitomo 170; J.Morita, Kyota, Japan). 20 cone beam CT images were obtained using 5 different fields of view (4×4 cm, 6×6 cm, 8×8 cm, 10×10 cm and 10×5 cm), 2 types of rotation steps (180° and 360°) and 2 scanning resolutions (standard and high). Image analysis software was used to assess the trabecular bone microstructural parameters (number, thickness and spacing). All parameters were measured twice by one trained observer. Intraclass correlation coefficients showed high intraobserver repeatability (intraclass correlation coefficient, 0.95-0.97) in all parameters across all tested scan parameters. Trabecular bone microstructural measurements varied significantly, especially in smaller fields of view (p = 0.001). There was no significant difference in the trabecular parameters when using different resolutions (number, p = 0.988; thickness, p = 0.960; spacing, p = 0.831) and rotation steps (number, p = 1.000; thickness, p = 0.954; spacing, p = 0.759). The scan field of view significantly influences the trabecular bone microstructure measurements. Rotation steps (180° or 360°) and resolution (standard or high) selections are not relevant.

Diagnostic imaging of trabecular bone microstructure for oral implants: a literature review

Several dental implant studies have reported that radiographic evaluation of bone quality can aid in reducing implant failure. Bone quality is assessed in terms of its quantity, density, trabecular characteristics and cells. Current imaging modalities vary widely in their efficiency in assessing trabecular structures, especially in a clinical setting. Most are very costly, require an extensive scanning procedure coupled with a high radiation dose and are only partially suitable for patient use. This review examines the current literature regarding diagnostic imaging assessment of trabecular microstructure prior to oral implant placement and suggests cone beam CT as a method of choice for evaluating trabecular bone microstructure.

The effect of scan parameters on cone beam CT trabecular bone microstructural measurements of human mandible

The objective of this study was to investigate the effect of different cone beam CT scan parameters on trabecular bone microstructure measurements. A human mandibular cadaver was scanned using a cone beam CT (3D Accuitomo 170; J.Morita, Kyota, Japan). 20 cone beam CT images were obtained using 5 different fields of view (4×4 cm, 6×6 cm, 8×8 cm, 10×10 cm and 10×5 cm), 2 types of rotation steps (180° and 360°) and 2 scanning resolutions (standard and high). Image analysis software was used to assess the trabecular bone microstructural parameters (number, thickness and spacing). All parameters were measured twice by one trained observer. Intraclass correlation coefficients showed high intraobserver repeatability (intraclass correlation coefficient, 0.95–0.97) in all parameters across all tested scan parameters. Trabecular bone microstructural measurements varied significantly, especially in smaller fields of view (p = 0.001). There was no significant difference in the trabecular parameters when using different resolutions (number, p = 0.988; thickness, p = 0.960; spacing, p = 0.831) and rotation steps (number, p = 1.000; thickness, p = 0.954; spacing, p = 0.759). The scan field of view significantly influences the trabecular bone microstructure measurements. Rotation steps (180° or 360°) and resolution (standard or high) selections are not relevant.

Influence of cone beam CT scanning parameters on grey value measurements at an implant site

OBJECTIVES

The aim of this study was to determine the grey value variation at the implant site with different scan settings, including field of view (FOV), spatial resolution, number of projections, exposure time and dose selections in two cone beam CT (CBCT) systems and to compare the results with those obtained from a multislice CT system.

METHODS

A partially edentulous human mandibular cadaver was scanned by three CT modalities: multislice CT (MSCT) (Philips, Best, the Netherlands), and two CBCT systems: (Accuitomo 170(®), Morita, Japan) and (NewTom 5G(®), QR, Verona, Italy). Using different scan settings 36 and 24 scans were obtained from the Accuitomo and the NewTom, respectively. The scans were converted to digital imaging and communications in medicine 3 format. The analysis of the data was performed using 3Diagnosys(®) software (v. 3.1, 3diemme, Cantù, Italy) and Geomagic studio(®) 2012 (Morrisville, NC). On the MSCT scan, one probe designating the site for pre-operative implant placement was inserted. The inserted probe on MSCT was transformed to the same region on each CBCT scan using a volume-based three-dimensional registration algorithm. The mean voxel grey value of the region around the probe was derived separately for each CBCT. The influence of scanning parameters on the measured mean voxel grey values was assessed.

RESULTS

Grey values in both CBCT systems significantly deviated from Hounsfield unit values measured with MSCT (p = 0.0001). In both CBCT systems, scan FOV and spatial resolution selections had a statistically significant influence on grey value measurements (p = 0.0001). The number of projections selection had a statistically significant influence in the Accuitomo system (p = 0.0001) while exposure time and dose selections had no statistically significant influence on grey value measurements in the NewTom (p = 0.43 and p = 0.37, respectively).

CONCLUSIONS

Grey-level values from CBCT images are influenced by device and scanning settings.

P2X7 receptor gene polymorphism analysis in rheumatoid arthritis

The P2X7 receptor, a member of the P2X family of nucleotide-gated channels, is predominantly expressed by monocytic cells. The activation of this receptor has been associated with downstream-signalling cascades, resulting in the release of a number of inflammatory mediators. There are more than 815 single nucleotide polymorphisms (SNPs) that have been described in the human P2X7R gene, but only few have been functionally characterized. The main aim of this study is to determine whether P2X7R gene polymorphisms confer susceptibility to rheumatoid arthritis (RA). A total of 125 patients with RA and 158 healthy volunteers were enrolled in this study. DNA fragment was PCR amplified and sequenced on the AB 3130 Genetic Analyzer. No significant difference in allele frequencies of 489 C→T, 1096 C→G and 1513 A→C polymorphisms, among sporadic cases of RA and healthy controls was found. However, the 1513A/C genotype was significantly associated with the presence of rheumatoid factor and anti-MCV autoantibody in RA patients. Interestingly, the genotype frequency of 1068 A/A was 0.19 in the RA group and 0.09 in control group (P = 0.025). Consequently, this polymorphism (AA) is two folds greater in the RA group compared to controls. Moreover, this polymorphism was significantly associated with mean concentration of C-reactive protein in RA patients. In contrast, 946G→A and 1729 T→A were not detected in both groups. As a result, these two polymorphisms are uncommon in Omani Arab population. Polymorphism at position 1068 and 1513 in the P2X7R gene might contribute to the pathogenesis of RA. Moreover, the loss-of-function SNP at position 1096 C→G or the gain-of-function SNP at position 489 C→T of the P2X7 gene does not appear to be a susceptibility gene locus for the development of RA. Further studies are required to confirm this finding.

Phase II trial of combretastatin A4 phosphate, carboplatin, and paclitaxel in patients with platinum-resistant ovarian cancer

BACKGROUND

A previous dose-escalation trial of the vascular disrupting agent combretastatin A4 phosphate (CA4P) given before carboplatin, paclitaxel, or both showed responses in 7 of 18 patients with relapsed ovarian cancer.

PATIENTS AND METHODS

Patients with ovarian cancer that had relapsed and who could start trial therapy within 6 months of their last platinum chemotherapy were given CA4P 63 mg/m(2) minimum 18 h before paclitaxel 175 mg/m(2) and carboplatin AUC (area under the concentration curve) 5, repeated every 3 weeks.

RESULTS

Five of the first 18 patients' disease responded, so the study was extended and closed after 44 patients were recruited. Grade ≥2 toxic effects were neutropenia in 75% and thrombocytopenia in 9% of patients (weekly blood counts), tumour pain, fatigue, and neuropathy, with one patient with rapidly reversible ataxia. Hypertension (23% of patients) was controlled by glyceryl trinitrate or prophylactic amlodipine. The response rate by RECIST was 13.5% and by Gynecologic Cancer InterGroup CA 125 criteria 34%.

CONCLUSIONS

The addition of CA4P to paclitaxel and carboplatin is well tolerated and appears to produce a higher response rate in this patient population than if the chemotherapy was given without CA4P. A planned randomised trial will test this hypothesis.

[Treatment of idiopathic facial pain following implant placement]

A 39-year-old woman suffered from chronic a-typicalfacial pain and complaints associated with Post Traumatic Stress Disorder. The pain originated from the surgical removal of a residual tooth root under an oral implant and the stress symptoms were the consequences of the pain. Eventually, these problems had led to dismissalfrom work and family problems. She was unable to attend her dentist for a periodic oral survey due to extreme fear. Pharmacologic treatment, acupuncture, homeopathy and hypnotherapy had not improved her condition. Treatment aimed at coping with the memories of the oral treatment using 'eye movement desensitization and reprocessing' ultimately led to decline of complaints. This case report demonstrates that an oral problem may disrupt a patient's life and how psychotherapy can complete medical treatment.

Combretastatin A-4 phosphate (CA4P) carboplatin and paclitaxel in patients with platinum-resistant ovarian cancer: Final phase II trial results

5502

Background: CA4P is a vascular disrupting agent that in pre-clinical models can increase the efficacy of a variety of therapies. A dose escalation trial of CA4P given prior to carboplatin, paclitaxel or both showed the combination was well tolerated and responses were seen in several tumor types including 6/17 with relapsed ovarian cancer. The trial was therefore extended into a phase II trial in patients with platinum resistant ovarian cancer. Methods: Patients with ovarian cancer that had relapsed and could start trial therapy within 6 months of their last platinum chemotherapy were given CA4P 63mg/m2 18–20 hours prior to paclitaxel 175mg/m2 and carboplatin AUC 5 repeated 3 weekly. If > 2 responses were seen in first 18 patients 43 patients were to be treated to confirm response rate>19%. Results: Five of the first 18 patients responded so the study was extended and closed after 44 patients were recruited, with full data available to date on 34. Weekly blood counts have demonstrated grade 3/4 neutropenia in 11 and thrombocytopenia in only 1 patient. Other grade > 2 toxicity seen in > 1 patient was fatigue, nausea / vomiting, pain, alopecia, rapidly reversible ataxia, diarrhoea, neuropathy and was little different to what would be expected with paclitaxel and carboplatin. Hypertension is the commonest CA4P related toxicity and was easily controlled by GTN, then prophylactic amlodipine. Responses according to GCIG criteria, have been seen in 11/34 (32%) patients with an additional unconfirmed PR. Conclusions: The addition of CA4P to paclitaxel and carboplatin is well tolerated and appears to produce a higher response rate in this patient population than if the chemotherapy was given without CA4P. A planned randomised trial will hopefully confirm this.

[Table: see text]

A role for Drosophila SMC4 in the resolution of sister chromatids in mitosis

BACKGROUND

Faithful segregation of the genome during mitosis requires interphase chromatin to be condensed into well-defined chromosomes. Chromosome condensation involves a multiprotein complex known as condensin that associates with chromatin early in prophase. Until now, genetic analysis of SMC subunits of the condensin complex in higher eukaryotic cells has not been performed, and consequently the detailed contribution of different subunits to the formation of mitotic chromosome morphology is poorly understood.

RESULTS

We show that the SMC4 subunit of condensin is encoded by the essential gluon locus in Drosophila. DmSMC4 contains all the conserved domains present in other members of the structural-maintenance-of-chromosomes protein family. DmSMC4 is both nuclear and cytoplasmic during interphase, concentrates on chromatin during prophase, and localizes to the axial chromosome core at metaphase and anaphase. During decondensation in telophase, most of the DmSMC4 leaves the chromosomes. An examination of gluon mutations indicates that SMC4 is required for chromosome condensation and segregation during different developmental stages. A detailed analysis of mitotic chromosome structure in mutant cells indicates that although the longitudinal axis can be shortened normally, sister chromatid resolution is strikingly disrupted. This phenotype then leads to severe chromosome segregation defects, chromosome breakage, and apoptosis.

CONCLUSIONS

Our results demonstrate that SMC4 is critically important for the resolution of sister chromatids during mitosis prior to anaphase onset.

Development of a logically devised line drawing atlas for grading of knee osteoarthritis

OBJECTIVES

To (a) develop an atlas of line drawings for the assessment and grading of narrowing and osteophyte (that is, changes of osteoarthritis) on knee radiographs, and (b) compare the performance of this atlas with that of the standard Osteoarthritis Research Society (OARS) photographic atlas of radiographs.

METHODS

Normal joint space widths (grade 0) for the medial and lateral tibiofemoral and medial and lateral patellofemoral compartments were obtained from a previous community study. Grades 1-3 narrowing in each compartment was calculated separately for men and women, grade 3 being bone on bone, grades 1 and 2 being two thirds and one third the value of grade 0. Maximum osteophyte size (grade 3) for each of eight sites was determined from 715 bilateral knee x ray films obtained in a knee osteoarthritis (OA) hospital clinic; grades 1-2 were calculated as two thirds and one third reductions in the area of grade 3. Drawings for narrowing and osteophyte were presented separately. 50 sets of bilateral knee x ray radiographs (standing, extended anteroposterior; flexed skyline) showing a spectrum of OA grades were scored by three observers, twice using the OARS atlas and twice using the drawn atlas.

RESULTS

Intraobserver and interobserver reproducibility was similar and generally good with both atlases, though varied according to site. All three observers preferred the line drawing atlas for ease and convenience of use. Higher scores for patellofemoral narrowing and lower scores for osteophyte, especially medial femoral osteophyte, were seen using the line drawing atlas, showing that the two atlases are not equivalent instruments.

CONCLUSION

A logically derived line drawing atlas for grading of narrowing and osteophyte at the knee has been produced. The atlas showed comparable reproducibility with the OARS atlas, but was discordant in several aspects of grading. Such a system has several theoretical and practical advantages and should be considered for use in knee OA studies.

Daughterless is required for the expression of cell cycle genes in peripheral nervous system precursors of Drosophila embryos

The function of the neuronal differentiation gene daughterless (da) is required for the proper initiation of neuronal lineage development in all PNS lineages following the selection of neuronal precursor cells. Previous studies have shown that the ubiquitously expressed da protein is required for the proper expression of neuronal precursor genes and lineage identity genes in the PNS of Drosophila melanogaster embryos. These genes are required for differentiation and cell fate determination in the developing PNS. These findings, however, did not explain the failure of the nascent PNS precursors to undergo a normal cell cycle and divide. Here we show that four genes whose products are required for various stages of the cell cycle are misexpressed in the PNS of da mutant embryos. This suggests that all aspects of PNS precursor differentiation examined so far are under the transcriptional control of da.

Ochronotic arthropathy: case report and review of the literature

Alkoptonuria is an inherited metabolic disorder which is associated with various systemic abnormalities and related to the deposition of homogentisic acid pigment in connective tissues. These pigmentary changes are termed "ochronosis". We describe two patients with ochronotic arthropathy who presented with progressive and advanced degenerative changes in the lumbo-sacral spine. The literature, differential diagnosis and management of this rare condition are reviewed in this article. Management is usually conservative, but replacement surgery may be offered for severely affected major joints.

The management of inferior vena cava obstruction complicating metastatic germ cell tumors

BACKGROUND

Inferior vena cava obstruction (IVCO) is a poorly characterized complication of metastatic germ cell tumor (GCT). The authors identified 31 cases to describe the clinical features, radiologic findings, complications, and treatment of this clinical entity.

METHODS

Patients with GCT and IVCO were identified from case records of a GCT database. The records of 333 male patients with metastatic GCT (27% with seminoma and 73% with nonseminomatous GCTs) were screened for either clinical or computed tomography (CT) scan evidence of inferior vena cava compression or involvement.

RESULTS

Thirty-one patients were identified (9.3% of patients with metastatic GCT). Common presenting symptoms were leg swelling and dilated abdominal wall veins. Approximately 29% of patients had thromboembolic complications and there was a single case of fatal pulmonary embolism. Nine patients had no clinical features at presentation but either had CT scan evidence of IVCO or developed symptoms during treatment. Right-sided testicular primary tumors were associated more frequently with IVCO compared with left-sided primary tumors (14% vs. 4% of cases of metastatic GCT, respectively). All patients had an abdominal mass measuring > 5 cm in maximum transverse dimension.

CONCLUSIONS

The authors recommend careful clinical and radiologic evaluation for the presence of IVCO in cases of bulky metastatic GCT. A high index of suspicion must accompany the evaluation of a patient with a right-sided primary testicular tumor and a paracaval abdominal mass measuring > 5 cm in maximum transverse dimension. When IVCO is identified, prophylactic anticoagulation is recommended.

Radiological appearances of lymphomas arising from mucosa-associated lymphoid tissue (MALT) in the lung

We review the radiological findings in 13 patients with histologically proven (n = 10) or clinically diagnosed (n = 3) lymphomas arising in mucosa-associated lymphoid tissue (MALT) of the lung. These rare B-cell lymphomas typically follow an indolent course, and many cases are still being incorrectly described in current radiological literature under the term pseudolymphoma. The patients frequently give a history of autoimmune disease involving the affected organ, and involvement of another mucosal site as part of a disseminated MALT lymphoma, is common. The radiographic patterns of pulmonary parenchymal involvement in lung MALT lymphomas have been reviewed, and correlation made with their clinical behaviour.