Simulation of Al0.85Ga0.15As0.56Sb0.44 avalanche photodiodes.

Al0.85Ga0.15As0.56Sb0.44 is a promising avalanche material for near infrared avalanche photodiodes (APDs) because they exhibit very low excess noise factors. However electric field dependence of ionization coefficients in this material have not been reported. We report a Simple Monte Carlo model for Al0.85Ga0.15As0.56Sb0.44, which was validated using reported experimental results of capacitance-voltage, avalanche multiplication and excess noise factors from five APDs. The model was used to produce effective ionization coefficients and threshold energies between 400-1200 kV.cm-1 at room temperature, which are suitable for use with less complex APD simulation models.

Fabrication of infrared linear arrays of InAs planar avalanche photodiodes.

We report a, to the best of our knowledge, new device fabrication process for 128-pixel linear arrays of InAs planar avalanche photodiodes, utilizing selective area implantation of Beryllium ions into epitaxially-grown InAs wafers. The pixels exhibited uniform avalanche gain and responsivity. Room temperature responsivity values at 1550 and 2004 nm wavelengths are 0.49 ± 0.017 and 0.89 ± 0.024 A/W, respectively. Reverse dark current-voltage and avalanche gain measurements were carried out at different temperatures (from room temperature to 150 K). At 200 K at -15 V reverse bias, the pixels exhibited an avalanche gain of 22.5 ± 1.18 and dark current density of 0.68 ± 0.48 A/cm2.

[Clinical features and prognostic factors of primary gastric neuroendocrine neoplasms].

Objective: To study the clinical characteristics and classification of gastric neuroendocrine neoplasm(NEN) and prognostic factors of mixed adenoneuroendocrine carcinoma (MANEC) and gastric neuroendocrine carcinoma(NEC). Methods: A total of 148 gastric NENs were divided into type Ⅰ, type Ⅱ and type Ⅲ based on the classification of European Neuroendocrine Tumor Society (ENETS). Kaplan-Meier test and Cox regression model were used in univariate and multivariate survival analysis in 108 cases with pathological G3 gastric NEN. Results: In this study, the percentages of type Ⅰ, type Ⅱ and type Ⅲ were 25.0%(37), 3.4%(5) and 71.6%(106) respectively. Among type Ⅰ patients, 28(75.7%) lesions were located in gastric fundus or body, 29(78.4%) had bumps. Lymph node involvement was found in 4 (10.8%) patients. Twenty-six (70.3%) patients received endoscopic treatment and 11 (29.7%) with surgery. All 5 type Ⅱ patients presented lesions in gastric fundus or body, including 4 with ulcers, who were all treated by endoscope. Three type Ⅱ patients had gastrinoma, and 2 combined with multiple endocrine neoplasmⅠ. In type Ⅲ patients, 56(52.8%) showed ulcerative lesions. The majority of patients (102, 96.2%) had a single lesion, 94(88.7%) with lymph node or other organ metastasis. In this study, no deaths were reported in gastric NEN with a pathological grade of G1 or G2. The mortality rate was 38.9%(42/108) in patients with G3 NEN. Survival analysis suggested that age, metastasis of tumor were associated with poor prognosis (P=0.041, 0.025). Conclusions: Patients with gastric NEN have heterogenous clinical presentations according to gender, age, endoscopic features, infiltration and metastasis, and pathological grade. Aging and metastasis are negative prognostic factors of G3 gastric NEN.

Mesoscopic Energy Minimization Drives Pseudomonas aeruginosa Biofilm Morphologies and Consequent Stratification of Antibiotic Activity Based on Cell Metabolism.

Segregation of bacteria based on their metabolic activities in biofilms plays an important role in the development of antibiotic resistance. Mushroom-shaped biofilm structures, which are reported for many bacteria, exhibit topographically varying levels of multiple drug resistance from the cap of the mushroom to its stalk. Understanding the dynamics behind the formation of such structures can aid in design of drug delivery systems, antibiotics, or physical systems for removal of biofilms. We explored the development of metabolically heterogeneous Pseudomonas aeruginosa biofilms using numerical models and laboratory knockout experiments on wild-type and chemotaxis-deficient mutants. We show that chemotactic processes dominate the transformation of slender and hemispherical structures into mushroom structures with a signature cap. Cellular Potts model simulation and experimental data provide evidence that accelerated movement of bacteria along the periphery of the biofilm, due to nutrient cues, results in the formation of mushroom structures and bacterial segregation. Multidrug resistance of bacteria is one of the most threatening dangers to public health. Understanding the mechanisms of the development of mushroom-shaped biofilms helps to identify the multidrug-resistant regions. We decoded the dynamics of the structural evolution of bacterial biofilms and the physics behind the formation of biofilm structures as well as the biological triggers that produce them. Combining in vitro gene knockout experiments with in silico models showed that chemotactic motility is one of the main driving forces for the formation of stalks and caps. Our results provide physicists and biologists with a new perspective on biofilm removal and eradication strategies.

Predicting early recurrence of hepatocellular carcinoma with texture analysis of preoperative MRI: a radiomics study.

AIM: To investigate the feasibility of using texture analysis in preoperative magnetic resonance imaging (MRI) to predict early recurrence (ER) in hepatocellular carcinoma (HCC) post-curative surgery. MATERIAL AND METHODS: Institutional review board was obtained. A retrospective review of all patients who underwent hepatectomy between 1 January 2007 and 31 December 2015 was performed. Inclusion criteria included preoperative MRI, tumour size ≥1 cm, new cases of HCC. Exclusion criteria included loss to follow-up, ruptured HCCs, movement artefacts, and previous hepatectomy or interval adjuvant therapy. Patients were divided into ER and late or no recurrence (LNR) groups. ER was defined as new foci of HCC within 730 days of curative surgery. Radiomics feature extraction was performed on T2, diffusion-weighted imaging (DWI), T1 arterial, and T1 portovenous acquisitions on MATLAB (Mathworks, Matick, MA, USA). The MaZda software was used to analyse 290 texture parameters and PRTools was used for feature selection. RESULTS: Fifty patients (43 male, mean age 67 years) were divided into ER (n=20) and LNR (n=30) groups. Serum alpha-fetoprotein level (p=0.026), serum É£-glutamyltranspeptidase (p=0.014), Child-Pugh score (p=0.02) and the presence of vascular invasion (gross and/or microvascular, p=0.025) were found to be statistically significant different between the two groups. Parameters S(4,0)SumVarnc, S(0,3)SumOfSqs, and S(1,1)DifVarnc of the equilibrium phase were most accurate, achieving 84%, 82%, and 78% accuracy, respectively. CONCLUSION: Texture analysis of preoperative MRI has the potential to predict ER of HCC with up to 84% accuracy using an appropriate, single texture analysis parameter. Future studies are needed to validate these findings.

Validity of estimating muscle and fat volume from a single MRI section in older adults with sarcopenia and sarcopenic obesity.

AIM: To determine if there is a correlation between the cross-sectional areas (CSAs) in a single section and the volumes of muscles and fat in the thigh of sarcopenic and sarcopenic obesity (SO) populations using magnetic resonance imaging (MRI), and to assess the correlation between thigh MRI data and patient health status, i.e., normal, obese, sarcopenia, and SO. MATERIALS AND METHODS: One hundred and ninety community-dwelling older adults were recruited and categorised into four subgroups based on Asian established criteria: normal, obese, sarcopenia, and SO. MRI images were acquired and muscles, subcutaneous fat (SF), and intermuscular fat (IMF) were automatically segmented in the thighs. Volumes of muscles and fat were calculated for the middle third of the thigh, while CSAs were assessed using a single section at 50% femur length. RESULTS: Correlation between CSA and volume were significantly high (p<0.001) for all components of muscle (0.907), SF (0.963), and IMF (0.939). Thigh CSA and volume both correlated significantly with a clinical diagnosis of normal, obesity, sarcopenia, and SO (p<0.03). CONCLUSIONS: A single CSA at 50% of femur length yields good estimation of muscle and fat volume in the thighs of older adults and correlates closely with the clinical criteria for sarcopenia and SO. This has the potential to greatly reduce costs, scan time, and post-processing time in clinical practice for the prediction of these conditions.

Doxycycline-induced hypoglycaemia.

Tetracyclines, including doxycycline, are widely used drugs that form an integral part of daily prescribing, and serious adverse reactions (SARs) are rarely reported. The frequency of hypoglycaemia complicating tetracycline treatment remains unknown, and is not a recognized complication. We describe an 80-year-old man with a history of insulin-dependent diabetes who was recruited into a large research study, and subsequently experienced the unexpected SAR of hypoglycaemia following treatment with doxycycline.

Water as neutral oral contrast agent in abdominopelvic CT: comparing effectiveness with Gastrografin in the same patient.

INTRODUCTION: Positive oral contrast is no longer deemed necessary for abdominopelvic computed tomography (CT) scans. Studies have shown water to be an equally effective oral contrast agent. However, to our knowledge no study has compared effectiveness between gastrografin and water in the same patient, which will provide a more objective evaluation of the two oral contrast agents. We aim to make a head-to-head comparison of water as neutral oral contrast (OC) against gastrografin as positive OC for abdominopelvic CT scans in the same patient. METHODS: A retrospective review of 206 abdominopelvic CT scans of 103 patients was performed. The scans were reviewed in consensus by two blinded radiologists. The ability to visualise each abdominopelvic organ, contrastassociated artefacts and small bowel wall delineation, was qualitatively scored on a 5-point scale. Each patient had two sets of scores, one with water and another with gastrografin as OC. Paired scores from the two OCs were evaluated by Wilcoxon signed rank test to determine any significant difference in performance between the two OCs for visualisation of abdominopelvic anatomy on CT. RESULTS: There was significantly better delineation of duodenal wall (p<0.001) and overall visualisation of the duodenum (p=0.011) using water as OC compared to gastrografin. No statistically significant differences were demonstrated between water and gastrografin for visualisation of the rest of the abdominopelvic organs, walldelineation of the rest small bowel and contrast-associated artefacts. CONCLUSIONS: Water can be used in place of gastrografin as oral contrast in abdominopelvic CT without compromising visualization of abdominopelvic organs.

Emergency computed tomography for acute pelvic trauma: where is the bleeder?

Contrast medium extravasation at computed tomography (CT) is an accurate indicator of active haemorrhage in pelvic trauma. When this is present, potentially lifesaving surgical or endovascular treatment should be considered. Identification of the site or territory of haemorrhage is helpful for the interventional radiologist as it allows for focused angiographic evaluation and expedites haemostatic angio-embolisation. Even with thin-section arterial phase CT, tracing the bleeding vessel is not always possible and is often time consuming. We introduce a technique for predicting the bleeding vessel based on knowledge of the cross-sectional anatomical territory of the vessel as an alternative to tracing the vessel's course. Several case examples with digital subtraction angiography (DSA) correlation will be provided.

CT volumetry of the liver: where does it stand in clinical practice?

Imaging-based volumetry has been increasingly utilised in current clinical practice to obtain accurate measurements of the liver volume. This is particularly useful prior to major hepatic resection and living donor liver transplantation where the size of the remnant liver and liver graft, respectively, affects procedural success and postoperative mortality and morbidity. The use of imaging-based volumetry, with emphasis on computed tomography, will be reviewed. We will explore the various technical factors that contribute to accurate volumetric measurements, and demonstrate how the accuracies of these techniques are influenced by their methodologies. The strengths and limitations of using anatomical imaging to estimate liver volume will be discussed, in relation to laboratory and functional imaging methods of assessment.

Pancreatic cystic lesions and guidelines: a review.

No abstract available.

Cognitive frailty in older adults: examining the impact of frailty criteria on neuropsychological profile, functional outcomes, activity levels, and quality of life.

PURPOSE: Cognitive frailty (CF) is the co-existence of cognitive impairment and physical frailty without dementia, conferring greater risks of adverse clinical outcomes compared to either condition alone. However, the impact of physical frailty components on cognitive performance remains unclear. This study aims to evaluate CF by determining the neuropsychological profiles, functional outcomes, activity levels, and quality of life across the Fried Frailty Phenotype (FFP) and its components. METHODS: Cross-sectional study involving 120 community-dwelling older adults without dementia, but with subjective cognitive complaints (SCC, defined as AD8 ≥ 1). Participants were stratified into three groups to assess CF: SCC-Robust, SCC-Prefrail, and SCC-Frail, and further categorized by individual FFP components. Cognitive performance was assessed by comparing neuropsychological test battery (NTB) Z-scores between CF and non-CF groups with Cohen's d for effect sizes. We performed linear regression to examine the relationships between both groups with NTB scores, Instrumental Activities of Daily Living (IADL), Frenchay Activities Index (FAI), and quality of life scores. RESULTS: NTB scores showed no differences between individuals with CF when classified according to FFP criteria. Individuals with SCC-slow gait speed exhibited reduced processing speed (d = 0.62) and memory (d = 0.61); SCC-fatigue was associated with decreased working memory (d = 0.55). Regression analyses, adjusted for demographic and clinical variables, identified significant associations: slow gait speed with logical memory (- 0.42; 95% CI - 0.79 to - 0.038]) and symbol search (- 0.28; 95% CI - 0.56 to - 0.006]); fatigue with digit span backwards (- 0.66; 95% CI - 1.19 to - 0.14) and color trails 2 (- 0.67; 95% CI, - 1.15 to - 0.20). SCC-slow gait speed and SCC-fatigue were associated with reduced quality of life scores, but not with IADL and FAI scores. CONCLUSION: Specific frailty components, notably slow gait speed and fatigue, influence cognitive function and quality of life. Our findings provide greater insights into characterizing CF. Further longitudinal studies are required to determine the cognitive and functional trajectories of CF.

Age-related genes affecting the immune cell infiltration in ulcerative colitis revealed by weighted correlation network analysis and machine learning.

OBJECTIVE: The crosstalk between age and immunity in the context of ulcerative colitis (UC) remains incompletely understood. Our objective is to elucidate the specific age-associated genetic factors that modulate immune cell infiltration in UC, with the aim of identifying innovative therapeutic targets for the treatment of this disease. MATERIALS AND METHODS: Potential batch effects between samples were removed by R package "inSilicoMerging". Unsupervised clustering analysis via the "ConsensusClusterPlus" R package was utilized to perform consensus molecular subtyping of immune subtypes in UC. The construction of a heat map was accomplished through the utilization of the R package "pheatmap", while functional enrichment analysis was executed by means of the Metascape database. The identification of the age-related gene module was achieved by performing weighted gene co-expression network analysis (WGCNA) analysis using the R package "WGCNA". The support vector machine (SVM), least absolute shrinkage and selector operation (LASSO), and random forest algorithms were performed via the "e1071", "glmnet" and "randomForest" packages in R, respectively. The diagnostic performance of the parameter was assessed using the receiver operating characteristic (ROC) curve. Correlation analysis was performed by Spearman correlation. The "XSum" package in R was employed to identify potential small-molecule drugs for UC utilizing the Connectivity Map (CMap) database. Molecular docking was performed with Autodock Vina molecular docking software. RESULTS: A significantly greater frequency of UC patients aged below 40 years was observed in the group with extensive disease extent as compared to those with non-extensive disease extent (70% vs. 47%; Chi-square test, p = 0.02). The application of unsupervised clustering analysis allowed for the stratification of UC patients into two distinct immune subtypes, namely cluster C1 and cluster C2. The distribution of immune subtypes was significantly different between different age categories (Chi-square test,  p = 0.00219). The UC samples that were grouped under cluster C1 were distinguished by a higher abundance of macrophages and an elevated number of neutrophils relative to those in cluster C2. Based on both WGCNA and Limma analysis, 146 age-related genes were identified, which exhibited a predominant enrichment in the biological process of cellular senescence. Two age-related genes (MIDN, and PLD6) affecting the immune cell infiltration in UC were identified based on machine learning algorithms (SVM, LASSO, and random forest). The diagnostic performance of MIDN (AUC = 0.93) and PLD6 (AUC = 0.90) in discerning UC patients belonging to cluster C1 was found to be satisfactory, as demonstrated by ROC curve analysis. MIDN demonstrated a positive correlation (r = 0.50,  p < 0.0001) with Neutrophil, while PLD6 exhibited a negative correlation (r = -0.52, p < 0.0001) with Neutrophil levels. The "XSum" algorithm revealed that Entinostat has therapeutic potential for UC. The docking glide score between Entinostat and MIDN, and PLD6 protein was -8.9 kcal/mol and -6.8 kcal/mol, respectively. CONCLUSIONS: We have identified two age-related genes, MIDN and PLD6, that are involved in immune cell infiltration in patients with ulcerative colitis. Furthermore, a small molecule drug (Entinostat) with potential therapeutic effects for UC was screened out. This study presented new perspectives on personalized clinical management and therapy research for UC.

Achieving treat to target in gout: a clinical practice improvement project.

OBJECTIVE: Gout care is suboptimal because of lack of translation of knowledge into real-world practice, despite evidence-based guidelines. We have developed processes to ensure systematic care for gout patients and determined the predictors for achievement of a target serum uric acid (SUA) concentration of < 360 µmol/L in a prospective cohort of Asian gout patients requiring allopurinol therapy. METHODS: A 1-year clinical practice improvement project was undertaken using evidence-based guidelines and quality planning tools. Interventions included comprehensive patient education, enhanced telephone access, reappointments and refills, upward titration of allopurinol with no limitation specified by renal function, and increased frequency of visits until the target SUA concentration was achieved. The primary outcome was the time to achieve an SUA level of <360 µmol/L. RESULTS: We recruited 126 gout patients. The median time to achieving the target SUA concentration was 36.9 weeks [95% confidence interval (CI) 29.3-44.4]. Based on survival analysis, the proportion of patients achieving the target was 8.1% (95% CI 3.2-13.0), 40.6% (95% CI 31.4-50.8), and 72.0% (95% CI 61.2-82.8) at 3, 6, and 12 months, respectively. On average, our patients who achieved the target were seen once every 2 months and achieved the target after a mean of 2.5 (SD = 1.1) visits. Frequency of follow-up visits and older patients not taking aspirin were independent predictors associated with achieving the target outcome, regardless of renal function. CONCLUSIONS: Optimization of control of SUA is achievable, even in the setting of renal impairment, by redesigning and implementing processes involving changes in physician prescribing habits, enhanced nursing interventions, and patient empowerment and education.

Diffusion-weighted MRI of adult male pelvic cancers.

Magnetic resonance imaging (MRI), with its superior soft-tissue delineation, plays a pivotal role in the staging and surveillance of cancers affecting adult males, in particular, rectal, urinary bladder, and prostate cancers. There has been much recent interest in the complementary roles of diffusion-weighted imaging (DWI) for imaging of pelvic cancers. DWI measures the diffusivity of water molecules in biological tissue. Cancer, with its high cellular density and nuclear:cytoplasmic ratio, and extracellular disorganization, typically shows significant restricted diffusivity compared with surrounding normal tissue. In theory, diffusivity of water molecules may vary according to degree of tumour aggressiveness and changes in cell density and extracellular fluid content after treatment. Information regarding these variations may be used to study the histological grades of cancers and their response to treatment. In this article, we present the currently available evidence on the potential roles of DWI for the assessment of pelvic cancers in men, and demonstrate with imaging examples how this knowledge may be applied to daily clinical practice.

Adjunctive mood stabilizer and benzodiazepine use in older Asian patients with schizophrenia, 2001-2009.

OBJECTIVE: This study surveyed the use of adjunctive mood stabilizers (MS) and benzodiazepines (BZD) in older Asian schizophrenia patients and examined their demographic and clinical correlates. METHOD: Information on hospitalized schizophrenia patients aged 55 years or more were extracted from the database of the Research on Asian Psychotropic Prescription Patterns (REAP) study. A total of 1,452 patients from 9 Asian countries and territories was included in the study. The patients' sociodemographic and clinical characteristics and the prescriptions of antipsychotics, MS and BZD were recorded using a standardized protocol and data collection procedure. RESULTS: The frequency of MS prescription was 26.7% in the pooled sample, with 25.5% in 2001, 26.9% in 2004 and 27.7% in 2009. The corresponding figures for BZD were 20.7%, 20.2%, 18.4% and 23.1%, respectively. Multiple logistic regression analysis of the whole sample revealed that patients on MS were younger and more likely to be men and to have extrapyramidal side effects (EPS) and a longer duration of illness. Compared to patients in China, those in Japan were more likely to receive MS, while Korean patents were prescribed less MS. In contrast, there were no significant sociodemographic or clinical correlates of BZD use. Compared to patients in China, their Korean and Singaporean counterparts were more likely to be on BZD. CONCLUSIONS: The use of MS and BZD is not uncommon in older Asian patients with schizophrenia. Given the paucity of empirical data on the efficacy of these agents in individuals with schizophrenia of any age and concerns about added side effects in older patients in particular, the rationale for the prescription of these agents in this population warrants further examination.

Antipsychotic polypharmacy in inpatients with schizophrenia in Asia (2001-2009).

OBJECTIVE: This study aimed to identify trends in the use of antipsychotic polypharmacy (APP) and their demographic and clinical correlates in the treatment of schizophrenia in Asia between 2001 and 2009. METHOD: A total of 6,761 schizophrenia inpatients in 9 Asian countries and territories were examined; 2,399 in 2001, 2,136 in 2004, and 2,226 in 2009. Patients' socio-demographic and clinical characteristics and prescriptions of psychotropic drugs were recorded using a standardized protocol and data collection procedure. RESULTS: The proportion of APP prescription decreased from 46.8 % in 2001, to 38.3 % in 2004, and increased to 43.4 % in 2009, with wide intercountry variations at each survey. Multiple logistic regression analysis of the whole sample revealed that patients on APP were younger, had a higher dose of antipsychotics in chlorpromazine equivalents, and more severe positive and negative symptoms. They were also more likely to receive depot and fi rst-generation antipsychotic drugs. CONCLUSIONS: The frequency of APP prescription varied between countries and territories, suggesting that a host of clinical and socio-cultural factors played a role in determining APP use in Asia. To resolve the discrepancy between treatment recommendation and clinical practice, regular reviews of prescription patterns are needed.

Acute renal failure and posterior reversible encephalopathy syndrome following multiple wasp stings: a case report.

Wasp stings can present in various ways, ranging from mild self-limiting illness to severe multi organ failure with a potentially fatal outcome. We report a case of multiple wasp stings leading to acute renal failure needing prolonged dialysis support and posterior reversible encephalopathy syndrome.