Defining the Science of Learning: A scoping review.

BACKGROUND: Interest in research on the Science of Learning continues to grow. However, ambiguity about what this field is can negatively impact communication and collaboration and may inadequately inform educational training programs or funding initiatives that are not sufficiently inclusive in focus. METHODS: The present scoping review aimed to synthesize a working definition of the Science of Learning using Web of Science and ProQuest database searches. RESULTS: In total, 43 unique definitions were identified across 50 documents including journal articles, theses, conference papers, and book chapters. Definitions of the Science of Learning differed considerably when describing the fields thought to contribute to research on this topic. CONCLUSIONS: Based on findings, we propose a working definition of the Science of Learning for discussion and further refinement: the scientific study of the underlying bases of learning with the goal of describing, understanding, or improving learning across developmental stages and diverse contexts.

Evaluating Quality-of-Life, Length of Stay and Cost-Effectiveness of a Front-Door Geriatrics Program: An Exploratory Proof-of-Concept Study.

BACKGROUND: The Emergency Department Interventions for Frailty (EDIFY) program was developed to deliver early geriatric specialist interventions at the Emergency Department (ED). EDIFY has been successful in reducing acute admissions among older adults. OBJECTIVES: We aimed to examine the effectiveness of EDIFY in improving health-related quality-of-life (HRQOL) and length of stay (LOS), and evaluate EDIFY's cost-effectiveness. DESIGN: A quasi-experiment study. SETTING: The ED of a 1700-bed tertiary hospital. PARTICIPANTS: Patients (≥85 years) pending acute hospital admission and screened by the EDIFY team to be potentially suitable for discharge or transfer to low-acuity care areas. INTERVENTION: EDIFY versus standard-care. MEASUREMENTS: Data on demographics, comorbidities, premorbid function, and frailty status were gathered. HRQOL was measured using EQ-5D-5L over 6 months. We used a crosswalk methodology to compute Singapore-specific index scores from EQ-5D-5L responses and calculated quality-adjusted life-years (QALYs) gained. LOS and bills in Singapore-dollars (SGD) before subsidy from ED attendances (including admissions, if applicable) were obtained. We estimated average programmatic EDIFY cost and performed multiple imputation (MI) for missing data. QALYs gained, LOS and cost were compared. Potential uncertainties were also examined. RESULTS: Among 100 participants (EDIFY=43; standard-care=57), 61 provided complete data. For complete cases, there were significant QALYs gained at 3-month (coefficient=0.032, p=0.004) and overall (coefficient=0.096, p=0.002) for EDIFY, whilst treatment cost was similar between-groups. For MI, we observed only overall QALYs gained for EDIFY (coefficient=0.102, p=0.001). EDIFY reduced LOS by 17% (Incident risk ratio=0.83, p=0.015). In a deterministic sensitivity analysis, EDIFY's cost-threshold was SGD$2,500, and main conclusions were consistent in other uncertainty scenarios. Mean bills were: EDIFY=SGD$4562.70; standard-care=SGD$5530.90. EDIFY's average programmatic cost approximated SGD$469.30. CONCLUSIONS: This exploratory proof-of-concept study found that EDIFY benefits QALYs and LOS, with equivalent cost, and is potentially cost-effective. The program has now been established as standard-care for older adults attending the ED at our center.

A case report of refractory kawasaki disease.

Kawasaki disease is an autoimmune disease that commonly affects children below the age of 5 years. It is a vasculitic disease of unknown aetiology effecting the skin, eyes, lymph nodes and mucosal layer. Intravenous Immunoglobulin (IVIG) and aspirin therapy are the mainstay treatment however a number of cases have been shown to be refractory to this treatment. Evidence regarding approach and treatment for such cases is limited. This case report is to share our experience in the management of Refractive Kawasaki disease at a district level.

A systematic review and meta-analysis of workplace intervention strategies to reduce sedentary time in white-collar workers.

Prolonged sedentary behaviour has been associated with various detrimental health risks. Workplace sitting is particularly important, providing it occupies majority of total daily sedentary behaviour among desk-based employees. The aim of this systematic review and meta-analysis was to examine the effectiveness of workplace interventions overall, and according to different intervention strategies (educational/behavioural, environmental and multi-component interventions) for reducing sitting among white-collar working adults. Articles published through December 2015 were identified in five online databases and manual searches. Twenty-six controlled intervention studies published between 2003 and 2015 of 4568 working adults were included. All 26 studies were presented qualitatively, and 21 studies with a control group without any intervention were included in the meta-analysis. The pooled intervention effect showed a significant workplace sitting reduction of -39.6 min/8-h workday (95% confidence interval [CI]: -51.7, -27.5), favouring the intervention group. Multi-component interventions reported the greatest workplace sitting reduction (-88.8 min/8-h workday; 95% CI: -132.7, -44.9), followed by environmental (-72.8 min/8-h workday; 95% CI: -104.9, -40.6) and educational/behavioural strategies -15.5 min/8-h workday (95% CI:-22.9,-8.2). Our study found consistent evidence for intervention effectiveness in reducing workplace sitting, particularly for multi-component and environmental strategies. Methodologically rigorous studies using standardized and objectively determined outcomes are warranted. © 2016 World Obesity.

Influence of menopausal status on diagnostic accuracy of myometrial invasion in endometrial cancer: diffusion-weighted and dynamic contrast-enhanced MRI at 3 T.

AIM: To assess the influence of menopausal status on the diagnostic accuracy of diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) for evaluating myometrial invasion in patients diagnosed with endometrial cancer. MATERIALS AND METHODS: In this prospective study, 91 consecutive female patients diagnosed with endometrial cancer were enrolled for preoperative evaluation using 3 T MRI. Two radiologists interpreted myometrial invasion depth on DW (b=1000 s/mm(2)) and DCE MRI images, with surgical histopathology as the reference standard. Statistical methods included kappa statistics for evaluating reader agreement and diagnostic performance analysis between pre- and postmenopausal groups. RESULTS: Reader agreement of DW MRI was poor (κ=0.20) for premenopausal patients. The diagnostic accuracy of DW MRI in detecting myometrial involvement was significantly lower in premenopausal compared with postmenopausal patients (0.42 versus 0.73, p=0.006). There was no difference in the diagnostic accuracy of DW MRI in detecting deep myometrial invasion between premenopausal and postmenopausal groups (0.94 versus 0.95, p>0.99). CONCLUSION: For premenopausal patients who plan to receive fertility-preserving treatment for endometrial cancer, DCE MRI is superior to DW MRI in excluding any possible myometrial invasion. For preoperative assessment of deep myometrial invasion, DW MRI can be a legitimate alternative to DCE MRI regardless of menopausal status and is particularly beneficial for patients at risk of nephrogenic systemic fibrosis.

Chain of rings: a radiographic sign of papillary thyroid cancer.

Papillary thyroid cancer is the most common form of thyroid malignancy in children and adult with frequent metastases to the cervical lymph nodes. We present a case of metastatic papillary thyroid cancer with remarkable imaging findings of consecutive metastatic calcified lymph nodes resembling a chain of rings. While accompanying by a coarsely calcified thyroid mass, possible thyroid cancer should be considered and serve as a guide to warrant further thyroid cancer evaluation.

Tumefactive acute disseminated encephalomyelitis complicating human swine influenza (H1N1).

This report illustrates an adult patient presenting with tumefactive acute disseminated encephalomyelitis complicating human swine influenza. Its presentation, diagnosis, investigation findings, course, and response to treatment are discussed herein.

Facile gold nanorod purification by fractionated precipitation.

An efficient and facile size- and shape-selective separation of gold nanorod (GNR) solutions is developed using a fractionated precipitation strategy. This convenient method has the benefit of eliminating nanoparticulate side products that can substantially deteriorate the quality of self-assembled nanostructures. The fabrication of advanced plasmonic metamaterials crucially depends on the capacity to supply feedstocks of high-purity building blocks.

Assessment of angiographic vascularity of meningiomas with dynamic susceptibility contrast-enhanced perfusion-weighted imaging and diffusion tensor imaging.

BACKGROUND AND PURPOSE: The roles of DTI and dynamic susceptibility contrast-enhanced-PWI in predicting the angiographic vascularity of meningiomas have not been studied. We aimed to investigate if these 2 techniques could reflect the angiographic vascularity of meningiomas. MATERIALS AND METHODS: Thirty-two consecutive patients with meningiomas who had preoperative dynamic susceptibility contrast-enhanced-PWI, DTI, and conventional angiography were retrospectively included. The correlations between angiographic vascularity of meningiomas, classified with a 4-point grading scale, and the clinical or imaging variables-age and sex of patient, as well as size, CBV, fractional anisotropy, and ADC of meningiomas-were analyzed. The meningiomas were dichotomized into high-vascularity and low-vascularity groups. The differences in clinical and imaging variables between the 2 groups were compared. Receiver operating characteristic curve analysis was used to determine the diagnostic performance of these variables. RESULTS: In meningiomas, angiographic vascularity correlated positively with CBV but negatively with fractional anisotropy. High-vascularity meningiomas demonstrated significantly higher CBV but lower fractional anisotropy as compared with low-vascularity meningiomas. In differentiating between the 2 groups, the area under the curve values were 0.991 for CBV and 0.934 for fractional anisotropy on receiver operating characteristic curve analysis. CONCLUSIONS: CBV and fractional anisotropy correlate well with angiographic vascularity of meningiomas. They may differentiate between low-vascularity and high-vascularity meningiomas.

The first case report of McLeod syndrome in a Chinese patient.

We report the first case of McLeod syndrome (MLS) in a 47-year-old Chinese man who presented with progressive limb weakness, chorea of feet, red blood cell acanthocytosis, absence of Kx red blood cell antigen and weak expression of Kell antigens. The diagnosis of MLS was confirmed by genetic testing showing a hemizygous mutation of XK gene. We review literature on neuroacanthocytosis in the Chinese population.

Cerebral diffusion tensor MR tractography in tuberous sclerosis complex: correlation with neurologic severity and tract-based spatial statistical analysis.

BACKGROUND AND PURPOSE: The neurologic significance of residual cerebral white matter tracts, identified on diffusion tensor tractography, has not been well studied in tuberous sclerosis complex. We aimed to correlate the quantity of reconstructed white matter tracts with the degree of neurologic impairment of subjects with the use of DTI and determined differences in white matter integrity between patients with tuberous sclerosis complex and controls with the use of voxelwise analysis. MATERIALS AND METHODS: In this case-control study, 16 patients with tuberous sclerosis complex and 12 control subjects underwent DTI. Major white matter tracts, comprising bilateral PF and CF, were reconstructed and assessed for quantity, represented by NOP and NOF. A neurologic severity score, based on the presence of developmental disability, seizure, autism, and other neuropsychiatric disorders, was calculated for each subject. We then correlated this score with white matter quantity. Voxelwise tract-based spatial statistics was used to determine differences in FA, axial, and radial diffusivity values between the tuberous sclerosis complex group and the control subjects. RESULTS: NOP and NOF of CF, bilateral PF, and MWT in the tuberous sclerosis complex group were all significantly lower than those in the control subjects (P < .05). The neurologic severity score was moderately negatively correlated with NOF and NOP regarding CF (r = -.70; r = -.75), bilateral PF (r = -.66; r = -.68), and MWT (r = -.71; r = -.74). Tract-based spatial statistics revealed that patients with tuberous sclerosis complex showed a widespread reduction (P < .05) in FA and axial diffusivity in most cerebral white matter regions. CONCLUSIONS: Patients with tuberous sclerosis complex with reduced residual white matter were neurologically more severely affected. Tract-based spatial statistics revealed decreased FA and axial diffusivity of the cerebral white matter in the tuberous sclerosis complex group, suggesting reduced axonal integrity.

Differentiation of primary central nervous system lymphomas and glioblastomas: comparisons of diagnostic performance of dynamic susceptibility contrast-enhanced perfusion MR imaging without and with contrast-leakage correction.

BACKGROUND AND PURPOSE: Contrast leakage results in underestimation of the CBV of brain tumors. Our aim was to compare the diagnostic performance of DSC perfusion MR imaging without and with mathematic contrast-leakage correction in differentiating PCNSLs and glioblastomas. MATERIALS AND METHODS: Perfusion parameters-CBV, corrected CBV, and leakage coefficient-were measured in enhancing tumor portions and contralateral NAWM of 15 PCNSLs and 20 glioblastomas, respectively. The ratios of CBV and corrected CBV were calculated by dividing the tumor values by those obtained from contralateral NAWM. A paired t test was used to compare tumor K2 and NAWM K2, as well as tumor CBV ratios without and with leakage correction. Comparisons of CBV, corrected CBV, and K2 between PCNSLs and glioblastomas were done by using a 2-sample t test. The diagnostic performance of DSC perfusion MR imaging without and with contrast-leakage correction was assessed with receiver operating characteristic curve analysis. RESULTS: PCNSLs and glioblastomas demonstrated higher K2 than those in their contralateral NAWM. Corrected CBV ratios were significantly higher than the uncorrected ones for both tumors. PCNSLs had lower CBV ratios (P < .001), lower corrected CBV ratios (P < .001), and higher K2 (P = .001) compared with glioblastomas. In differentiating between PCNSLs and glioblastomas, the area under the curve of the CBV ratio, corrected CBV ratio, and K2 were 0.984, 0.940, and 0.788, respectively. CONCLUSIONS: PCNSL can be differentiated from glioblastoma with CBV ratios, corrected CBV ratios, and K2. CBV without contrast-leakage correction seems to have the best diagnostic performance in differentiating the 2 tumors.

Differentiation of pyogenic brain abscesses from necrotic glioblastomas with use of susceptibility-weighted imaging.

BACKGROUND AND PURPOSE: A common imaging finding in brain abscess and necrotic glioblastoma is a T2 hypointense margin. The features of this hypointense rim on SWI have not been previously described, to our knowledge. We aimed to differentiate abscesses from glioblastomas by assessing the morphology of their lesion margin by using SWI. MATERIALS AND METHODS: T2WI and SWI were performed in 12 abscesses and 20 rim-enhancing glioblastomas. On T2WI and SWI, the prevalence and the border types (complete versus incomplete) of hypointense rims were qualitatively assessed. On SWI, the contour (smooth versus irregular) and the location of hypointense rims relative to the contrast-enhancing rims as well as the prevalence of the "dual rim sign," defined as 2 concentric rims at lesion margins with the outer one being hypointense and the inner one hyperintense relative to cavity contents, were also analyzed. RESULTS: Prevalence and the border types of the hypointense rims on T2WI were not different between abscesses and glioblastomas. On SWI, there were significantly more hypointense rims that were complete (P < .001) and smooth (P < .001), having the same location as the contrast-enhancing rims (P < .001) for abscesses. A dual rim sign was present in 9 of 12 abscesses but absent in all glioblastomas (P < .001). CONCLUSIONS: SWI may be helpful in differentiating pyogenic abscesses from necrotic glioblastomas. The dual rim sign is the most specific imaging feature distinguishing the 2.

Clinical outcomes of 174 nasopharyngeal carcinoma patients with radiation-induced temporal lobe necrosis.

PURPOSE: To retrospectively study the clinical outcomes of nasopharyngeal carcinoma patients with radiation-induced temporal lobe necrosis (TLN) treated with steroids, surgery, or observation only. METHODS AND PATIENTS: We performed a retrospective analysis of 174 consecutive patients diagnosed with TLN between 1990 and 2008. Before 1998, symptomatic patients were treated with oral steroids, while asymptomatic patients were treated conservatively. After 1998, most symptomatic and asymptomatic patients with a large volume of necrosis were treated by intravenously pulsed-steroid therapy with a standardized protocol. We examined factors affecting grade 4 complication-free survival and overall survival. Outcomes of the three treatment groups, those receiving conservative treatment, those receiving oral steroid, and those receiving intravenous pulse steroid, were compared. RESULTS: The mean follow-up time was 115 months. Rates of grade 4 complication-free survival at 2 years and at 5 years after diagnosis of TLN were 72.2% and 54.1%, respectively. The 2-year and 5-year overall survival rates were 57.5% and 35.4%, respectively. Multivariate analysis revealed that being symptomatic at diagnosis (relative risk [RR], 4.5; p = 0.0001), re-irradiation of the nasopharynx (NP) (RR, 1.56; p = 0.008), salvage brachytherapy to the NP (RR, 1.75; p = 0.012), and a short latency period before the diagnosis of TLN (RR, 0.96, p < 0.0001) were independent prognosticators of poor grade 4 complication-free survival. Patients with all four factors had a 100% risk of developing grade 4 complications within 5 years; whereas if no factor was present, the risk was 12.5%. Intravenous pulse steroid therapy was associated with a higher clinical response rate compared with conventional steroid therapy (p < 0.0001); however, it did not affect complication-free survival in multivariate analysis. CONCLUSIONS: TLN patients with good prognosticators could be observed without active treatment. Although treatment with intravenously pulsed steroid was associated with better clinical response than conventional steroid delivery, it did not affect the complication-free survival rate of TLN patients.

Differentiation of tumefactive demyelinating lesions from high-grade gliomas with the use of diffusion tensor imaging.

BACKGROUND AND PURPOSE: TDLs may be indistinguishable from high-grade gliomas on conventional MR imaging. The role of DTI in differentiating TDLs from high-grade gliomas is not clear, and quantitative comparison between the 2 has not been reported. Here we aimed to differentiate TDLs from high-grade gliomas by using DTI. MATERIALS AND METHODS: DTI was performed in 8 TDLs and 13 high-grade gliomas. The presence of 3 findings (ie, intralesional hyperintensities on the FA map, restricted diffusion in the lesion periphery, and a perilesional hyperintense FA rim) was assessed by visual inspection. The FA and MD values were measured in the central nonenhancing portion, peripheral enhancing portion, and perilesional edema for each lesion and compared between the 2 groups respectively. RESULTS: TDLs had a significantly higher incidence of intralesional hyperintensities on FA maps (P = .049) but a lower incidence of a perilesional hyperintense FA rim (P < .001), compared with those of high-grade gliomas on visual inspection. TDLs had significantly higher FA (P = .004) and lower MD (P = .001) values in the peripheral enhancing portions of the lesions compared with those of high-grade gliomas. In perilesional edema, FA values were significantly higher in high-grade gliomas (P = .001). CONCLUSIONS: DTI is helpful in differentiating TDLs from high-grade gliomas by using visual inspection and quantitative analysis.

Differentiation of brain abscesses from necrotic glioblastomas and cystic metastatic brain tumors with diffusion tensor imaging.

BACKGROUND AND PURPOSE: The differentiation of abscesses from glioblastomas and metastases may not always be possible on the basis of DWI. Our hypothesis was that differences in diffusion properties as detected by DTI allow differentiation of abscess from glioblastomas and metastasis. Furthermore, diagnostic performance of tensor metrics quantifying anisotropy or tensor shapes is better than that of ADC in measuring mean diffusivity for this purpose. MATERIALS AND METHODS: DTI was performed in 15 abscesses, 15 necrotic glioblastomas, and 26 cystic metastases. In each lesion, manually segmented into 4 regions of interest (ie, cystic cavity, enhancing rim, and immediate [edema most adjacent to the enhancing rim] and distant zones of edema), FA, ADC, C(l), C(p), and C(s) values were measured and statistically compared among groups and evaluated with ROC curve analysis. The presence of a hyperintense FA rim (a rim of edematous tissue that was hyperintense on the FA map) was assessed visually. RESULTS: Abscess was significantly different from glioblastoma for all tensor metrics measured in the cystic cavity and immediate zone of edema and for all except C(l) in the enhancing rim. Abscess was significantly different from metastasis for all tensor metrics measured in the cystic cavity and enhancing rim and for FA, ADC, and C(l) in immediate zone of edema. The incidence of a hyperintense FA rim was significantly higher in glioblastoma and metastasis compared with abscess. The 3 tensor metrics with the highest performance in differentiating abscess from glioblastoma and metastasis were FA, C(l), and C(s) of the cystic cavity. CONCLUSIONS: DTI is able to differentiate abscess from glioblastoma and metastasis. FA, C(l), and C(s) outperformed ADC in diagnostic performance comparisons.

Emergency department presentation of ketamine abusers in Hong Kong: a review of 233 cases.

OBJECTIVES: To study the acute clinical presentations of ketamine abusers in Hong Kong. DESIGN: Retrospective chart review. SETTING: Fifteen accident and emergency departments in Hong Kong. PATIENTS: Consultations associated with recent ketamine use either confirmed by history or urine test were searched for from the database of the Hospital Authority Hong Kong Poison Information Centre from 1 July 2005 to 30 June 2008. Their medical records and investigation results were analysed. RESULTS: A total of 233 records of ketamine use were included for review. Patient ages ranged from 13 to 60, with a median of 22 years, and the male-to-female ratio being 2.1:1. The most common symptoms of ketamine misuse were impaired consciousness (45%), abdominal pain (21%), lower urinary tract symptoms (12%), and dizziness (12%). The most common abnormal physical findings were high blood pressure (40%), followed by tachycardia (39%), abdominal tenderness (18%), and white powder in the nostrils (17%). CONCLUSION: Most ketamine abusers presented acutely with transient central nervous system depression, abdominal pain, or lower urinary tract symptoms. Clinicians should be alert to the typical age-group, signs and symptoms of such abusers presenting in an acute medical setting.

Differentiating Components of Cerebral Arteriovenous Malformations Using T1-Weighted Gradient Recall Echo MR Imaging.

Cerebral arteriovenous malformation (AVM) typically shows signal void on conventional MR images, making differentiation of each component difficult. We analyzed the MR signal intensity of AVM components on T1-weighted gradient recalled echo pulse sequence images. We retrospectively studied 29 patients with AVM between 2006 and 2008. Patients were excluded if they had 1) intracranial hemorrhage, 2) previous intervention for AVM. All patients underwent MR study on a 3T system (Magentom TIM Trio, Siemens). Pulse sequences included T1-weighted gradient recalled echo (T1GRE), T2-weighted (T2), time-of-flight (TOF), and contrast-enhanced T1-weighted (cT1) images. Digital subtracted angiography (DSA) was performed in all patients as a diagnostic standard. Signal intensity of each AVM component was recorded and compared between pulse sequences. Nine patients were studied (five men; mean age 39.1 years) and nine AVM were identified (mean size, 3.9 cm). Three different signal intensities (hypo-, iso-, and hyper-intensity) were observed in all nine patients on T1GRE. Only one signal intensity was seen on T2 (flow void) and cT1 images (hyperintensity) in nine patients. Two different signal intensities were observed in all seven patients with TOF images. The T1GRE image showed the largest number of different signal intensities of AVM when compared with other pulse sequences, thus providing clearer structural delineation. Routine use of the T1GRE pulse sequence can help pre-therapeutic planning or follow-up of AVM.