Using the Johns Hopkins ACG Case-Mix System for population segmentation in a hospital-based adult patient population in Singapore.

OBJECTIVE: Population health management involves risk characterisation and patient segmentation. Almost all population segmentation tools require comprehensive health information spanning the full care continuum. We assessed the utility of applying the ACG System as a population risk segmentation tool using only hospital data. DESIGN: Retrospective cohort study. SETTING: Tertiary hospital in central Singapore. PARTICIPANTS: 100 000 randomly selected adult patients from 1 January to 31 December 2017. INTERVENTION: Hospital encounters, diagnoses codes and medications prescribed to the participants were used as input data to the ACG System. PRIMARY AND SECONDARY OUTCOME MEASURES: Hospital costs, admission episodes and mortality of these patients in the subsequent year (2018) were used to assess the utility of ACG System outputs such as resource utilisation bands (RUBs) in stratifying patients and identifying high hospital care users. RESULTS: Patients placed in higher RUBs had higher prospective (2018) healthcare costs, and were more likely to have healthcare costs in the top five percentile, to have three or more hospital admissions, and to die in the subsequent year. A combination of RUBs and ACG System generated rank probability of high healthcare costs, age and gender that had good discriminatory ability for all three outcomes, with area under the receiver-operator characteristic curve (AUC) values of 0.827, 0.889 and 0.876, respectively. Application of machine learning methods improved AUCs marginally by about 0.02 in predicting the top five percentile of healthcare costs and death in the subsequent year. CONCLUSION: A population stratification and risk prediction tool can be used to appropriately segment populations in a hospital patient population even with incomplete clinical data.

Temporal characterization of biocycles of mycelium-bound composites made from bamboo and Pleurotus ostreatus for indoor usage.

Mycelium-bound composites (MBCs) are materials obtained by growing fungi on a ligno-cellulosic substrate which have various applications in packaging, furniture, and construction industries. MBCs are particularly interesting as they are sustainable materials that can integrate into a circular economy model. Indeed, they can be subsequently grown, used, degraded, and re-grown. Integrating in a meaningful biocycle for our society therefore demands that MBCs fulfil antagonistic qualities which are to be at the same time durable and biodegradable. In this study, we conduct experiments using MBCs made from the fungus species Pleurotus ostreatus grown on bamboo microfibers substrate. By measuring the variations of the mechanical properties with time, we provide an experimental demonstration of a biocycle for such composites for in-door applications. We found that the biocycle can be as short as 5 months and that the use of sustainable coatings is critical to increase the durability of the composites while maintaining biodegradability. Although there are many scenarios of biocycles possible, this study shows a tangible proof-of-concept example and paves the way for optimization of the duration of each phase in the biocycle depending on the intended application and resource availability.

AFM Manipulation of EGaIn Microdroplets to Generate Controlled, On-Demand Contacts on Molecular Self-Assembled Monolayers.

Liquid metal droplets, such as eutectic gallium-indium (EGaIn), are important in many research areas, such as soft electronics, catalysis, and energy storage. Droplet contact on solid surfaces is typically achieved without control over the applied force and without optimizing the wetting properties in different environments (e.g., in air or liquid), resulting in poorly defined contact areas. In this work, we demonstrate the direct manipulation of EGaIn microdroplets using an atomic force microscope (AFM) to generate repeated, on-demand making and breaking of contact on self-assembled monolayers (SAMs) of alkanethiols. The nanoscale positional control and feedback loop in an AFM allow us to control the contact force at the nanonewton level and, consequently, tune the droplet contact areas at the micrometer length scale in both air and ethanol. When submerged in ethanol, the droplets are highly nonwetting, resulting in hysteresis-free contact forces and minimal adhesion; as a result, we are able to create reproducible geometric contact areas of 0.8-4.5 µm2 with the alkanethiolate SAMs in ethanol. In contrast, there is a larger hysteresis in the contact forces and larger adhesion for the same EGaIn droplet in air, which reduced the control over the contact area (4-12 µm2). We demonstrate the usefulness of the technique and of the gained insights in EGaIn contact mechanics by making well-defined molecular tunneling junctions based on alkanethiolate SAMs with small geometric contact areas of between 4 and 12 µm2 in air, 1 to 2 orders of magnitude smaller than previously achieved.

Effect of common foods as supplements for the mycelium growth of Ganoderma lucidum and Pleurotus ostreatus on solid substrates.

The transition from a linear to a circular economy is urgently needed to mitigate environmental impacts and loss of biodiversity. Among the many potential solutions, the development of entirely natural-based materials derived from waste is promising. One such material is mycelium-bound composites obtained from the growth of fungi onto solid lignocellulosic substrates, which find applications such as insulating foams, textiles, packaging, etc. During growth, the fungus degrades and digests the substrate to create a web-like stiff network called mycelium. The development of the mycelium is influenced by several factors, including the substrate composition. As food waste accounts for nearly 44% of total municipal solid waste, incorporating food in the substrate composition could be a means to increase the nutrients absorbed by the fungus. In this paper, we study the effects of the addition of food supplements on the growth of two fungal species, Ganoderma lucidum and Pleurotus ostreatus. The substrates, the food supplements, and the mycelia are characterized using Fourier-transform infrared spectroscopy, scanning electron microscopy, and optical microscopy. Our results show that addition of barley as a supplement significantly boosts the growth of G. lucidum and P. ostreatus. Using a common food as a nutritious enrichment for the development of mycelium is a simple and straightforward strategy to create waste-based mycelium-bound biocomposites for a large range of applications, on-site, therefore promoting a circular economy.

Joint Trauma System Clinical Practice Guideline: Acute Coronary Syndrome (ACS). 14 May 2021.

Deployed medical providers at all roles of care must be prepared to recognize and manage acute coronary syndrome (ACS). Under optimal conditions, treatment is initiated with medical therapy and may be followed by prompt coronary angiography and revascularization. Emergent percutaneous coronary intervention (PCI) is not available in most deployed locations, however, and the time for such intervention is often dependent on long-range evacuation. This CPG provides guidance on best management for ACS patients in the deployed and resource-constrained environment.

Nanoscale Bilayer Mechanical Lithography Using Water as Developer.

Sustainability has become a critical concern in the semiconductor industry as hazardous wastes released during the manufacturing process of semiconductor devices have an adverse impact on human beings and the environment. The use of hazardous solvents in existing fabrication processes also restricts the use of polymer substrates because of their low chemical resistance to such solvents. Here, we demonstrate an environmentally friendly mechanical, bilayer lithography that uses just water for development and lift-off. We show that we are able to create arbitrary patterns achieving resolution down to 310 nm. We then demonstrate the use of this technique to create functional devices by fabricating a MoS2 photodetector on a polyethylene terephthalate (PET) substrate with measured response times down to 42 ms.

Filamentary High-Resolution Electrical Probes for Nanoengineering.

Confining electric fields to a nanoscale region is challenging yet crucial for applications such as high-resolution probing of electrical properties of materials and electric-field manipulation of nanoparticles. State-of-the-art techniques involving atomic force microscopy typically have a lateral resolution limit of tens of nanometers due to limitations in the probe geometry and stray electric fields that extend over space. Engineering the probes is the most direct approach to improving this resolution limit. However, current methods to fabricate high-resolution probes, which can effectively confine the electric fields laterally, involve expensive and sophisticated probe manipulation, which has limited the use of this approach. Here, we demonstrate that nanoscale phase switching of configurable thin films on probes can result in high-resolution electrical probes. These configurable coatings can be both germanium-antimony-tellurium (GST) as well as amorphous-carbon, materials known to undergo electric field-induced nonvolatile, yet reversible switching. By forming a localized conductive filament through phase transition, we demonstrate a spatial resolution of electrical field beyond the geometrical limitations of commercial platinum probes (i.e., an improvement of ∼48%). We then utilize these confined electric fields to manipulate nanoparticles with single nanoparticle precision via dielectrophoresis. Our results advance the field of nanomanufacturing and metrology with direct applications for pick and place assembly at the nanoscale.

A Hidden Culprit Illuminated with Advanced Cardiac Imaging.

This case demonstrates the complementary benefit of utilizing multimodality cardiac imaging in the assessment of myocardial infarction with nonobstructive coronary artery disease especially when a culprit lesion is not discovered upon initial coronary catheterization. Use of cardiac magnetic resonance imaging, optical coherence tomography, and invasive coronary angiography together solidified the diagnosis of unstable, complex coronary artery disease in this case.

Singapore's regional health systems-a data-driven perspective on frequent admitters and cross utilization of healthcare services in three systems.

INTRODUCTION: With population health management being a priority in the Singapore, this paper aims to provide a data-driven perspective of the population health management initiatives to aid program planning and serves as a baseline for evaluation of future implemented programs. METHODS: A database with information on patient demographics, health services utilization, cost, diagnoses and chronic disease information from 2008 to 2013 for three regional health systems in Singapore was used for analysis. Patients with three or more inpatient admissions were considered as "Frequent Admitters." Health service utilization was quantified, and cross utilization of services was studied. One-year readmission rate for inpatients was studied, and a predictive model for readmission or death was developed. RESULTS: There were a total of 2.8 M patients in the database. Frequent admitters accounted for 0.9% of all patients with an average cost per patient of S$29 547. Of these, 89% had chronic diseases. Cross utilization of health services showed that 8.2% of the patients utilized services from more than one hospital with 19.6% utilizing hospital and polyclinic services in 2013. The highest risk of readmission or death was for those patients who had five or more inpatient episodes in each of the preceding 2 years. CONCLUSION: By understanding the profile of the patients and their utilization patterns in the three regional health systems, our study will help clinicians and decision makers design appropriate integrated care programs for patients with the aim of covering the healthcare needs for the enitre population across the healthcare spectrum in Singapore. Copyright © 2015 John Wiley & Sons, Ltd.

Randomized, double-blind, placebo-controlled clinical trial of a two-day regimen of dihydroartemisinin-piperaquine for malaria prevention halted for concern over prolonged corrected QT interval.

Dihydroartemisinin-piperaquine, the current first-line drug for uncomplicated malaria caused by Plasmodium falciparum and Plasmodium vivax in Cambodia, was previously shown to be of benefit as malaria chemoprophylaxis when administered as a monthly 3-day regimen. We sought to evaluate the protective efficacy of a compressed monthly 2-day treatment course in the Royal Cambodian Armed Forces. The safety and efficacy of a monthly 2-day dosing regimen of dihydroartemisinin-piperaquine were evaluated in a two-arm, randomized, double-blind, placebo-controlled cohort study with 2:1 treatment allocation. Healthy military volunteers in areas along the Thai-Cambodian border where there is a high risk of malaria were administered two consecutive daily doses of 180 mg dihydroartemisinin and 1,440 mg piperaquine within 30 min to 3 h of a meal once per month for a planned 4-month period with periodic electrocardiographic and pharmacokinetic assessment. The study was halted after only 6 weeks (69 of 231 projected volunteers enrolled) when four volunteers met a prespecified cardiac safety endpoint of QTcF (Fridericia's formula for correct QT interval) prolongation of >500 ms. The pharmacodynamic effect on the surface electrocardiogram (ECG) peaked approximately 4 h after piperaquine dosing and lasted 4 to 8 h. Unblinded review by the data safety monitoring board revealed mean QTcF prolongation of 46 ms over placebo at the maximum concentration of drug in serum (Cmax) on day 2. Given that dihydroartemisinin-piperaquine is one of the few remaining effective antimalarial agents in Cambodia, compressed 2-day treatment courses of dihydroartemisinin-piperaquine are best avoided until the clinical significance of these findings are more thoroughly evaluated. Because ECG monitoring is often unavailable in areas where malaria is endemic, repolarization risk could be mitigated by using conventional 3-day regimens, fasting, and avoidance of repeated dosing or coadministration with other QT-prolonging medications. (This study has been registered at ClinicalTrials.gov under registration no. NCT01624337.).

Sixty-four-multislice computed tomography in a patient with arrhythmogenic right ventricular dysplasia.

Arrhythmogenic right ventricular dysplasia (ARVD) is an inheritable cardiomyopathy that is characterized by fibrofatty infiltration of the RV myocardium, often resulting in arrhythmias and sudden cardiac death. The diagnosis often requires imaging of the right ventricle, typically by magnetic resonance imaging. We describe a case of AVRD in which cardiac computed tomography was used as the imaging method for the right ventricle. The CT images showed changes consistent with ARVD to include RV enlargement, excessive trabeculations, fatty infiltration, and marked RV hypokinesia. We believe these images show a novel use for multislice CT in the diagnostic evaluation of patients with suspected ARVD.

Isolated cardiac cysticercosis in an adolescent.

Cardiac cysticercosis is a rare and typically asymptomatic infection. We report a case of a young man from Cameroon with a left ventricular cyst discovered during a screening echocardiogram. Computed tomography and plain films did not reveal additional cysts. Serology was negative. The patient had the cyst surgically removed for suspected echinococcosis. Sectioning demonstrated a cysticercus. The literature on cardiac cysticercosis is reviewed.

Impact of perioperative cardiac assessment guidelines on management of orthopedic surgery patients.

PURPOSE: The study assessed whether the American College of Cardiology/American Heart Association (ACC/AHA) preoperative cardiac assessment guidelines impact patient management and predict major cardiac events in patients undergoing orthopedic surgery. SUBJECTS AND METHODS: We conducted a retrospective review of 338 consecutive orthopedic preoperative evaluations performed by internal medicine consultants. Major cardiac events were defined as myocardial infarction, congestive heart failure, and sudden cardiac death. RESULTS: Major cardiac events occurred in 5.7% of patients. Patients with minor or absent ACC/AHA clinical risk predictors were less likely to have major cardiac events (P = .007). More than half (51%) of patients meeting ACC/AHA indications for noninvasive cardiac tests did not receive them. However, most (69%) major cardiac events occurred in patients not meeting criteria for cardiac testing. Abnormal noninvasive cardiac testing results did not alter medication recommendations and only resulted in coronary revascularization in 0.6% of patients. Only 3% of patients with abnormal noninvasive cardiac testing results had major cardiac events. Patients with abnormal cardiac test results were more likely to have recommendations for perioperative beta-blockade (P <.01). Patients aged more than 70 years (odds ratio 5.0; 95% confidence interval, 1.32-19.28) and patients undergoing hip surgery (odds ratio 7.5, 95% confidence interval, 1.02-54.55) were more likely to have major cardiac events. Major cardiac events occurred in 12% of urgent and 4% of elective procedures (P = .009). CONCLUSIONS: The ACC/AHA guidelines accurately predict cardiac risk in orthopedic surgery. Abnormal noninvasive cardiac test results rarely affected preoperative recommendations, but improved compliance with beta-blocker therapy. Advanced age, urgent procedures, and hip surgery were associated with increased risk of major cardiac events.

An international landmine telehealth symposium between Hawaii and Thailand using an Internet2 and multi-protocol videoconferencing bridge.

An international telehealth symposium was conducted between healthcare institutions in Hawaii and Thailand using a combination of Asynchronous Transfer Mode, and Internet2 connectivity. Military and civilian experts exchanged information on the acute and rehabilitative care of landmine victims in Southeast Asia. Videoconferencing can promote civil-military cooperation in healthcare fields that have multiple international stakeholders.

A novel approach to tele-echocardiography across the Pacific.

Telecardiology provides remote delayed interpretation of echocardiographic images through a store and forward program between the interpreting center, Tripler Army Medical Center, Honolulu Hawaii, and the image acquisition center, Guam Naval Hospital, Guam USA. This routine store and forward system has inherent delay, limiting application for management of acute medical conditions. In this case report we describe a novel methodology for real-time echocardiograpic interpretation methodology integrated methodology with the eICU system (VISICU Inc., Baltimore MD). This case report demonstrates the feasibility of a clinically relevant remote real-time echocardiographic interpretation strategy, utilizing commonly available equipment.