Hollow optical pin-like beam based Cassegrain system performance enhancement under atmospheric turbulence.

Cassegrain system, widely used in laser ranging systems, faces emission efficiency challenges due to central obstruction. Current methods utilizing hollow beams based on orbital angular momentum (OAM) aim to mitigate these effects. However, such beams maintain the hollow structure, leading to an ineffective target illumination.

In-situ observation of nanoscale transformations in dehydrating lizardite.

Dehydration of serpentine is an important prograde metamorphic reaction within the lithosphere and subduction zones, potentially causing profound changes in rock properties. Imaging these transitions in real time provides direct insight into the process. We have used in-situ transmission electron microscopy (TEM) to continuously monitor nanoscale transformations in lizardite from 20 to 600 °C.

Strong Interference Elimination in Seismic Data Using Multivariate Variational Mode Extraction.

Seismic data acquired in the presence of mechanical vibrations or power facilities may be contaminated by strong interferences, significantly decreasing the data signal-to-noise ratio (S/N). Conventional methods, such as the notch filter and time-frequency transform method, are usually inadequate for suppressing non-stationary interference noises, and may distort effective signals if overprocessing. In this study, we propose a method for eliminating mechanical vibration interferences in seismic data.

Hollow Gaussian beam-based experimental investigation on echo measurements under atmospheric turbulence and central obstruction.

Despite their potential, Cassegrain systems face challenges due to central obstruction, resulting in reduced emitting efficiency. Optical vortex (OV) beams, known for their unique orbital angular momentum (OAM) characteristics, show promise in enhancing transmission efficiency. However, the existence of central phase singularity in OV beams may limits their effectiveness in laser ranging.

COVID-19 pandemic unmasking cardiovascular risk factors and non-communicable diseases among migrant workers: a cross-sectional study in Singapore.

Objectives: This study aims to report the prevalence of cardiovascular risk factors (CVRFs) and other non-communicable diseases among migrant workers in Singapore admitted for COVID-19 infection, to highlight disease burden and the need for changes in health screening and healthcare delivery in this unique population.

Setting: The study was conducted in the largest tertiary hospital in Singapore.

Design: Retrospective cross-sectional study.

Population Segmentation Based on Healthcare Needs: Validation of a Brief Clinician-Administered Tool.

Background: As populations age with increasingly complex chronic conditions, segmenting populations into clinically meaningful categories of healthcare and related service needs can provide healthcare planners with crucial information to optimally meet needs. However, while conventional approaches typically involve electronic medical records (EMRs), such records do not always capture information reliably or accurately.

Objective: We describe the inter-rater reliability and predictive validity of a clinician-administered tool, the Simple Segmentation Tool (SST) for categorizing older individuals into one of six Global Impression (GI) segments and eight complicating factors (CFs) indicative of healthcare and related social needs.

Respiratory surveillance wards as a strategy to reduce nosocomial transmission of COVID-19 through early detection: The experience of a tertiary-care hospital in Singapore.

Objectives: Patients with COVID-19 may present with respiratory syndromes indistinguishable from those caused by common viruses. Early isolation and containment is challenging. Although screening all patients with respiratory symptoms for COVID-19 has been recommended, the practicality of such an effort has yet to be assessed.

Clarithromycin and Glipizide Drug-drug Interaction Leading to Refractory Hypoglycemia.

A 70-year-old end-stage renal disease patient was admitted for refractory hypoglycemia secondary to drug-drug interaction between clarithromycin and glipizide. We discussed the mechanism of antimicrobial and sulfonylurea interactions as well as the importance of understanding these interactions in the primary care setting to reduce medication-related hospitalizations.

Misled by the Air: Pneumocephalus.

Pneumocephalus, the presence of air within the cranium, commonly suggests a breach in the meningeal layer or an intracranial infection by a gas-producing organism. Trauma is the most common cause of pneumocephalus, followed by cranial surgery. Other causes include infection and intracranial neoplasm.

Chyluria in non-filarial endemic areas: an internist's perspective.

A 60-year-old Chinese woman presented with intermittent, painless, gross haematuria and subsequently complained of persistent milky urine. The diagnosis of chyluria was confirmed after cystoscopy demonstrated ureteric milky fluid discharge which had elevated levels of triglycerides. The patient did not travel to filarial endemic areas and her serum circulating filarial antigen was negative.