Platelet Index in Patients with Confirmed Coronavirus Disease 2019 Cases

BACKGROUND: Changes found on hematological examination are a helpful modality for assessing coronavirus disease 2019 (COVID-19). In addition, platelet index is a parameter that can help in assessing the COVID-19 disease prognosis. AIM: Objective of the study is to determine the difference in platelet index in nucleid acid amplification test (NAAT) confirmed COVID-19 patients, suspected COVID-19 with negative NAAT results, and non-COVID-19 controls. METHODS: This is an analytical observational study with 96 subjects; 48 subjects with confirmed COVID-19, 23 subjects suspected COVID-19 with negative NAAT results, and 24 non-COVID-19 control subjects. First, NAAT examination was carried out using the GeneXpert tool with the target genes of the E and N2 genes. Then, the platelet index was compared between the three groups by the Kruskal-Wallis test. RESULTS: There was no significant difference in the number of platelet (PLT), mean PLT volume (MPV), and PLT crit (PCT) between the three groups with p = 0.732, 0.741 and 0.483, respectively. In general, the number of PLT, MPV, and PCT in the three groups was within the normal reference value. CONCLUSIONS: There were no significant differences observed in the number of PLT, MPV, and PCT between COVID-19 patients with positive NAAT, COVID-19 suspects with negative NAAT, and non-COVID-19 controls. Therefore, detecting the severe acute respiratory syndrome coronavirus 2 virus by NAAT examination in COVID-19 patients has not altered the PLT index changes.

Magnetic resonance imaging-based body composition is associated with nutritional and inflammatory status: a longitudinal study in patients with Crohn's disease

Objective To evaluate the changes in magnetic resonance imaging-based body composition parameters during follow-ups in patients with Crohn's disease (CD). Methods Between November 1, 2017, and June 30, 2021, patients diagnosed with CD, who underwent two or more magnetic resonance enterography (MRE) scans at our institution were retrospectively reviewed. The baseline and one subsequent follow-up scan for each patient were paired to form longitudinal comparisons. Skeletal muscle, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) indexes were calculated from tissue areas measured at the third lumbar vertebra level per scan, standardized by dividing the height2 and lumbar height2 (heightL1–L5). We also assessed the correlation between changes in VAT to total adipose tissue ratio (VA/TA index) and CD activity scores (5-point MRE classification) using Spearman’s correlation analysis. A multivariate linear regression model was used to adjust for the follow-up duration and treatment type. Results Overall, 49 patients (with 49 paired scans) were enrolled. VA/TA index changes were negatively correlated with changes in skeletal muscle index (SMI; r = − 0.339, p < 0.05). The VA/TA index (52.69 ± 10.66% vs. 49.18 ± 10.80%, p < 0.001) and the total MRE score (8.0 ± 3.9 vs. 5.7 ± 3.4, p < 0.001) decreased significantly during follow-up, regardless of follow-up duration and treatment type (both p > 0.05). Changes in total MRE score were negatively correlated with SMI changes (r = − 0.408, p < 0.01) but positively correlated with VA/TA index changes (r = 0.479, p < 0.01). Conclusion An increase in SMI and a decrease in VA/TA index could reflect improved nutritional and inflammatory status.

Towards non-blind optical tweezing by finding 3D refractive index changes through off-focus interferometric tracking

In modern 3D microscopy, holding and orienting arbitrary biological objects with optical forces instead of using coverslips and gel cylinders is still a vision. Although optical trapping forces are strong enough and related photodamage is acceptable, the precise (re-) orientation of large specimen with multiple optical traps is difficult, since they grab blindly at the object and often slip off. Here, we present an approach to localize and track regions with increased refractive index using several holographic optical traps with a single camera in an off-focus position. We estimate the 3D grabbing positions around several trapping foci in parallel through analysis of the beam deformations, which are continuously measured by defocused camera images of cellular structures inside cell clusters. Although non-blind optical trapping is still a vision, this is an important step towards fully computer-controlled orientation and feature-optimized laser scanning of sub-mm sized biological specimen for future 3D light microscopy.

Plasmon-induced transparency sensor for detection of minuscule refractive index changes in ultra-low index materials

Detection of low-index materials such as aerogels and also detection of refractive index variations in these materials is still a challenging task. Here, a high figure of merit (FOM) sensor based on plasmon-induced transparency (PIT) is proposed for the detection of aerogel refractive index changes. In the proposed PIT sensor, the transparency window in an opaque region arises from the coupling between surface plasmon polariton (SPP) mode and planar waveguide mode. By comprising sub-wavelength grating (SWG) in the planar waveguide region, the maximum of the electric field of waveguide occurs in a low index media. This facilitates detection of the aerogels when they are used as the low index material (sensing material). Application of the subwavelength grating waveguide also improves the sensitivity of the sensor by a factor of six compared to a conventional structure with a homogenous waveguide. The proposed structure has a quality factor of Q ≥ 1800, and a reflection of 86%, and can detect the refractive index changes as low as Δn = 0.002 (around n = 1.0). The lineshape, Q-factor, and resonant wavelength of the transparency spectrum can be controlled by tailoring the structural parameters. Our work also has potential application in switching, filtering, and spectral shaping.

Design and Manufacturing Optoelectronic Sensors for the Measurement of Refractive Index Changes under Unknown Polarization State

This article proposes a new method for detecting slight refractive index changes under conditions of unknown polarization state. It is argued that an insignificant modification of the tilted fiber Bragg grating (TFBG) structure and selecting the appropriate spectral region allows us to accurately track changes in the refractive index. It has also been proven that the method can be easily made insensitive to temperature and that the sensitivity to changes in the polarization plane of the input light can be significantly reduced, which is crucial in later practical applications. Analytes in the form of an aqueous glucose solution were used to calibrate the sensor. The proposed method, based on perpendicular tilted fiber Bragg grating (P-TFBG), has a wide range of universality because its development and slight modification will enable the detection of glucose, pathogens, and viruses.

Simulated Changes in Tropical Cyclone Size, Accumulated Cyclone Energy and Power Dissipation Index in a Warmer Climate

Detection, attribution and projection of changes in tropical cyclone intensity statistics are made difficult from the potentially decreasing overall storm frequency combined with increases in the peak winds of the most intense storms as the climate warms. Multi-decadal simulations of stabilized climate scenarios from a high-resolution tropical cyclone permitting atmospheric general circulation model are used to examine simulated global changes from warmer temperatures, if any, in estimates of tropical cyclone size, accumulated cyclonic energy and power dissipation index. Changes in these metrics are found to be complicated functions of storm categorization and global averages of them are unlikely to easily reveal the impact of climate change on future tropical cyclone intensity statistics.