Dynamic Hyperspectral Holography Enabled by Inverse-Designed Metasurfaces with Oblique Helicoidal Cholesterics.

Metasurfaces are flat arrays of nanostructures that allow exquisite control of phase and amplitude of incident light. Although metasurfaces offer new active element for both fundamental science and applications, the challenge still remains to overcome their low information capacity and passive nature. Here, by integrating an inverse-designed-metasurface with oblique helicoidal cholesteric liquid crystal (ChOH ), simultaneous spatial and spectral tunable metasurfaces with a high information capacity for dynamic hyperspectral holography, are demonstrated. The inverse design facilitates a single-phase map encoding of ten independent holographic images at different wavelengths. ChOH provides precise spectral modulation with narrow bandwidth and wide tunable regime in response to programmed stimuli, thus enabling dynamic switching of the multicolor holography. The results provide simple and generalizable principles for the rational design of interactive metasurfaces that will find numerous applications, including security platform.

Nectar Characteristics and Honey Production Potential of Five Rapeseed Cultivars and Two Wildflower Species in South Korea.

The growing beekeeping industry in South Korea has led to the establishment of new honey plant complexes. However, studies on honey production from each species are limited. This study aimed to assess the honey production potential of various Brassica napus cultivars and two wildflower species. The nectar characteristics of B. napus varied significantly among the cultivars. Absolute sugar concentrations differed among the cultivars, but sugar composition ratios were similar. In contrast, the amino acid content remained relatively uniform regarding percentage values, irrespective of the absolute concentrations. Estimations of honey potential production per hectare (kg/ha) resulted in the following ranking among cultivars: 'JM7003' (107.1) > 'YS' (73.0) > 'JM7001' (63.7) > 'TL' (52.7) > 'TM' (42.4). The nectar volume of Pseudolysimachion rotundum var. subintegrum and Leonurus japonicus increased during the flowering stage. P. rotundum var. subintegrum was sucrose-rich and L. japonicus was sucrose-dominant. Both species predominantly contained phenylalanine, P. rotundum var. subintegrum had glutamine as the second most abundant amino acid, and L. japonicus had tyrosine. The honey production potential was 152.4 kg/ha for P. rotundum var. subintegrum and 151.3 kg/ha for L. japonicus. These findings provide a basis for identifying food resources for pollinators and selecting plant species to establish honey plant complexes.

Multivariate Analysis among Marker Compounds, Environmental Factors, and Fruit Quality of Schisandra chinensis at Different Locations in South Korea.

This study aimed to investigate the correlation among the contents of marker compounds, growth characteristics, and environmental factors of Schisandra chinensis fruits across South Korea. The fruits were collected from 36 cultivation sites in 28 regions across the country. We investigated nine growth characteristics, twelve soil physicochemical properties, eight meteorological data, and three marker compounds in this study. We optimized and validated an optimized method for quantifying marker compounds using UPLC and performed correlation analysis among the contents of marker compounds, growth characteristics, and environmental factors. The UPLC-UV method for analyzing marker compounds was validated by measuring linearity, LOD, LOQ, precision, and accuracy. The marker compounds were negatively correlated with the fruit size and sugar contents, and growth characteristics were negatively correlated with some physicochemical properties of the soil. The results of this study can be used as basic data for the standard cultural practices and quality control of S. chinensis fruits.

Serum biochemical reference interval determination in wild Siberian weasel (Mustela sibirica).

Determining reference intervals (RI) is a valuable asset for assessing the health of wildlife species. This is the first study to establish serum biochemical RIs in Siberian weasels. Forty-two healthy free-ranging Siberian weasels were captured live and brought to Seoul Wildlife Center between June 2021 and August 2022. Blood samples from 42 healthy Siberian weasels of both sexes were used to calculate RIs. An automated analyser was used to perform serum biochemistry profiles. The American Society for Veterinary Clinical Pathology recommendations were used to calculate a nonparametric RI with 90% confidence intervals. The RIs of albumin, total protein, globulin, calcium, glucose, blood urea nitrogen, phosphorus, amylase, cholesterol, alanine aminotransferase, total bilirubin, alkaline phosphatase, creatinine, and creatine kinase were determined. The RIs established in this study will serve as a good starting point for analysing serum biochemical data in Siberian weasels.

VERTEBRAL HEART SCALE SYSTEM IN CLINICALLY HEALTHY SIBERIAN WEASEL (MUSTELA SIBIRICA).

In several species, the vertebral heart scale (VHS) measurement is frequently used to provide a more objective evaluation of cardiomegaly. However, normal-sized parameters for radiographic measures of the cardiac silhouette in Siberian weasels (Mustela sibirica) have not been determined. Right lateral (n = 24) and ventrodorsal (n = 20) thoracic radiographs from free-ranging Siberian weasels with clinically normal cardiac and pulmonary function were acquired and evaluated to determine the specific VHS for the Siberian weasel. The mean (SD) VHS of the right lateral (RL) and the ventrodorsal (VD) views were 6.70 (0.60) and 6.95 (0.69), respectively. VD view radiographs had a considerably higher VHS than RL view radiographs, and RL view measures were less variable than VD view values. The VHS of Siberian weasels was unaffected by age, body weight, or sex. The results determined in this study can be used in clinical diagnostic and radiographic evaluations of Siberian weasels.

Involvement of the spinal γ-aminobutyric acid receptor in the analgesic effects of intrathecally injected hypertonic saline in spinal nerve-ligated rats.

Background: : Hypertonic saline is used for treating chronic pain; however, clinical studies that aid in optimizing therapeutic protocols are lacking. We aimed to determine the concentration of intrathecally injected hypertonic saline at which the effect reaches its peak as well as the underlying γ-aminobutyric acid (GABA) receptor-related antinociceptive mechanism. Methods: : Spinal nerve ligation (SNL; left L5 and L6) was performed to induce neuropathic pain in rats weighing 250-300 g. Experiment 1: one week after implanting the intrathecal catheter, 60 rats were assigned randomly to intrathecal injection with 0.45%, 0.9%, 2.5%, 5%, 10%, and 20% NaCl, followed by behavioral testing at baseline and after 30 minutes, 2 hours, 1 day, and 1 week to determine the minimal concentration which produced maximal analgesia. Experiment 2: after determining the optimal intrathecal hypertonic saline concentration, 60 rats were randomly divided into four groups: Sham, hypertonic saline without pretreatment, and hypertonic saline after pretreatment with one of two GABA receptor antagonists (GABAA [bicuculline], or GABAB [phaclofen]). Behavioral tests were performed at weeks 1 and 3 following each treatment. Results: : Hypertonic saline at concentrations greater than 5% alleviated SNL-induced mechanical allodynia and had a significant therapeutic effect, while showing a partial time- and dose-dependent antinociceptive effect on thermal and cold hyperalgesia. However, pretreatment with GABA receptor antagonists inhibited the antinociceptive effect of 5% NaCl. Conclusions: : This study indicates that the optimal concentration of hypertonic saline for controlling mechanical allodynia in neuropathic pain is 5%, and that its analgesic effect is related to GABAA and GABAB receptors.

Association between fatty infiltration in the cervical multifidus and treatment response following cervical interlaminar epidural steroid injection.

Background: Recent attention has been directed towards fatty infiltration in the cervical extensor muscles for predicting clinical outcomes in several cervical disorders. This study aimed to investigate the potential association between fatty infiltration in the cervical multifidus and treatment response following cervical interlaminar epidural steroid injection (CIESI) in patients with cervical radicular pain. Methods: The data of patients with cervical radicular pain who received CIESIs between March 2021 and June 2022 were reviewed. A responder was defined as a patient with a numerical rating scale decrease of ≥ 50% from the baseline to three months after the procedure. The presence of fatty infiltration in the cervical multifidus was assessed, along with patient characteristics, and cervical spine disease severity. To assess cervical sarcopenia, fatty infiltration in the bilateral multifidus muscles was evaluated at the C5-C6 level using the Goutallier classification. Results: Among 275 included patients, 113 (41.1%) and 162 (58.9%) were classified as non-responders and responders, respectively. The age, severity of disc degeneration, and grade of cervical multifidus fatty degeneration were significantly lower in responders. Multivariate logistic regression analysis revealed that pre-procedural symptoms (radicular pain with neck pain, odd ratio [OR] = 0.527, P = 0.024) and high-grade cervical multifidus fatty degeneration (Goutallier grade 2.5-4, OR = 0.320, P = 0.005) were significantly associated with an unsuccessful response to CIESI. Conclusions: These results suggest high-grade cervical multifidus fatty infiltration is an independent predictor of poor response to CIESI in patients with cervical radicular pain.

Bright-Field and Edge-Enhanced Imaging Using an Electrically Tunable Dual-Mode Metalens.

The imaging of microscopic biological samples faces numerous difficulties due to their small feature sizes and low-amplitude contrast. Metalenses have shown great promise in bioimaging as they have access to the complete complex information, which, alongside their extremely small and compact footprint and potential to integrate multiple functionalities into a single device, allow for miniaturized microscopy with exceptional features. Here, we design and experimentally realize a dual-mode metalens integrated with a liquid crystal cell that can be electrically switched between bright-field and edge-enhanced imaging on the millisecond scale. We combine the concepts of geometric and propagation phase to design the dual-mode metalens and physically encode the required phase profiles using hydrogenated amorphous silicon for operation at visible wavelengths. The two distinct metalens phase profiles include (1) a conventional hyperbolic metalens for bright-field imaging and (2) a spiral metalens with a topological charge of +1 for edge-enhanced imaging. We demonstrate the focusing and vortex generation ability of the metalens under different states of circular polarization and prove its use for biological imaging. This work proves a method for in vivo observation and monitoring of the cell response and drug screening within a compact form factor.

Liquid Crystalline Systems from Nature and Interaction of Living Organisms with Liquid Crystals.

Biomaterials, which are substances interacting with biological systems, have been extensively explored to understand living organisms and obtain scientific inspiration (such as biomimetics). However, many aspects of biomaterials have yet to be fully understood. Because liquid crystalline phases are ubiquitously found in biomaterials (e.g., cholesterol, amphiphile, DNA, cellulose, bacteria), therefore, a wide range of research has made attempts to approach unresolved issues with the concept of liquid crystals (LCs). This review presents these studies that address the interactive correlation between biomaterials and LCs. Specifically, intrinsic LC behavior of various biomaterials such as DNA, cellulose nanocrystals, and bacteriaare first introduced. Second, the dynamics of bacteria in LC media are addressed, with focus on how bacteria interact with LCs, and how dynamics of bacteria can be controlled by exploiting the characteristics of LCs. Lastly, how the strong correlation between LCs and biomaterials has been leveraged to design a new class of biosensors with additional functionalities (e.g., self-regulated drug release) that are not available in previous systems is reviewed. Examples addressed in this review convey the message that the intersection between biomaterials and LCs offers deep insights into fundamental understanding of biomaterials, and provides resources for development of transformative technologies.

Epidemiology of occupational injuries in construction workers between 2009 and 2018 in South Korea.

BACKGROUND: This study aimed to investigate the characteristics of occupational injuries based on fatality, sex, and classification of occupations among construction workers using workers' compensation (WC) insurance data in South Korea. METHODS: We collected WC insurance data from the Korea Workers' Compensation & Welfare Service for all construction workers between 2009 and 2018. Data from 158,947 accepted claims for occupational injury were extracted, and the demographic features, occupational injury types, and annual trends were analyzed for fatal and nonfatal cases. The annual incidence and mortality trends of occupational injury were estimated using negative binomial regression and Poisson regression models, for injury incidence and mortality respectively. RESULTS: Among a total of 158,947 occupational injury cases, there were 155,772 (98%) nonfatal injuries and 3175 (2%) fatal injuries. For all occupational injuries, Construction Elementary Workers (6th Korean Standard Classification of Occupations (KSCO) 910; 45.7%) was the most frequent occupation, followed by Construction-Related Technical Workers (6th KSCO 772; 39.2%). The most frequent injury type was a fracture, followed by ruptures or lacerations and contusions. The incidence of all occupational injuries increased from 700.36 per 100,000 persons in 2009 to 1,195.98 per 100,000 persons in 2018. Further, deaths from injuries at work followed a significantly increasing annual trend [mortality rate ratio 1.04 (95% CI: 1.03-1.05)] from 2009 to 2018. CONCLUSION: The over two-thirds increased incidence of occupational injuries and significantly increasing mortality trends for occupational injuries during the last 10 years indicate the need for aggressive intervention in occupational safety and health management within the Korean construction industry.

Approval status and characteristics of work-related musculoskeletal disorders among Korean workers in 2020.

Background: This study aimed to investigate the characteristics of work-related musculoskeletal disorders (WRMSDs) in occupational disease claims and identify patterns of WRMSDs for each body part by industry and occupation. Methods: This study analyzed the raw data of occupational disease claims for musculoskeletal disorders deliberated by the Occupational Disease Decision Committee of the Korea Workers' Compensation & Welfare Service in 2020. The data was classified into 6 body parts with the highest numbers of occupational disease cases by using the complete enumeration data on principal diagnoses and 4 types of subdiagnoses in the raw data. The characteristics and approval rates of WRMSDs by body part, industry and occupation were examined and summarized. Results: A total of 13,015 occupational disease cases for WRMSDs were classified, and lumbar spinal (back) diseases accounted for the largest proportion of claimed diseases, followed by shoulder, elbow, wrist, knee, and neck diseases in a descending order. The occupations with the highest and second highest numbers of occupational disease cases by body part were found to be automobile assemblers and production-related elementary workers for the neck, school meal service workers and cooks for the back, construction frame mold carpenters and school meal service workers for the shoulder, elementary workers in mining and food service workers for the elbow, food service workers and automobile parts assemblers for the wrist, and ship welders and school meal service workers for the knee. Conclusions: This study examined the characteristics and approval status of WRMSDs by body part and occupation. Based on the study results, management strategies for the prevention of WRMSDs should be established regarding occupations with a high risk of WRMSDs for each body part.

Chemical Pneumonitis Caused by the Inhalation of Zinc Oxide Fumes in an Arc Welder.

Acute respiratory illness caused by exposure to welding-associated zinc oxide fumes is known as metal fume fever (MFF). MFF is generally characterized as a self-limiting disease. Few studies have reported chemical pneumonitis associated with zinc fume inhalation. We report a case study involving severe episodes of MFF accompanied by chemical pneumonitis due to the inhalation of zinc oxide fumes while operating an arc welder. A 54-year-old man developed flu-like symptoms after arc welding galvanized steel in a poorly ventilated area. Despite intravenous antibiotics therapy, his clinical course worsened, and his urine zinc concentration was remarkably elevated (3579 µg/24 h; reference range, 0-616 µg/24 h). A chest computed tomography revealed extensive consolidation, ground-glass opacity in the lungs, and right pleural effusion. After corticosteroid treatment, the patient's symptoms and radiologic findings significantly improved. It should be noted that the inhalation of zinc oxide fumes can occasionally induce acute lung injury via inflammatory responses and oxidative stress.

Colonoscopy decreases mortality in colorectal cancer patients compared with fecal immunochemical test.

BACKGROUND AND AIM: Colonoscopy and fecal immunochemical test (FIT) are commonly used screening methods for the detection of colorectal cancer (CRC), but their effects on survival have not been compared. We compared survival outcomes in patients with CRC according to the exposure history to colonoscopy or FIT before diagnosis of CRC. METHODS: We performed a nationwide population-based retrospective cohort study using Korean national-insurance claims data. In total, 24 875 patients with CRC diagnosed in 2012 were included. The patients were divided into three groups in terms of examinations performed during the 10 years prior to CRC diagnosis: the colonoscopy group, the FIT group, and the never-screened group. Survival outcomes were compared among the three groups. The colonoscopy group and FIT group were matched using propensity score-matching method. RESULTS: The cohort consisted of 9619 patients in the colonoscopy group, 6936 patients in the FIT group, and 8320 patients in the never-screened group. The 5-year overall survival rates were 74.1% in the colonoscopy group, 65.9% in the FIT group, and 59.6% in the never-screened group (P < 0.001). The adjusted hazard ratios for death were 0.56 (95% confidence interval [CI], 0.53-0.59) in the colonoscopy group and 0.78 (95% CI, 0.74-0.82) in the FIT group compared with the never-screened group. In the matched cohort, the adjusted hazard ratios for death was 0.76 (95% CI, 0.72-0.81) in the colonoscopy group compared with the FIT group. CONCLUSION: Colonoscopy is a more effective method for reducing mortality in patients with CRC compared with FIT.

Liquid crystal-powered Mie resonators for electrically tunable photorealistic color gradients and dark blacks.

Taking inspiration from beautiful colors in nature, structural colors produced from nanostructured metasurfaces have shown great promise as a platform for bright, highly saturated, and high-resolution colors. Both plasmonic and dielectric materials have been employed to produce static colors that fulfil the required criteria for high-performance color printing, however, for practical applications in dynamic situations, a form of tunability is desirable. Combinations of the additive color palette of red, green, and blue enable the expression of further colors beyond the three primary colors, while the simultaneous intensity modulation allows access to the full color gamut. Here, we demonstrate an electrically tunable metasurface that can represent saturated red, green, and blue pixels that can be dynamically and continuously controlled between on and off states using liquid crystals. We use this to experimentally realize ultrahigh-resolution color printing, active multicolor cryptographic applications, and tunable pixels toward high-performance full-color reflective displays.

Conformal quantum dot-SnO2 layers as electron transporters for efficient perovskite solar cells.

Improvements to perovskite solar cells (PSCs) have focused on increasing their power conversion efficiency (PCE) and operational stability and maintaining high performance upon scale-up to module sizes. We report that replacing the commonly used mesoporous-titanium dioxide electron transport layer (ETL) with a thin layer of polyacrylic acid-stabilized tin(IV) oxide quantum dots (paa-QD-SnO2) on the compact-titanium dioxide enhanced light capture and largely suppressed nonradiative recombination at the ETL-perovskite interface. The use of paa-QD-SnO2 as electron-selective contact enabled PSCs (0.08 square centimeters) with a PCE of 25.7% (certified 25.4%) and high operational stability and facilitated the scale-up of the PSCs to larger areas. PCEs of 23.3, 21.7, and 20.6% were achieved for PSCs with active areas of 1, 20, and 64 square centimeters, respectively.

Stimuli-Responsive Liquid Crystal Printheads for Spatial and Temporal Control of Polymerization.

Polymerization reactions triggered by stimuli play a pivotal role in materials science, with applications ranging from lithography to biomedicine to adaptive materials. However, the development of chemically triggered, stimuli-responsive systems that can confer spatial and temporal control on polymerization remains a challenge. Herein, chemical-stimuli-induced polymerization based on a liquid crystal (LC) printhead is presented. The LC responds to a local chemical stimulus at its aqueous interface, resulting in the ejection of initiator into the solution to trigger polymerization. Various LC printhead geometries are designed, allowing programming of: i) bulk solution polymerization, ii) synthesis of a thin surface-confined polymeric coating, iii) polymerization-induced self-assembly of block copolymers to form various nanostructures (sphere, worm-like, and vesicles), and iv) 3D polymeric structures printed according to local solution conditions. The approach is demonstrated using amphiphiles, multivalent ions, and biomolecules as stimuli.

Interfacial Polyelectrolyte-Surfactant Complexes Regulate Escape of Microdroplets Elastically Trapped in Thermotropic Liquid Crystals.

Polyelectrolytes adsorbed at soft interfaces are used in contexts such as materials synthesis, stabilization of emulsions, and control of rheology. Here, we explore how polyelectrolyte adsorption to aqueous interfaces of thermotropic liquid crystals (LCs) influences surfactant-stabilized aqueous microdroplets that are elastically trapped within the LCs. We find that adsorption of poly(diallyldimethylammonium chloride) (PDDA) to the interface of a nematic phase of 4-cyano-4'-pentylbiphenyl (5CB) triggers the ejection of microdroplets decorated with sodium dodecylsulfate (SDS), consistent with an attractive electrical double layer interaction between the microdroplets and LC interface. The concentration of PDDA that triggers release of the microdroplets (millimolar), however, is three orders of magnitude higher than that which saturates the LC interfacial charge (micromolar). Observation of a transient reorientation of the LC during escape of microdroplets leads us to conclude that complexes of PDDA and SDS form at the LC interface and thereby regulate interfacial charge and microdroplet escape. Poly(sodium 4-styrenesulfonate) (PSS) also triggers escape of dodecyltrimethylammonium bromide (DTAB)-decorated aqueous microdroplets from 5CB with dynamics consistent with the formation of interfacial polyelectrolyte-surfactant complexes. In contrast to PDDA-SDS, however, we do not observe a transient reorientation of the LC when using PSS-DTAB, reflecting weak association of DTAB and PSS and slow kinetics of formation of PSS-DTAB complexes. Our results reveal the central role of polyelectrolyte-surfactant dynamics in regulating the escape of the microdroplets and, more broadly, that LCs offer the basis of a novel probe of the structure and properties of polyelectrolyte-surfactant complexes at interfaces. We demonstrate the utility of these new insights by triggering the ejection of microdroplets from LCs using peptide-polymer amphiphiles that switch their net charge upon being processed by enzymes. Overall, our results provide fresh insight into the formation of polyelectrolyte-surfactant complexes at aqueous-LC interfaces and new principles for the design of responsive soft matter.

Physiological and molecular responses of the Antarctic harpacticoid copepod Tigriopus kingsejongensis to salinity fluctuations - A multigenerational study.

Since Antarctica and the surrounding Southern Ocean are facing global climate change, biota inhabiting those coastal regions is now challenged by environmental fluctuations including coastal freshening. In this study, the effects of salinity range of 0-75 (practical salinity unit, PSU) on the Antarctic harpacticoid copepod Tigriopus kingsejongensis was investigated by measurement of 96 h survival rate, lifespan, and sex ratio with further analysis of multigenerational growth parameters and mRNA expressions under salinity of 15-45. Different stages of the copepods (i.e., nauplius, male, and female) generally showed tolerance to hypo- and hypersalinity, wherein female copepods were more tolerant than males when exposed to salinity fluctuations. Lifespan was significantly shortened by hypo- and hypersalinity compared to control salinity (34), but there was no significant difference in the sex ratio between salinity treatments. Multigenerational experiments across five generations revealed that exposure to salinities of 15 and 45 reduced body length compared to that in control salinity and the first generation of each salinity group. Our results provide evidence regarding T. kingsejongensis on their preferred salinity ranges, physiological limit to salinity fluctuations, and population dynamics in future salinity.

Perovskite solar cells with atomically coherent interlayers on SnO2 electrodes.

In perovskite solar cells, the interfaces between the perovskite and charge-transporting layers contain high concentrations of defects (about 100 times that within the perovskite layer), specifically, deep-level defects, which substantially reduce the power conversion efficiency of the devices1-3. Recent efforts to reduce these interfacial defects have focused mainly on surface passivation4-6. However, passivating the perovskite surface that interfaces with the electron-transporting layer is difficult, because the surface-treatment agents on the electron-transporting layer may dissolve while coating the perovskite thin film. Alternatively, interfacial defects may not be a concern if a coherent interface could be formed between the electron-transporting and perovskite layers. Here we report the formation of an interlayer between a SnO2 electron-transporting layer and a halide perovskite light-absorbing layer, achieved by coupling Cl-bonded SnO2 with a Cl-containing perovskite precursor. This interlayer has atomically coherent features, which enhance charge extraction and transport from the perovskite layer, and fewer interfacial defects. The existence of such a coherent interlayer allowed us to fabricate perovskite solar cells with a power conversion efficiency of 25.8 per cent (certified 25.5 per cent)under standard illumination. Furthermore, unencapsulated devices maintained about 90 per cent of their initial efficiency even after continuous light exposure for 500 hours. Our findings provide guidelines for designing defect-minimizing interfaces between metal halide perovskites and electron-transporting layers.