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This study proposes a finite element analysis (FEA) model for complex fractures at the osteoporotic proximal humerus and investigates the relevance of using a calcar screw in surgical treatments using this model. Two types of three-dimensional (3D) fracture models of patients with osteoporotic humerus were constructed reflecting the mechanical properties of the osteoporotic humerus, such as the Young’s modulus and Poisson’s ratio, and two load conditions mimicking the clinical environment were applied for simulation. Using the 3D models and the conditions, the FEA software calculated the concentration and distribution of stresses developing in the humerus, locking compression plate (LCP), and screws. Then, we evaluated and predicted the fixed state of a LCP system depending on whether the maximum stress value exceeded tensile strength. When axial force was applied, insertion of the calcar screw led to significant reduction of stress applied on screws in the fracture model having a medial gap by approximately 61%, from 913.20 MPa to 351.84 MPa. Based on the results, it was clearly confirmed that using of calcar screws improved the stability of a three-part fractures and simultaneously reinforced medial support.

This study aimed to investigate the contemporary characteristics of sedentary behavior and physical activity levels in breast cancer survivors. The cross-sectional data of 10,073 community-dwelling Korean women aged ≥50 years in the Korea National Health and Nutrition Examination Survey were analyzed. The differences in sedentary behavior, walking activity, and moderate-to-vigorous physical activity (MVPA) levels between breast cancer survivors, other cancer survivors, and women with no history of cancer were compared by complex-sample general linear models. Breast cancer survivors spent significantly less mean time in sedentary behavior than other cancer survivors and women with no history of cancer; however, among them, 48.34% spent a long sedentary time of ≥420 min/day. Breast cancer survivors had a significantly higher level of walking activity and similar total MVPA levels compared to women with no history of cancer. When comparing domain-specific MVPA levels, breast cancer survivors showed significantly lower work-related MVPA levels than women with no history of cancer. In recent years, community-dwelling Korean breast cancer survivors were less sedentary, walked more, and had equivalent MVPA levels compared with women with no history of cancer. Considering the growing emphasis on healthy lifestyles, our results may reflect more contemporary behavior trends of breast cancer survivors.

Background We investigated the sociodemographic and health-related factors associated with health checkup participation in community-dwelling stroke survivors. Methods Among participants of the Korea National Health and Nutrition Examination Survey, 642 stroke survivors were included. We investigated the sociodemographic, medical, and health-related quality of life factors—evaluated by the EuroQol 5-Dimension Questionnaire (EQ-5D)—associated with participation in any type of health checkup. To explore the associations between multiple variables and health checkup participation, a multivariable complex-sample logistic regression model was used. Results One-third of the community-dwelling stroke survivors did not receive a health checkup in the past two years. Insufficient physical activity (OR: 0.5, 95% CI: 0.3–0.9), current smoking (OR: 0.4, 95% CI: 0.2–0.8), low education level (OR: 0.5, 95% CI: 0.3–0.9), living alone (OR: 0.5, 95% CI: 0.3–0.998), and no occupation (OR: 0.5, 95% CI: 0.3–0.9) showed independent negative associations with health checkup participation. Among the five EQ-5D dimensions, mobility, self-care, usual activities, and pain/discomfort dimensions were associated with health checkup participation rate. Conclusion Policies and further research are needed to promote health checkups for stroke survivors who are physically inactive, currently smoking, living alone, unemployed, less educated, or having extreme problems in their daily lives.

Trans-anethole (AN), which exhibits strong insect-repellent activity against Plodia interpunctella larvae, was applied on a polyethylene terephthalate (PET) film as an active packaging coating layer. All developed films at different concentrations (25%, 30%, 40%, and 50%) exhibited significant insect repellent activities. However, these films did not significantly differ from the control film in terms of color and transparency. In addition, the developed polypropylene (PP) and PET laminated films containing 25% AN (PP/AN25/PET) exhibited strong and continuous insect-repellent activity for up to 42 days. Finally, the developed film showed 2.86-fold stronger repellent activity than that of the control film when applied to the almond flake cereals packaging. These results suggest that PP/AN25/PET could be used as a potent insect-repelling packaging film in a realistic grain-packaging system. PRACTICAL APPLICATION: A PP/trans-anethole/PET film that exhibited good insect-repellent activity for 42 days was newly developed in this study. As it showed strong insect repellency, especially in almond flake cereals packaging, it is expected to have high potential as an insect-repelling grain-packaging film.

Upper-extremity deep vein thrombosis (DVT) accounts for 1% to 4% of DVT cases. Brachial plexus injury can result from venous distention due to thrombosis in the upper extremity, leading to neurologic deficits. We report a patient diagnosed with brachial plexopathy caused by venous thrombosis in the upper extremity. A 66-year-old female patient with a medical history of Parkinson disease and dementia presented to the emergency department with drowsy mental status. She was diagnosed with pre-renal acute kidney injury with multi-organ dysfunction. On the second hospital day, right upper extremity edema and muscle weakness were observed. On the sixth hospital day, the patient’s overall medical condition improved after conservative treatment, but severe edema was noticed, and muscle weakness did not show significant improvement in the right upper extremity. Computed tomography showed multifocal pulmonary thromboembolism and DVT in the pulmonary arteries, superior vena cava, and popliteal veins. After anticoagulant administration, the swelling subsided, but the weakness in the entire right upper extremity did not improve. Electromyography demonstrated right brachial pan-plexopathy involving the upper, middle, and lower trunks. A follow-up examination showed no significant improvement of muscle strength and function in the right upper extremity at 3 months after the first hospital day.

Dysphagia is one of the main serious issues for amyotrophic lateral sclerosis (ALS) patients because of causing malnutrition and aspiration pneumonia. Early detection and management of dysphagia are essential for the long-term survival. In this study, videofluoroscopic swallowing study (VFSS) results of bulbar and spinal onset ALS patients were compared. VFSS results and revised ALS Functional Rating Scale (ALSFRS-R) score were also analyzed to assess the correlation between dysphagia and functional status of patients. ALS patients with swallowing difficulties who underwent VFSS were recruited retrospectively. Two oral, seven pharyngeal, and two esophageal components of VFSS were evaluated. An ALSRFRS-R bulbar subtype score 9 was used to divide the groups with severe bulbar symptoms. Total 109 Korean ALS patients (39 bulbar vs 70 spinal) were included. Bulbar ALS patients exhibited a significantly longer oral transit time (OTT) then spinal ALS patients, especially in severe bulbar patients with low ALSRFRS-R bulbar subscale. In bulbar ALS patients, penetration (thick liquid), aspiration, OTT, and Penetration-Aspiration Scale (PAS) were significantly correlated with ALSFRS-R bulbar subscale score. However, in spinal ALS patients, only OTT (thin liquid) and aspiration (thick liquid) were significantly correlated with ALSFRS-R bulbar subscale score. Bulbar ALS patients demonstrated significantly longer OTT than spinal ALS patients, and ALSFRS-R bulbar subscale score also correlated well with bulbar ALS patients. Therefore, high vigilance and aggressive treatment for dysphagia especially in bulbar ALS patients rather than spinal ALS patients are mandatory.

An interatomic potential for the ternary Ag–Cu–Sn system, an important material system related to the applications of lead-free solders, is developed on the basis of the second nearest-neighbor modified embedded-atom-method formalism. Potential parameters for the ternary and related binary systems are determined based on the recently improved unary description of pure Sn and the present improvements to the unary descriptions of pure Ag and Cu. To ensure the sufficient performance of atomistic simulations in various applications, the optimization of potential parameters is conducted based on the force-matching method that utilizes density functional theory predictions of energies and forces on various atomic configurations. We validate that the developed interatomic potential exhibits sufficient accuracy and transferability to various physical properties of pure metals, intermetallic compounds, solid solutions, and liquid solutions. The proposed interatomic potential can be straightforwardly used in future studies to investigate atomic-scale phenomena in soldering applications. Graphical abstract

Capturing human annotators' subjective responses in image annotation has become crucial as vision-based classifiers expand the range of application areas. While there has been significant progress in image annotation interface design in general, relatively little research has been conducted to understand how to elicit reliable and cost-efficient human annotation when the nature of the task includes a certain level of subjectivity. To bridge this gap, we aim to understand how different sampling methods in image batch labeling, a design that allows human annotators to label a batch of images simultaneously, can impact human annotation performances. In particular, we developed three different strategies in forming image batches: (1) uncertainty-based labeling (UL) that prioritizes images that a classifier predicts with the highest uncertainty, (2) certainty-based labeling (CL), a reverse strategy of UL, and (3) random, a baseline approach that randomly selects images. Although UL and CL solely select images to be labeled from a classifier's point of view, we hypothesized that human-side perception and labeling performance may also vary depending on the different sampling strategies. In our study, we observed that participants were able to recognize a different level of perceived cognitive load across three conditions (CL the easiest while UL the most difficult). We also observed a trade-off between annotation task effectiveness (CL and UL more reliable than random) and task efficiency (UL the most efficient while CL the least efficient). Based on the results, we discuss the implications of design and possible future research directions of image batch labeling.

Most of the investigations on the micro-Doppler (MD) effect caused by a small unmanned aerial vehicle (UAV) have been conducted using joint time–frequency (JTF) images rather than the Doppler spectrum. On the other hand, several researchers utilized the Doppler spectrum instead of JTF images to observe the MD signature of a small UAV, and found the relationship between the spectral distribution of a small UAV and its physical specifications. However, the studies using the Doppler spectrum still lack concrete and theoretical foundations of the MD effects of a small UAV, focusing mainly on phenomena identified by measurement data. In this article, we establish the theoretical foundation connecting the MD signatures and motion dynamics of small UAVs based on the Doppler spectrum, and analyze their spectral distribution using simulations and measured data. In addition, experimental analysis is conducted using the data measured from various types of small UAVs considering the translational motion and aspect change. In contrast to already existing investigations, we completely explain and predict the changes on the Doppler spectrum relative to the physical specifications of a small UAV (e.g., blade length and rotor rotation rate). In particular, we show that the Doppler spectrum, compared to the JTF images, is a considerably simple and useful tool for analyzing the MD effects of small flying UAVs. The analysis results reveal that the MD features obtained from the measured echoes of small UAVs have considerable potential for detection and classification of small UAVs.

Poly(ionic liquid)s (PILs) are used in many electrochemical energy storage/conversion devices owing to their favorable physical properties. Therefore, PIL binders have been examined as polymeric binders for electrodes in energy storage systems (ESSs) and have shown superior performance. Several innovative technologies have been developed to improve the properties of polymers, with cross-linking being the most effective and easy strategy to achieve this. In this study, we designed a breakthrough complex cross-linking and composite technique that could successfully develop the physical properties of a polymer in a simple one-step process. Additionally, the technique could improve the thermal stability and mechanical properties of the polymer. The proposed polymeric binder showed better adhesion, higher capacitance, and good energy density with improved cyclic stability compared to that shown by conventional polyvinylidene fluoride (PVDF). This study revealed that cross-linked networks in polymeric binders are long-cycle-life features for electrochemical redox capacitors.

BACKGROUND Global warming and the indiscriminate use of pesticides have increased the propagation of the stored-product insect pests, leading to enormous losses in the agriculture and food industries. The most used insect repellents are synthetic derivatives; however, these have an adverse effect on human health as well as on the environment. Therefore, we attempted to find materials with insect repellent activity in natural products. The present study aimed to identify the single chemical component with intense insect repellent activity in extracts from four different Oriental medicinal plant materials: (i) Anethum graveolens L. (dill) seeds; (ii) Artemisia capillaris Thunb. (capillary wormwood) leaves; (iii) smoked Prunus mume Siebold & Zucc. (mume) fruits; and (iv) Rhus javanica L. (galls). RESULTS As a result of the bioassay-guided fractionation of each extract against the Plodia interpunctella, stored-product insect, the n-hexane fraction of dill seeds extract was confirmed as the optimal fraction between all of the fractions. In total, 32 chemical components were identified from the n-hexane fraction of dill seeds by gas chromatography-mass spectrometry analysis, and the two main components were dillapiole (47.51%) and carvone (26.76%). Of the two components, dillapiole was confirmed as the key component playing an essential role in insect repellent activity. CONCLUSION Our study suggests that dillapiole has the potential to be used as a natural insect repellent for the control of P. interpunctella infestation in agricultural and food products during distribution and storage. © 2021 Society of Chemical Industry.

Microthermoelectric modules can be used as energy harvesters, active coolers and thermal sensors in integrated systems. However, manufacturing such modules with traditional microfabrication processes is costly and produces only two-dimensional thermoelectric films, which limit the formation of high-temperature gradients and thus the amount of power generated. Here we show that microscale three-dimensional thermoelectric architectures can be fabricated through the direct writing of particle-based thermoelectric inks. Using size control and surface oxidation, the characteristics of (Bi,Sb)2(Te,Se)3-based particle inks are engineered to create colloidal inks with high viscoelasticity and without organic binders, and the inks are directly written into complex architectures using a 3D printing process. The resulting structures exhibit high thermoelectric figures of merit of 1.0 (p type) and 0.5 (n type), which are comparable to those of bulk ingots. Microthermoelectric generators made from three-dimensionally written vertical filaments exhibit large temperature gradients and a power density of 479.0 μW cm–2. Microscale three-dimensional thermoelectric architectures can be fabricated through the direct writing of particle-based thermoelectric inks and used to create microthermoelectric generators that exhibit a power density of 479.0 μW cm–2.

Background and Purpose: Structural brain networks possess a few hubs, which are not only highly connected to the rest of the brain but are also highly connected to each other. These hubs, which form a rich-club, play a central role in global brain organization. To investigate whether the concept of rich-club sheds new light on poststroke recovery, we applied a novel network-theoretical quantification of lesions to patients with stroke and compared the outcomes with what lesion size alone would indicate. Methods: Whole-brain structural networks of 73 patients with ischemic stroke were reconstructed using diffusion-weighted imaging data. Disconnectomes, a new type of network analyses, were constructed using only those fibers that pass through the lesion. Fugl-Meyer upper extremity scores and their changes were used to determine whether the patients show natural recovery or not. Results: Cluster analysis revealed 3 patient clusters: small-lesion-good-recovery, midsized-lesion-poor-recovery (MLPR), and large-lesion-poor-recovery (LLPR). The small-lesion-good-recovery consisted of subjects whose lesions were small, and whose prospects for recovery were relatively good. To explain the nondifference in recovery between the MLPR and LLPR clusters despite the difference (LLPR>MLPR) in lesion volume, we defined the metric to be the sum of the entries in the disconnectome and, more importantly, the to be the sum of all entries in the disconnectome corresponding to edges with at least one node in the rich-club. Unlike lesion volume and corticospinal tract damage (MLPR , this relationship was reversed (MLPR>LLPR) or showed no difference for . Conclusions: Smaller lesions that focus on the rich-club can be just as devastating as much larger lesions that do not focus on the rich-club, pointing to the role of the rich-club as a backbone for functional communication within brain networks and for recovery from stroke.

Introduction Contemporary epidemiological data on Bell's palsy are crucial to clarify disease burden and improve management strategies. We aimed to examine the epidemiology of, and factors associated with, Bell's palsy treated with steroids in Korea. Methods Using the National Health Insurance claims data from 2008 to 2018, we determined the incidence, recurrence rate, and management trends of Bell's palsy treated with steroids. We defined Bell's palsy cases based on diagnostic codes and concurrent treatment with steroids. Results The incidence of Bell's palsy showed an increasing trend (from 23.0 per 100 000 persons in 2008 to 30.8 per 100 000 persons in 2018). Age (60-69 y), sex (men), and month (January) were risk factors of Bell's palsy. The recurrence rate of Bell's palsy over the 11-y period was 1.5%. Male sex (hazard ratio [HR], 1.1; 95% confidence interval [CI], 1.0-1.2) and physiotherapy (HR, 0.9; 95% CI, 0.8-0.99) were independently associated with the recurrence of Bell's palsy. During the study period, the use of electrodiagnostic testing steadily increased, whereas that of physiotherapy steadily decreased, and antiviral therapy fluctuated,. Discussion The incidence and recurrence rates presented in this study are comparable with those reported in earlier studies that included patients with Bell's palsy, regardless of the use of steroids, and documented an increase in the burden of Bell's palsy. Further randomized controlled trials are required to ascertain the long-term effects of physiotherapy on recurrent Bell's palsy.

Accomplishing slow translocation speed with high sensitivity has been the most critical mission for solid-state nanopore (SSN) device to electrically detect nucleobases in ssDNA. In this study, a method to detect nucleobases of ssDNA using a 2D SSN is introduced by considerably reducing the translocation speed and effectively increasing its sensitivity. The ultra-thin titanium dioxide coated hexagonal boron nitride nanopore was fabricated, along with an ionic-liquid 1-butyl-3-methylimidazolium hexafluorophosphate/2.0 M KCl aqueous (cis/trans) interface, for increasing both the spatial and the temporal resolutions. As the ssDNA molecules entered the nanopore, a brief surge of electrical conductivity occurred, which was followed by multiple resistive pulses from nucleobases during the translocation of ssDNA and another brief current surge flagging the exit of the molecule. The continuous detection of nucleobases using a 2D SSN device is a novel achievement: the water molecules bound to ssDNA increased the molecular conductivity and amplified electrical signals during the translocation. Along with the experiment, computational simulations using COMSOL Multiphysics are presented to explain the pivotal role of water molecules bound to ssDNA to detect nucleobases using a 2D SSN.

Cortical connectivity analysis is a widely used method for understanding the causes of neurological disorders and related brain mechanisms. Although there exist numerous activity analysis toolboxes for functional near-infrared spectroscopy (fNIRS), there are only a few cortical connectivity analysis toolboxes. In 2019, we released a MATALB toolbox named OptoNet , which has helped researchers to analyze brain networks using fNIRS. In this study, we developed an advanced MATLAB toolbox, named OptoNet II, to add new features that overcome the shortcomings of OptoNet . With these new features, OptoNet II can efficiently analyze cortical connectivity according to brain region using any fNIRS channel sets and can present the results of two connectivity analyses with auto-thresholding based on surrogate tests. To evaluate the efficacy of the new functions, the finger-tapping task experiment was carried out before and after transcranial direct current stimulation (tDCS) in the primary motor area. OptoNet II can efficiently show the effects of tDCS on functional brain region connectivity, which has been difficult to confirm by conventional methods. In this article, we propose the OptoNet II as a useful and efficient toolbox for researchers who want to perform cortical connectivity analysis using fNIRS.

The effects of different nutrient solution quantities on growth, physicochemical, nutritional, and postharvest qualities of lettuce were investigated. Two differently pigmented Korean leaf lettuce cultivars “Geockchima” and “Cheongchima” were grown in soilless perlite culture supplied with 250, 500, 1000, and 2000 mL·d−1·plant−1 nutrient solutions. Several growth parameters (plant height, leaf number, fresh weight, dry matter) were evaluated. The highest lettuce growth was observed when plants were supplied with 1000 mL·d−1·plant−1. Cultivating lettuces in the lowest nutrient solution quantity showed higher dry matter, crude fiber, osmolality, chlorophyll, and anthocyanin contents. Upon increasing the nutrient solution, the crispiness, greenness, and levels of ascorbic acid, nitrogen, and potassium, increased, while phosphorus and magnesium were unaffected, and calcium content declined. Postharvest qualities were better maintained in lettuces irrigated with the least amount of nutrient solution, extending their shelf life. We conclude that lettuce can be grown with 1000 mL·d−1·plant−1 for higher yield, and short-term storage and/or transportation. However, when lettuces need to be stored for a certain period, such as long-distance shipment, they should be cultivated with a limited nutrient solution, which requires further detailed investigation. The results of this study can be applied for distributing, storing, transporting, and marketing lettuce.

The appropriate plot effectively conveys the author's conclusions to the readers.

Ordered mesoporous carbons (OMCs) have attracted considerable interest owing to their broad utility. OMCs reported to date comprise amorphous rod-like or tubular or graphitic rod-like frameworks, which exhibit tradeoffs between conductivity and surface area. Here we report ordered mesoporous carbons constructed with graphitic tubular frameworks (OMGCs) with tunable pore sizes and mesostructures via dual templating, using mesoporous silica and molybdenum carbide as exo- and endo-templates, respectively. OMGCs simultaneously realize high electrical conductivity and large surface area and pore volume. Benefitting from these features, Ru nanoparticles (NPs) supported on OMGC exhibit superior catalytic activity for alkaline hydrogen evolution reaction and single-cell performance for anion exchange membrane water electrolysis compared to Ru NPs on other OMCs and commercial catalysts. Further, the OMGC-based full-carbon symmetric cell demonstrates excellent performances for Li-ion capacitors.

The self-organization of colloidal nanoparticles into programmed suprastructures is an important research area in various disciplines of nano, colloid, and polymer sciences. However, despite the re...

Objectives The number of patients undergoing oral anticoagulant therapy for cardiovascular and cerebrovascular disease is increasing. However, the risk of bleeding after tooth extraction in patients receiving warfarin is unclear. Here, we assess the risk of bleeding after tooth extraction in patients on warfarin. Materials and methods The study included 260 patients taking warfarin who underwent tooth extraction (694 teeth). The patients were divided into those whose teeth were extracted while they were taking warfarin, those who discontinued warfarin before extraction, and those who underwent extraction while receiving heparin bridging therapy. Bleeding complications in the two groups were compared. Results Of the 260 patients, 156 underwent extraction while taking warfarin, 70 stopped taking warfarin before extractions, and 34 received heparin bridging therapy and stopped taking either medication before extractions. Bleeding complications occurred in 9 patients (3.5%) and 9 tooth sites (1.3%). Among the 9 patients with bleeding complications, 6 underwent extraction while taking warfarin, 2 stopped warfarin before extraction, and 1 underwent extraction after receiving heparin bridging therapy. No significant difference was seen between patient groups regarding bleeding after extractions (P=0.917). Conclusion Warfarin use does not increase the risk of post-extraction bleeding and can therefore be continued during tooth extraction.

In the field of stimuli-responsive polymer research, poly-N-isopropylacrylamide (PNIPAAm) has been widely studied, because this material has unique properties which respond to temperatures near to that of the human body, approximately 36 °C. In this study, a nano-patterned PNIPAAm hydrogel was prepared using UV-irradiation and soft lithography. Chemical changes in the C–C double bonds of the PNIPAAm hydrogel were confirmed by FT-IR analysis. The thermal properties of the hydrogel were analyzed by differential scanning calorimetry (DSC), which confirmed its low critical solution temperature (LCST). The highest gel content of approximately 46% was achieved at 120 min UV-irradiation. The nano-patterned morphology of the PNIPAAm hydrogel exhibited temperature-dependent reversible shape transformation. This study shows that the reversible shape transformation of the PNIPAAm hydrogel was due to swelling and shrinking.

In this study, we developed a facile and template-free strategy for the preparation of activated porous carbon beads (APCBs) from polyacrylonitrile. The chemical activation with KOH was found to enhance the pore properties, such as specific surface area (SSA), pore volume, and pore area. The APCBs exhibited a large SSA of 1147.99 m2/g and a pore area of 131.73 m2/g. The APCB-based electrodes showed a good specific capacitance of 112 F/g at 1 A/g in a 6 M KOH electrolyte, and excellent capacitance retention of 100% at a current density of 5 A/g after 1000 cycles. Therefore, the APCBs prepared in this study can be applied as electrode materials for electric double-layer capacitors.

Objectives:Heavy metals caused by industrialization have affected human society for several decades. Because of their toxicity for humans, lots of heavy metal treatments have been developed. However, many of those treatments have economic considerations and environmental disadvantages. This work explored an experimental assessment of adsorption of heavy metals using starfish (SF) biochar through quantitative and qualitative characterization and batch-tests.Methods:Biochar (NACSF) was produced at 300℃ for 2 h in anaerobic conditions. The NACSF was characterized with XRD, XRF, FT-IR, SEM-EDX and elemental analyses. Moreover, batch-tests for each heavy metal using NACSF were conducted with ICP-OES analyses in order to evaluate the adsorption characteristics.Results and Discussion:Based on the characterization results, the NACSF consisted of carbon and CaCO3 mainly. The adsorption rates of Pb, Cu, Zn and Cd decreased in the following order: Pb≫Cu>Zn≥Cd. Moreover, the Langmuir equation fit all adsorption data better than the Freundlich equation. Also, due to the alkalinity of NACSF, the measured pH values of all experimental groups were approximately 7~8.Conclusions:The NACSF treatment was the most effective for Pb removal and it was determined that precipitation and surface adsorption were the most likely mechanisms for Pb removal. Thus, NACSF derived from starfish could be an cost-effective and eco-friendly treatment for heavy metal contaminated wastewater.

A comparison of the shelf-life of various lettuces (i.e., Ezabel, Butterhead, Pagero, mini Romaine, Caipira and red leaf lettuce) during storage was carried out based on different packaging types. More specifically, the Butterhead lettuce sample was packaged in a polyethylene terephthalate (PET) tray, while the Ezabel, Pagero, mini Romaine, Caipira and red leaf lettuce samples were packaged in polypropylene (PP) film. Changes in the sample weight loss, respiration rate, chlorophyll content, and visual quality were then investigated during storage at 10°C. The Ezabel and Caipira samples exhibited the highest weight loss, whereas the Butterhead sample showed the lowest weight loss. Among the various lettuce samples, the chlorophyll content of the mini Romaine lettuce was the highest. In addition, the freshness of the Butterhead lettuce sample was maintained during 18 days at 10°C, compared to 12 d for the Ezabel, Pagero, mini Romaine, and Caipira samples. These results therefore suggest that tray packaging was effective in maintaining the lettuce quality, while packaging in a PP resulted in leaf softening and discoloration. Larger leaf areas also resulted in longer shelf-life. The development of an optimal packaging for lettuce to ensure that freshness is maintained during storage is therefore necessary.