Publications by authors named "YoungHun Lee"

The accurate prediction of soil heavy metal contamination is crucial for the effective environmental management of abandoned mining areas. However, conventional machine learning models (CMLMs) often fail to account for the spatial heterogeneity of soil contamination, which limits their predictive accuracy. This study evaluated the performance of geographically weighted machine learning models (GWMLMs) in predicting soil Cd and Pb concentrations in abandoned mines in the Republic of Korea.

View Article and Find Full Text PDF

Background: Osteoporotic vertebral compression fractures commonly involve the superior vertebral body; however, their associated causes have not yet been clearly established. This study aimed to determine the trabecular structural differences between the superior and inferior regions of the vertebral body using cadaveric and clinical studies.

Materials And Methods: First, five vertebrae were collected from three human cadavers.

View Article and Find Full Text PDF

Background: Paraspinal muscle asymmetry is associated with low back pain (LBP) problems. This study aimed to analyze skeletal muscle areas around the lumbar vertebra and compare the ratio of anterior and posterior muscles between patients with lumbar herniated nucleus pulposus (HNP) and healthy individuals using abdominal pelvic computed tomography (APCT).

Methods: After propensity score matching, 122 HNP patients and 122 non-HNP individuals were finally used for analyses.

View Article and Find Full Text PDF

The recycling of filaments used in three-dimensional (3D) printing systems not only mitigates the environmental issues associated with conventional 3D printing approaches but also simultaneously reduces manufacturing costs. This study investigates the effects of successive recycling of polylactic acid (PLA) filaments, which were used in the printing process, on the mechanical properties of recycled filaments and printed objects. The mechanical strengths of the printed PLA and the adhesion strengths between 3D-printed beads were evaluated via the tensile testing of the horizontally and vertically fabricated specimens.

View Article and Find Full Text PDF

Background: A retear after rotator cuff repair is a common problem; however, there is little information related to the prognosis after a retear. In addition, some patients with retears have satisfactory outcomes, which raises the question of whether a retear leads to a poor prognosis.

Purpose: To identify radiological factors that influence the prognosis after a retear.

View Article and Find Full Text PDF

Background: Various complications related to the prosthesis, such as implant loosening and stress shielding phenomenon, could develop after prosthetic replacement of the radial head. Stress shielding is known to occur around rigidly fixed implants. The purpose of this study was to evaluate the clinical influence and causative factors of the stress shielding phenomenon after radial head arthroplasty (RHA).

View Article and Find Full Text PDF

Purpose: Patch augmentation for large and massive rotator cuff tears (LMRCTs) has been suggested as a repair strategy that can mechanically reinforce tendons and biologically enhance healing potential. The purpose of this study was to determine whether patients who underwent patch augmentation would have lower rates of retears and superior functional outcomes.

Methods: Patients who underwent arthroscopic rotator cuff repair (ARCR) with patch augmentation (group A) were matched by age, sex, degree of retraction, and supraspinatus muscle occupation ratio to those treated with ARCR without using a patch (group B) with a minimum follow-up of 24 months.

View Article and Find Full Text PDF

Multiple dorsal fracture-dislocations of the carpometacarpal joints (CMCJ) occur from very high-energy trauma and are often associated with soft tissue injury or ischaemia. We report a 54-year-old male manual worker and a smoker who presented to the emergency room with history of compression of his right hand in a press machine. Radiographs showed dorsal fracture-dislocations of the scapho-trapezio-trapezoidal and third to fifth CMCJ's.

View Article and Find Full Text PDF

This study aimed to determine whether the prevalence of acute vertebral osteoporotic compression fractures (VOCF) in the elderly population is related to the distribution of muscles and fat in the human body. Data of acute VOCF and non-VOCF patients presenting at our institution between January 2018 and May 2020 were analyzed. Patients aged 65 years and older, who underwent body composition test and dual-energy X-ray absorptiometry at the same time were enrolled.

View Article and Find Full Text PDF

Hydrogel is in the spotlight as a useful biomaterial in the field of drug delivery and tissue engineering due to its similar biological properties to a native extracellular matrix (ECM). Herein, we proposed a ternary hydrogel of gellan gum (GG), silk fibroin (SF), and chondroitin sulfate (CS) as a biomaterial for cartilage tissue engineering. The hydrogels were fabricated with a facile combination of the physical and chemical crosslinking method.

View Article and Find Full Text PDF

Introduction: Distal radius fracture (DRF) is the most common upper extremity fracture. After the introduction of volar locking plate (VLP) fixation, treatment has shifted from conservative management to more operative management. The implant removal rate after VLP fixation in patients with DRF varies and the reasons for removal and associated patient characteristics have not been clearly defined.

View Article and Find Full Text PDF

Purpose: Osteoporosis has a high worldwide prevalence and detrimental consequences (e.g., increased fracture risk).

View Article and Find Full Text PDF

This research objective was to determine the significant parameters for effective plasma assisted machining (PAM) of Ti-6Al-4V and to derive optimal processing conditions. PAM parameters such as feed rate, spindle speed, and depth of cut have significant effects on its machining characteristic. In this study, the design of experiments (DOE) was used to select optimal machining conditions for PAM.

View Article and Find Full Text PDF

Nickel cobalt sulfide nanoparticles embedded in holey defect graphene hydrogel (HGH) that exhibit highly porous structures and uniform nickel cobalt sulfide nanoparticle sizes are successfully prepared by a facile solvothermal-hydrothermal method. As an electrode material for supercapacitors, the as-prepared NiCo S @HGH shows ultra-high specific capacitances of 1000 F g and 800 F g at 0.5 and 6 A g , respectively, owing to the outstanding electrical conductivity of HGH and high specific capacitance of NiCo S .

View Article and Find Full Text PDF

Epiregulin (EPR) is a ligand of the epidermal growth factor (EGF) family that upon binding to its epidermal growth factor receptor (EGFR) stimulates proliferative signaling, especially in colon cancer cells. Here, we describe the three-dimensional structure of the EPR antibody (the 9E5(Fab) fragment) in the presence and absence of EPR. Among the six complementarity-determining regions (CDRs), CDR1-3 in the light chain and CDR2 in the heavy chain predominantly recognize EPR.

View Article and Find Full Text PDF

Growth factors are implicated in several processes essential for cancer progression. Specifically, epidermal growth factor (EGF) family members, including epiregulin (EREG), are important prognostic factors in many epithelial cancers, and treatments targeting these molecules have recently become available. Here, we constructed and expressed humanized anti-EREG antibodies by variable domain resurfacing based on the three-dimensional (3D) structure of the Fv fragment.

View Article and Find Full Text PDF

A catadioptric wide-angle lens having a rectilinear projection scheme has been developed with a view to possible applications in the security-surveillance area. The lens has been designed for a miniature camera with a video graphics array-grade 1/3 in. color CCD sensor.

View Article and Find Full Text PDF