Fast digitally reconstructed radiograph generation using particle-based statistical shape and intensity model.

Purpose: Statistical shape and intensity models (SSIMs) and digitally reconstructed radiographs (DRRs) were introduced for non-rigid 2D-3D registration and skeletal geometry/density reconstruction studies. The computation of DRRs takes most of the time during registration or reconstruction. The goal of this study is to propose a particle-based method for composing an SSIM and a DRR image generation scheme and analyze the quality of the images compared with previous DRR generation methods. Approach: Particle-based SSIMs consist of densely scattered particles on the surface and inside of an object, with each particle having an intensity value. Generating the DRR resembles ray tracing, which counts the particles that are binned with each ray and calculates the radiation attenuation. The distance between adjacent particles was considered to be the radiologic path during attenuation integration, and the mean linear attenuation coefficient of the two particles was multiplied. The proposed method was compared with the DRR of CT projection. The mean squared error and peak signal-to-noise ratio (PSNR) were calculated between the DRR images from the proposed method and those of existing methods of projecting tetrahedral-based SSIMs or computed tomography (CT) images to verify the accuracy of the proposed scheme. Results: The suggested method was about 600 times faster than the tetrahedral-based SSIM without using the hardware acceleration technique. The PSNR was 37.59 dB, and the root mean squared error of the normalized pixel intensities was 0.0136. Conclusions: The proposed SSIM and DRR generation procedure showed high temporal performance while maintaining image quality, and particle-based SSIM is a feasible form for representing a 3D volume and generating the DRR images.

Electrochemical Investigations of Double Perovskite M2NiMnO6 (Where M = Eu, Gd, Tb) for High-Performance Oxygen Evolution Reaction.

Double perovskites are known for their special structures which can be utilized as catalyst electrode materials for electrochemical water splitting to generate carbon-neutral hydrogen energy. In this work, we prepared lanthanide series metal-doped double perovskites at the M site such as M2NiMnO6 (where M = Eu, Gd, Tb) using the solid-state reaction method, and they were investigated for an oxygen evolution reaction (OER) study in an alkaline medium. It is revealed that the catalyst with a configuration of Tb2NiMnO6 has outstanding OER properties such as a low overpotential of 288 mV to achieve a current density of 10 mAcm-2, a lower Tafel slope of 38.76 mVdec-1, and a long cycling stability over 100 h of continuous operation. A-site doping causes an alteration in the oxidation or valence states of the NiMn cations, their porosity, and the oxygen vacancies. This is evidenced in terms of the Mn4+/Mn3+ ratio modifying electronic properties and the surface which facilitates the OER properties of the catalyst. This is discussed using electrochemical impedance spectroscopy (EIS) and electrochemical surface area (ECSA) of the catalysts. The proposed work is promising for the synthesis and utilization of future catalyst electrodes for high-performance electrochemical water splitting.

The Study of a Validated Assessment Scale for a Localized Submental Fat Volume.

BACKGROUND: This aim of this study was to develop an objective tool for rating submental fat applied to Koreans. METHODS: The study was conducted between April 2019 and October 2019. A total of 92 subjects were enrolled in the study. Clinical photos of the subjects were categorized using validated CR-SMFRS by three plastic surgeons and one dermatologist. The categorized photos were then shown to six different plastic surgeons for evaluation. RESULTS: The Cohen's kappa value for the six raters were 0.830, 0.742, 0.703, 0.907, 0.862, and 0.793 with statistical significance (p < 0.001). ICC value was between 0.860 and 0.966 (p < 0.001). Since the Cohen's value and ICC were above 0.6 for all raters, the ratings performed by all six raters were used in the analysis. The ICC values between raters were between 0.899 and 0.902. CONCLUSIONS: We came up with a set of reference photos that can be used for submental fat rating scale applicable to Korean subjects. LEVEL OF EVIDENCE: II.

Cranioplasty Using Three-Dimensional-Printed Polycaprolactone Implant and Free Latissimus Dorsi Musculocutaneous Flap in a Patient with Repeated Wound Problem following Titanium Cranioplasty.

Titanium mesh is an alloplastic material widely used for the reconstruction of moderate-to-large skull defects. Repeated wound problems or infection following these reconstructions inevitably lead to the replacement of the cranioplasty material. Among the various alloplastic materials, polycaprolactone implants are usually used for the coverage of small defects such as burr holes. 1 Herein, we present a case of a large cranial defect successfully reconstructed with three-dimensional-printed polycaprolactone implant and a free latissimus dorsi musculocutaneous flap. Until 1-year follow-up, the patient showed a favorable esthetic outcome with no complications or wound relapse.

Generation of a more efficient prime editor 2 by addition of the Rad51 DNA-binding domain.

Although prime editing is a promising genome editing method, the efficiency of prime editor 2 (PE2) is often insufficient. Here we generate a more efficient variant of PE2, named hyPE2, by adding the Rad51 DNA-binding domain. When tested at endogenous sites, hyPE2 shows a median of 1.5- or 1.4- fold (range, 0.99- to 2.6-fold) higher efficiencies than PE2; furthermore, at sites where PE2-induced prime editing is very inefficient (efficiency < 1%), hyPE2 enables prime editing with efficiencies ranging from 1.1% to 2.9% at up to 34% of target sequences, potentially facilitating prime editing applications.

BellaGel breast implant: 6-Year results of a prospective cohort study.

BACKGROUND: This is the first clinical study conducted among Asian women using breast implants manufactured by an Asian company. Four-year data regarding the safety and efficacy of BellaGel breast implants have already been published, and we now report 6-year data. METHODS: This study was designed to take place over 10 years. It included 103 patients who underwent breast reconstruction or augmentation using BellaGel breast implants. The rates of implant rupture and capsular contracture were measured and analyzed to evaluate the effectiveness of the breast implant. RESULTS: At patients' 6-year postoperative visits, the implant rupture and capsular contracture rates were 1.15% and 2.30%, respectively. The implant rupture rate was 3.77% among reconstruction cases and 0% among augmentation cases. The capsular contracture rate was 5.66% among reconstruction cases and 0.83% among augmentation cases. CONCLUSIONS: The 6-year data from this planned 10-year study suggest that the BellaGel cohesive silicone gel-filled breast implant is an effective and safe medical device that can be used in breast reconstruction and augmentation.

Flap reconstruction of soft tissue defect after resecting a huge hemangioma of the nose.

Hemangioma is a benign vascular tumor that grows by endothelial cell hyperplasia. It occurs most frequently in the head and neck region. Nose reconstruction is tricky because of its unique threedimensional structure and different tissue components. We report a case of successful reconstruction of near-total nose defect using the paramedian forehead flap combined with a nasolabial flap, immediately after excision of nasal hemangioma. A 49-year-old male patient was presented with a huge mass at the nose. Preoperative magnetic resonance imaging showed prominent vascular channels extending to the forehead and cheek. Complete resection of the mass was performed, which resulted in an eccentric defect. The right paramedian forehead flap and the left nasolabial flap were designed and transferred to the defect. Flap division was performed 1 month later. The patient is satisfied with the overall appearance and did not develop any functional deficit.

The island-type pedicled TRAM flap: Improvement of the aesthetic outcomes of breast reconstruction.

BACKGROUND: The pedicled transverse rectus abdominis myocutaneous flap (TRAM) remains an effective and widely-used method for breast reconstruction despite well-documented donor-site morbidity. We present the island-type pedicled TRAM flap as a way to obtain better and more reliable outcomes in breast reconstruction. METHODS: A retrospective chart review of patients who underwent breast reconstruction with an island-type pedicled TRAM flap was performed. Patient demographics and complications were reviewed. In the island-type pedicled TRAM flap, we transversely resected the upper ipsilateral rectus muscle surrounding the origin of the superior epigastric vessels, preserving only a 1-cm muscle strip including the vascular pedicle to prevent epigastric bulging and inframammary fold (IMF) disruption. The flap was turned over into the ipsilateral breast pocket. The IMF was repaired except for the portion where the pedicle was placed. RESULTS: From January 2013 to November 2017, 88 patients underwent surgery using the island-type pedicled TRAM flap. The etiology of the defect was breast cancer with mastectomy in 86 cases, and paraffinoma in two cases. Seventy-seven patients underwent unilateral reconstruction, and 11 patients underwent bilateral reconstruction. Minor fat necrosis occurred in eight cases. Mild inframammary or epigastric bulging was observed in five cases, and neither partial nor total flap necrosis was observed. The aesthetic outcome of the IMF was evaluated in 55 cases, and 53 cases received good overall scores. CONCLUSION: Although the island-type pedicled TRAM flap is technically challenging because careful dissection and pedicle identification is required, it can provide more reliable and better aesthetic results without an increased risk of vascular compromise.

Extensive full thickness abdominal wall reconstruction using anterolateral thigh compound flap modifications.

PURPOSE: Abdominal wall reconstruction is challenging, which demands adequate skin coverage and structural support. The anterolateral thigh (ALT) flap including fascial portion can be useful in such cases. METHODS: Retrospective chart review of five patients that underwent complex abdominal wall defects reconstruction with ALT free flaps with fascia lata was conducted. Patient age ranged from 49 to 69 years (average: 57.4). The etiology of defects was infected liposuction site, small bowel perforation, esophageal cancer, diverticulum perforation, and Hartmann operation. The average size of the defect was 17.4 × 10 cm (9 × 9 ~ 21 × 18). Single-stage reconstruction using ALT flaps based on the lateral circumflex femoral artery was done in all patients. Exposed intestines were successfully covered and reinforced utilizing fascial component. RESULTS: The average size of the flap was 17.4 × 8 cm (9 × 9 cm ~25 × 10 cm). One partial flap necrosis, venous congestion, and infection occurred. These complications were treated successfully. During the follow-up (12-96 months, mean: 63), all patients achieved functional stabilization and returned to normal activities. CONCLUSION: ALT flap combined with its fascial component is useful for abdominal wall. It can be a reliable option in cases of intestinal exposure.

Exclusive tongue tip reconstruction of hemiglossectomy defects using the underrated lateral arm free flap with bilobed design.

BACKGROUND: Tongue reconstruction is challenging with the unique function and anatomy. Goals for reconstruction differ depending on the extent of reconstruction. Thin and pliable flaps are useful for tongue tip reconstruction, for appearance and mobility. This study reports lateral arm free flap (LAFF) as a safe and optimal option for hemi-tongue reconstruction, especially for tongue tip after hemiglossectomy. METHODS: Thirteen LAFFs were performed for hemi-tongue reconstruction after hemiglossectomy from 1995 to 2018. Of the 13 patients, seven were male and six were female, age varying from 24 to 64 years. RESULTS: All flaps healed uneventfully without complications. Donor sites were closed primarily. The recipient vessels for microvascular anastomosis were mainly superior thyroidal artery, external jugular vein. All patients returned to normal diet, with no complaints regarding reconstructed tongue and donor site. CONCLUSION: The LAFF is hairless, thin (especially with lateral epicondyle approach), and potentially sensate. They are advantageous features for tongue tip and hemi-tongue reconstruction. Donor site sacrifices the inessential posterior radial collateral artery, and the scar is hidden under short sleeve shirts. We believe that LAFF can be considered as the first choice flap for hemitongue reconstruction, over radial forearm free flaps.

Treatment of deep cavities using a perforator-based island flap with partial de-epithelization.

BACKGROUND: The perforator-based island flap is a popular option for defect coverage. In cases with deep cavities, however, the classical island flap may not be a suitable option. By de-epithelization of the peripheral portion of a perforator-based island flap, the distal part of the flap can be used to fill deep spaces, as the flap can be folded and inserted into the spaces. METHODS: From June 2015 to April 2017, 21 cases of deep internal defects were reconstructed with perforator-based island flaps with peripheral de-epithelization. A fasciocutaneous flap was elevated and rotated with the pivot point on the perforator. After performing de-epithelization on the periphery of the flap, the de-epithelized portion of the flap was inserted and anchored into the internal defect. Demographic information about the patients, the size of the defects, the perforators that were used, and complications were recorded. RESULTS: During the follow-up period (mean, 14.2 months) of total 21 cases, no major complications such as flap loss occurred. In 2 cases, a minor complication was observed. Temporary flap congestion was seen in 1 case, and was treated with a short period of leech therapy, and the other case was partial necrosis on the flap margin, which was cured with minimal debridement and conservative treatment. No major problems have occurred, especially on the de-epithelized part of the flap and in the occupied space. CONCLUSIONS: With performing careful procedure, a perforator-based island flap with partial de-epithelization can be a useful option for the surgical treatment of deep cavities. TRIAL REGISTRATION: This study was retrospectively registered in the institutional review board on human subjects research and the ethics committee, Hanyang University Guri Hospital (Institutional Review Board File No. 2018-01-003-002 https://www.e-irb.com:3443/devlpg/nlpgS200.jsp ).

Simultaneous reconstruction of the forearm extensor compartment tendon, soft tissue, and skin.

Malignant peripheral nerve sheath tumor (MPNST) is a very rare type of sarcoma, with an incidence of 0.001%. MPNST has a 5-year survival rate near 80%, so successful reconstruction techniques are important to ensure the patient's quality of life. Sarcoma of the forearm is known for its poor prognosis, which leads to wider excision, making reconstruction even more challenging due to the unique anatomical structure and delicate function of the forearm. A 44-year-old male presented with a large mass that had two aspects, measuring 9×6 cm and 7×5 cm, on the dorsal aspect of the right forearm. The extensor compartment muscles (EDM, EDC, EIP, EPB, EPL, ECRB, ECRL, APL) and invaded radius were resected with the mass. Tendon transfer of the entire extensor compartment with skin defect coverage using a 24×8 cm anterolateral thigh (ALT) perforator free flap was performed. The patient was discharged after 18 days without wound complications, and has not complained of discomfort during supination, pronation, or wrist extension/flexion through 3 years of follow-up. To our knowledge, this is the first report of successful reconstruction of the entire forearm extensor compartment with ALT free flap coverage after resection of MPNST.

Pectoralis Major Musculocutaneous Flap With a Midline Sternal Skin Paddle for Head and Neck Reconstruction: A New Design.

PURPOSE: The pectoralis major musculocutaneous (PMMC) flap is a classic flap for head and neck reconstruction, relatively unpopular with the advancement of microsurgery and free flaps. The classic parasternal paddle design provided a thick flap with a small rotation arch leaving objectionable scarring. Our new symmetric midsternal design overcomes these problems. METHODS: Chart review was done from the years 2000 to 2017. Flap skin paddle was placed symmetrically on both sides of the midsternal line. The pectoralis major (PM) muscle and aponeurosis were attached in the lateral half of the skin paddle. Most of PM muscle was elevated with the thoracoacromial vessel and dissected to the main trunk, where the PM muscle was cut and used for bulk. The flap was transferred to the neck and lower mandibular area. The flap was inset either supraclavicularly, covering the anterior neck, or subclavicularly, for intraoral/maxillary defects. RESULTS: Eight patients underwent head and neck reconstruction using the new design of PMMC flap between the years 2000 and 2017. The etiologies of the defect were radiation necrosis in 3 patients, repair of cutaneous fistulas in 3, recurrent hypopharyngeal cancer in 1, and recurrent tongue cancer in 1 patient. There were no flap losses or major complications. CONCLUSIONS: With the advancement of free-flap techniques, the classic flaps have become less popular. Our new design supplements the PMMC flap by providing a thin pliable flap with a long pedicle and rotation arc, allowing a combination of different types of flaps to cover composite head and neck defects, especially in cases that lack a reliable recipient vessel due to radiation.

Umbilical Quilting Suture Technique during Single-Port Laparoscopic Surgery.

BACKGROUND AND OBJECTIVES: Single-port laparoscopic surgery (SPLS) is popular in the gynecological field, because it is less invasive and leaves a smaller scar. However, the postoperative shape of the umbilicus is often distorted due to the intensive procedures performed through the small opening. In this report, we describe a technique for forming a satisfactory umbilicus in SPLS. METHODS: From March 2016 through April 2017, 32 patients were treated with SPLS by a single gynecologic surgeon. Group A (14 cases) underwent conventional umbilicus closure, and group B (18 cases) underwent a quilting suture technique. The umbilical shapes of each group were assessed by a plastic surgeon as was the patients' satisfaction. Evaluations were performed immediately after surgery and every month for 6 months thereafter. RESULTS: The postoperative umbilical shape in group A showed features, such as loss of depression, disappearance of the central vertical line, and irregularly bulging tissue, whereas group B had a shape similar to that of the natural umbilicus and maintained its depression and vertical line. The average scores of the plastic surgeons' evaluations immediately after the operation were 10.4 for group A and 15.1 for group B. The final scores obtained 6 months after surgery were 15.2 and 17.8, respectively. The patients' satisfaction scores immediately after the operation were 4.9 for group A and 7.3 for group B. The scores increased gradually, to 8.1 and 9.2, respectively, at 6 months after surgery. CONCLUSION: Performing quilting sutures during wound closure in SPLS is effective for making an ideal umbilicus and ensuring patients' satisfaction.

Effects of exogenous growth hormone administration on dexamethasone-induced growth impairment in adolescent male rats.

Growth impairment (GI) is one of the adverse effects of dexamethasone (DXM), and growth hormone (GH) has been used clinically to improve GI. The present study aimed to evaluate the manner in which DXM disturbs the growth rate of longitudinal bones, and the recovery effects of GH on DXM-induced GI in the longitudinal bones of adolescent male rats. In the first experiment, DXM (0, 0.5, 1, 2 and 5 mg/kg) was administered subcutaneously to identify a potential dose-dependent activity and calculate the median effective dose (ED50) of DXM-induced GI. The ED50 was identified to be 1.15 mg/kg. In the second experiment, GH (0, 2.5, 5 and 10 mg/kg) with 1.15 mg/kg DXM was injected subcutaneously to assess the recovery effects of GH on DXM-induced GI. The growth rates of the longitudinal bones, total height of the growth plate, local mRNA expressions of insulin-like growth factor 1 (IGF-1), GH receptor (GHR) and IGF-1 receptor (IGF-1R), and local protein expression of IGF-1 were measured to evaluate the recovery effects of GH on DXM-induced GI. The local expressions of IGF-1, GHR and IGF-1R mRNA, and IGF-1 protein were measured using quantitative polymerase chain reaction following laser microdissection and antigen-specific immunohistochemistry, respectively. GH administration partially recovered DXM-induced GI in the longitudinal bones and growth plate. GH significantly increased the levels of IGF-1, GHR and IGF-1R mRNA in the proliferative zone of the control group (P<0.05), whereas it failed to increase them in the proliferative zone of the DXM-treated group. Furthermore, GH increased the levels of IGF-1, GHR and IGF-1R mRNA in the hypertrophic zone of both the vehicle and DXM-treated groups (P<0.05). Immunohistochemical analysis of IGF-1 protein expression revealed a similar pattern to that of IGF-1 mRNA. These results suggest that increased GH insensitivity in the proliferative zone of the growth plate, induced by DXM, leads to GI in longitudinal bones. Thus, combined administration of GH with GH insensitivity-alleviating medications may be more effective in the treatment of DXM-induced GI.

Functional assembly of minicellulosomes on the Saccharomyces cerevisiae cell surface for cellulose hydrolysis and ethanol production.

We demonstrated the functional display of a miniscaffoldin on the Saccharomyces cerevisiae cell surface consisting of three divergent cohesin domains from Clostridium thermocellum (t), Clostridium cellulolyticum (c), and Ruminococcus flavefaciens (f). Incubation with Escherichia coli lysates containing an endoglucanase (CelA) fused with a dockerin domain from C. thermocellum (At), an exoglucanase (CelE) from C. cellulolyticum fused with a dockerin domain from the same species (Ec), and an endoglucanase (CelG) from C. cellulolyticum fused with a dockerin domain from R. flavefaciens (Gf) resulted in the assembly of a functional minicellulosome on the yeast cell surface. The displayed minicellulosome retained the synergistic effect for cellulose hydrolysis. When a beta-glucosidase (BglA) from C. thermocellum tagged with the dockerin from R. flavefaciens was used in place of Gf, cells displaying the new minicellulosome exhibited significantly enhanced glucose liberation and produced ethanol directly from phosphoric acid-swollen cellulose. The final ethanol concentration of 3.5 g/liter was 2.6-fold higher than that obtained by using the same amounts of added purified cellulases. The overall yield was 0.49 g of ethanol produced per g of carbohydrate consumed, which corresponds to 95% of the theoretical value. This result confirms that simultaneous and synergistic saccharification and fermentation of cellulose to ethanol can be efficiently accomplished with a yeast strain displaying a functional minicellulosome containing all three required cellulolytic enzymes.