Dynamical Study of Adsorbate-Induced Restructuring Kinetics in Bimetallic Catalysts Using the PdAu(111) Model System.

Dynamic restructuring of bimetallic catalysts plays a crucial role in their catalytic activity and selectivity. In particular, catalyst pretreatment with species such as carbon monoxide and oxygen has been shown to be an effective strategy for tuning the surface composition and morphology. Mechanistic and kinetic understanding of such restructuring is fundamental to the chemistry and engineering of surface active sites but has remained challenging due to the large structural, chemical, and temporal degrees of freedom. Here, we combine time-resolved temperature-programmed infrared reflection absorption spectroscopy, ab initio thermodynamics, and machine-learning molecular dynamics to uncover previously unidentified timescale and kinetic parameters of in situ restructuring in Pd/Au(111), a highly relevant model system for dilute Pd-in-Au nanoparticle catalysts. The key innovation lies in utilizing CO not only as a chemically sensitive probe of surface Pd but also as an agent that induces restructuring of the surface. Upon annealing in vacuum, as-deposited Pd islands became encapsulated by Au and partially dissolved into the subsurface, leaving behind isolated Pd monomers on the surface. Subsequent exposure to 0.1 mbar CO enabled Pd monomers to repopulate the surface up to 373 K, above which complete Pd dissolution occurred by 473 K, with apparent activation energies of 0.14 and 0.48 eV, respectively. These restructuring processes occurred over the span of ∼1000 s at a given temperature. Such a minute-timescale dynamics not only elucidates the fluxional nature of alloy catalysts but also presents an opportunity to fine-tune the surface under moderate temperature and pressure conditions.

Guidelines to Achieving High Selectivity for the Hydrogenation of α,ß-Unsaturated Aldehydes with Bimetallic and Dilute Alloy Catalysts: A Review.

Selective hydrogenation of α,ß-unsaturated aldehydes to unsaturated alcohols is a challenging class of reactions, yielding valuable intermediates for the production of pharmaceuticals, perfumes, and flavorings. On monometallic heterogeneous catalysts, the formation of the unsaturated alcohols is thermodynamically disfavored over the saturated aldehydes. Hence, new catalysts are required to achieve the desired selectivity. Herein, the literature of three major research areas in catalysis is integrated as a step toward establishing the guidelines for enhancing the selectivity: reactor studies of complex catalyst materials at operating temperature and pressure, surface science studies of crystalline surfaces in ultrahigh vacuum, and first-principles modeling using density functional theory calculations. Aggregate analysis shows that bimetallic and dilute alloy catalysts significantly enhance the selectivity to the unsaturated alcohols compared to monometallic catalysts. This comprehensive review focuses primarily on the role of different metal surfaces as well as the factors that promote the adsorption of the unsaturated aldehyde via its C═O bond, most notably by electronic modification of the surface and formation of the electrophilic sites. Furthermore, challenges, gaps, and opportunities are identified to advance the rational design of efficient catalysts for this class of reactions, including the need for systematic studies of catalytic processes, theoretical modeling of complex materials, and model studies under ambient pressure and temperature.

Evolution of Metastable Structures at Bimetallic Surfaces from Microscopy and Machine-Learning Molecular Dynamics.

The restructuring of interfaces plays a crucial role in materials science and heterogeneous catalysis. Bimetallic systems, in particular, often adopt very different compositions and morphologies at surfaces compared to the bulk. For the first time, we reveal a detailed atomistic picture of long-time scale restructuring of Pd deposited on Ag using microscopy, spectroscopy, and novel simulation methods. By developing and performing accelerated machine-learning molecular dynamics followed by an automated analysis method, we discover and characterize previously unidentified surface restructuring mechanisms in an unbiased fashion, including Pd-Ag place exchange and Ag pop-out as well as step ascent and descent. Remarkably, layer-by-layer dissolution of Pd into Ag is always preceded by an encapsulation of Pd islands by Ag, resulting in a significant migration of Ag out of the surface and a formation of extensive vacancy pits within a period of microseconds. These metastable structures are of vital catalytic importance, as Ag-encapsulated Pd remains much more accessible to reactants than bulk-dissolved Pd. Our approach is broadly applicable to complex multimetallic systems and enables the previously intractable mechanistic investigation of restructuring dynamics at atomic resolution.

Early one-stage surgical treatment of infected preauricular sinus.

The objective of this study was to review outcomes of early one-stage surgery of acutely infected preauricular sinus compared to conventional delayed surgery after infection control. The study is a case series with chart review conducted in an academic center. From January 1, 2007 to January 31, 2012, we performed surgical treatments for 136 congenital preauricular sinuses on 103 patients aged 0-15 years. We classified the sinuses according to the state of their infection at the time of the surgery intraoperatively--Group I (asymptomatic; n = 68, 50 %), Group II (infected state; n = 26, 19 %) and Group III (infected state with abscess formation; n = 42, 31 %). The surgical outcomes of Groups I, II, and III were documented during an outpatient department observation period. The follow-up period was from 6 months to over 2 years. One patient from Group II and one patient from Group III had a recurrent infection which could be managed by local infection control. One patient from Group I and one patient from Group III had skin defects by necrosis of a skin flap margin which could be secondarily healed. All patients had no recurrence or significant chronic complications. We performed early one-stage surgical treatments on a total of 136 sinuses with an even acute infection with abscess formation and achieved good surgical outcomes, and patients were satisfied in aspects of treatment period and cost. So we present our early one-stage surgical treatment as a good option for infected preauricular sinus management.

An analysis of pure blowout fractures and associated ocular symptoms.

Blowout fractures are one of the commonly occurring facial bone fractures and clinically important, as they may cause serious complications such as diplopia, extraocular movement limitation, and enophthalmos. The purpose of this study was to evaluate the current patient demographics and surgical outcomes of 952 pure blowout fractures from 2 hospitals of the Catholic University of Korea, from 2003 to 2011. The medical records were reviewed according to the cause, fracture site, ocular symptoms, time of operation, and sequela. Male patients outnumbered female patients, and blowout fractures were most often seen in 21- to 30-year-old men. The most common cause was violent assault (40.7%). The medial orbital wall (45.8%) was the most common site, followed by floor (29.4%) and inferomedial wall (24.6%). The most common ocular injury was hyphema. Diplopia was presented in 27.6%; extraocular movement limitation was detected in 12.8% patients, and enophthalmos was encountered in 3.4% patients. Diplopia, extraocular movement limitation, and enophthalmos were significantly improved by surgical repair (P < 0.05). Postoperative complications were persistent diplopia (1.6%) and enophthalmos (0.4%). We surveyed a large series of blowout fracture in the Republic of Korea and recommend this study to serve as an important guideline in treating pure blowout fractures.

Primary non-Hodgkin lymphoma of the parotid gland: a case report.

Most malignant lymphomas of the head and neck region are non-Hodgkin lymphomas (NHL), and diffuse large B-cell lymphoma is the most common subtype. The prevalence of malignant lymphoma among parotid tumors is low, approximately 1% to 4%. The most common symptom of parotid lymphoma is a unilateral, non-tender, firm mass that slowly grows in size over time. As its clinical manifestations are non-specific, a comprehensive assessment is required for an accurate diagnosis. The initial work-up includes imaging tools, such as computed tomography and magnetic resonance imaging. However, NHL of the parotid gland is difficult to distinguish from other types of benign tumors prior to biopsy; histopathological evaluation and subsequent immunohistochemical staining are needed for the final diagnosis. Once a definitive diagnosis is established, patients should be referred to an oncologist for staging. Treatment is mainly based on systemic chemotherapy, whereas radiotherapy is indicated for certain cases. Here, we report the case of a 53-year-old man who presented with a progressively enlarging mass in the right parotid area, which was later diagnosed as malignant lymphoma of the parotid gland after superficial parotidectomy.

Active learning of reactive Bayesian force fields applied to heterogeneous catalysis dynamics of H/Pt.

Atomistic modeling of chemically reactive systems has so far relied on either expensive ab initio methods or bond-order force fields requiring arduous parametrization. Here, we describe a Bayesian active learning framework for autonomous "on-the-fly" training of fast and accurate reactive many-body force fields during molecular dynamics simulations. At each time-step, predictive uncertainties of a sparse Gaussian process are evaluated to automatically determine whether additional ab initio training data are needed. We introduce a general method for mapping trained kernel models onto equivalent polynomial models whose prediction cost is much lower and independent of the training set size. As a demonstration, we perform direct two-phase simulations of heterogeneous H2 turnover on the Pt(111) catalyst surface at chemical accuracy. The model trains itself in three days and performs at twice the speed of a ReaxFF model, while maintaining much higher fidelity to DFT and excellent agreement with experiment.

Malignant transformation of nevus sebaceous to basal-cell carcinoma: Case series, literature review, and management algorithm.

Nevus sebaceous (NS) is a common congenital hamartoma of the skin composed predominantly of sebaceous glands. Although most NS are benign skin tumors, malignant transformations have been reported. There is still controversy about the lifetime risk of malignant degeneration and precise surgical criteria. This study reports cases of malignant degeneration and suggests a surgical treatment algorithm. The medical records of patients with basal-cell carcinoma (BCC) arising from NS between January 2001 and January 2021 were retrospectively reviewed. Patient demographics including lesion location, and tumor size were investigated. The symptoms, histological findings before and after excision, complications, and recurrence during 2-year follow-up periods were investigated. Ten patients were identified with BCC arising from NS lesions. All patients were female and the mean age was 52.11 years. All patients complained of sudden morphological changes, the most common type being rapid color changes. Two cases had histological findings that showed a miss-match between punch biopsy and excisional biopsy results. No recurrence was detected 2 years after surgeries in any patients. Cases after third stage, especially in over 40 years who report morphologic changes, should undergo total surgical excision as the first approach, with strong suspicion of malignant degeneration.

Evaluation of tongue mobility following release operation of ankyloglossia with genioglossus myotomy.

Ankyloglossia is a congenital anomaly characterized by a short lingual frenulum and severe form needs release surgery. Our goal in this study was to confirm the long-term safety and efficacy of Z-plasty with genioglossus myotomy compared with traditional Z-plasty alone and to develop a proper measurement tool to validate the postoperative results of release operations for ankyloglossia. Patients were divided in 2 groups, release with Z-plasty only group (group 1) and Z-plasty combined with genioglossus myotomy group (group 2) In group 2, the release of central longitudinal fiber of genioglossus muscle was added in the conventional Z-plasty operative procedure. To analyze the results of the surgery, we developed an objective assessment tool which is the direct length from the innermost point of the floor of mouth to the tip of the tongue, preoperatively and postoperatively, which is called "functional tongue length." A total of 101 patients with ankyloglossia ranging in age from 36 months to 8 years underwent release operation. Although there was no significant difference in terms of postoperative measurements between groups in Kotlow class II, group 2 patients in Class III and IV showed greater postoperative functional tongue length. Also, there was no significant complication requiring secondary surgery. Our study demonstrated that adding genioglossus myotomy to a simple Z-plasty is a safe and effective method for improving the tongue mobility required to make lingual sounds, especially in moderate to severe form of ankyloglossia, along with suggestion of a new measurement tool, which can objectively assess tongue mobility with possibility for universal utilization in ankyloglossia release operation.

Microbial Identification Using rRNA Operon Region: Database and Tool for Metataxonomics with Long-Read Sequence.

Recent development of long-read sequencing platforms has enabled researchers to explore bacterial community structure through analysis of full-length 16S rRNA gene (∼1,500 bp) or 16S-ITS-23S rRNA operon region (∼4,300 bp), resulting in higher taxonomic resolution than short-read sequencing platforms. Despite the potential of long-read sequencing in metagenomics, resources and protocols for this technology are scarce. Here, we describe MIrROR, the database and analysis tool for metataxonomics using the bacterial 16S-ITS-23S rRNA operon region. We collected 16S-ITS-23S rRNA operon sequences extracted from bacterial genomes from NCBI GenBank and performed curation. A total of 97,781 16S-ITS-23S rRNA operon sequences covering 9,485 species from 43,653 genomes were obtained. For user convenience, we provide an analysis tool based on a mapping strategy that can be used for taxonomic profiling with MIrROR database. To benchmark MIrROR, we compared performance against publicly available databases and tool with mock communities and simulated data sets. Our platform showed promising results in terms of the number of species covered and the accuracy of classification. To encourage active 16S-ITS-23S rRNA operon analysis in the field, BLAST function and taxonomic profiling results with 16S-ITS-23S rRNA operon studies, which have been reported as BioProject on NCBI are provided. MIrROR (http://mirror.egnome.co.kr/) will be a useful platform for researchers who want to perform high-resolution metagenome analysis with a cost-effective sequencer such as MinION from Oxford Nanopore Technologies. IMPORTANCE Metabarcoding is a powerful tool to investigate community diversity in an economic and efficient way by amplifying a specific gene marker region. With the advancement of long-read sequencing technologies, the field of metabarcoding has entered a new phase. The technologies have brought a need for development in several areas, including new markers that long-read can cover, database for the markers, tools that reflect long-read characteristics, and compatibility with downstream analysis tools. By constructing MIrROR, we met the need for a database and tools for the 16S-ITS-23S rRNA operon region, which has recently been shown to have sufficient resolution at the species level. Bacterial community analysis using the 16S-ITS-23S rRNA operon region with MIrROR will provide new insights from various research fields.

Decoding reactive structures in dilute alloy catalysts.

Rational catalyst design is crucial toward achieving more energy-efficient and sustainable catalytic processes. Understanding and modeling catalytic reaction pathways and kinetics require atomic level knowledge of the active sites. These structures often change dynamically during reactions and are difficult to decipher. A prototypical example is the hydrogen-deuterium exchange reaction catalyzed by dilute Pd-in-Au alloy nanoparticles. From a combination of catalytic activity measurements, machine learning-enabled spectroscopic analysis, and first-principles based kinetic modeling, we demonstrate that the active species are surface Pd ensembles containing only a few (from 1 to 3) Pd atoms. These species simultaneously explain the observed X-ray spectra and equate the experimental and theoretical values of the apparent activation energy. Remarkably, we find that the catalytic activity can be tuned on demand by controlling the size of the Pd ensembles through catalyst pretreatment. Our data-driven multimodal approach enables decoding of reactive structures in complex and dynamic alloy catalysts.

Ankyloglossia correction: Z-plasty combined with genioglossus myotomy.

Ankyloglossia or tongue-tie is a disease in which the tongue has a mobility disorder because the lingual frenulum is short and tight, and as a result, the tongue tip is tied up. It may be asymptomatic or may cause various problems such as articulation disorder. Surgical treatment is required in many of the patients, and conventional methods release only the mucosal layer of the frenulum. However, conventional method alone is not as effective; therefore, the authors studied the addition of a partial myotomy of the genioglossus muscle along with mucosal layer release for treatment. The authors performed the surgery on 106 patients from 2005 to 2010, and during the surgery, the mucosal layer was released through Z-plasty after myotomy was performed on the contracted genioglossus muscle. During the follow-up, none of the patients showed signs and symptoms of tongue mobility impairment or articulation disorder caused by the partial myotomy of the genioglossus muscle, and a satisfactory outcome was obtained in achieving mobility of the tongue tip. Because tongue mobility disorder in ankyloglossia is accompanied by the contracture and shortening of the genioglossus muscle, an improved outcome is expected in the projection and mobility of the tongue tip from the combined application of conventional Z-plasty and genioglossus muscle release.

Effects of adipose-derived stromal cells and of their extract on wound healing in a mouse model.

In this study, the authors investigated the effects of adipose-derived stromal cells (ADSCs) and of their extract on wound healing. After creating wound healing splint model on the backs of mice, ADSCs and their extract were applied. Wound healing rates were calculated at 3, 5, 7, 10, and 14 days after the wounding, and tissues were harvested at 7 and 14 days for histological analysis. Wound healing rates were significantly higher at 7, 10, and 14 days in the cell group than in the control, but in the cell extract group wound healing rates were significantly decreased (P<0.05). Histological scores and capillary densities in the cell group were significantly higher at 2 weeks (P<0.05). In the cell group, thick inflammatory cell infiltration and many capillaries were observed at 1 week, and thick epithelium and numerous large capillaries were observed at 2 weeks. The present study suggests that ADSCs accelerate wound healing as known, and the effects of ADSCs on wound healing may be due to replacing insufficient cells by differentiation of ADSCs in the wound and secreting growth factors by differentiated cells, and not due to the effect of factors within ADSCs.

Eyeball deviation by orbital mucocele after midface sinus injury.

A mucocele is an epithelium-lined, mucus-filled cavity in the paranasal sinuses. Mucocele may develop due to scarring and obstruction of the sinus ostium caused by midface sinus trauma, such as orbital bone fracture or endoscopic sinus surgery. The authors report two cases of orbital mucocele as complications following midface sinus injury (endoscopic sinus surgery in one case, and orbital fracture repair in the other). In both cases, imaging studies showed a large orbital mucocele accompanied by bony erosion and orbital wall remodeling, compressing the ocular muscle. Using an open approach, the lesion was excised and marsupialized. The symptoms resolved, and the postoperative eyeball position was normal. Orbital mucocele may cause serious complications such as ocular symptoms, orbital cellulitis, osteomyelitis, and the formation of an abscess with the potential to invade the brain. Therefore, surgeons should consider the possibility of mucocele as a late complication of surgery and initiate an immediate work-up and surgical treatment if needed.

Tissue engineering of injectable soft tissue filler: using adipose stem cells and micronized acellular dermal matrix.

In this study of a developed soft tissue filler, adipose tissue equivalents were constructed using adipose stem cells (ASCs) and micronized acellular dermal matrix (Alloderm). After labeling cultured human ASCs with fluorescent green protein and attaching them to micronized Alloderm (5 x 10(5) cells/1 mg), ASC-Alloderm complexes were cultured in adipogenic differentiation media for 14 days and then injected into the dorsal cranial region of nude male mice. The viabilities of ASCs in micronized Alloderm were determined at 1, 4, 7, and 14 days, and complexes, which had been cultured for 14 days and implanted in vivo for 2 months, were histologically evaluated by light, confocal, and scanning electron microscopy. The viabilities represented that ASCs in micronized Alloderm were alive during the culture period. ASC-Alloderm complexes cultured for 14 days contained round cells with large lipid vesicles by light microscopy and many spherical cells by SEM. ASCs in implanted ASC-Alloderm complexes harvested from mice at 2 months postinjection were histologically found to have differentiated into adipocytes which had green fluorescence dye. Micronized Alloderm may be found useful as scaffold for human ASCs when constructing fat tissue for three-dimensional soft tissue filling. The present study suggests that ASC-Alloderm complexes can be used as injectable three-dimensional soft tissue fillers.

First-principles modeling of water permeation through periodically porous graphene derivatives.

Polyphenylene superhoneycomb network (PSN) and covalent triazine framework (CTF) are experimentally realized periodically porous graphene derivatives. Such ultrathin layers with homogeneously distributed pores of controllable sizes are highly desirable for applications in molecular separations such as water purification. The permeation energy barrier is expected to be a function of not only the pore size, but also the specific permeation trajectory as determined by hydrogen bonding interactions at the water-pore interface. Here, we report a detailed first-principles study of permeation of a single H2O molecule through a monolayer PSN and CTF-0, as well as its diffusion behavior inside a bilayer PSN. The calculated energy barrier of 1.44 eV indicates the infeasibility of using PSN as a water permeation membrane. However, the barrier decreases considerably to 0.94 eV when three C-H pairs at the pore are replaced with N atoms into CTF-0. Inside a bilayer PSN, we find facile interlayer sliding as well as interlayer expansion owing to out-of-plane reorientation of the H2O molecule. In all cases, the functional groups at the pore significantly alter the orientation of the H2O molecule and the corresponding barriers. Such atomistic insights at the porous interface would provide a valuable guidance in advancing rational pore design principles.

Reconstruction of the Three-Dimensional Mandibulofacial Defects Using a Single Cutaneous Perforator-Based Fibula Osteocutaneous Flap.

The reconstruction of the mandibulofacial defects is a difficult task when there are full-thickness cheek defects involving mandible, inner mucosa and outer skin. There are several reconstructive options for the coverage of large defects, but most of the methods are complicated, and time- and effort-consuming. We hereby present a case of fibula osteocutaneous flap based on a single peroneal artery perforator in the reconstruction of a three-dimensional mandibulofacial defects.

Immediate Near-Total Scalp Reconstruction with Artificial Dermis on Exposed Calvarium.

Scalp defect management is complicated secondary to reduced laxity in the scalp and forehead area. For reconstruction of larger defects with exposed bone and loss of the periosteal layer, free flap reconstruction is one option for single-stage surgery, although the procedure is lengthy and includes the possibility of flap loss. We successfully performed a single-stage reconstruction of a large scalp defect using a combination of artificial dermis, split-thickness skin graft, and full-thickness skin graft following wide excision of a cutaneous angiosarcoma, and present our method as one option for the treatment of large oncologic surgical defects in patients who are poor candidates for free flap surgery.

Recurrent Pleomorphic Adenoma of the Parotid Gland.

Pleomorphic adenoma is the most common type of salivary gland tumor and the most common tumor of the parotid gland. Because of its propensity for invasion, pleomorphic adenoma of the parotid requires superficial parotidectomy or total parotidectomy to minimize the risk of tumor recurrence. We report a case of pleomorphic adenoma of the parotid gland with repeated recurrences. A 23-year-old male patient presented with a protruding neck mass. Six years prior to this presentation, the patient had undergone superficial parotidectomy for the removal of pleomorphic adenoma of the right parotid gland at our institution. The patient experienced recurrence at 17 months after the initial resection, which required a total parotidectomy with partial resection of the facial nerve. Pathologic examination revealed histologic findings consistent with pleomorphic adenoma across the surgical specimen from all three of the operations. The patient suffered from facial nerve paralysis, with facial expressions partially recovered over a year.

Leiomyosarcoma of the Face.

Leiomyosarcoma is a rare form of soft tissue neoplasm, with only 1% to 5% occurring in the head and neck region. Current recommended treatment suggests surgical excision with a wide lateral margin, but no definite guidelines regarding excisional margin have been established yet. Recently, complete excision with a narrow surgical margin has been recommended, and the authors present a case of cutaneous leiomyosarcoma on the face that was successfully managed by complete removal with a narrow excisional margin. A 74-year-old woman presented with a 3 cm sized, rapidly growing cutaneous mass on her right preauricular area. Preoperative biopsy of the skin lesion suggested a cutaneous leiomyosarcoma. The authors performed complete surgical excision with a 1 cm lateral margin, and the resulting skin defect was repaired with bilateral V-Y advancement local flaps. Histopathology and immunohistochemistry evaluation confirmed a moderately differentiated cutaneous leiomyosarcoma, with negative margin involvement. The patient refused of any additional treatment, but showed no locoregional recurrence during the 1.5 years of postoperative follow-up period. With a regular postoperative follow-up, cutaneous leiomyosarcomas may be successfully treated with a narrow surgical margin.