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BACKGROUND: The causes and treatment of pneumothorax in older patients are different from those in younger patients. However, studies on this topic are limited thus; pneumothorax in older patients is often inadequately managed. The purpose of this research was to investigate the characteristics of pneumothorax in patients over 45 years old, understand patterns of management and factors of recurrence, and propose reasonable guidelines for the treatment of older patients. METHODS: Of 438 consecutive patients with spontaneous pneumothorax between 2013 and 2017, 120 patients were enrolled and divided into two groups: (I) 45–64 years and (II) ≥65 years. Basic demographics, treatment modality, and patterns of surgery/recurrence were described. Clinical variables were compared between groups, and risk factors of recurrence were analyzed using logistic regression. RESULTS: The study population was divided into group A (younger, n=61) and B (older, n=59). Chest tube drainage was the most common procedure for both groups and chemical pleurodesis was applied more often in B (27% vs. 11%, P=0.03). The length of hospital stay was longer in B (8.8 vs. 5.9 days, P

In metal product manufacturing, additive manufacturing (AM) is a method that has the advantage of fabricating complex shapes and customized production, unlike existing machining methods. However, owing to the characteristics of the AM process, anisotropy of macrostructure occurs because of various causes such as the scan direction, melting, fusion, and cooling of the powdered material. The macrostructure anisotropy is realized from the scan direction, and when a single layer is stacked in one direction, it is expressed as orthogonal anisotropy. Here, the classical lamination theory is applied to simply calculate the individual orthotropic layers by superimposing them. Through this, the authors analyzed whether the mechanical properties of the product are isotropically expressed with a periodic layer rotation strategy. To determine if the mechanical properties can be reasonably considered to be isotropic, a shock absorber mount for a vehicle was manufactured by AM. The tensile and vibration test performed on the product was compared with the finite element analysis and experimental results. As a result of the comparison, it was confirmed that the macroscopically of the product was considered isotropic as the load-displacement diagram and the fracture location coincided, as well as the natural frequency and mode shape.

Under certain conditions, numerous soluble proteins possess an inherent tendency to convert into insoluble amyloid aggregates, which are associated with several sporadic and genetic human diseases. Transthyretin (TTR) is one of the more than 30 human amyloidogenic proteins involved in conditions such as senile systemic amyloidosis, familial amyloid polyneuropathy, and familial amyloid cardiomyopathy. Considerable effort has been focused on identifying the native tetrameric TTR stabilizers to inhibit rate-limiting tetramer dissociation and, consequently, ameliorate TTR amyloidogenesis. Here, we describe the design and synthesis of quinolin-2(1H)-one derivatives that could be structurally complementary to the thyroxine-binding site within tetrameric TTR. Among these quinolin-2(1H)-one derivatives, compound 7a allowed 16.7% of V30M-TTR (3.6 μM) fibril formation at the same concentration and 49.6% at a concentration of 1.8 μM. Compound 7a exhibited much greater potency in complex biological samples like human plasma than that observed with tafamidis, the drug approved for the treatment of TTR amyloid cardiomyopathy for wild-type or hereditary TTR-mediated amyloidosis. Furthermore, the unique spectral properties of compound 7a demonstrated its high potential for TTR quantification, imaging sensors, and fluorescent tools to study the mechanism of TTR amyloidogenesis.

This study was performed To investigate the use of hydrophilic guidewires for facilitating catheter advancement during varicose vein treatment using radiofrequency ablation (RFA) or cyanoacrylate closure (CAC).From March 2016 to April 2019, 463 limbs of 285 with incompetent great saphenous veins were subjected to RFA (321 limbs of 197 patients) or CAC (142 limbs of 88 patients). Procedure records were reviewed for the use of a hydrophilic guidewire, reason for the guidewire usage, and diameter of the guidewire.A hydrophilic guidewire was used to facilitate catheter advancement to treat 92 of 463 limbs (19.9%). For RFA, a guidewire was used to treat 53 of 321 limbs (16.5%). Among them, 15 limbs (28.3%) had vasospasm, and 38 limbs (71.7%) had venous tortuosity. For CAC, guidewire was used for 39 of 142 limbs (27.5%). Among them, 10 limbs (25.6%) had vasospasm, 23 limbs (59.0%) had venous tortuosity, and 6 limbs (15.4%) had repeated engagement of a J-tip guidewire into the varicose tributaries. In CAC, the frequency of hydrophilic guidewire usage was higher than that in RFA (P = 0.006). All varicose vein treatment sessions were technically successful.Hydrophilic guidewire usage could facilitate catheter advancement when hindered by vasospasm, tortuosity of the saphenous vein, or repeated engagement into the varicose tributaries.

Background: Limited evidence exists in the literature regarding the detection rates of lateral hinge fracture (LHF) on computed tomography (CT) after medial closing wedge distal femoral osteotomy (MCDFO). Moreover, the effect of LHF on bone healing after MCDFO remains unclear. Hypothesis: The detection rates of LHF after MCDFO would be higher on CT than on plain radiography. The incidence of problematic bone healing would be higher in the knees with LHF than in those without LHF. Study Design: Cohort study (diagnosis), Level of evidence, 3. Methods: Patients who underwent MCDFO between May 2009 and July 2019 were retrospectively evaluated. The presence of LHF was evaluated using immediate postoperative plain radiography and CT. The detection rates of LHF on plain radiography and CT were compared. The incidence of problematic bone healing (nonunion, delayed union, and loss of correction) was also compared between the knees with LHF and those without LHF. Results: A total of 55 knees of 43 patients (mean age, 37.7 ± 16.7 years) were included in the study. Although 33 LHFs were detected on CT, only 19 LHFs were detected on plain radiography. The detection rate of LHF was significantly higher on CT than on plain radiography (60% vs 34.5%; P = .008). At 1-year follow-up, 10 cases of problematic bone healing (1 nonunion, 4 delayed unions, and 5 losses of correction) were identified. The incidence of problematic bone healing was significantly higher in the knees with LHF than in those without LHF as shown on plain radiography (36.8% vs 8.3%; P = .001) and CT (30.3% vs 0%; P = .004). Conclusion: LHF can be detected better on CT than on plain radiography and has a negative effect on bone healing after MCDFO. For patients with LHF detected on either plain radiography or CT, careful rehabilitation with close follow-up is recommended.

The interplay between disorder and topology triggers interesting effects for the propagation of quantum particles in low-dimensional network structures. For instance, the occurrence of Anderson localization, a commonly observed effect in a quantum network with static disorder, can be suppressed by introducing topology-a phenomenon dubbed as topological Anderson localization transition [1] . In one-dimensional systems, for example, disorder induces localization on a short length scale while topology counters that through long-range correlations, yielding divergent correlation length and extremely slow spreading at quantum criticality. However, its experimental demonstration still remains an outstanding challenge as that would require, in contrast to Anderson localization transition, addi¬tional control over internal degrees of freedom, which is hard to implement, for instance, in cold-atom systems [2] . Quantum walks (QWs), a quantum analog of random walks, comprising quantum coin toss and conditioned step operations are already established for studying quantum transport phenomena, such as, disorder and topology [5] . Based on our theoretical proposal [3] , here, we provide an experimental route using time-multiplexed quantum walk [4] for evidencing the targeted phenomenon.

Chronic stress has a negative impact on many fertility-related functions; thus, the recent decline in female fertility seems to be at least partially associated with increased stress. The secretion of glucocorticoids is a typical endocrine response to chronic stress and indirectly reduces uterine receptivity through the hypothalamus-pituitary-gonadal (HPG) axis. However, in addition to its well-known canonical role, the direct effects of chronic stress-induced glucocorticoids on various uterine functions and their underlying molecular mechanisms are complex and have not yet been revealed. Recent studies have found that resident stem cell deficiency is responsible for the limited regenerative potential of the endometrium (the innermost lining of the uterine cavity) during each menstrual cycle, which subsequently increases infertility rates. In this context, we hypothesized that stress-induced glucocorticoids directly damage endometrial stem cells and consequently negatively affect endometrial reconstruction, which is important for uterine receptivity. In addition to its well-known canonical roles, we identified for the first time that cortisol, the most abundant and potent glucocorticoid in humans, directly suppresses the multiple beneficial functions (self-renewal, transdifferentiation, and migratory potential) of human endometrial stem cells through its functional receptor, glucocorticoid receptor (GR). Glucocorticoids inhibit well-known survival signals, such as the PI3K/Akt and FAK/ERK1/2 pathways. More importantly, we also found that immobilization of stress-induced glucocorticoids suppresses the various beneficial functions of tissue resident stem cells in vivo. To the best of our knowledge, this is the first study to investigate the direct effects of glucocorticoids on the regenerative capacity of endometrial stem cells, and the findings will facilitate the development of more promising therapeutic approaches to increase female fertility.

Inflammatory myofibroblastic tumors are mesenchymal neoplasms with intermediate biological potential. They tend to affect the lungs and abdominopelvic area but rarely occur in the esophagus. Only a few cases of esophageal inflammatory myofibroblastic tumors have been reported in the English literature. Herein, we report an esophageal inflammatory myofibroblastic tumor masquerading as an esophageal cancer. A 39-year-old woman complained of progressive dysphagia, and esophagogastroscopy revealed a 5-cm tumor in the lower esophagus. Ivor-Lewis surgery was performed, and the tumor was diagnosed as an inflammatory myofibroblastic tumor; the patient was successfully treated with surgery.

The discovery of two-dimensional gapless Dirac fermions in graphene and topological insulators (TI) has sparked extensive ongoing research toward applications of their unique electronic properties. The gapless surface states in three-dimensional insulators indicate a distinct topological phase of matter with a non-trivial Z2 invariant that can be verified by angle-resolved photoemission spectroscopy or magnetoresistance quantum oscillation. In TI nanowires, the gapless surface states exhibit Aharonov-Bohm (AB) oscillations in conductance, with this quantum interference effect accompanying a change in the number of transverse one-dimensional modes in transport. Thus, while the density of states (DOS) of such nanowires is expected to show such AB oscillation, this effect has yet to be observed. Here, we adopt nanomechanical measurements that reveal AB oscillations in the DOS of a topological insulator. The TI nanowire under study is an electromechanical resonator embedded in an electrical circuit, and quantum capacitance effects from DOS oscillation modulate the circuit capacitance thereby altering the spring constant to generate mechanical resonant frequency shifts. Detection of the quantum capacitance effects from surface-state DOS is facilitated by the small effective capacitances and high quality factors of nanomechanical resonators, and as such the present technique could be extended to study diverse quantum materials at nanoscale., 15+16 pages, 4+11 figures

BACKGROUND: Sarcopenia is associated with poor prognosis in lung cancer. Skeletal muscle area can be quantified based on radiodensity of CT scan. The purpose of this study was to evaluate the prognostic significance of radiodensity-based detailed skeletal muscle quantification on outcomes after surgery of non-small cell lung cancer (NSCLC). METHODS: Single cross-sectional area of the skeletal muscle (−29 to 150 HU) at the 3rd lumbar vertebra (L3) level retrospectively measured on preoperative CT for NSCLC patients (n=272), who underwent surgical resection during 2011 to 2016. The diagnosis of sarcopenia was made when a L3 muscle index (L3MI; L3 muscle area/height2) of less than 55 cm(2)/m(2) for men and less than 39 cm(2)/m(2) for women. Skeletal muscle was subsequently classified based on radiodensity level as low attenuation muscle (−29 to

Tumour-unrelated, virus-specific bystander CD8We studied the characteristics of bystander CD8We show that bystander CD8Thus, the study demonstrates that bystander CD8

We consider one-dimensional quantum walks in optical linear networks with synthetically introduced disorder and tunable system parameters allowing for the engineered realization of distinct topological phases. The option to directly monitor the walker's probability distribution makes this optical platform ideally suited for the experimental observation of the unique signatures of the one-dimensional topological Anderson transition. We analytically calculate the probability distribution describing the quantum critical walk in terms of a (time staggered) spin polarization signal and propose a concrete experimental protocol for its measurement. Numerical simulations back the realizability of our blueprint with current date experimental hardware., Comment: 17 pages, 9 figures

Summary Background & aims Sarcopenic obesity (SO) increases the risk of mortality more than sarcopenia or obesity alone. Sarcopenia weakens the peripheral and respiratory muscles, leading to respiratory complications. It also induces mitochondrial dysfunction in the peripheral muscle; however, whether mitochondrial dysfunction in respiratory muscles differs among individuals with obesity, sarcopenia, and SO remains unknown. We evaluated the deterioration of respiratory muscle strength and mitochondrial function among normal, sarcopenia, obesity, and SO subjects. Methods Twenty-five patients who underwent lung resections were enrolled between April 2017 and January 2021, and their intercostal muscles were harvested. Based on their L3 muscle index and visceral fat area, the patients were divided into four groups (normal, obesity, sarcopenia, and SO). The clinical data, mRNA expression, and protein expressions associated with mitochondrial biogenesis/fusion/fission in the intercostal muscles were compared among the four groups. Results The respiratory muscle strength was evaluated using peak expiratory flow rate (PEFR). The PEFR values of the four groups were not significantly different. The levels of pAkt/Akt and mTOR (a marker of protein synthesis) were not significantly different among the four groups; however, those in the SO group were substantially lower than those in the sarcopenia or obesity groups. The levels of Atrogen-1 and MuRF1 (a marker of protein degradation) were not significantly different among the four groups; however, those in the SO group were substantially higher than those in the sarcopenia or obesity groups. Expression of PGC1-α (a marker of mitochondrial biogenesis) in the SO group was significantly lower than that in the normal group. MFN1 and MFN2 (marker of mitochondrial fusion) levels were significantly lower in the SO group than those in the normal group. DRP1 (a marker of mitochondrial fission) level in the SO group was substantially lower than that in the normal group. The expression of TNF-α (a pro-inflammatory cytokine) in the SO group was substantially lower than that in the normal group. Conclusion Our results suggest that the deterioration of protein synthesis and degradation of mitochondrial function in the respiratory muscles was most prominent in the SO before the weakening of the respiratory muscles. The deterioration mechanism may differentially regulate obesity, sarcopenia, and SO.

Sarcopenia is the degenerative loss of skeletal muscle mass and function associated with aging and occurs in the absence of any underlying disease or condition. A comparison of the age-related molecular signaling signatures of different muscles has not previously been reported. In this study, we compared the age-related molecular signaling signatures of the intercostal muscles, the diaphragm, and the gastrocnemii using 6-month and 20-month-old rats. The phosphorylation of Akt, ribosomal S6, and Forkhead box protein O1 (FoxO1) in diaphragms significantly increased with age, but remained unchanged in the intercostal and gastrocnemius muscles. In addition, ubiquitin-proteasome degradation, characterized by the levels of MuRF1 and Atrogin-1, did not change with age in all rat muscles. Interestingly, an increase in LC3BII and p62 levels marked substantial blockage of autophagy in aged gastrocnemii but not in aged respiratory muscles. These changes in LC3BII and p62 levels were also associated with a decrease in markers of mitochondrial quality control. Therefore, our results suggest that the age-related signaling events in respiratory muscles differ from those in the gastrocnemii, most likely to preserve the vital functions played by the respiratory muscles.

Spin current generation through the spin-orbit interaction in non-magnetic materials lies at the heart of spintronics. When the generated spin current is injected to a ferromagnet, it produces spin-orbit torque and manipulates magnetization efficiently. Optically generated spin currents are expected to be superior to their electrical counterparts in terms of the manipulation speed. Here we report optical spin-orbit torques in heavy metal/ferromagnet heterostructures. The strong spin-orbit coupling of heavy metals induces photo-excited carriers to be spin-polarized, and their transport from heavy metals to ferromagnets induces a torque on magnetization. Our results demonstrate that heavy metals can generate spin-orbit torque not only electrically but also optically., It is known that torques can be exerted on spins in a ferromagnet (FM) layer when an in-plane electric current is injected into a heavy metal (HM) layer in contact with the FM layer. Here, the authors demonstrate that torques can be generated without the current injection by shining instead circularly polarized light on the HM.

The absolute nodal coordinate formulation was developed in the mid-1990s to express large deformations and large rotations in flexible multi-body dynamics. It is a non-incremental finite-element procedure wherein the mass matrix is expressed as a constant while the stiffness matrix carries highly nonlinear features. The formulation for a thin plate can be developed on the basis of continuum or structural mechanics similar to that for a beam. Absolute nodal coordinate formulation necessarily uses the global slope vector, and this results in an increase in the degree of freedom. In this study, to reduce analysis time, the non-dimensional equation of motion of a thin plate is derived from the dimensional equation of motion using non-dimensional variables. An example of a thin cantilever plate is used to present the improved efficiency of analysis due to the non-dimensional equation of motion, and the simulations are shown with various numbers of elements. The non-dimensional equation of motion is thus verified by demonstrating the similarities of the solutions for both the dimensional and non-dimensional equations of motion.

Absolute nodal coordinate formulation can be used to represent large displacement and large deformation in flexible body analysis based on the concept of continuum mechanics. However, the analysis takes a long time because of the increase in the degrees of freedom at a nodal point. In this study, the analysis time was reduced by using non-dimensional variables for the time, length, and force to convert a dimensional equation of motion into a non-dimensional one. Revolute and spherical joint were used to obtain numerical solutions by applying the non-dimensional equation of motion of free-falling pendulum. The non-dimensional equation of motion was verified by comparing the solutions with the numerical solution obtained using a dimensional equation of motion. The motion of a flexible hose was predicted by using the absolute nodal coordinate formulation, and it was shown the efficiency of non-dimensional equation of motion.

Early diagnosis followed by primary repair is the best treatment for spontaneous esophageal perforation. However, the appropriate management of esophageal leakage after surgical repair is still controversial. Recently, the successful adaptation of vacuum-assisted closure therapy, which is well established for the treatment of chronic surface wounds, has been demonstrated for esophageal perforation or leakage. Conservative treatment methods require long-term fasting with total parenteral nutrition or enteral feeding through invasive procedures, such as percutaneous endoscopic gastrostomy or a feeding jejunostomy. We report 2 cases of esophageal leakage after primary repair treated by endoscopic vacuum therapy with continuous enteral feeding using a Sengstaken-Blakemore tube.

Background: Sarcopenia, reduced skeletal muscle mass, is associated with frailty, injuries, and mortality. The purpose of this study was to evaluate the impact of computed tomography–determined sarcopenia on surgical complications and outcomes after resection of non-small cell lung cancer. Methods: For a total 272 non-small cell lung cancer patients that underwent surgery between 2011 and 2016, cross-sectional area of muscle at the third lumbar vertebra (L3) was retrospectively measured using preoperative chest computed tomography images. Sarcopenia was defined as an L3 muscle index of 2/m2 for men and of 2/m2 for women. Clinical characteristics, postoperative complications, disease-free survival, and overall survival of patients with or without sarcopenia were compared. Results: A total of 60.3% ( n = 164) were male, and mean patient age was 62.9 ± 9.6 years. The prevalence of sarcopenia was 22.4% for all study subjects, 32.9% for men, and 6.5% for women. No significant difference was observed between patients with or without sarcopenia in terms of intensive care unit or hospital stay ( p = 0.502 and p = 0.378, respectively), and the presence of sarcopenia was not associated with postoperative complications. Furthermore, no significant difference was observed between the 3-year disease-free survival rate (74.3% vs 66.7%, p = 0.639) or 3-year overall survival rate (83.9% vs 87.7%, p = 0.563) of patients with or without sarcopenia. Conclusion: Sarcopenia as determined by preoperative computed tomography does not appear to have a negative impact on surgical outcome or overall survival for resected non-small cell lung cancer patients.

One of the factors that influence the dynamic characteristics of machining systems is the cutting tool. Cutting tools are very diverse, and receptance coupling substructure analysis (RCSA) is essential for analyzing the dynamic characteristics of each tool. For RCSA, a full receptance matrix of the equipment and tools is essential. In this study, rotational degree-of-freedom receptance was estimated and analyzed using translational receptance. Displacement/moment receptance was analyzed according to the distance of the response point using the first-and second-order finite difference methods. The rotation/moment receptance was estimated according to the distance of the response point. Rotation/moment receptance was analyzed using Schmitz’s method and compensation strategies. The limitations of these strategies were analyzed, and the rotation/moment receptance for the beam under free-free boundary conditions was predicted using the second compensation strategy.

Objective To compare swallowing function between healthy subjects and patients with pharyngeal dysphagia using high resolution manometry (HRM) and to evaluate the usefulness of HRM for detecting pharyngeal dysphagia. Methods Seventy-five patients with dysphagia and 28 healthy subjects were included in this study. Diagnosis of dysphagia was confirmed by a videofluoroscopy. HRM was performed to measure pressure and timing information at the velopharynx (VP), tongue base (TB), and upper esophageal sphincter (UES). HRM parameters were compared between dysphagia and healthy groups. Optimal threshold values of significant HRM parameters for dysphagia were determined. Results VP maximal pressure, TB maximal pressure, UES relaxation duration, and UES resting pressure were lower in the dysphagia group than those in healthy group. UES minimal pressure was higher in dysphagia group than in the healthy group. Receiver operating characteristic (ROC) analyses were conducted to validate optimal threshold values for significant HRM parameters to identify patients with pharyngeal dysphagia. With maximal VP pressure at a threshold value of 144.0 mmHg, dysphagia was identified with 96.4% sensitivity and 74.7% specificity. With maximal TB pressure at a threshold value of 158.0 mmHg, dysphagia was identified with 96.4% sensitivity and 77.3% specificity. At a threshold value of 2.0 mmHg for UES minimal pressure, dysphagia was diagnosed at 74.7% sensitivity and 60.7% specificity. Lastly, UES relaxation duration of

This paper proposes an optimal button arrangement of a percussion drill bit and its operating condition to improve drilling efficiency. A new evaluation method is introduced for the button arrangement that utilizes the superimposed impact area, blank area, and drilling deviation moment as the quantitative indices to evaluate the impact of buttons on the rock surface. To determine the optimal button arrangement and its operating conditions, a progressive metamodel-based design optimization was conducted using the new evaluation indices as the analysis response, and then the optimal solution was determined through iteration. Consequently, all the button evaluation indices were reduced significantly and the impact areas were distributed uniformly under a specific operating condition. Additionally, the drilling performances of the optimal button arrangement were investigated according to the operating conditions to obtain the maximum drilling performance in terms of the drilling machine operation.

Absolute nodal-coordinate formulation is a technique that was developed in 1996 for expressing the large rotation and deformation of a flexible body. It utilizes global slopes without a finite rotation in order to define nodal coordinates. The method has a shortcoming in that the central processing unit time increases because of increases in the degrees of freedom. In particular, when considering the deformation of a cross section, the shortcoming due to the increase in the degrees of freedom becomes clear. Therefore, in the present research, the dimensional equation of motion concerning a two-dimensional shear deformable beam, developed by Omar and Shabana, is converted into a nondimensional equation of motion in order to reduce the central processing unit time. By utilizing an example of a cantilever beam, wherein an exact solution for the static deflection exists, the nondimensional equation of motion was verified. Moreover, by using an example of a free-falling flexible pendulum, the efficiency of the nondimensional equation of motion gained by increasing the number of elements was compared with that of the dimensional equation of motion.

The transient-state unwinding equation of motion for a thin cable can be derived by using Hamilton’s principle for an open system, which can consider the mass change produced by the unwinding velocity in a control volume. In general, most engineering problems can be analyzed in Cartesian, cylindrical, and spherical coordinate systems. In the field of unwinding dynamics, until now, only Cartesian and cylindrical coordinate systems have been used. A spherical coordinate system has not been used because of the complexity of derivatives. Therefore, in this study, the unwinding motion of a thin cable was analyzed using a spherical coordinate system in both water and air, and the results were compared with the results in Cartesian and cylindrical coordinate systems. The unwinding motions in the spherical, Cartesian, and cylindrical coordinate systems were nearly same in both water and air. The error related to the total length was within 0.5% in water, and the error related to the maximum balloon radius was also within 0.5 % in air. Therefore, it can be concluded that it is possible to solve the transient-state unwinding equation of motion in a spherical coordinate system.

The manufacturing process of long fiber thermoplastic is initiated by supplying reinforced fiber wound in a spool dispenser. If problems such as tangling or kinking occur in the apparatus used for supplying the reinforced fiber in the long-fiber thermoplastic direct process, the productivity of the long-fiber thermoplastic decreases. Therefore, it is important to enhance the supply stability of reinforced fiber. In general, the increase in supply stability can be achieved by maintaining a steady balloon shape that is controlled by the unwinding velocity or tensile force of the reinforced fiber. In this research, the range of suitable tensile force was determined under the assumption that the unwinding velocity remained constant. The reinforced fiber was assumed to be inextensible, homogeneous, and isotropic and to have uniform density. The transient-state unwinding equation of motion to analyze the unwinding motion of reinforced fiber can be derived by using Hamilton’s principle for an open system in which mass can change within a control volume. In the process of solving the transient-state unwinding equation of motion, the exact two-point boundary conditions are adopted for each time step.

Unilateral absence of a pulmonary artery (UAPA) is a rare congenital anomaly that may present with various symptoms, depending on the nature and severity of other cardiovascular anomalies. Furthermore, contralateral lung surgery in patients with UAPA is extremely rare, and clinical experience is limited. This report describes a case of surgical treatment of contralateral primary lung cancer in a patient with isolated UAPA. A 56-year-old man was diagnosed with primary lung cancer accompanied by isolated UAPA on the contralateral side. He underwent meticulous cardiorespiratory function tests preoperatively. We performed a right lower lobectomy. Although in the immediate postoperative period, the patient suffered from a mild decline in his respiratory function, he recovered uneventfully. The present case shows that preoperative awareness of UAPA and meticulous perioperative management enable contralateral lung surgery to be performed safely.

The anomalous Floquet Anderson insulator (AFAI) is a two dimensional periodically driven system in which static disorder stabilizes two topologically distinct phases in the thermodynamic limit. The presence of a unit-conducting chiral edge mode and the essential role of disorder induced localization are reminiscent of the integer quantum Hall (IQH) effect. At the same time, chirality in the AFAI is introduced via an orchestrated driving protocol, there is no magnetic field, no energy conservation, and no (Landau level) band structure. In this paper we show that in spite of these differences the AFAI topological phase transition is in the IQH universality class. We do so by mapping the system onto an effective theory describing phase coherent transport in the system at large length scales. Unlike with other disordered systems, the form of this theory is almost fully determined by symmetry and topological consistency criteria, and can even be guessed without calculation. (However, we back this expectation by a first principle derivation.) Its equivalence to the Pruisken theory of the IQH demonstrates the above equivalence. At the same time it makes predictions on the emergent quantization of transport coefficients, and the delocalization of bulk states at quantum criticality which we test against numerical simulations., 15 pages, 5 figures

We demonstrate an unusual manifestation of coherent scattering for electron waves in mesoscopic quantum point contacts, in which fast electron dynamics allows the phonon system to serve as a quasistatic source of disorder. The low-temperature conductance of these devices exhibits a giant ($\ensuremath{\gg}2{e}^{2}/h$) zero bias anomaly (ZBA), the features of which are reproduced in a nonequilibrium model for coherent scattering from the ``frozen'' phonon disorder. According to this model, the ZBA is understood to result from the in situ electrical manipulation of the phonon disorder, a mechanism that could open up a pathway to the on-demand control of coherent scattering in the solid state.

Room-temperature superconductivity has been one of the most challenging subjects in modern physics. Recent experiments reported that lanthanum hydride ${\mathrm{LaH}}_{10\ifmmode\pm\else\textpm\fi{}x}$ ($xl1$) raises a superconducting transition temperature ${T}_{\mathrm{c}}$ up to $\ensuremath{\sim}260$ (or 250) K at high pressures around 190 (170) GPa. Here, based on first-principles calculations, we reveal that compressed ${\mathrm{LaH}}_{10}$ has symmetry-protected Dirac-nodal-line states, which split into holelike and electronlike bands at the high-symmetry points near the Fermi energy (${E}_{\mathrm{F}}$), thereby producing a van Hove singularity (vHs). The crystalline symmetry and the band topology around the high-symmetry points near ${E}_{\mathrm{F}}$ are thus demonstrated to be important for room-temperature superconductivity. Further, we identify that the electronic states at the vHs are composed of strongly hybridized La $f$ and H $s$ orbitals, giving rise to a peculiar characteristic of electrical charges with anionic La and both anionic and cationic H species. Consequently, a large number of electronic states at the vHs are strongly coupled to the H-derived high-frequency phonon modes that are induced via the unusual, intricate bonding network of ${\mathrm{LaH}}_{10}$, therefore yielding a high ${T}_{\mathrm{c}}$. Our findings elucidate the microscopic mechanism of the observed high-${T}_{\mathrm{c}}$ BCS-type superconductivity in ${\mathrm{LaH}}_{10}$, which can be generic to another recently observed high-${T}_{\mathrm{c}}$ hydride ${\mathrm{H}}_{3}\mathrm{S}$.

Topological semimetals with a nodal line is a class of topological matter extending the concept of topological matter beyond topological insulators and Weyl/Dirac semimetals. Here we show theoretically that a Floquet topological semimetal with a helical nodal line can be generated in 2+1 dimensions by irradiating graphene or the surface of a topological insulator with circularly polarized light. The helical nodal line is the nodal line running across the Brillouin zone with helical winding. Specifically, it is shown that the dynamics of irradiated graphene is described by the time Stark Hamiltonian, which can host a Floquet topological insulator and a weakly driven Floquet topological semimetal with a helical nodal line in the high and low frequency limits, respectively. One of the most striking features of the Floquet topological semimetal at low frequency is that the Berry phase accumulated along the time direction, also known as the Zak phase, has a topological discontinuity of $\ensuremath{\pi}$ across the projected helical nodal line. It is predicted that such a topological discontinuity of the Berry phase manifests itself as the topological discontinuity of the Floquet states. At intermediate frequency, this topological discontinuity can create an interesting change of patterns in the quasienergy dispersion of the Floquet states.

A dc (e.g. electric) field with commensurate lattice direction turns a single particle band structure in $d=3$ dimensions into an infinite set of equally spaced irreducible $(d-1)=2$-dimensional Wannier-Stark (WS) band structures that are spatially localized along the field direction. Particle transport is expected to be suppressed once the WS bands are gapped in energy. The topological character of the irreducible band structure leads to one-dimensional sets of boundary states which fill the energy gaps. As a result, eigenmodes are smoothly connected in energy and space and yield anomalous particle transport throughout the ladder. The number of chiral boundary modes can be tuned by the dc field strength and manifests through the distribution of dissipated energy and spatial motion, and the temperature dependence of angular momentum carried by particles., Comment: 10 pages, 6 figures

Guiding waves through a stable physical channel is essential for reliable information transport. However, energy transport in high-frequency mechanical systems, such as in signal-processing applications, is particularly sensitive to defects and sharp turns because of back-scattering and losses. Topological phenomena in condensed matter systems have shown immunity to defects and unidirectional energy propagation. Topological mechanical metamaterials translate these properties into classical systems for efficient phononic energy transport. Acoustic and mechanical topological metamaterials have so far been realized only in large-scale systems, such as arrays of pendulums, gyroscopic lattices, structured plates and arrays of rods, cans and other structures acting as acoustic scatterers9. To fulfil their potential in device applications, mechanical topological systems need to be scaled to the on-chip level for high-frequency transport. Here we report the experimental realization of topological nanoelectromechanical metamaterials, consisting of two-dimensional arrays of free-standing silicon nitride nanomembranes that operate at high frequencies (10–20 megahertz). We experimentally demonstrate the presence of edge states, and characterize their localization and Dirac-cone-like frequency dispersion. Our topological waveguides are also robust to waveguide distortions and pseudospin-dependent transport. The on-chip integrated acoustic components realized here could be used in unidirectional waveguides and compact delay lines for high-frequency signal-processing applications.

Waterjet is a device that cuts or crushes materials using water pressure injected through the nozzle. Especially, Low pressure waterjet is used in stripping and cleaning work. The cleaning patterns of the low pressure waterjet is determined by various design variables, such as the number of nozzles, an angle of nozzles, gear ratio and so on. In order to optimize the cleaning pattern, the optimum waterjet design is required depending on the shape of the target structure. To do this, a large number of waterjet analysis models should be used. This study reduced design time by automating the creation of the desired analysis model with simple changes in design variables, and conducted evaluation of the cleaning patterns using numerical method for the most frequently used cylindrical structures. In addition, it analyzed the effects of changes in design variables and suggested improvements. Moreover, the idea of a module type waterjet was proposed to reduce the cost of waterjet replacement due to usage changes. This study can be used to design the waterjet, which suits a particular purpose.

Background: Guidelines for esophagogastroduodenoscopy (EGD) in the West allow the continued use of warfarin under therapeutic international normalized ratio (INR) level. In Korea, no guidelines have been issued regarding warfarin treatment before EGD. The authors surveyed Korean cardiac surgeons about how Korean cardiac surgeons handle warfarin therapy before EGD using a questionnaire. Participants were requested to make decisions regarding the continuation of warfarin therapy in two hypothetical cases. Methods: The questionnaire was administered to cardiac surgeons and consisted of eight questions, including two case scenarios. Results: Thirty- six cardiac surgeons at 28 hospitals participated in the survey, and 52.7% of the participants chose to stop warfarin before EGD in aortic valve replacement patients without risk factors for thromboembolism. When the patient’s INR level was 2, 31% of the participants indicated that they would choose to continue warfarin therapy. For EGD with biopsy, 72.2% of the participants chose warfarin withdrawal, and 25% of the participants chose heparin replacement. In mitral valve replacement patients, 47.2% of the participants chose to discontinue warfarin, and 22.2% of the participants chose heparin replacement. For EGD with biopsy in patients with a mitral valve replacement, 58.3% of the participants chose to stop warfarin, and 41.7% of the participants chose heparin replacement. Conclusion: This study demonstrated that attitudes regarding warfarin treatment for EGD are very different among Korean surgeons. Guidelines specific to the Korean population are required.