Coupling Effect of Structural Lubrication and Thermal Excitation on Phononic Friction.

This work investigates the coupling effect of structural lubrication and thermal excitation on phononic friction between black phosphorus (BP) layers. As the rotation angle increases from commensurate to incommensurate states, the friction gradually decreases at any temperature. However, the role of temperature in friction depends on commensurability. For a rotation angle less than 10°, increasing temperature leads to a decrease in friction due to thermal excitation. Conversely, when the rotation angle exceeds 10°, elevated temperature results in an increase in friction due to the effect of thermal collision. At a critical rotation angle of 10°, higher temperatures lead to reduced friction through thermal lubrication at low speeds, and at large speeds, the thermal excitation duration becomes so short that the role of thermal lubrication is weakened, and instead thermal collision dominates. Further research reveals that BP's ability to withstand different maximum speeds is also determined by commensurability. Finally, a method to measure the sliding period length of a rotated tip through an unrotated substrate potential energy topography is proposed and simply verified by using the phonon spectrum.

Phonon energy dissipation in friction between black phosphorus layers.

Herein, we employ molecular dynamics simulations to decode the friction properties and phonon energy dissipation between black phosphorus layers. The observations reveal the influence of three factors, temperature, velocity, and normal load, on the friction force of monolayer/bilayer black phosphorus. Specifically, friction is negatively correlated with layer thickness and temperature, and positively correlated with velocity and normal load. The change in friction force is further explained in terms of frictional energy dissipation, and supplemented by the height of potential barriers as well as the number of excited phonons. From the phonon spectrum analysis, the phonon number at the contact interface is found to be higher than that at the non-contact interface. This is due to the larger distance of the contact interface atoms deviate from their equilibrium positions, resulting in higher total energy generated by more intense oscillations, and therefore contributes greater to friction.

Advances in understanding the reproductive toxicity of endocrine-disrupting chemicals in women.

Recently, there has been a noticeable increase in disorders of the female reproductive system, accompanied by a rise in adverse pregnancy outcomes. This trend is increasingly being linked to environmental pollution, particularly through the lens of Endocrine Disrupting Chemicals (EDCs). These external agents disrupt natural processes of hormones, including synthesis, metabolism, secretion, transport, binding, as well as elimination. These disruptions can significantly impair human reproductive functions. A wealth of animal studies and epidemiological research indicates that exposure to toxic environmental factors can interfere with the endocrine system's normal functioning, resulting in negative reproductive outcomes. However, the mechanisms of these adverse effects are largely unknown. This work reviews the reproductive toxicity of five major environmental EDCs-Bisphenol A (BPA), Phthalates (PAEs), Triclocarban Triclosan and Disinfection Byproducts (DBPs)-to lay a foundational theoretical basis for further toxicological study of EDCs. Additionally, it aims to spark advancements in the prevention and treatment of female reproductive toxicity caused by these chemicals.

[Mechanism of Shikonin on spinal cord injury in rats based on TNFR/RIPK1 pathway].

OBJECTIVE: To explore the effect of shikonin on the recovery of nerve function after acute spinal cord injury(SCI) in rats. METHODS: 96 male Sprague-Dawley(SD)rats were divided into 4 groups randomly:sham operation group (Group A), sham operation+shikonin group (Group B), SCI+ DMSO(Group C), SCI+shikonin group (Group D).The acute SCI model of rats was made by clamp method in groups C and D . After subdural catheterization, no drug was given in group A. rats in groups B and D were injected with 100 mg·kg-1 of shikonin through catheter 30 min after modeling, and rats in group C were given with the same amount of DMSO, once a day until the time point of collection tissue. Basso-Beattie-Bresnahan(BBB) scores were performed on 8 rats in each group at 6, 12, and 3 d after moneling, and oblique plate tests were performed on 1, 3, 7 and 14 d after modeling, and then spinal cord tissues were collected. Eight rats were intraperitoneally injected with propidine iodide(PI) 1 h before sacrificed to detection PI positive cells at 24 h in each group. Eight rats were sacrificed in each group at 24 h after modeling, the spinal cord injury was observed by HE staining.The Nissl staining was used to observe survivor number of nerve cells. Western-blot technique was used to detect the expression levels of Bcl-2 protein and apoptosis related protein RIPK1. RESULTS: After modeling, BBB scores were normal in group A and B, but in group C and D were significantly higher than those in group A and B. And the scores in group D were higher than those in group C in each time point (P<0.05). At 12 h after modeling, the PI red stained cells in group D were significantly reduced compared with that in group C, and the disintegration of neurons was alleviated(P<0.05). HE and Nissl staining showed nerve cells with normal morphology in group A and B at 24h after operation. The degree of SCI and the number of neuronal survival in group D were better than those in group C, the difference was statistically significant at 24h (P<0.05). The expression of Bcl-2 and RIPK1 proteins was very low in group A and B;The expression of RIPK1 was significantly increased in Group C and decreased in Group D, with a statistically significant difference (P<0.05);The expression of Bcl-2 protein in group D was significantly higher than that in group C (P<0.05). CONCLUSION: Shikonin can alleviate the pathological changes after acute SCI in rats, improve the behavioral score, and promote the recovery of spinal nerve function. The specific mechanism may be related to the inhibition of TNFR/RIPK1 signaling pathway mediated necrotic apoptosis.

High-timing-precision detection of single X-ray photons by superconducting nanowires.

Precisely acquiring the timing information of individual X-ray photons is important in both fundamental research and practical applications. The timing precision of commonly used X-ray single-photon detectors remains in the range of one hundred picoseconds to microseconds. In this work, we report on high-timing-precision detection of single X-ray photons through the fast transition to the normal state from the superconductive state of superconducting nanowires. We successfully demonstrate a free-running X-ray single-photon detector with a timing resolution of 20.1 ps made of 100-nm-thick niobium nitride film with an active area of 50 µm by 50 µm. By using a repeated differential timing measurement on two adjacent X-ray single-photon detectors, we demonstrate a precision of 0.87 ps in the arrival-time difference of X-ray photon measurements. Therefore, our work significantly enhances the timing precision in X-ray photon counting, opening a new niche for ultrafast X-ray photonics and many associated applications.

[Analysis of ARX gene variant in a child with X-linked lissencephaly with abnormal genitalia].

OBJECTIVE: To explore the clinical characteristics and genetic basis for a child with X-linked lissencephaly with abnormal genitalia (XLAG). METHODS: A child with XLAG who had presented at the Third Affiliated Hospital of Zhengzhou University in May 2021 was selected as the study subject. Peripheral blood samples of the child and his parents were collected and subjected to high-throughput sequencing. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the result was analyzed by using bioinformatic software. RESULTS: The child was found to have harbored a hemizygous c.945_948del variant in exon 2 of the ARX gene, which as a frameshifting variant has resulted in a truncated protein. His mother was found to be heterozygous for the variant, whilst his father was of wild type. The variant was unreported previously. CONCLUSION: The hemizygous c.945_948del variant of the ARX gene probably underlay the XLAG in this patient. Above finding has provided a basis for the diagnosis and genetic counseling for this family.

Neural Network-Based Prediction for Secret Key Rate of Underwater Continuous-Variable Quantum Key Distribution through a Seawater Channel.

Continuous-variable quantum key distribution (CVQKD) plays an important role in quantum communications, because of its compatible setup for optical implementation with low cost. For this paper, we considered a neural network approach to predicting the secret key rate of CVQKD with discrete modulation (DM) through an underwater channel. A long-short-term-memory-(LSTM)-based neural network (NN) model was employed, in order to demonstrate performance improvement when taking into account the secret key rate. The numerical simulations showed that the lower bound of the secret key rate could be achieved for a finite-size analysis, where the LSTM-based neural network (NN) was much better than that of the backward-propagation-(BP)-based neural network (NN). This approach helped to realize the fast derivation of the secret key rate of CVQKD through an underwater channel, indicating that it can be used for improving performance in practical quantum communications.

Kisspeptin regulates the proliferation and apoptosis of ovary granulosa cells in polycystic ovary syndrome by modulating the PI3K/AKT/ERK signalling pathway.

BACKGROUND: The development of polycystic ovary syndrome (PCOS) is closely correlated with apoptosis and oxidative stress in ovarian granulosa cells. Kisspeptin plays an important role in reproductive organ function. This study aimed to explore the role of kisspeptin in PCOS and oxidative stress-triggered apoptosis of ovarian granular cells. METHODS: A PCOS rat model was established by injecting dehydroepiandrosterone (DHEA) and feeding the rats a high-fat diet. The RNA and protein levels of kisspeptin were analysed by quantitative PCR, western blotting, and histological staining. Tissue damage was evaluated using haematoxylin and eosin (H&E) staining. The viability and proliferation of human granulosa cell KGN were measured using the cell counting kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) assays. Cell cycle and apoptosis were analysed by flow cytometry. Oxidative stress was analysed by measuring reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) levels. RESULTS: Kisspeptin was downregulated in the ovarian granulosa cells of PCOS rats compared to those of control rats. Kisspeptin overexpression enhanced KGN cell proliferation and inhibited apoptosis. ROS generation was suppressed by kisspeptin, along with decreased levels of MDA and increased levels of the antioxidants GSH, SOD, and CAT. Kisspeptin activates PI3K/AKT and ERK signalling, and inactivation of ERK1/2 suppresses the protective role of kisspeptin in ovarian granulosa cells. CONCLUSION: Kisspeptin improves proliferation and alleviates apoptosis and oxidative stress in ovarian granulosa cells by activating PI3K/AKT and ERK signalling.

Circ_0007706 downregulation ameliorates neonatal hypoxic ischemic encephalopathy via regulating the miR-579-3p/TRAF6 axis.

BACKGROUND: Neonatal hypoxic ischemic encephalopathy (HIE) is a main factor of neonatal death and permanent neurologic deficit. This study sought to investigate the functional role of hsa_circ_0007706 (circ_0007706) in modulating neonatal HIE. METHODS: In vitro HIE cell model was established in hBMVECs under the condition of oxygen­glucose deprivation/reperfusion (OGD/R) treatment. qRT-PCR analysis was utilized for detecting the level of circ_0007706, microRNA-579-3p (miR-579-3p) and TNF receptor-associated factor 6 (TRAF6). RNase R treatment and Oligo (dT) 18 primers were employed to verify the features of circ_0007706, and nucleocytoplasmic separation was conducted for determining the location of circ_0007706. CCK-8 assay, EdU assay, and flow cytometry were carried out to measure cell proliferation and apoptosis, respectively. The protein expression of Bax, Bcl-2 and TRAF6 was detected using western blot. Meanwhile, the levels of the pro-inflammatory factors were determined via ELISA. SOD activity and MDA level were assessed via the respective kits. Besides, dual-luciferase reporter assay and RNA pull-down were used to identify the association between miR-579-3p and circ_0007706 or TRAF6. RESULTS: Circ_0007706 was elevated in HIE newborns and OGD/R cell model. Knockdown of circ_0007706 greatly alleviated OGD/R-induced injury, inflammatory response and oxidative stress. We found that miR-579-3p was a direct target of circ_0007706, and miR-579-3p inhibitor could reverse the impact of circ_0007706 knockdown on OGD/R-caused cell damage in hBMVECs. In addition, miR-579-3p directly interacted with TRAF6, and the protective effects of miR-579-3p on OGD/R-induced injury in hBMVECs were harbored by TRAF6 overexpression. Our data indicated that circ_0007706 knockdown could downregulate the expression of TRAF6 by sponging miR-579-3p in OGD/R-treated hBMVECs. CONCLUSION: This study demonstrated that circ_0007706 knockdown assuaged HIE-induced injury by decreasing TRAF6 expression via targeting miR-579-3p.

Balloon-Occluded Esophageal Variceal Obliteration Procedure: A Novel Technique Report from Three Centers.

Introduction: Esophageal variceal bleeding (EVB) is a potentially fatal complication of cirrhosis. The purpose of the present study was to evaluate the safety and efficacy of a novel technique of balloon-occluded esophageal varices (EVs) obliteration (BEVO) for EVs classified as F2 (medium size, F2-EVs) and F3 (large size, F3-EVs). Materials and Methods: Between December 2020 and December 2021, a total of 73 consecutive patients with EVs were treated using BEVO. An injection of sclerosant was administered via direct puncture of the varices during balloon occlusion. Immediate postprocedural Doppler endoscopic ultrasonography (EUS) was conducted to evaluate the blood flow in the EVs. Several factors, including the technical success, controlling of acute bleeding, intraoperative bleeding at the injection site, variceal eradication, variceal recurrence, and BEVO-related complications, were assessed. Results: BEVO was successfully performed in all patients. Immediate hemostasis was achieved in 100% (25/25) of patients with active EVB. The incidence of injection site intraoperative bleeding presenting as oozing and spurting bleeding was 76.71% (56/73) and 8.22% (6/73), respectively. Based on Doppler EUS and endoscopic examination, EVs were completely eradicated in 71 out of 73 patients (97.26%) after three sessions. A total of 3 (4.11%) patients were diagnosed with EV recurrence during follow-up after complete EV eradication. Retrosternal chest discomfort (13.70%; 10/73) and abdominal bloating (2.74%; 2/73) were spontaneously relieved after a few days. No serious BEVO-related complications were observed. Discussion: BEVO is a convenient and effective treatment for obliterating F2 and F3 EVs. Clinical Trial Registration No. ChiCTR2000039974.

[Retracted] MicroRNA-199b targets the regulation of ZEB1 expression to inhibit cell proliferation, migration and invasion in non­small cell lung cancer.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that cell migration assay data shown in Figs. 2D and 4D were strikingly similar to data that had appeared in different form in other articles by different authors (in addition to the apparent duplication of some of these data within this paper itself). Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 16: 5007­5014, 2017; DOI: 10.3892/mmr.2017.7195].

MicroRNA-584 inhibits cell proliferation and invasion in non-small cell lung cancer by directly targeting MTDH.

[This retracts the article DOI: 10.3892/etm.2017.5624.].

Robust Trajectory Tracking Control for Continuous-Time Nonlinear Systems with State Constraints and Uncertain Disturbances.

In this paper, a robust trajectory tracking control method with state constraints and uncertain disturbances on the ground of adaptive dynamic programming (ADP) is proposed for nonlinear systems. Firstly, the augmented system consists of the tracking error and the reference trajectory, and the tracking control problems with uncertain disturbances is described as the problem of robust control adjustment. In addition, considering the nominal system of the augmented system, the guaranteed cost tracking control problem is transformed into the optimal control problem by using the discount coefficient in the nominal system. A new safe Hamilton-Jacobi-Bellman (HJB) equation is proposed by combining the cost function with the control barrier function (CBF), so that the behavior of violating the safety regulations for the system states will be punished. In order to solve the new safe HJB equation, a critic neural network (NN) is used to approximate the solution of the safe HJB equation. According to the Lyapunov stability theory, in the case of state constraints and uncertain disturbances, the system states and the parameters of the critic neural network are guaranteed to be uniformly ultimately bounded (UUB). At the end of this paper, the feasibility of the proposed method is verified by a simulation example.

Comparison of Clinical Effects of the Modified Masquelet Technique and Kirschner Wire External Fixation-Assisted Autogenous Bone Transplantation in the Treatment of Segmental Metacarpophalangeal Bone Defects.

OBJECTIVE: The present study aims to explore the (1) clinical effects of the modified Masquelet technique, whose improved Masquelet technique innovates the in vitro plasticity of the bone cement module and prefabricated hollow design, and the Kirschner wire external fixation-assisted autologous bone transplantation technique in the treatment of segmental metacarpophalangeal bone defects and (2) the differences between the two techniques. METHODS: The clinical data of 32 patients with segmental metacarpophalangeal bone defects (15 patients treated with the modified Masquelet technique and 17 patients treated with the self-made Kirschner wire external fixation technique) admitted to our department between January 2012 and January 2020 were retrospectively analyzed. The postoperative bone healing time, hand function, and complications were compared between the two groups. RESULTS: The two groups were comparable; there were no significant differences in age, sex, length of bone defect, and time from injury to operation between the two groups (P > 0.05). All patients were followed up with for 6-24 months (average = 13.7 months), and all patients with segmental metacarpophalangeal bone defects achieved fracture healing. The postoperative hospital stay, fracture healing time, functionary scores of the affected limb, and incidence of severe complications were better in the modified group than in the external fixation group (P < 0.05). CONCLUSION: Compared with the Kirschner wire external fixation stent assisted autologous bone transplantation, the improved Masquelet technique has the advantages of simple operation, fast healing, accurate effect, wide indications, and less complications, making it more worthy of clinical promotion.

Femtosecond Pumping of Nuclear Isomeric States by the Coulomb Collision of Ions with Quivering Electrons.

Efficient production of nuclear isomers is critical for pioneering applications, like nuclear clocks, nuclear batteries, clean nuclear energy, and nuclear γ-ray lasers. However, due to small production cross sections and quick decays, it is extremely difficult to acquire a significant amount of isomers with short lifetimes via traditional accelerators or reactors because of low beam intensity. Here, for the first time, we experimentally present femtosecond pumping of nuclear isomeric states by the Coulomb excitation of ions with the quivering electrons induced by laser fields. Nuclei populated on the third excited state of ^{83}Kr are generated with a peak efficiency of 2.34×10^{15} particles/s from a tabletop hundred-TW laser system. It can be explained by the Coulomb excitation of ions with the quivering electrons during the interaction between laser pulses and clusters at nearly solid densities. This efficient and universal production method can be widely used for pumping isotopes with excited state lifetimes down to picoseconds, and could be a benefit for fields like nuclear transition mechanisms and nuclear γ-ray lasers.

Isopsoralen ameliorates rheumatoid arthritis by targeting MIF.

BACKGROUND: Isopsoralen (IPRN), one of the active ingredients of Psoralea corylifolia Linn, has anti-inflammatory properties. We attempted to investigate the inhibitory effects of IPRN on rheumatoid arthritis (RA) and characterize its potential mechanism. METHODS: RA fibroblast-like synoviocytes (FLSs) and mice with collagen-induced arthritis (CIA) were used as in vitro and in vivo models to analyze the antiarthritic effect of IPRN. Histological analysis of the inflamed joints from mice with CIA was performed using microcomputed tomography (micro-CT) and hematoxylin-eosin (HE) staining. RNA sequencing (RNA-Seq), network pharmacology analysis, molecular docking, drug affinity responsive target stability (DARTS) assay, and cellular thermal shift assay (CETSA) were performed to evaluate the targets of IPRN. RESULTS: IPRN ameliorated the inflammatory phenotype of RA FLSs by inhibiting their cytokine production, migration, invasion, and proangiogenic ability. IPRN also significantly reduced the severity of CIA in mice by decreasing paw thickness, arthritis score, bone damage, and serum inflammatory cytokine levels. A mechanistic study demonstrated that macrophage migration inhibitory factor (MIF), a key protein in the inflammatory process, was the specific target by which IPRN exerted its anti-inflammatory effects in RA FLSs. CONCLUSION: Our study demonstrates the antiarthritic effect of IPRN, which suggests the therapeutic potential of IPRN in RA.

Treatment of tibial plateau fractures involving the posterolateral column using the extended anterolateral approach.

ABSTRACT: To summarize the surgical technique and clinical effects of the extended anterolateral approach for the treatment of Schatzker type II and Schatzker type V/VI involving the posterolateral column tibial plateau.From January 2015 through December 2018, 28 patients with tibial plateau fractures involving the posterolateral column were included in the study. Among them, 16 patients were Schatzker type II treated using an extended anterolateral approach with lateral tibial locking compression plate fixation. Twelve patients were Schatzker type V or VI treated using an extended anterolateral combined with a medial approach using lateral tibial locking compression plate plus medial locking compression plate fixation. All cases were followed up for 15 to 31 months, with an average follow-up of 22.5 ±â€Š3.7 months. During the follow-up, the tibial plateau angle (TPA), lateral posterior angle (PA) and Rasmussen radiological criteria were used to evaluate the effect of fracture reduction and fixation; the Hospital for Special Knee Surgery score and the range of motion were used to evaluate knee function. Additionally, the Lachman and knee Valgus (Varus) stress tests were used to evaluate anteroposterior and lateral stability of the knee.All fractures healed. At the 12-month follow-up, the Schatzker type II group revealed a mean TPA of 86.38 ±â€Š3.92°, a mean PA of 7.43 ±â€Š2.68°, and a mean Rasmussen radiological score of 16.00 ±â€Š2.06 points. The Schatzker type V/VI group showed a mean TPA of 84.91 ±â€Š3.51°, a mean PA of 9.68 ±â€Š4.01°, and a mean Rasmussen radiological score of 15.33 ±â€Š2.99 points. During the 1-year follow-up, when the postoperative PA was re-measured, the TPA and Rasmussen score of the 2 groups did not change significantly (P > .05). At the last follow-up, the Schatzker type II group showed a knee flexion angle of 110° to 135° and a mean HHS score of 88.37 ±â€Š10.01 points. The Schatzker type V/VI group revealed a knee flexion angle of 100° to 130° and a mean HHS score of 82.17 ±â€Š10.76 points. Additionally, up to the last follow-up, the Lachman and knee Valgus (Varus) stress test results of the 2 groups were negative. No complications were found.The extended anterolateral approach is a good choice to treat tibial plateau fractures involving the posterolateral column.

Factors affecting failed trial of labor and countermeasures: A retrospective analysis.

BACKGROUND: Vaginal delivery is the ideal mode of delivery for the termination of a pregnancy. However, the cesarean section rate in China is much higher than the published by the World Health Organization in the Lancet in 2010. AIM: To retrospectively analyze the factors related to failed trial of labor and the clinical indications for cesarean section conversion, explore how to promote the trial of labor success rate, and determine the feasibility of reducing the rate of conversion to cesarean section. METHODS: A retrospective analysis was performed on 9240 maternal women who met vaginal delivery conditions and required a trial of labor from January 2016 to December 2018 at our hospital. Among them, 8164 pregnant women who had a successful trial of labor were used as a control group, and 1076 pregnant women who had a failed trial of labor and converted to an emergency cesarean section were used as an observation group. The patients' clinical data during hospitalization were collected for comparative analysis, the related factors of the failed trial of labor were discussed, and reasonable prevention and resolution strategies were proposed to increase the success rate of trial of labor. RESULTS: The analysis revealed that advanced age (≥ 35 years old), macrosomia (≥ 4000 g), delayed pregnancy (≥ 41 wk), use of uterine contraction drugs, primipara, and fever during labor were associated with conversion to an emergency cesarean section in the failed trial of labor. Multivariate regression analysis showed that age, gestational age, primipara, use of uterine contraction drugs, fever during birth, and newborn weight led to a higher probability of conversion to an emergency cesarean section in the failed trial of labor. The analysis indicated that the following clinical indications were associated with the conversion to cesarean section in the failed trial of labor: Fetal distress (44.3%), social factors (12.8%), malpresentation (face presentation, persistent occipitoposterior position, and persistent occipitotransverse position) (9.4%), and cephalopelvic disproportion (8.9%). CONCLUSION: The conversion to emergency cesarean section in failed trial of labor is affected by many factors. Medical staff should take appropriate preventive measures for the main factors, increase the trial of labor success rate, improve the quality of delivery, ensure the safety of mother and child during the perinatal period, and improve the relationship between doctors and patients.

Fatigue Life Assessment of the Shell Structure of Purified Terephthalic Acid Filter Press.

The filter press is one of the most important devices in purified terephthalic acid (PTA) refinement, and it is of great significance to ensure the fatigue strength of the structure in operation. In this study, the fatigue life prediction of the shell structure of the PTA filter press was investigated through numerical and experimental methods. Firstly, the accurate stress at the critical area of the stiffener was obtained based on the thermomechanical model and submodel approach proposed. Subsequently, the fatigue life was evaluated by the fatigue strength reduction method and hot spot stress method. Finally, the shell structure is optimized by increasing the size of the axial stiffener and continuous hoop stiffener. The results unveil that both thermal load and outer structure constraints have little effect on the radial displacement and stress amplitude of the shell structure. Through modifying the fatigue design curve of the fatigue strength reduction method, the shell structure of the PTA filter press has 42.0% and 0.3% failure probabilities in the previous and present cyclic pressure conditions. Furthermore, the hoop stiffener plays an important role in reducing radial displacement and stress amplitude, among which three hoop stiffeners exhibit the most satisfactory optimization.

Esophageal Scab Mimicking a Parasite: A Case Report.

BACKGROUND Parasitic helminths in the esophagus are rare. Here, we report a case of esophageal scab mimicking a parasite. CASE REPORT A 65-year-old man was admitted to our hospital because after choking on food. Gastroscopy showed 2 foreign bodies adherent to the esophagus wall 28 and 34 cm from the incisor, which appeared to be a fluke. Two fluke-like foreign bodies (1.5 and 1.8 cm in length) were removed from the esophageal ulcer with forceps. After fixation with alcohol, the suspected fluke-like foreign bodies were noted to be brown and woody. Under a light microscope, the structure of the foreign body was not apparent, and no typical flatworm tegument structure was demonstrated on pathologic sections, but it had a blood clot-like structure. Administration of albendazole did not expel any helminths. A stool examination showed no eggs of the putative flukes. The genomic DNA of the suspected flukes was extracted and a 700 bp fragment was amplified by universal barcoding primers. The sequencing showed that the homology with human cytochrome c oxidase subunit I gene was 98.8%. CONCLUSIONS The scab formed by the esophageal ulcer was identified based on clinical manifestations, anti-helminth and stool examinations, parasite morphology, and molecular biology. Our experience with this case suggests that the universal barcoding technique can be used for identification of foreign bodies suspected to be parasites.