2,977 research outputs found

    Novel interface-selected waves and their influences on wave competitions

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    The topic of interface effects in wave propagation has attracted great attention due to their theoretical significance and practical importance. In this paper we study nonlinear oscillatory systems consisting of two media separated by an interface, and find a novel phenomenon: interface can select a type of waves (ISWs). Under certain well defined parameter condition, these waves propagate in two different media with same frequency and same wave number; the interface of two media is transparent to these waves. The frequency and wave number of these interface-selected waves (ISWs) are predicted explicitly. Varying parameters from this parameter set, the wave numbers of two domains become different, and the difference increases from zero continuously as the distance between the given parameters and this parameter set increases from zero. It is found that ISWs can play crucial roles in practical problems of wave competitions, e.g., ISWs can suppress spirals and antispirals

    Resolving Taxonomic Names using Evidence Extracted from Text

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    Biological taxonomy is established on organism relationships with scientific names as the primary identifiers; however, resolving various taxonomic names remains one of the greatest challenges in taxonomy and systematic biology overall. We proposed an evidence-based approach that extracts trait (character) evidence from published literature to facilitate the comparison of taxonomic concepts. In this poster, we report an initial set of results from our first case study using the plant genus Rubus. The case study tested the entire pipeline of the Explorer of Taxon Concepts toolkit we have developed and revealed challenging phenomena to be solved in the near future

    Robust Control of Single-Qubit Gates at the Quantum Speed Limit

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    Fastness and robustness are both critical in the implementation of high-fidelity gates for quantum computation, but in practice, a trade-off has to be made between them. In this paper, we investigate the underlying robust time-optimal control problem so as to make the best balance. Based on the Taylor expansion of the system's unitary propagator, we formulate the design problem as the optimal control of an augmented finite-dimensional system at its quantum speed limit (QSL), where the robustness is graded by the degree of series truncation. The gradient-descent algorithm is then introduced to sequentially seek QSLs corresponding to different orders of robustness. Numerical simulations for single-qubit systems show that the obtained time-optimal control pulses can effectively suppress gate errors (to the prescribed robustness order) caused by qubit frequency and field amplitude uncertainties. These results provide a practical guide for selecting pulse lengths in the pulse-level compilation of quantum circuits

    Anti-Hepatitis B Virus Effect and Possible Mechanism of Action of 3,4-O-Dicaffeoylquinic Acid In Vitro and In Vivo

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    The anti-hepatitis B activity of 3,4-O-dicaffeoylquinic acid isolated from Laggera alata was studied using the D-galactosamine- (D-GalN-) induced hepatocyte damage model, HepG2.2.15 cells, and with HBV transgenic mice. In vitro results showed that 3,4-O-dicaffeoylquinic acid improved HL-7702 hepatocyte viability and markedly inhibited the production of HBsAg and HBeAg. At a concentration of 100 μg/mL, its inhibitory rates on the expression levels of HBsAg and HBeAg were 89.96% and 81.01%, respectively. The content of hepatitis B virus covalently closed circular DNA (HBV cccDNA) in HepG2.2.15 cells was significantly decreased after the cells were treated with the test compound. In addition, 3,4-O-dicaffeoylquinic acid significantly increased the expression of heme oxygenase-1 (HO-1) in HepG2.2.15 cells. In vivo results indicated that the test compound at concentrations of 100 μg/mL significantly inhibited HBsAg production and increased HO-1 expression in HBV transgenic mice. In conclusion, this study verifies the anti-hepatitis B activity of 3,4-O-dicaffeoylquinic acid. The upregulation of HO-1 may contribute to the anti-HBV effect of this compound by reducing the stability of the HBV core protein, which blocks the refill of nuclear HBV cccDNA. Furthermore, the hepatoprotective effect of this compound may be mediated through its antioxidative/anti-inflammatory properties and by the induction of HO-1 expression

    Influence of size of Nd:YAG capsulotomy on ocular biological parameters and refraction

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    AIM:To investigate the influences of Nd:YAG laser capsulotomy with different size on visual acuity(VA), intraocular pressure(IOP), refraction, anterior chamber depth(ACD), and macular thickness(MT)in patients with posterior capsular opacification(PCO). METHODS: In this retrospective, constantly study, 41 eyes of 41 patients treated with Nd:YAG laser posterior capsulotomy for PCO were divided into 2 groups according to the different incision sizes of capsulotomy: the patients received capsulotomy with the incision diameter less than or equal to 3.5mm were enrolled into group 1, while those received operation with incision diameter more than 3.5mm went to group 2. All patients were followed up before Nd:YAG laser capsulotomy, 1wk, 1 and 3mo after Nd:YAG laser capsulotomy, and the best-corrected visual acuity(BCVA), refraction, IOP, ACD, and MT were compared between two groups. RESULTS: In both groups, BCVA were significantly improved postoperatively compared with base line(PP>0.05). The diopter(SE)of the two groups were not significantly different before and after operation(P>0.05). Intraocular pressure in group 2 was higher than those in group1 at 1wk(t=-2.609, P=0.013). ACD decreased significantly at 1wk postoperatively(PP>0.05). Both groups had increased macular thickness lightly at 1wk postoperatively, but with no statistical significance(P>0.05), and there was no significant difference between the two groups at 1wk, 1 and 3mo postoperatively(P>0.05). CONCLUSION: The increase in intraocular pressure is more pronounced when the size of posterior capsulotomy was larger. However, the changes of BCVA, ACD, refraction, MT are not related with the incision size of posterior capsulotomy

    Latent profile analysis of psychological needs thwarting in Chinese school teachers: longitudinal associations with problematic smartphone use, psychological distress, and perceived administrative support

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    IntroductionIn light of the significant impact that teachers have on education quality and student growth, their mental health warrants special attention. With the increasing popularity of Information and Communication Technology (ICT) and the rise of online teaching during the pandemic, teachers have become a group prone to developing problematic smartphone use (PSU). Psychological need thwarting (PNT) has been shown to be closely related to PSU, psychological distress, and perceived administrative support. However, most previous studies have adopted a variable-centered approach, which may overlook the possibility that the three basic needs are not closely associated and could form distinct profiles. Therefore, this study aims to apply latent profile analysis to identify different PNT profiles and their associations with PSU, psychological distress, and perceived administrative support.MethodsA longitudinal survey was conducted using convenience and purposive sampling methods. The survey involved 1,642 primary and middle school teachers working in China over a two-month interval, with the first assessment in November 2021 (Time 1) and the second in January 2022 (Time 2).ResultsThe results indicate that a three-profile model, intricately based on the PNT data gathered at Time 1, is most optimal: Class 1 is labeled as ‘High autonomy-High competence and Moderate relatedness thwarting’, Class 2 as ‘High autonomy-High competence and High relatedness thwarting’, and Class 3 as ‘Low psychological needs thwarting’. Distinct associations were observed among the three profiles concerning PSU, psychological distress, and perceived administrative support. Specifically, in terms of PSU, the score of Class 2 was higher than Class 1, with that of Class 3 being the lowest at Time 1, while at Time 2 no significant difference was found between any two of these three groups; in terms of distress, the scores of the three profiles were arranged from high to low as Class 2, 1, and 3 at both time points; and in terms of perceived administrative support, the order was just the opposite, with 3, 1, and 2 from high to low at both Time 1 and Time 2.ConclusionNotably, the consistent ranking of the three classes in terms of psychological distress and administrative support suggests a lasting influence of PNT. Future studies should explore this enduring impact further by employing additional longitudinal data sets and examining potential mediators or moderators beyond the current study’s scope

    Severe fever with thrombocytopenia syndrome in children: a case report

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    BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by a novel bunyavirus (SFTSV) in China. Humans of all ages living in endemic areas have high risk of acquiring SFTS. Most clinical data so far have been from adults and no clinical study was available from children yet. The present study identified four SFTSV infected children through hospital based surveillance. A prospective observational study was performed to obtain their clinical and laboratory characteristics. CASE PRESENTATION: The patients’ age ranged from 4–15 years old and two were male. On hospitalization, fever, malaise and gastrointestinal syndromes were the most commonly presenting symptoms. Hemorrhagic symptoms or neurological manifestation was not recorded in any of the four pediatric patients. Hematological abnormalities at admission into hospital included leucopenia (4 cases), thrombocytopenia (1 case) and bicytopenia (1 case). The abnormal parameters included elevated aminotransferase (1 case), alanine transaminase (2 case), and lactate dehydrogenase (3 case). Laboratory parameters indicative of renal damage was not observed during the hospitalization. All the patients recovered well without sequelae being observed. CONCLUSION: Compared with adults, pediatric patients with SFTSV infection seem to have less vague subjective complaints and less aggressive clinical course. Thrombocytopenia is suggested to be used less rigorously in recognizing SFTSV infection in pediatric patients, especially at early phase of disease
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