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Background Urethritis in young males is most commonly caused by sexually transmitted pathogens, although other non-infectious diseases can cause similar symptoms. The study evaluated the prevalence of gonorrhoea and chlamydia infections in sexually active young males with urethritis-like symptoms and their treatment outcomes. Methods Data of 20–50-year-old males who visited our clinic with urethritis symptoms between March 2019 and April 2022 were retrospectively collected. All patients underwent urinalysis, urine culture, and urinary polymerase chain reaction (PCR) testing for gonorrhoea and chlamydia at the first visit. Student’s t-test and Pearson’s chi-square test were used to compare the differences between participants with at least one positive test result and those with negative results in all three tests. Regression analyses were used to evaluate the predictive factors for positive PCR results for gonorrhoea or chlamydia in patients with negative urinalysis and urine culture results. Results Of the 365 participants with urethritis symptoms, those with negative results (39%) in all tests were significantly older and showed less frequent urethral discharge than those with at least one positive result. Among the 202 patients with negative urinalysis and urine culture results, 29.7% were diagnosed with gonorrhoea or chlamydia using PCR. The presence of discharge was an independent predictor of positive PCR results for gonorrhoea or chlamydia. For patients showing negative results in all tests, the most common tentative diagnosis was balanitis. Patients with negative results for all three tests have good prognosis. Conclusion The present study outlined the high frequency of negative urinalysis and urine culture results in young male patients with gonorrhoea- and chlamydia-related urethritis and indicated the importance of a history of urethral discharge as an indicator for antibiotic treatment of gonorrhoea and chlamydia in these patients. The findings of this study will be valuable for urologists treating young males with urethritis symptoms, and the insights provided here will facilitate appropriate management and patient satisfaction in such cases.

Alkaline glazes were first used on clay-based ceramics in Mesopotamia around 1500 B.C., at the same time as the appearance of glass vessels. The Roman Empire used lead-based glazes, with alkaline natron glass being used only to produce objects of glass. Chemical analysis has had some success determining compositional groups for Roman/Byzantine/early Islamic glasses because of the discovery of major production sites. Parthian and Sasanian glass and glazed wares, however, have been found only in consumption assemblages, which have failed to inform on how they were made. Here we reanalyse compositional data for Parthian and Sasanian glazes and present new analyses for Parthian glazed pottery excavated at the early third century A.D. Roman military outpost of Ain Sinu in northern Iraq. We show that some Parthian glazes are from a different tradition to typical Mesopotamian glazes and have compositions similar to Roman glass. We propose that Roman glass was recycled by Parthian potters, thereby suggesting that as yet undiscovered Mesopotamian glass production centres ordinarily supplied glass for indigenous glazed pottery. Furthermore, if recycling glass to make glazed pottery was extended to indigenous glassware, this may provide an explanation for the paucity of Parthian and Sasanian glass in the archaeological record.

Drought represents one of the most severe constraints to agricultural production; therefore, resistance to drought has the highest priority in the development of new cultivars. How insect pests respond to drought-resistant cultivars is poorly understood. In this study, by using the rose-grain aphid, Metopolophium dirhodum (Walker), in controlled laboratory conditions, we investigated the level of antibiosis of six commercially available cultivars of spring wheat (Triticum aestivum L.), which differed in their resistance to drought (drought-resistant cultivars: Septima, Jarissa and Seance; drought-sensitive cultivars: Quintus, Kabot and SW Kadrilj). Leaf morphological and structural traits were also measured for each cultivar to determine which leaf traits may be responsible for the observed differences. We used an age-stage, two-sex life table approach for comprehensive quantification of the aphid response to a particular cultivar and for projecting population growth. Although we found significant differences in all the life table and population growth parameters between the cultivars (SW Kadrilj was the most resistant to the aphids and Septima and Quintus were the most susceptible to the aphids), resistance to drought alone did not explain the observed variation. The cultivars also varied in most of the morphological and structural leaf traits measured. An increase in cuticle thickness at the cell junction above the major vein hampered the development of the aphid nymphs, which resulted in slower rates of population increase. Trichome density seemed to reduce the survival of the aphid nymphs. These two traits support not only drought resistance in general but also resistance to aphids and are potentially useful for selection in the future breeding of cereals.

Use of interprofessional education has greatly expanded and is widely used to foster interprofessional collaborative practice competency in health professionals, especially during medical emergencies. Identifying the interprofessional education delivery mode that can maximize learning outcomes within available resources is crucial for achieving the sustainability of an interprofessional education program.To examine the learning outcomes of simulation-based interprofessional education and video-enhanced interactive discussion interprofessional education modules and to analyze the variable costs between these two interprofessional education modules.A prospective quasi-experimental study.A medical university in Northern Taiwan.24 medical students and 48 nursing students enrolled in a 4-week simulation-based interprofessional education or video-enhanced interactive discussion interprofessional education program.Students' medical task performance, critical medical task performance, team behavior performance, and interprofessional collaboration attitude were examined at the pretest and posttest by using an objective structured checklist and team performance rating scale with a hands-on simulation model and structured questionnaires. The variable costs for simulation-based interprofessional education and video-enhanced interactive discussion interprofessional education were estimated upon the completion of the course.All learning outcomes significantly improved for both the groups from the pretest to posttest. After the intervention, the simulation-based interprofessional education group exhibited significantly higher scores in medical task performance, critical medical task performance and team behavior performance than the video-enhanced interactive discussion interprofessional education group at the posttest. No significant difference was noted in interprofessional collaboration attitude between the groups. Cost analysis revealed that the simulation-based interprofessional education program was approximately two times more expensive in terms of staffing costs and required 1.3 times greater space charges than the video-enhanced interactive discussion interprofessional education program.Both simulation-based interprofessional education and video-enhanced interactive discussion interprofessional education modules effectively improved medical and nursing students' medical task performance, critical medical task performance and team behavior performance. The simulation-based interprofessional education group had more favorable learning outcomes, but the associated costs were higher. Educators should consider both learning outcomes and cost when choosing a design strategy simulation-based interprofessional education vs. video-enhanced interactive discussion interprofessional education for interprofessional education module development.

Topological crystalline superconductors are known to have possible higher-order topology, which results in Majorana modes on $d-2$ or lower-dimensional boundaries. Given the rich possibilities of boundary signatures, it is desirable to have topological invariants that can predict the type of Majorana modes from band structures. Although symmetry indicators, a type of invariant that depends only on the band data at high-symmetry points, have been proposed for certain crystalline superconductors, there exist symmetry classes in which symmetry indicators fail to distinguish superconductors with different Majorana boundaries. Here, we systematically obtain topological invariants for an example of this kind, two-dimensional time-reversal symmetric superconductors with twofold rotational symmetry $C_2$. First, we show that the nontrivial topology is independent of band data on the high-symmetry points by conducting a momentum-space classification study. Then, from the resulting K groups, we derive calculable expressions for four $\mathbb{Z}_2$ invariants defined on high-symmetry lines or general points in the Brillouin zone. Finally, together with a real-space classification study, we establish the bulk-boundary correspondence and show that the four $\mathbb{Z}_2$ invariants can predict Majorana boundary types from band structures. Our proposed invariants can fuel practical material searches for $C_2$-symmetric topological superconductors featuring Majorana edge and corner modes., 27 pages, 5 figures, close to the published version

The three-point-bending shape memory properties, microstructure, and magnetic properties of Fe40.95Ni28Co17Al11.5Ta2.5B0.05 (at.%) alloys were investigated. The magnetic results showed a martensitic transformation in the samples that were aged at 700 °C for 6 and 12 h under the applied magnetic fields of 0.05 and 7 Tesla. The martensitic start temperature increased from −113 °C to −97 °C as aging times increased from 6 to 12 h. Increasing the magnetic fields from 0.05 to 7 Tesla, the transformation temperatures increased to a higher temperature. Both samples reach saturation magnetization (140 emu/g) under 7 Tesla. The 98.5% cold-rolled alloys that were annealed at 1250 °C for 0.5 h presented a strong texture in the rolling direction with an average grain size of 360 μm. Increasing the annealing time to 1 h, the intensity of texture reduced from 31.61 to 23.19. The fraction of low angle grain boundaries (LABs) for the 98.5% CR samples after annealing at 1250 °C for 0.5 h and 1 h was about 24.6% and 16.1%, respectively. Three-point-bending results show that the sample aged at 700 °C for 6 h displayed 0.2% recoverable strain at a stress level of 800 MPa. Failure occurred before the 900 MPa cycle could be completed. The sample aged at 700 °C for 12 h shows no transformation before the applied stress level of 300 MPa. As the stress levels increase to 400 MPa, the sample shows the shape memory effect and displayed 0.8% recoverable strain at a stress level of 400 MPa. The samples are failures during the 500 MPa cycle. The observed recoverable strain values were lower than those that were theoretically predicted, which was possibly due to the larger volume fraction of high-angle grain boundary and the slightly lower than expected average grain size.

Topological superconductors have attracted tremendous excitement as they are predicted to host Majorana zero modes that can be utilized for topological quantum computing. Candidate topological superconductor Sn

Background: In Alzheimer’s disease (AD), cognitive impairment begins 10–15 years later than neurodegeneration in the brain. Plasma biomarkers are promising candidates for assessing neurodegeneration in people with normal cognition. It has been reported that subjects with the concentration of plasma amyloid-β 1-42×total tau protein higher than 455 pg2/ml2 are assessed as having a high risk of amnesic mild impairment or AD, denoted as high risk of AD (HRAD). Objective: The prevalence of high-risk for dementia in cognitively normal controls is explored by assaying plasma biomarkers. Methods: 422 subjects with normal cognition were enrolled around Taiwan. Plasma Aβ1-40, Aβ1-42, and T-Tau levels were assayed using immunomagnetic reduction to assess the risk of dementia. Results: The results showed that 4.6% of young adults (age: 20–44 years), 8.5% of middle-aged adults (age: 45–64 years), and 7.3% of elderly adults (age: 65–90 years) had HRAD. The percentage of individuals with HRAD dramatically increased in middle-aged and elderly adults compared to young adults. Conclusion: The percentage of HRAD in cognitively normal subjects are approximately 10%, which reveals that the potentially public-health problem of AD in normal population. Although the subject having abnormal levels of Aβ or tau is not definitely going on to develop cognitive declines or AD, the risk of suffering cognitive impairment in future is relatively high. Suitable managements are suggested for these high-risk cognitively normal population. Worth noting, attention should be paid to preventing cognitive impairment due to AD, not only in elderly adults but also middle-aged adults.

Fire assay by cupellation is an early form of quantitative chemical analysis that required the use of specialized vessels typically made with ashes. Its use became particularly prominent in Europe since the Middle Ages, as reflected in technical treatises and archaeological remains that record a variety of recipes for their manufacture and use. Here we present chemical and microstructural analyses of cupels from the Porto Mint in Portugal, recovered from two distinct contexts spanning from the 14th to the 16th century CE. Based on the data, we argue that one set of cupels was likely used for the analysis of bulk metals as they entered the mint, while the other was used for the assay of bullion coins for quality control. We also show that most cupels were made of a mixture of bone ash and wood ash. In addition, our work illustrates strategies to identify and study severely corroded cupels. We recommend further studies of cupellation contexts, which will allow us to map knowledge transfer and technological traditions in this crucial strand of early science.

Background Altered γ-aminobutyric acid signaling is believed to disrupt the excitation/inhibition balance in the striatum, which may account for the motor symptoms of Huntington's disease. Na-K-2Cl cotransporter-1 is a key molecule that controls γ-aminobutyric acid-ergic signaling. However, the role of Na-K-2Cl cotransporter-1 and efficacy of γ-aminobutyric acid-ergic transmission remain unknown in Huntington's disease. Methods We determined the levels of Na-K-2Cl cotransporter-1 in brain tissue from Huntington's disease mice and patients by real-time quantitative polymerase chain reaction, western blot, and immunocytochemistry. Gramicidin-perforated patch-clamp recordings were used to measure the Eγ-aminobutyric acid in striatal brain slices. To inhibit Na-K-2Cl cotransporter-1 activity, R6/2 mice were treated with an intraperitoneal injection of bumetanide or adeno-associated virus-mediated delivery of Na-K-2Cl cotransporter-1 short-hairpin RNA into the striatum. Motor behavior assays were employed. Results Expression of Na-K-2Cl cotransporter-1 was elevated in the striatum of R6/2 and Hdh150Q/7Q mouse models. An increase in Na-K-2Cl cotransporter-1 transcripts was also found in the caudate nucleus of Huntington's disease patients. Accordingly, a depolarizing shift of Eγ-aminobutyric acid was detected in the striatum of R6/2 mice. Expression of the mutant huntingtin in astrocytes and neuroinflammation were necessary for enhanced expression of Na-K-2Cl cotransporter-1 in HD mice. Notably, pharmacological or genetic inhibition of Na-K-2Cl cotransporter-1 rescued the motor deficits of R6/2 mice. Conclusions Our findings demonstrate that aberrant γ-aminobutyric acid-ergic signaling and enhanced Na-K-2Cl cotransporter-1 contribute to the pathogenesis of Huntington's disease and identify a new therapeutic target for the potential rescue of motor dysfunction in patients with Huntington's disease. © 2019 International Parkinson and Movement Disorder Society.

Silver-bearing lead ores at Laurion in Attica were considered to have been first exploited with the introduction of coinage sometime around the birth of Classical Greece. However, in the late 20th century this chronology was radically revised earlier, to the Bronze Age, largely supported by lead isotope analyses (LIA). Here, we acknowledge that lead and silver metallurgy emerged from the earliest times but we propose that any correlation between these metals in the archaeological record is not a consequence of a geological association between lead and silver in ores such as galena until the middle of the first millennium BCE. We suggest that ancient metallurgists recognised that silver minerals (such as horn silver) dispersed in host rocks could be concentrated in molten lead and that LIA signatures of Bronze Age silver artefacts reflect the use of exogenous lead to extract silver, perhaps applying processes similar to those used to acquire silver in Bronze Age Siphnos. We further propose that lead from Laurion used for silver extraction resulted in the inadvertent transfer of its LIA signature (probably aided by roving silver prospectors) to silver objects and metallurgical debris recovered around the Aegean. New compositional analyses for the Mycenaean shaft-grave silver (c. 1600 BCE) support these conclusions. We believe that reverting to the mid-first millennium BCE for the first exploitation of silver from argentiferous lead ores is consistent with the absence of archaeological evidence for centralised control over Laurion until the Archaic period, the paucity of lead slag associated with silver-processing debris at Bronze Age sites, the scarcity of silver artefacts recovered in post-shaft grave contexts at Mycenae and throughout the Early Iron Age Aegean, the few Attic silver coins with LIA signatures consistent with Laurion until after 500 BCE and a single unambiguous mention of silver in the Linear B texts.

Background This study focuses on probing preservice technology teachers’ cognitive structures and how they construct engineering design in technology-learning activities and explores the effects of infusing an engineering design process into science, technology, engineering, and mathematics (STEM) project-based learning to develop preservice technology teachers’ cognitive structures for engineering design thinking. Results The study employed a quasi-experimental design, and twenty-eight preservice technology teachers participated in the teaching experiment. The flow-map method and metalistening technique were utilized to enable preservice technology teachers to create flow maps of engineering design, and a chi-square test was employed to analyze the data. The results suggest that (1) applying the engineering design process to STEM project-based learning is beneficial for developing preservice technology teachers’ schema of design thinking, especially with respect to clarifying the problem, generating ideas, modeling, and feasibility analysis, and (2) it is important to encourage teachers to further explore the systematic concepts of engineering design thinking and expand their abilities by merging the engineering design process into STEM project-based learning. Conclusions The findings of this study provide initial evidence on the effects of infusing the engineering design process into STEM project-based learning to develop preservice technology teachers’ engineering design thinking. However, further work should focus on exploring how to overcome the weaknesses of preservice technology teachers’ engineering design thinking by adding a few elements of engineering design thinking pedagogy, e.g., designing learning activities that are relevant to real life.

Topological superconductors have attracted tremendous excitement as they are predicted to host Majorana zero modes that can be utilized for topological quantum computing. Candidate topological superconductor Sn1-xInxTe thin films (0, Comment: Manuscript in review

There is now compelling evidence that the normal state of superconducting overdoped cuprates is a strange metal comprising two distinct charge sectors, one governed by coherent quasiparticle excitations, the other seemingly incoherent and characterized by non-quasiparticle (Planckian) dissipation. The zero-temperature superfluid density n_s(0)ns(0) of overdoped cuprates exhibits an anomalous depletion with increased hole doping pp, falling to zero at the edge of the superconducting dome. Over the same doping range, the effective zero-temperature Hall number n_{\rm H}(0) transitions from pp to 1 + pp. By taking into account the presence of these two charge sectors, we demonstrate that in the overdoped cuprates Tl_22Ba_22CuO_{6+\delta}6+δ and La_{2-x}2−xSr_xxCuO_44, the growth in n_s(0)ns(0) as pp is decreased from the overdoped side may be compensated by the loss of carriers in the coherent sector. Such a correspondence is contrary to expectations from conventional BCS theory and implies that superconductivity in overdoped cuprates emerges uniquely from the sector that exhibits incoherent transport in the normal state.

Objectives Recent neuropathological research suggests that recognition memory supported by familiarity rather than recollection may be the earliest cognitive change in course of Alzheimer's disease (AD). Nonetheless, the findings on the issue of familiarity capacity in the prodromal AD remain inconsistent. Boundary extension (BE), in which the view recollected by the subject covers a wider angle than was actually observed, is a form of false memory. Given that BE occurs implicitly and automatically, it may be a candidate for assessing familiarity functioning in cases of AD. This was the issue explored in the current study. Methods : One-hundred and six participants comprising a younger adult group (YA, n = 40), a healthy older adult group (OA, n = 40), and a group of patients with mild cognitive impairment (MCI, n = 26) underwent testing for BE and neuropsychological functions. Parts of OA and MCI underwent analysis for plasma tau levels. Receiver-operating characteristic analysis was used to assess memory associated with familiarity and recollection among participants. Results : The OA and MCI groups could be differentiated by the degree of familiarity associated with BE, wherein the latter group displayed minimal familiarity. Among OAs, familiarity was positively associated with education level. We observed a correlation between plasma tau levels and various neuropsychological functions. Most of the associations between plasma tau levels and neuropsychological functions were mediated by education level. Conclusions : Our findings indicate that BE could detect early decline in familiarity and assess preserved cognitive functions in aging

Recent experiments have observed possible spin- and valley-polarized insulators and spin-triplet superconductivity in twisted double bilayer graphene, a moire structure consisting of a pair of Bernal-stacked bilayer graphene. Besides the continuously tunable band widths controlled by an applied displacement field and twist angle, these moire bands also possess van Hove singularities near the Fermi surface and a field-dependent nesting which is far from perfect. Here we carry out a perturbative renormalization group analysis to unbiasedly study the competition among all possible instabilities in twisted double bilayer graphene and related systems with a similar van Hove fermiology in the presence of weak but finite repulsive interactions. Our key finding is that there are several competing magnetic, valley, charge, and superconducting instabilities arising from interactions in twisted double bilayer graphene, which can be tuned by controlling the displacement field and the twist angle. In particular, we show that spin- or valley-polarized uniform instabilities generically dominate under moderate interactions smaller than the band width, whereas $p$-wave spin-triplet topological superconductivity and exotic spin-singlet modulated paired state become important as the interactions decrease. Realization of our findings in general moire systems with a similar van Hove fermiology should open up new opportunities for manipulating topological superconductivity and spin- or valley-polarized states in highly tunable platforms., Comment: 11 pages, 6 figures

To ascertain the direct effects of water stress upon wheat plants (Triticum aestivum L.) and how these effects, in turn, influence the population growth of the bird cherry-oat aphid (Rhopalosiphum padi L.), we conducted a physiological analysis of wheat seedlings grown under three different watering regimes and subsequently determined the population parameters of the aphid using the age-stage, two-sex life table. A significantly higher content of free amino acids and soluble sugars were observed in wheat seedlings exposed to drought stress compared to seedlings that were well-watered and those that were grown under waterlogged conditions. Extended phloem salivation and stylet penetration with shorter duration of sustained ingestion from phloem was observed in an electrical penetration graph (EPG) of R. padi on drought-stressed wheat seedlings. This suggested that the aphid’s feeding activity, as well as nutrient intake, were impeded. The significantly higher percentage of essential amino acids found in wheat seedlings grown under waterlogged conditions promoted significantly higher fecundity and intrinsic rate of increase in R. padi populations compared to aphids fed on drought-treated or well-watered wheat seedlings. Our findings suggest that wheat seedling responses to water stress involve changes in sap composition that are responsible for altering the aphids’ nutrient intake and consequently affect their population growth. From a grower’s perspective, extending wheat cultivation in a rice–wheat rotation paddy field during the winter season may not be economically profitable if the fields are chronically waterlogged, since this may potentially lead to a higher infestation of cereal aphids.

Cerebrovascular disease is the second commonest cause of mortality globally and among the commonest causes of disability. However, research executed to probe the heavy metal exposure-stroke incidence relationship is scarce. Accordingly, we executed our study to probe the relationship of heavy metal concentrations (ie, concentrations of lead [Pb], mercury [Hg], cadmium [Cd], and arsenic) in the serum and urine of acute ischemic stroke (AIS) patients with several patient variables.For enrollment, we chose patients who had a first AIS within 7 days after the onset of a stroke. Thus, 33 newly diagnosed patients with AIS were recruited. We determined the aforementioned metals' concentrations by executing inductively coupled plasma mass spectrometry. We also gauged the association between such metal concentrations and patient variables by employing Spearman correlation coefficient. To examine the differences in metal concentrations between the different variables, we implemented an independent Mann-Whitney U test.In our cohort analysis, we noted serum Pb and Cd concentrations to be positively correlated with serum creatinine and hemoglobin. Serum and urine Cd concentrations had a negative correlation with impaired HbA1c in AIS patients. Urine Hg had a positive correlation with C-reactive protein in the participants. Participants who smoked or consumed alcohol had significantly higher Pb and Cd levels in serum than did those who neither smoked nor drank. Patients with AIS who smoked or consumed alcohol had high levels of serum Pb and serum Cd than did those who did not. Patients with AIS who consumed alcohol had significantly higher Pb and Hg urine concentrations than did those who did not.Our study indicated that serum Cd and Pb elevation increased the AIS risk in southern Taiwan patients.

Consumer behavior researchers often used two competing versions of Consumer Learning Theory to study how consumers response to Word-Of-Mouth (WOM) after a product harm crisis. The Original version predicts that real quality perception in consumer cognition is constant. By contrast, the revised version of this theory posits that it is never constant. Both versions of this theory have received support in studies that used traditional experimental methods. This study applied functional Magnetic Resonance Imaging (fMRI), the advanced brain imaging technique to examine (1) the neural substrates of theories of consumer behavior (i.e., the original compared with the revised versions of the Consumer Learning Theory) and (2) whether gender influences brain activation associated with WOM communication after a product harm crisis. The fMRI results showed clear biological evidence of the differentiation and localization of brain response to consumer in different WOM communication after a product harm crisis. In addition, we concluded that male tend to support the Original Consumer Learning Theory; female participants, however, showed differentiable brain activation across three factors, suggesting appear to be more sensitive to the Revised Consumer Learning Theory. Therefore, gender determines whether the original or revised version of the Consumer Learning Theory works in consumers’ decision-making.

A material system known as magic-angle twisted trilayer graphene exhibits superconductivity. The observation that this superconductivity persists under a strong magnetic field could lead to advances in quantum computation. Evidence of spin-triplet superconductivity in a quasi-2D system.

Purpose The purpose of this paper is to examine the impact of gender on the neural substrates of theories on consumer behavior (i.e. the original compared with the revised versions of consumer learning [CL] theory) and to examine whether gender influences brain activation associated with word-of-mouth (WOM) communications (i.e. information specificity, source expertise and tie strength) after a product harm crisis. This article also discusses the WOM effects of product quality perception, negative emotion and purchase intentions by precise localizing brain activity. Design/methodology/approach This study applied functional magnetic resonance imaging to measure brain activity (i.e. the blood oxygen level-dependent signal) during WOM communication after a product harm crisis. Findings The male participants treat the product quality as a constant and tend to support the original CL theory. The female participants, however, showed differentiable brain activation across three factors, suggesting a dynamic representation for product quality (i.e. not a constant), and they appear to be more sensitive to the revised CL theory. Originality/value This paper concluded that the original CL theory applies to males and the revised version applies to females. Therefore, gender determines whether the original or the revised version of the CL theory works in consumers’ decision-making, and the extant of research has not focused on the information after a product harm crisis in terms of whether the information being communicated is specific or tensile through WOM communication.

Background: Disruptions in gamma-aminobutyric (GABA) acid signaling are believed to be involved in Huntington's disease pathogenesis, but the regulation of GABAergic signaling remains elusive. Here we evaluated GABAergic signaling by examining the function of GABAergic drugs in Huntington's disease and the expression of GABAergic molecules using mouse models and human brain tissues from Huntington's disease. Methods: We treated wild-type and R6/2 mice (a transgenic Huntington's disease mouse model) acutely with vehicle, diazepam, or gaboxadol (drugs that selectively target synaptic or extrasynaptic GABAA receptors) and monitored their locomotor activity. The expression levels of GABAA receptors and a major neuron-specific chloride extruder (potassium-chloride cotransporter-2) were analyzed by real-time quantitative polymerase chain reaction, Western blot, and immunocytochemistry. Results: The R6/2 mice were less sensitive to the sedative effects of both drugs, suggesting reduced function of GABAA receptors. Consistently, the expression levels of α1/α2 and δ subunits were lower in the cortex and striatum of R6/2 mice. Similar results were also found in 2 other mouse models of Huntington's disease and in Huntington's disease patients. Moreover, the interaction and expression levels of potassium-chloride cotransporter-2 and its activator (brain-type creatine kinase) were decreased in Huntington's disease neurons. These findings collectively suggest impaired chloride homeostasis, which further dampens GABAA receptor-mediated inhibitory signaling in Huntington's disease brains. Conclusions: The dysregulated GABAergic responses and altered expression levels of GABAA receptors and potassium-chloride cotransporter-2 in Huntington's disease mice appear to be authentic and may contribute to the clinical manifestations of Huntington's disease patients. © 2017 International Parkinson and Movement Disorder Society

Genome-editing techniques such as CRISPR/Cas9 have been widely used in crop functional genomics and improvement. To efficiently deliver the guide RNA and Cas9, most studies still rely on Agrobacterium-mediated transformation, which involves a selection marker gene. However, several limiting factors may impede the efficiency of screening transgene-free genome-edited plants, including the time needed to produce each life cycle, the response to selection reagents, and the labor costs of PCR-based genotyping. To overcome these disadvantages, we developed a simple and high-throughput method based on visual detection of antibiotics-derived H2O2 to verify transgene-free genome-edited plants. In transgenic rice containing hygromycin phosphotransferase (HPT), H2O2 content did not change in the presence of hygromycin B (HyB). In contrast, in transgenic-free rice plants with 10-h HyB treatment, levels of H2O2 and malondialdehyde, indicators of oxidative stress, were elevated. Detection of H2O2 by 3,3′-diaminobenzidine (DAB) staining suggested that H2O2 could be a marker to efficiently distinguish transgenic and non-transgenic plants. Analysis of 24 segregating progenies of an HPT-containing rice plant by RT-PCR and DAB staining verified that DAB staining is a feasible method for detecting transformants and non-transformants. Transgene-free genome-edited plants were faithfully validated by both PCR and the H2O2-based method. Moreover, HyB induced overproduction of H2O2 in leaves of Arabidopsis, maize, tobacco, and tomato, which suggests the potential application of the DAB method for detecting transgenic events containing HPT in a wide range of plant species. Thus, visual detection of DAB provides a simple, cheap, and reliable way to efficiently identify transgene-free genome-edited and HPT-containing transgenic rice.

This study set out to re-examine the effectiveness of study abroad programs in second language (L2) acquisition through a multi-level meta-analysis. Overall, 42 primary studies published between 1995 and 2019 were identified, and in total 283 effect sizes were meta-analysed. This study implemented a three-level random effects model to account for the clustered, mutually dependent effect sizes often nested in the primary studies of L2 study abroad research. The results indicated a medium-to-large effect ( g = 0.87) on study abroad language programs. Essentially, the featured moderators in general explained more heterogeneity variances at level 3 (i.e. the between-study level) than at level 2 (i.e. the within study level). For study abroad language learners, language acquisition is optimal when learners, in particular those of a lower proficiency level, take both formal and content-based language courses while living with host families. Learners’ age and pre-program training may not moderate the effectiveness of study abroad language programs. Importantly, this study further established that the length of study abroad programs are positively associated with learners’ language gains, but that an extended and prolonged domestic program does not necessarily lead to such gains. Research and pedagogical implications are further discussed based on the research findings.

Autonomic dysfunctions including impaired baroreflex sensitivity (BRS) can develop after acute ischemic stroke (AIS) and may predispose patients to subsequent cardiovascular adverse events and serve as potential indicators of long-term mortality. This study aimed to determine the potential short-term prognostic significance of BRS after AIS. All patients admitted to Kaohsiung Veterans General Hospital within 72 h after onset of first-ever AIS between April 2008 and December 2012 were enrolled. Autonomic evaluation with continuous 10-minute monitoring of beat-to-beat hemodynamic and intracranial parameters was performed within 1 week after stroke by using the Task Force Monitor and transcranial Doppler. The 176 enrolled AIS patients were divided into high-BRS and low-BRS groups. All but two enrolled patients (who died within 3 months after stroke) attended scheduled follow-ups. The high-BRS group had significantly lower National Institutes of Health Stroke Scale (NIHSS) scores at 1 and 2 weeks after stroke and at discharge, lower modified Rankin scale (mRS) scores 1, 3, 6, and 12 months after stroke, and lower rates of complications and stroke recurrence compared to the low-BRS group. This study provides novel evidence of the utility of BRS to independently predict outcomes after AIS. Furthermore, modifying BRS may hold potential in future applications as a novel therapeutic strategy for acute stroke.

We introduce higher-order topological Dirac superconductor (HOTDSC) as a new gapless topological phase of matter in three dimensions, which extends the notion of Dirac phase to a higher-order topological version. Topologically distinct from the traditional topological superconductors and known Dirac superconductors, a HOTDSC features helical Majorana hinge modes between adjacent surfaces, which are direct consequences of the symmetry-protected higher-order band topology manifesting in the system. Specifically, we show that rotational, spatial inversion, and time-reversal symmetries together protect the coexistence of bulk Dirac nodes and hinge Majorana modes in a seamless way. We define a set of topological indices that fully characterizes the HOTDSC. We further show that a practical way to realize the HOTDSC phase is to introduce unconventional odd-parity pairing to a three-dimensional Dirac semimetal while preserving the necessary symmetries. As a concrete demonstration of our idea, we construct a corresponding minimal lattice model for HOTDSC obeying the symmetry constraints. Our model exhibits the expected topological invariants in the bulk and the defining spectroscopic features on an open geometry, as we explicitly verify both analytically and numerically. Remarkably, the HOTDSC phase offers an example of a higher-order topological quantum critical point, which enables realizations of various higher-order topological phases under different symmetry-breaking patterns. In particular, by breaking the inversion symmetry of a HOTDSC, we arrive at a higher-order Weyl superconductor, which is yet another new gapless topological state that exhibits hybrid higher-order topology., Comment: 18 pages, 8 figures

Altered γ-aminobutyric acid signaling is believed to disrupt the excitation/inhibition balance in the striatum, which may account for the motor symptoms of Huntington's disease. Na-K-2Cl cotransporter-1 is a key molecule that controls γ-aminobutyric acid-ergic signaling. However, the role of Na-K-2Cl cotransporter-1 and efficacy of γ-aminobutyric acid-ergic transmission remain unknown in Huntington's disease.We determined the levels of Na-K-2Cl cotransporter-1 in brain tissue from Huntington's disease mice and patients by real-time quantitative polymerase chain reaction, western blot, and immunocytochemistry. Gramicidin-perforated patch-clamp recordings were used to measure the EExpression of Na-K-2Cl cotransporter-1 was elevated in the striatum of R6/2 and HdhOur findings demonstrate that aberrant γ-aminobutyric acid-ergic signaling and enhanced Na-K-2Cl cotransporter-1 contribute to the pathogenesis of Huntington's disease and identify a new therapeutic target for the potential rescue of motor dysfunction in patients with Huntington's disease. © 2019 International Parkinson and Movement Disorder Society.

To identify and describe the various patterns of parents' perspectives on avoiding secondhand smoke exposure.Q methodology was applied to investigate the parental perspectives of 50 parents.The study was implemented from September-December 2016. Forty-two Q-statements were constructed based on the literature related to parental attitudes and prevention practices regarding preventing young children from experiencing secondhand smoke exposure. A series of Q-sorts was performed by the participants to rank the statements into a Q-sort grid. PQMethod 2.35 software was used to perform principal component analysis to identify different patterns of parents' perspectives.Five patterns of shared perspectives, which accounted for 62% of the total variance, were derived from the analysis: (a) lack of confidence to confront smokers in non-smoking areas; (b) awareness of health hazards but not ready to take preventive actions; (c) emphasis on parental responsibility and behavioural guidance; (d) awareness of health rights protected by legislation; and (e) strong willingness to take protective actions.Our findings revealed the shared perspectives of five groups of parents. The exploration of clusters of parents could assist healthcare professionals in acknowledging parents' tendencies related to attitudes and responses towards secondhand smoke exposure.Using a forced distribution through the Q-sorting technique, the particular perspective patterns of parents' experiences would be captured. These findings can serve as a useful guide for researchers and practitioners to develop tailored intervention programs for parents with the purpose of reducing secondhand smoke exposure in young children.目的: 识别并描述家长对避免二手烟暴露的看法的不同模式。 设计: 采用Q方法论来对50位家长的观点进行调查。 方法: 该研究于2016年九月至十二月实施。根据和父母态度相关的文献和防止幼童接触二手烟的防护实践,创建了四十二份问题陈诉。参与者对一系列Q类问题进行排序,将不同陈诉排列在Q网格中。采用PQ方法2.35软件进行主要成分分析,以确定不同父母的观点模式。 结果: 一共有五种共同观点模式来自于此分析,占了总方差的62%: (a) 对在非吸烟区面对吸烟者缺乏信心;(b) 意识到了健康危害,但尚未做好采取预防措施的准备;(c) 强调父母责任和行为指导;(d) 受立法保护的健康权意识;(e) 强烈的采取保护行动的意识。 结论: 我们的研究发现揭示了五组父母的共同观点。对父母群体的探索可以帮助医疗保健专业人员认识到父母对二手烟暴露的态度和反应的倾向。 影响: 通过Q排序技术使用强制分布法,可以捕捉到父母经历的特别观点模式。这些发现可以作为研究人员和从业人员制定针对父母的干预计划的有用指南,目的是减少儿童暴露于二手烟中。.

Huntington's disease (HD) is an autosomal dominant progressive neurodegenerative disease that is characterized by a triad of motor, psychiatric and cognitive impairments. There is still no effective therapy to delay or halt the disease progress. The striatum and cortex are two particularly affected brain regions that exhibit dense reciprocal excitatory glutamate and inhibitory gamma-amino butyric acid (GABA) connections. Imbalance between excitatory and inhibitory signalling is known to greatly affect motor and cognitive processes. Emerging evidence supports the hypothesis that disrupted GABAergic circuits underlie HD pathogenesis. In the present review, we focused on the multiple defects recently found in the GABAergic inhibitory system, including altered GABA level and synthesis, abnormal subunit composition and distribution of GABA

The methionine residues of proteins are the preferred targets of oxidation by reactive oxygen species resulting in the formation of methionine sulfoxide (MetSO), which impairs protein function. Methionine sulfoxide reductase A and B (MSR) catalyze the reduction of the MetSO S and R epimers back to Met residues, respectively. The roles of abscisic acid (ABA) and nitric oxide (NO) on the transcript levels of methionine sulfoxide reductase (MSR; EC 1.8.4.6) in the roots of 2-d-old etiolated rice (Oryza sativa L.) seedlings exposed to NaCl were examined. The OsMSR transcript levels increased upon exposure to NaCl, which increased as the NaCl concentrations increased. Fluridone (Flu) pretreatment inhibited the increases in ABA and NO contents and the OsMSRA4, OsMSRA5, OsMSRB1.1, OsMSRB3 and OsMSRB5 transcripts by NaCl, while ABA application reversed the effects of Flu. Flu did not affect the OsMSRA2 and OsMSRB1.2 transcripts. The application of the NO scavenger, 2-(4-carboxyphenyl)-4,4,5,5,-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), to NaCl-treated roots inhibited the increase in all of the OsMSRs transcripts with the exception of OsMSRB1.2. Treatment with the NO donor sodium nitroprusside (SNP) increased all the OsMSRs transcripts. The inhibitory effect of Flu on the increase of the OsMSRA4, OsMSRA5, OsMSR1.1, OsMSRB 3, and OsMSRB5 transcripts in the NaCl-treated roots was reversed by SNP. cPTIO inhibited the expression of all the OsMSR genes. The OsMSRA2.1 and OsMSRB1.2 transcripts can be increased by SNP. The Flu-inhibited internal ABA contents cannot be recovered by treatment with cPTIO or SNP. In addition, NaCl-induced NO production can be divided into ABA-dependent and ABA-independent routes. Therefore, the ABA-dependent NO route regulated the expression of OsMSRA4, OsMSRA5, OsMSRB1.1, OsMSRB 3, and OsMSRB5 in the NaCl-treated rice roots, while the ABA-independent NO pathway modulated OsMSRA2.1, and the ABA-independent and NO-independent pathway modulated OsMSRB1.2 expression in response to NaCl treatment.

A previous study demonstrated that purified Glycine max β-glucosidase (GmBGL) could hydrolyze glucosyl isoflavone to the aglyconic form. This study reports the cloning and functional characterization of a soybean cDNA encoding the β-glucosidase. GmBGL was isolated by use of a purified soybean N-terminal amino acid sequence and conserved sequences of β-glucosidase genes from other plants. Sequence analysis of GmBGL revealed an open reading frame of 1884 bp encoding a polypeptide of 627 amino acids with a calculated molecular mass of 69 kDa. Phylogenetic analysis classified the GmBGL into the glycosyl hydrolase 3 family. In soybean, the GmBGL transcript was predominantly accumulated in roots and leaves. To examine the enzymatic activity and substrate specificity, GmBGL was ectopically expressed in transgenic rice. Purified GmBGL protein from transgenic rice could catalyze the hydrolysis of genistin and daidzin to produce genistein and daidzein, respectively, which confirmed GmBGL as a functional β-glucosidase with isoflavone glucoside-hydrolyzing activity. This paper reveals that GmBGL is a key enzyme in transforming glucosyl isoflavones to aglycones in soybean, which may help in genetic manipulation of aglycone-rich soybean seeds.

We investigated the relationship between Chinese medicine pattern (CMP) types, their severity, and prognosis in patients (n = 187) with acute cerebral infarct (ACI). Six CMPs (wind, phlegm, fire-heat, blood stasis, qi deficiency, and yin deficiency and yang hyperactivity) were evaluated according to inspection, listening and smelling, inquiry, and palpitation. The severity and prognosis of each pattern type was determined according to the Glasgow Coma Scale (GCS), Modified Rankin Scale (MRS), National Institutes of Health Stroke Scale (NIHSS), Barthel Index (BI), and Functional Independence Measure (FIM), recorded at stroke onset and 12 weeks after stroke onset. The phlegm pattern (PP) patients displayed lower GCS, BI, and FIM scales scores, and higher MRS and NIHSS scales scores, than the nonphlegm pattern (N-PP) patients at, and 12 weeks after stroke onset, suggesting the clinical severity is greater and the prognosis is worse in PP patients with ACI than in non-PP patients with ACI.

Sturge-Weber syndrome is known to be associated with migraine attacks and prolong aura even without cerebral infarction. We report the case of a 36-year-old woman with type III Sturge-Weber syndrome developing with prolonged left homonymous hemianopsia after an intractable migraine-like headache and becoming a permanent visual field defect at 18-month follow up. By adopting a multimodality imaging study, we suggested that the underlying mechanism of prolonged visual field defect was due to blood flow disturbance and vasogenic leakage under the leptomeningeal angioma combining with atrophy and the damaged integrity of white matter in right occipital lobe.

Recent experiments demonstrating large spin-transfer torques in topological insulator (TI)-ferromagnetic metal (FM) bilayers have generated a great deal of excitement due to their potential applications in spintronics. The source of the observed spin-transfer torque, however, remains unclear. This is because the large charge transfer from the FM to TI layer would prevent the Dirac cone at the interface from being anywhere near the Fermi level to contribute to the observed spin-transfer torque. Moreover, there is yet little understanding of the impact on the Dirac cone at the interface from the metallic bands overlapping in energy and momentum, where strong hybridization could take place. Here, we build a simple microscopic model and perform first-principles-based simulations for such a TI-FM heterostructure, considering the strong hybridization and charge transfer effects. We find that the original Dirac cone is destroyed by the hybridization as expected. Instead, we find a new interface state which we dub 'descendent state' to form near the Fermi level due to the strong hybridization with the FM states at the same momentum. Such a `descendent state' carries a sizable weight of the original Dirac interface state, and thus inherits the localization at the interface and the same Rashba-type spin-momentum locking. We propose that the `descendent state' may be an important source of the experimentally observed large spin-transfer torque in the TI-FM heterostructure., Comment: 7 pages, 7 figures

Disruptions in gamma-aminobutyric (GABA) acid signaling are believed to be involved in Huntington's disease pathogenesis, but the regulation of GABAergic signaling remains elusive. Here we evaluated GABAergic signaling by examining the function of GABAergic drugs in Huntington's disease and the expression of GABAergic molecules using mouse models and human brain tissues from Huntington's disease.We treated wild-type and R6/2 mice (a transgenic Huntington's disease mouse model) acutely with vehicle, diazepam, or gaboxadol (drugs that selectively target synaptic or extrasynaptic GABAThe R6/2 mice were less sensitive to the sedative effects of both drugs, suggesting reduced function of GABAThe dysregulated GABAergic responses and altered expression levels of GABA

Theoretically, it has been known that breaking spin degeneracy and effectively realizing spinless fermions is a promising path to topological superconductors. Yet, topological superconductors are rare to date. Here we propose to realize spinless fermions by splitting the spin degeneracy in momentum space. Specifically, we identify monolayer hole-doped transition metal dichalcogenide (TMD)s as candidates for topological superconductors out of such momentum-space-split spinless fermions. Although electron-doped TMDs have recently been found superconducting, the observed superconductivity is unlikely topological because of the near spin degeneracy. Meanwhile, hole-doped TMDs with momentum-space-split spinless fermions remain unexplored. Employing a renormalization group analysis, we propose that the unusual spin-valley locking in hole-doped TMDs together with repulsive interactions selectively favours two topological superconducting states: interpocket paired state with Chern number 2 and intrapocket paired state with finite pair momentum. A confirmation of our predictions will open up possibilities for manipulating topological superconductors on the device-friendly platform of monolayer TMDs., Nature Communications, 8, ISSN:2041-1723

Background and purpose Astragalus membranaceus (AM) is the first-choice herb for fatigue treatment in traditional Chinese medicine and the main herb used for stroke treatment in China and Taiwan. The purpose of this study was to evaluate the effect of AM on poststroke fatigue (PSF). Materials and methods This study was designed as a double-blind, randomized, controlled preliminary study. Sixty-four patients with PSF were assigned to treatment group (TG; 31 patients), which received oral administration of AM (2.8 g three times per day) for 28 days, and a control group (CG; 33 patients), which received a placebo. The primary outcome measures were the changes in the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and Brief Fatigue Index (BFI) scores Results A total of 61 patients (29 patients in the TG and 32 patients in the CG) completed the trial. The difference in BFI scores between Visit 2 and Visit 1 was –17.83±17.70 in the TG, which was greater than that in the CG (–8.03±9.95; p=0.01); additionally, the difference in BFI scores between Visit 3 and Visit 1 was –16.48±16.41 in the TG, which was also greater than that in the CG (–9.47±13.39; p=0.05). In the EORTC QLQ-C30, the difference in cognitive functioning scores between Visit 2 and Visit 1 was 14.37±13.89 in the TG, which was greater than that in the CG (3.65±19.74; p=0.02); additionally, the difference in these scores between Visit 3 and Visit 1 was 14.37±16.50 in the TG, which again was greater than that in the CG (6.25±19.74; p=0.04). The difference in social functioning scores between Visit 3 and Visit 1 was 9.77±15.12 in the TG, which was greater than that in the CG (–1.56±20.46; p=0.01). The difference in global quality of life (QOL) scores between Visit 2 and Visit 1 was 14.08±18.78 in the TG, which was also greater than that in the CG (1.56±18.14; p=0.003); moreover, the difference in these scores between Visit 3 and Visit 1 was 10.92±17.55 in the TG, and this was greater than that in the CG (1.82±15.8; p=0.05). Conclusion AM can improve BFI scores; cognitive functioning, social functioning, and global QOL scores in the EORTC QLQ-C30. Our results suggest that physicians should pay close attention to the unmet medical needs of patients with PSF. AM is helpful for treating patients with PSF; however, additional studies with a larger sample and a longer period of investigation are required.

The sub-thalamic nucleus (STN) is relevant to the preparation of movement ignition but its role in movement termination is uncertain. Fourteen patients with Parkinson's disease (PD) received local field potentials (LFPs) recording at the left STN on the fourth day after deep brain stimulation surgery. They performed phasic and tonic movements of the right wrist extensor. Movement onset (Mon) and movement offset (Moff) of the electromyographic activities were used as triggers to determine an eight-second LFPs epoch for time-frequency analysis. Movement-related power changes were assessed by repeated measures analysis of variance with within-subject factors of Event (Mon and Moff), Period (ten time periods for phasic movement and six time periods for tonic movement), and Frequency (alpha, low-beta, and high-beta). There was significant triple interaction in both the phasic and tonic movements. By post-hoc analysis, high-beta event-related de-synchronization (ERD) appeared earlier (3 s prior to Mon) than those of low-beta and alpha for the Mon phasic movement. There was no alpha ERD for the Mon tonic movement. Alpha, low-beta, and high-beta ERD all appeared about 1 s prior to the Moff tonic movement. The current findings suggest that STN participates in the preparation of volitional movement termination but via a different mechanism from that in movement initiation. Unlike asynchronous ERD frequency bands present in movement initiation, a simultaneous ERD across wide frequency bands in STN may play a pivotal role in terminating volitional movement.

We used reduced slice reparations to study ASIC-like currents in the rat central clock suprachiasmatic nucleus (SCN). In reduced SCN preparations, a drop of extracellular pH evoked a desensitizing inward current to excite SCN neurones to fire at higher rates. Under voltage-clamped conditions, all SCN neurones responded to a 5 s pH step to 6.4 with an inward current that decayed with an average time constant of 1.2 s to 10% of the peak at the end of step. The current was blocked by amiloride with an IC50 of 14 μm and was carried mainly by Na+, suggesting an origin of ASIC-like channels. The SCN neurones were sensitive to neutral pH, with 94% of cells responding to pH 7.0 with an inward current. The study of sensitivity to pH between 7.0 and 4.4 revealed a two-component dose-dependent H+ activation in most SCN neurones, with the first component (85% in amplitude) having a pH50 of 6.6, and the second (15%) a pH50 of 5. The ASIC-like currents were potentiated by lactate and low Ca2+, but were inhibited by Zn2+. RT-PCR analysis demonstrated the presence of mRNA for ASIC1a, 2a, 2b, and 3 in SCN. Compared to other central neurones, the unique presence of ASIC3 along with ASIC1a in SCN neurones may contribute to the high pH sensitivity and unusual inhibition by Zn2+. The high pH sensitivity suggests that the SCN neurones are susceptive to extracellular acidification of physiological origins and that the ASIC current might play a role in regulating SCN excitability.

The role of reduced glutathione (GSH) in heat shock (HS)- and H2O2-induced protection of rice (Oryza sativa L., cv. Taichung 1) seedlings from Cd stress was investigated. HS- and H2O2-pretreatment resulted in an increase in GSH content in leaves of rice seedlings. Addition of exogenous GSH under non-HS conditions, which resulted in an increase in GSH in leaves, enhanced subsequent Cd tolerance of rice seedlings. Pretreatment with buthionine sulfoximine (BSO), a specific inhibitor of GSH synthesis, which effectively inhibited GSH content induced by HS and H2O2, reduced subsequent Cd tolerance. Furthermore, the effect of BSO on HS- and H2O2-induced GSH accumulation and toxicity by subsequent Cd stress can be reversed by the addition of GSH. The time-course analyses of HS in rice seedlings demonstrated that the accumulation of H2O2 preceded the increase in GSH. Based on the data obtained in this study, it could be concluded that the early accumulation of H2O2 during HS signals the increase in GSH content, which in turn protects rice seedlings from oxidative damage caused by Cd.

Rice (Oryza sativa L.) seedlings stressed with CdCl2 (0.5 mM or 50 μM) showed typical Cd toxicity (leaf chlorosis, decrease in chlorophyll content, or increase in H2O2 and malondialdehyde contents). Rice seedlings pretreated with heat shock at 45°C (HS) for 2 or 3 h were protected against subsequent Cd stress. Rice seedlings pretreated with HS had similar Cd concentration in leaves caused by CdCl2 as those non-HS. The content of H2O2 increased in leaves 1 h after HS exposure. However, APX and GR activities were higher in HS-treated leaves than their respective control, and it occurred after 2 h of HS treatment. Pretreatment of rice seedlings with H2O2 under non-HS conditions resulted in an increase in APX, GR, and CAT activities and protected rice seedlings from subsequent Cd stress. HS-induced H2O2 production and protection against subsequent Cd stress can be counteracted by imidazole, an inhibitor of NADPH oxidase complex. Results of the present study suggest that early accumulation of H2O2 during HS signals the increase in APX and GR activities, which in turn prevents rice seedlings from Cd-caused oxidative damage.

The production of H2O2 in detached rice leaves of Taichung Native 1 (TN1) caused by CdCl2 was investigated. CdCl2 treatment resulted in H2O2 production in detached rice leaves. Diphenyleneiodonium chloride (DPI) and imidazole (IMD), inhibitors of NADPH oxidase (NOX), prevented CdCl2-induced H2O2 production, suggesting that NOX is a H2O2-genearating enzyme in CdCl2-treated detached rice leaves. Phosphatidylinositol 3-kinase inhibitors wortmanin (WM) or LY294002 (LY) inhibited CdCl2-inducted H2O2 production in detached rice leaves. Exogenous H2O2 reversed the inhibitory effect of WM or LY, suggesting that phosphatidylinositol 3-phosphate is required for Cd-induced H2O2 production in detached rice leaves. Nitric oxide donor sodium nitroprusside (SNP) was also effective in reducing CdCl2-inducing accumulation of H2O2 in detached rice leaves. Cd toxicity was judged by the decrease in chlorophyll content. The results indicated that DPI, IMD, WM, LY, and SNP were able to reduce Cd-induced toxicity of detached rice leaves. Twelve-day-old TN1 and Tainung 67 (TNG67) rice seedlings were treated with or without CdCl2. In terms of Cd toxicity (leaf chlorosis), it was observed that rice seedlings of cultivar TN1 are Cd-sensitive and those of cultivar TNG67 are Cd-tolerant. On treatment with CdCl2, H2O2 accumulated in the leaves of TN1 seedlings but not in the leaves of TNG67. Prior exposure of TN1 seedlings to 45oC for 3 h resulted in a reduction of H2O2 accumulation, as well as Cd tolerance of TN1 seedlings treated with CdCl2. The results strongly suggest that Cd toxicity of detached leaves and leaves attached to rice seedlings are due to H2O2 accumulation.

The protective effect of polyamines against Cd toxicity of rice (Oryza sativa) leaves was investigated. Cd toxicity to rice leaves was determined by the decrease in protein content. CdCl2 treatment results in (1) increased Cd content, (2) induction of Cd toxicity, (3) increase in H2O2 and malondialdehyde (MDA) contents, (4) decrease in ascorbic acid (ASC) and reduced glutathione (GSH) contents, and (5) increase in the activities of antioxidative enzymes (superoxide dismutase, glutathione reductase, ascorbate peroxidase, catalase, and peroxidase). Spermidine (Spd) and spermine (Spm), but not putrescine (Put), were effective in reducing CdCl2-induced toxicity. Spd and Spm prevented CdCl2-induced increase in the contents of H2O2 and MDA, decrease in the contents of ASC and GSH, and increase in the activities of antioxidative enzymes. Spd and Spm pretreatments resulted in a decrease in Cd content when compared with H2O pretreatment, indicating that Spd and Spm may reduce the uptake of Cd. Results of the present study suggest that Spd and Spm are able to protect Cd-induced oxidative damage and this protection is most likely related to the avoidance of H2O2 generation and the reduction of Cd uptake.

In this study, we examined interaction between cadmium (Cd) and temperature in rice seedlings. Effects of CdCl2 (0.5 mM) simultaneously applied at high (35/30°C day/night), medium (25/20°C) and low (15/13°C) temperatures to rice seedlings were detected by measuring changes in biomass production and NH 4 + content. Results indicated that Cd-induced biomass reduction and NH 4 + accumulation increased in parallel with temperature increases. On treatment with CdCl2, the abscisic acid (ABA) content markedly increased in the leaves of seedlings grown at high temperature but not at medium and low temperatures. Exogenous application of ABA at medium temperature increased ABA and NH 4 + contents in the leaves of rice seedlings. Fluridone (Flu) treatment, an inhibitor of carotenoid biosynthesis, reduced ABA content, as well as Cd-induced NH 4 + accumulation in the leaves of rice seedlings grown at high temperature. These Flu effects can be reversed by application of ABA. Furthermore, Flu treatment did not reduce Cd content in leaves of seedlings grown at high temperature. All these results suggest that Cd-induced NH 4 + accumulation at high temperature is mediated through ABA.

The role of H2O2 in the senescence of detached rice leaves induced by methyl jasmonate (MJ) was investigated. MJ treatment resulted in H2O2 production in detached rice leaves, which was prior to the occurrence of leaf senescence. Dimethylthiourea, a chemical trap of H2O2, was observed to be effective in inhibiting MJ-induced senescence and MJ-increased malondialdehyde (MDA) content in detached rice leaves. Diphenyleneiodonium chloride (DPI) and imidazole (IMD), inhibitors of NADPH oxidase, prevented MJ-induced H2O2 production, suggesting that NADPH oxidase is a H2O2-generating enzyme in MJ-treated detached rice leaves. DPI and IMD also inhibited MJ-promoted senescence and MJ-increased MDA content in detached rice leaves. Phosphatidylinositol 3-kinase inhibitors wortmannin (WM) or LY 294002 (LY) inhibited MJ-induced H2O2 production and senescence of detached rice leaves. Exogenous H2O2 reversed the inhibitory effect of WM or LY. In terms of leaf senescence, it was observed that rice seedlings of cultivar Taichung Native 1 (TN1) are jasmonic acid (JA)-sensitive and those of cultivar Tainung 67 (TNG67) are JA-insensitive. On treatment with JA, H2O2 accumulated in the leaves of TN1 seedlings but not in the leaves of TNG67. Evidence was also provided to show that MJ-induced H2O2 production in detached rice leaves is abscisic acid (ABA)-independent. Ethylene action inhibitor, silver thiosulfate, was observed to inhibit MJ- and ABA-induced H2O2 production and senescence of detached rice leaves, suggesting that the action of MJ and ABA is ethylene-dependent.

Rice (Oryza sativa L.) seeds were soaked for 18 h in distilled water in the absence (-PBZ) or presence (+PBZ, a triazole) of 100 mg I -1 paclobutrazol and then air dried. These air-dried seeds were germinated in the dark and then cultivated in a Phytotron. Twelve-day-old -PBZ and +PBZ seedlings were treated or not with CdCl 2 . Cd toxicity was judged by the decrease in biomass production, decrease in chlorophyll and protein content, increase in NH 4 + content and induction of oxidative stress. The results indicated that PBZ applied to seeds was able to protect rice seedlings from Cd toxicity. On treatment with CdCl 2 , the abscisic acid (ABA) content increased in +PBZ leaves, but not in -PBZ leaves. The decrease in the transpiration rate of-PBZ seedlings by CdCl 2 was less than that of +PBZ seedlings. Exogenous application of the ABA biosynthesis inhibitor, fluridone (Flu), reduced ABA accumulation, increased the transpiration rate and Cd content, and decreased the Cd tolerance of +PBZ seedlings. The effects of Flu on the Cd toxicity, transpiration rate and Cd content were reversed by the application of ABA. It seems that the PBZ-induced Cd tolerance of rice seedlings is mediated through an accumulation of ABA.