49 research outputs found

    Spontaneous breaking of mirror symmetry beyond critical doping in Pb-Bi2212

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    Identifying ordered phases and their underlying symmetries is the first and most important step toward understanding the mechanism of high-temperature superconductivity; critical behaviors of ordered phases are expected to be correlated with superconductivity. Efforts to find such ordered phases have been focused on symmetry breaking in the pseudogap region while the Fermi liquid-like metal region beyond the so-called critical doping pcp_{c} has been regarded as a trivial disordered state. Here, we used rotational anisotropy second harmonic generation and uncovered a broken mirror symmetry in the Fermi liquid-like phase in (Bi,Pb)2_{2}Sr2_{2}CaCu2_{2}O8+ÎŽ_{8+\delta} with p=0.205>pcp = 0.205 > p_{c}. By tracking the temperature evolution of the symmetry-breaking response, we verify an order parameter-like behavior with the onset temperature TupT_{up} at which the strange metal to Fermi liquid-like-metal crossover takes place. Complementary angle-resolved photoemission study showed that the quasiparticle coherence between CuO2\mathrm{CuO_{2}} bilayers is enhanced in proportion to the symmetry-breaking response as a function of temperature, indicating that the change in metallicity and symmetry breaking are linked. These observations contradict the conventional quantum disordered scenario for over-critical-doped cuprates and provide new insight into the nature of the quantum critical point in cuprates.Comment: 8 pages, 4 figure

    Reduction of cycles of neoadjuvant chemotherapy for advanced epithelial ovarian, fallopian or primary peritoneal cancer (ROCOCO): study protocol for a phase III randomized controlled trial

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    Primary debulking surgery (PDS) and adjuvant chemotherapy is the standard treatment for advanced ovarian, fallopian or primary peritoneal cancer. However, neoadjuvant chemotherapy (NAC) followed by interval debulking surgery (IDS) has been introduced as an alternative, showing similar efficacy and decreased postoperative complications compared with PDS. Although there is still no evidence for whether three or four cycles of NAC used clinically could be adequate, reducing one cycle of NAC is expected to remove more visible tumours and thereby improve prognosis. Thus, we proposed with this study to evaluate the efficacy and safety of reducing one cycle of NAC for advanced ovarian, fallopian or primary peritoneal cancer. This study is a prospective, multi-centre, open-label, randomized phase III trial. A total of 298 patients with advanced ovarian, fallopian or primary peritoneal cancer will be recruited and randomly assigned to either three (control group) or two cycles of NAC (experimental group). After the NAC, we will conduct IDS with maximal cytoreduction and then administer the remaining three or four cycles for a total of six cycles of adjuvant chemotherapy. The primary end point is progression-free survival, and the secondary end points are time to tumour progression, overall survival, tumour response after NAC, IDS and adjuvant chemotherapy, radiologic investigation after IDS, tumour response by positron emission tomography-computed tomography after NAC, quality of life, adverse events, success rate of optimal cytoreduction, surgical complexity, postoperative complications and safety of IDS. We will assess these factors at screening, at every cycle of chemotherapy, at IDS, after the completion of chemotherapy, every 3 months for the first 2 years after the planned treatment and every 6 months thereafter for 3 years. We hypothesize that reducing one cycle of NAC will contribute to more resection of visible tumours despite 10% reduction of optimal cytoreduction, which could improve survival. Moreover, two cycles of NAC may increase postoperative complications by 5% compared with three cycles, which may be acceptable. This study has been prospectively registered at ClinicalTrials.gov on Oct. 2nd, 2018 (NCT03693248, URL: https://clinicaltrials.gov/ct2/show/NCT03693248).Shin Poong. Pharm. Co., Ltd. plays no role in the study design, data collection, data analysis, data interpretation, or writing for the current study

    Virtual reality-based monitoring test for MCI: A multicenter feasibility study

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    ObjectivesAs the significance of the early diagnosis of mild cognitive impairment (MCI) has emerged, it is necessary to develop corresponding screening tools with high ecological validity and feasible biomarkers. Virtual reality (VR)-based cognitive assessment program, which is close to the daily life of the older adults, can be suitable screening tools for MCI with ecological validity and accessibility. Meanwhile, dehydroepiandrosterone (DHEA) has been observed at a low concentration in the older adults with dementia or cognitive decline, indicating its potential as a biomarker of MCI. This study aimed to determine the efficacy and usability of a VR cognitive assessment program and salivary DHEA for screening MCI.MethodsThe VR cognitive assessment program and the traditional Montreal Cognitive Assessment (MOCA) test were performed on 12 patients with MCI and 108 healthy older adults. The VR program operates in a situation of caring for a grandchild, and evaluates the memory, attention, visuospatial, and executive functions. An analysis of covariance (ANCOVA), a partial correlation analysis, and receiving operating characteristic (ROC) curve analysis were conducted for statistical analysis.ResultsAccording to the ANCOVA, no significant difference in MOCA scores was found between the normal and MCI groups (F = 2.36, p = 0.127). However, the VR total score of the MCI group was significantly lower than that of the normal group (F = 8.674, p = 0.004). There was a significant correlation between the MOCA and VR scores in the total and matched subdomain scores. The ROC curve analysis also showed a larger area under the curve (AUC) for the VR test (0.765) than for the MOCA test (0.598), and the sensitivity and specificity of the VR program were 0.833 and 0.722, respectively. Salivary DHEA was correlated with VR total (R2 = 0.082, p = 0.01) and attention scores (R2 = 0.086, p = 0.009).ConclusionThe VR cognitive test was as effective as the traditional MOCA test in the MCI classification and safe enough for older adults to perform, indicating its potential as a diagnostic tool. It has also been shown that salivary DHEA can be used as a biomarker for MCI

    Nonvirally Modified Autologous Primary Hepatocytes Correct Diabetes and Prevent Target Organ Injury in a Large Preclinical Model

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    BACKGROUND: Current gene- and cell-based therapies have significant limitations which impede widespread clinical application. Taking diabetes mellitus as a paradigm, we have sought to overcome these limitations by ex vivo electrotransfer of a nonviral insulin expression vector into primary hepatocytes followed by immediate autologous reimplantation in a preclinical model of diabetes. METHODS AND RESULTS: In a single 3-hour procedure, hepatocytes were isolated from a surgically resected liver wedge, electroporated with an insulin expression plasmid ex vivo and reimplanted intraparenchymally under ultrasonic guidance into the liver in each of 10 streptozotocin-induced diabetic Yorkshire pigs. The vector was comprised of a bifunctional, glucose-responsive promoter linked to human insulin cDNA. Ambient glucose concentrations appropriately altered human insulin mRNA expression and C-peptide secretion within minutes in vitro and in vivo. Treated swine showed correction of hyperglycemia, glucose intolerance, dyslipidemia and other metabolic abnormalities for > or = 47 weeks. Metabolic correction correlated significantly with the number of hepatocytes implanted. Importantly, we observed no hypoglycemia even under fasting conditions. Direct intrahepatic implantation of hepatocytes did not alter biochemical indices of liver function or induce abnormal hepatic lobular architecture. About 70% of implanted hepatocytes functionally engrafted, appeared histologically normal, retained vector DNA and expressed human insulin for > or = 47 weeks. Based on structural tissue analyses and transcriptome data, we showed that early correction of diabetes attenuated and even prevented pathological changes in the eye, kidney, liver and aorta. CONCLUSIONS: We demonstrate that autologous hepatocytes can be efficiently, simply and safely modified by electroporation of a nonviral vector to express, process and secrete insulin durably. This strategy, which achieved significant and sustained therapeutic efficacy in a large preclinical model without adverse effects, warrants consideration for clinical development especially as it could have broader future applications for the treatment of other acquired and inherited diseases for which systemic reconstitution of a specific protein deficiency is critical

    Insect pathogens as biological control agents: back to the future

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    The development and use of entomopathogens as classical, conservation and augmentative biological control agents have included a number of successes and some setbacks in the past 15 years. In this forum paper we present current information on development, use and future directions of insect-specific viruses, bacteria, fungi and nematodes as components of integrated pest management strategies for control of arthropod pests of crops, forests, urban habitats, and insects of medical and veterinary importance. Insect pathogenic viruses are a fruitful source of MCAs, particularly for the control of lepidopteran pests. Most research is focused on the baculoviruses, important pathogens of some globally important pests for which control has become difficult due to either pesticide resistance or pressure to reduce pesticide residues. Baculoviruses are accepted as safe, readily mass produced, highly pathogenic and easily formulated and applied control agents. New baculovirus products are appearing in many countries and gaining an increased market share. However, the absence of a practical in vitro mass production system, generally higher production costs, limited post application persistence, slow rate of kill and high host specificity currently contribute to restricted use in pest control. Overcoming these limitations are key research areas for which progress could open up use of insect viruses to much larger markets. A small number of entomopathogenic bacteria have been commercially developed for control of insect pests. These include several Bacillus thuringiensis sub-species, Lysinibacillus (Bacillus) sphaericus, Paenibacillus spp. and Serratia entomophila. B. thuringiensis sub-species kurstaki is the most widely used for control of pest insects of crops and forests, and B. thuringiensis sub-species israelensis and L. sphaericus are the primary pathogens used for medically important pests including dipteran vectors,. These pathogens combine the advantages of chemical pesticides and microbial control agents (MCAs): they are fast acting, easy to produce at a relatively low cost, easy to formulate, have a long shelf life and allow delivery using conventional application equipment and systemics (i.e. in transgenic plants). Unlike broad spectrum chemical pesticides, B. thuringiensis toxins are selective and negative environmental impact is very limited. Of the several commercially produced MCAs, B. thuringiensis (Bt) has more than 50% of market share. Extensive research, particularly on the molecular mode of action of Bt toxins, has been conducted over the past two decades. The Bt genes used in insect-resistant transgenic crops belong to the Cry and vegetative insecticidal protein families of toxins. Bt has been highly efficacious in pest management of corn and cotton, drastically reducing the amount of broad spectrum chemical insecticides used while being safe for consumers and non-target organisms. Despite successes, the adoption of Bt crops has not been without controversy. Although there is a lack of scientific evidence regarding their detrimental effects, this controversy has created the widespread perception in some quarters that Bt crops are dangerous for the environment. In addition to discovery of more efficacious isolates and toxins, an increase in the use of Bt products and transgenes will rely on innovations in formulation, better delivery systems and ultimately, wider public acceptance of transgenic plants expressing insect-specific Bt toxins. Fungi are ubiquitous natural entomopathogens that often cause epizootics in host insects and possess many desirable traits that favor their development as MCAs. Presently, commercialized microbial pesticides based on entomopathogenic fungi largely occupy niche markets. A variety of molecular tools and technologies have recently allowed reclassification of numerous species based on phylogeny, as well as matching anamorphs (asexual forms) and teleomorphs (sexual forms) of several entomopathogenic taxa in the Phylum Ascomycota. Although these fungi have been traditionally regarded exclusively as pathogens of arthropods, recent studies have demonstrated that they occupy a great diversity of ecological niches. Entomopathogenic fungi are now known to be plant endophytes, plant disease antagonists, rhizosphere colonizers, and plant growth promoters. These newly understood attributes provide possibilities to use fungi in multiple roles. In addition to arthropod pest control, some fungal species could simultaneously suppress plant pathogens and plant parasitic nematodes as well as promote plant growth. A greater understanding of fungal ecology is needed to define their roles in nature and evaluate their limitations in biological control. More efficient mass production, formulation and delivery systems must be devised to supply an ever increasing market. More testing under field conditions is required to identify effects of biotic and abiotic factors on efficacy and persistence. Lastly, greater attention must be paid to their use within integrated pest management programs; in particular, strategies that incorporate fungi in combination with arthropod predators and parasitoids need to be defined to ensure compatibility and maximize efficacy. Entomopathogenic nematodes (EPNs) in the genera Steinernema and Heterorhabditis are potent MCAs. Substantial progress in research and application of EPNs has been made in the past decade. The number of target pests shown to be susceptible to EPNs has continued to increase. Advancements in this regard primarily have been made in soil habitats where EPNs are shielded from environmental extremes, but progress has also been made in use of nematodes in above-ground habitats owing to the development of improved protective formulations. Progress has also resulted from advancements in nematode production technology using both in vivo and in vitro systems; novel application methods such as distribution of infected host cadavers; and nematode strain improvement via enhancement and stabilization of beneficial traits. Innovative research has also yielded insights into the fundamentals of EPN biology including major advances in genomics, nematode-bacterial symbiont interactions, ecological relationships, and foraging behavior. Additional research is needed to leverage these basic findings toward direct improvements in microbial control

    ICAR: endoscopic skull‐base surgery

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    Optimal option selection for finishing works of high-rise building

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    Time-Cost Trade-Off Problem (TCTP), to determine optimal option among many options of construction work of high-rise building, is an issue that needs to be addressed to optimize construction duration with minimal cost. Despite the fact that the crashing process entailed in a network scheduling method is not suitable for the repetitive activities of a construction project, traditional time-cost trade-off focuses on the techniques for minimizing construction cost and time in a network-based scheduling method. In addition, time-cost relationships are usually presumed to be linear, not nonlinear. Since only integer durations (days) are considered in construction scheduling, linear approximation is not fully suitable to solve the TCTP. Thus, time-cost relationships need to be redefined at discrete points representing time-cost options. In addition, Tact scheduling is one of the most useful scheduling methods to reflect the repetitiveness usually demonstrated in a LOB (Line of Balance) form. However, Tact scheduling requires too much time and effort to determine Tact time, options (cost and time of activity), and the group of activities with the same option. Genetic Algorithms (GAs) are efficient in searching for optimal solutions among decision alternatives. Thus, the authors propose a time-cost trade-off method of Tact scheduling that uses GAs.This research was supported by a grant (05CIT-D05-01) from Construction Technology Innovation Program funded by Ministry of Land, Transport and Maritime Affairs of Korean government.
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