2,396 research outputs found
Hunting for Heavy Majorana Neutrinos with Lepton Number Violating Signatures at LHC
The neutrinophilic two-Higgs-doublet model (2HDM) provides a natural way
to generate tiny neutrino mass from interactions with the new doublet scalar
() and singlet neutrinos of TeV scale. In this
paper, we perform detailed simulations for the lepton number violating (LNV)
signatures at LHC arising from cascade decays of the new scalars and neutrinos
with the mass order . Under constraints from lepton
flavor violating processes and direct collider searches, their decay properties
are explored and lead to three types of LNV signatures: , , and . We
find that the same-sign trilepton signature is quite
unique and is the most promising discovery channel at the high-luminosity LHC.
Our analysis also yields the C.L. exclusion limits in the plane of the
and masses at 13 (14) TeV LHC with an integrated luminosity of
100~(3000)/fb.Comment: 31 pages, 17 figures, 6 tables; v2: added a few refs and updated one
ref, without other change
Expression of transmembrane carbonic anhydrases, CAIX and CAXII, in human development
Background: Transmembrane CAIX and CAXII are members of the alpha carbonic anhydrase (CA) family. They play a crucial role in differentiation, proliferation, and pH regulation. Expression of CAIX and CAXII proteins in tumor tissues is primarily induced by hypoxia and this is particularly true for CAIX, which is regulated by the transcription factor, hypoxia inducible factor-1 (HIF-1). Their distributions in normal adult human tissues are restricted to highly specialized cells that are not always hypoxic. The human fetus exists in a relatively hypoxic environment. We examined expression of CAIX, CAXII and HIF-1 alpha in the developing human fetus and postnatal tissues to determine whether expression of CAIX and CAXII is exclusively regulated by HIF-1. Results: The co-localization of CAIX and HIF-1 alpha was limited to certain cell types in embryonic and early fetal tissues. Those cells comprised the primitive mesenchyma or involved chondrogenesis and skin development. Transient CAIX expression was limited to immature tissues of mesodermal origin and the skin and ependymal cells. The only tissues that persistently expressed CAIX protein were coelomic epithelium (mesothelium) and its remnants, the epithelium of the stomach and biliary tree, glands and crypt cells of duodenum and small intestine, and the cells located at those sites previously identified as harboring adult stem cells in, for example, the skin and large intestine. In many instances co-localization of CAIX and HIF-1 alpha was not evident. CAXII expression is restricted to cells involved in secretion and water absorption such as parietal cells of the stomach, acinar cells of the salivary glands and pancreas, epithelium of the large intestine, and renal tubules. Co-localization of CAXII with CAIX or HIF-1 alpha was not observed. Conclusion: The study has showed that: 1) HIF-1 alpha and CAIX expression co-localized in many, but not all, of the embryonic and early fetal tissues; 2) There is no evidence of co-localization of CAIX and CAXII; 3) CAIX and CAXII expression is closely related to cell origin and secretory activity involving proton transport, respectively. The intriguing finding of rare CAIX-expressing cells in those sites corresponding to stem cell niches requires further investigation
Clinical significance of time to positivity for yeast in candidemia
PurposeCandidemia is an important issue of nosocomial bloodstream infections, and is associated with a high mortality rate. However, little information is available before final species identification, which takes days after the episode of candidemia. This study tried to determine whether time to positivity (TTP) for yeast helps in predicting the species of candidemia.MethodsA retrospective cohort study was conducted in Taiwan, which included 434 episodes of nonduplicated candidemia during the period between 2006 and 2009. The demographic features, clinical characteristics, TTP for yeast, and acute illness scores were included for analysis.ResultsThe mean age of patients with candidemia was 70.4 ± 15.2 years, and the 30-day crude mortality rate was 48.2%. Forty-five percent of patients suffered from shock status with a mean Acute Physiological and Chronic Health Evaluation II score of 27.0 ± 8.7 and a mean Sequential Organ Failure Assessment score of 9.7 ± 4.5, whereas 50% were admitted to the intensive care units. Candida albicans was still the most commonly identified pathogen (58.1%), followed by C. tropicalis (14.7%), C. parapsilosis (13.1%), and C. glabrata (8.3%). Results of multivariate logistic regression showed that TTP for yeast within 48 hours would more favor C. tropicalis (p = 0.044), and less favor C. glabrata (p = 0.025) and C. parapsilosis (p < 0.001). Patients with parenteral nutrition usage were more frequently associated with a TTP for yeast within 48 hours, whereas those with previous exposure to an antifungal agent had a longer TTP for yeast.ConclusionThe TTP for yeast might provide a hint of the responsible Candida species before final identification among critical patients with candidemia. The association between antifungal agents and TTP would need more evidence for elucidation
Three-level Back-to-Back Converter Simulation for Wind Turbine Energy Source
AbstractThis paper presents the simulation of three-level back-to-back converter for wind turbine energy source. For this paper, it will be focused on wind turbine energy source and determined the voltage from wind turbine energy source being regular value. The operation of the converter can be simulated by using MATLAB/SIMULINK program. Moreover, the voltage and current of the converter can be properly controlled by SVPWM. The simulation results shown that the output current waveform have signal distortion less than the input current waveform, and also the output voltage waveform is more than the input as well. Therefore, this converter can convert the voltage and current from the AC to DC and from the DC to AC for more performance, and it can be connected to the grid
Immunotherapeutic allogeneic dendritic cell and autologous tumor cell fusion vaccine alone or combined with radiotherapy in canine oral malignant melanoma is safe and potentially effective
IntroductionImmunotherapy represents a promising breakthrough in cancer management and is being explored in canine melanomas. Dendritic cells (DCs) play a crucial role in priming T-cell-mediated immune reactions through the antigen-presenting function. Combining immunotherapy and radiation therapy may generate more substantial anti-cancer efficacy through immunomodulation.ObjectivesOur research reported a preliminary result of the safety and outcome of a kind of immunotherapy, the allogeneic dendritic cell and autologous tumor cell fusion vaccine, alone or in combination with hypofractionated radiation therapy, in canine oral malignant melanoma.MethodsTwo groups of dogs with histopathological diagnoses of oral malignant melanoma were recruited. In group 1 (DCRT), dogs received a combination of DC fusion vaccine and radiotherapy. In group 2 (DC), dogs received DC fusion vaccine alone. DC vaccination was given once every 2 weeks for four doses. Radiotherapy was performed weekly for five fractions. Dogs that received carboplatin were retrospectively collected as a control group (group 3).ResultsFive dogs were included in group 1 (two stage II, three stage III), 11 in group 2 (three stage I/II, eight stage III/IV), and eight (two stage I/II, six stage III/IV) in the control group. Both DC and DCRT were well-tolerated, with only mild adverse events reported, including mucositis, gastrointestinal discomfort, and injection site reactions. The median progression-free intervals in groups 1, 2, and 3 were 214 (95% CI, NA, due to insufficient data), 100 (95% CI, 27–237), and 42 days (95% CI, NA-170), respectively, which were not significantly different. The 1-year survival rates were 20, 54.5, and 12.5% in groups 1, 2, and 3. Dogs in the DCRT group exhibited significantly higher TGF-β signals than the DC group throughout the treatment course, indicating a possible higher degree of immunosuppression.ConclusionThe manuscript demonstrated the safety of dendritic cell/tumor cell fusion vaccine immunotherapy, alone or in combination with radiotherapy. The results support further expansion of this immunotherapy, modification of combination treatment and protocols, and investigation of combining DC vaccine with other treatment modalities.Clinical trial registrationPreclinical Trials, PCTE0000475
Exogenous Melatonin Alleviates Oxidative Damages and Protects Photosystem II in Maize Seedlings Under Drought Stress
The protective role of melatonin in plants against various abiotic stresses have been widely demonstrated, but poorly explored in organ-specific responses and the transmission of melatonin signals across organs. In this study, the effects of melatonin with the root-irrigation method and the leaf-spraying method on the antioxidant system and photosynthetic machinery in maize seedlings under drought stress were investigated. The results showed that drought stress led to the rise in reactive oxygen species (ROS), severe cell death, and degradation of D1 protein, which were mitigated by the melatonin application. The application of melatonin improved the photosynthetic activities and alleviated the oxidative damages of maize seedlings under the drought stress. Compared with the leaf-spraying method, the root-irrigation method was more effective on enhancing drought tolerance. Moreover, maize seedlings made organ-specific physiological responses to the drought stress, and the physiological effects of melatonin varied with the dosage, application methods and plant organs. The signals of exogenous melatonin received by roots could affect the stress responses of leaves, and the melatonin signals perceived by leaves also led to changes in physiological metabolisms in roots under the stress. Consequently, the whole seedlings coordinated the different parts and made a systemic acclimation against the drought stress. Melatonin as a protective agent against abiotic stresses has a potential application prospect in the agricultural industry
Photothermal responsivity of van der Waals material-based nanomechanical resonators
Nanomechanical resonators made from van der Waals materials (vdW NMRs)
provide a new tool for sensing absorbed laser power. The photothermal response
of vdW NMRs, quantified from the resonant frequency shifts induced by optical
absorption, is enhanced when incorporated in a Fabry-Perot (FP) interferometer.
Along with the enhancement comes the dependence of the photothermal response on
NMR displacement, which lacks investigation. Here, we address the knowledge gap
by studying electromotively driven niobium diselenide drumheads fabricated on
highly reflective substrates. We use a FP-mediated absorptive heating model to
explain the measured variations of the photothermal response. The model
predicts a higher magnitude and tuning range of photothermal responses on
few-layer and monolayer NbSe drumheads, which outperform other clamped
vdW drum-type NMRs at a laser wavelength of nm. Further analysis of the
model shows that both the magnitude and tuning range of NbSe drumheads
scale with thickness, establishing a displacement-based framework for building
bolometers using FP-mediated vdW NMRs.Comment: 7 pages, 4 figure
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