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Ice breaking has become one of the main problems faced by ships and other equipment operating in an ice-covered water region. New methods are always being pursued and studied to improve ice-breaking capabilities and efficiencies. Based on the strong damage capability, a high-speed water jet impact is proposed to be used to break an ice plate in contact with water. A series of experiments of water jet impacting ice were performed in a transparent water tank, where the water jets at tens of metres per second were generated by a home-made device and circular ice plates of various thicknesses and scales were produced in a cold room. The entire evolution of the water jet and ice was recorded by two high-speed cameras from the top and front views simultaneously. The focus was the responses of the ice plate, such as crack development and breakup, under the high-speed water jet loads, which involved compressible pressure ${P_1}$ and incompressible pressure ${P_2}$. According to the main cause and crack development sequence, it was found that the damage of the ice could be roughly divided into five patterns. On this basis, the effects of water jet strength, ice thickness, ice plate size and boundary conditions were also investigated. Experiments validated the ice-breaking capability of the high-speed water jet, which could be a new auxiliary ice-breaking method in the future.
The physical picture of interacting magnetic islands provides a useful paradigm for certain plasma dynamics in a variety of physical environments, such as the solar corona, the heliosheath and the Earth's magnetosphere. In this work, we derive an island kinetic equation to describe the evolution of the island distribution function (in area and in flux of islands) subject to a collisional integral designed to account for the role of magnetic reconnection during island mergers. This equation is used to study the inverse transfer of magnetic energy through the coalescence of magnetic islands in two dimensions. We solve our island kinetic equation numerically for three different types of initial distribution: Dirac delta, Gaussian and power-law distributions. The time evolution of several key quantities is found to agree well with our analytical predictions: magnetic energy decays as $\tilde {t}^{-1}$, the number of islands decreases as $\tilde {t}^{-1}$ and the averaged area of islands grows as $\tilde {t}$, where $\tilde {t}$ is the time normalised to the characteristic reconnection time scale of islands. General properties of the distribution function and the magnetic energy spectrum are also studied. Finally, we discuss the underlying connection of our island-merger models to the (self-similar) decay of magnetohydrodynamic turbulence.
We report on experimental observation of non-laminar proton acceleration modulated by a strong magnetic field in laser irradiating micrometer aluminum targets. The results illustrate the coexistence of ring-like and filamentation structures. We implement the knife edge method into the radiochromic film detector to map the accelerated beams, measuring a source size of 30–110 μm for protons of more than 5 MeV. The diagnosis reveals that the ring-like profile originates from low-energy protons far off the axis whereas the filamentation is from the near-axis high-energy protons, exhibiting non-laminar features. Particle-in-cell simulations reproduced the experimental results, showing that the short-term magnetic turbulence via Weibel instability and the long-term quasi-static annular magnetic field by the streaming electric current account for the measured beam profile. Our work provides direct mapping of laser-driven proton sources in the space-energy domain and reveals the non-laminar beam evolution at featured time scales.
The recent FDA marketing authorizations granted for testing for mutations associated with hereditary breast and colon cancer, as well as pharmacogenomic susceptibilities, provide an opportunity to re-examine the medical as well as regulatory underpinnings of DTC genetic testing. In this chapter, we first examine the historical emergence of enabling technologies that have provided for the availability of DNA sequence information on a broad scale, the efforts by the medical community to incorporate these advances into models of “precision” or “personalized” medicine, and the risks and benefits of offering access to DNA germline sequence analysis outside of the traditional medical model. We then turn to the current and proposed regulatory schemes to provide oversight over DTC genetic testing, with a focus on the role of the FDA as an information regulator and guardian of public health and safety.
Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2–4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a Neutron Star Extreme Matter Observatory (NEMO): a gravitational-wave interferometer optimised to study nuclear physics with merging neutron stars. The concept uses high-circulating laser power, quantum squeezing, and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above 1 kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year and potentially allow for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.
To evaluate the dynamic properties of a coupled structure based on the dynamic properties of its substructures, this paper investigates the dynamic substructuring issue from the perspective of response prediction. The main idea is that the connecting forces at the interface of substructures can be expressed by the unknown coupled structural responses, and the responses can be solved rather easily. Not only rigidly coupled structures but also resiliently coupled structures are investigated. In order to further comprehend and visualize the nature of coupling problems, the Neumann series expansion for a matrix describing the relation between the coupled and uncoupled substructures is also introduced in this paper. Compared with existing response prediction methods, the proposed method does not have to measure any forces, which makes it easier to apply than the others. Clearly, the frequency response function matrix of coupled structures can be derived directly based on the response prediction method. Compared with existing frequency response function synthesis methods, it is more straightforward and comprehensible. Through demonstration of two examples, it is concluded that the proposed method can deal with structural coupling problems very well.
Data on the prevalence of extrapulmonary tuberculosis (EPTB) patients are limited in many African countries including Malawi. We conducted a retrospective review of all histology reports for cancer suspected patients at Mzuzu Central Hospital (MZCH) between 2013 and 2018 to determine the proportion of EPTB cases among cancer suspected patients and characterised them epidemiologically. All reports with inconclusive findings were excluded. In total, 2214 reports were included in the review, 47 of which reported EPTB, representing 2.1% (95% CI 1.6−2.8). The incidence of EPTB was significantly associated with sex, age and HIV status. Men were more than twice (OR 2.1; 95% CI 1.2–3.9) as likely to have EPTB as women while those with HIV were more than six times (OR 6.4; 95% CI 1.7–24.8) as likely to have EPTB compared to those who were HIV-negative. EPTB demonstrated an inverse relationship with age. The highest proportion of EPTB was found from neck lymph nodes (10.3% (5.4–17.2)). A reasonable number of EPTB cases are diagnosed late or missed in Malawi's hospitals. There is a need for concerted efforts to increase EPTB awareness and likely come up with a policy to consider EPTB as a differential diagnosis in cancer suspected patients.
During the past decade, genetics research has allowed scientists and clinicians to explore the human genome in detail and reveal many thousands of common genetic variants associated with disease. Genetic risk scores, known as polygenic risk scores (PRSs), aggregate risk information from the most important genetic variants into a single score that describes an individual’s genetic predisposition to a given disease. This article reviews recent developments in the predictive utility of PRSs in relation to a person’s susceptibility to breast cancer and coronary artery disease. Prognostic models for these disorders are built using data from the UK Biobank, controlling for typical clinical and underwriting risk factors. Furthermore, we explore the possibility of adverse selection where genetic information about multifactorial disorders is available for insurance purchasers but not for underwriters. We demonstrate that prediction of multifactorial diseases, using PRSs, provides population risk information additional to that captured by normal underwriting risk factors. This research using the UK Biobank is in the public interest as it contributes to our understanding of predicting risk of disease in the population. Further research is imperative to understand how PRSs could cause adverse selection if consumers use this information to alter their insurance purchasing behaviour.
In this paper, the generation of relativistic electron mirrors (REM) and the reflection of an ultra-short laser off the mirrors are discussed, applying two-dimension particle-in-cell simulations. REMs with ultra-high acceleration and expanding velocity can be produced from a solid nanofoil illuminated normally by an ultra-intense femtosecond laser pulse with a sharp rising edge. Chirped attosecond pulse can be produced through the reflection of a counter-propagating probe laser off the accelerating REM. In the electron moving frame, the plasma frequency of the REM keeps decreasing due to its rapid expansion. The laser frequency, on the contrary, keeps increasing due to the acceleration of REM and the relativistic Doppler shift from the lab frame to the electron moving frame. Within an ultra-short time interval, the two frequencies will be equal in the electron moving frame, which leads to the resonance between laser and REM. The reflected radiation near this interval and corresponding spectra will be amplified due to the resonance. Through adjusting the arriving time of the probe laser, a certain part of the reflected field could be selectively amplified or depressed, leading to the selective adjustment of the corresponding spectra.
This chapter reviews Narcissistic and Histrionic Personality Disorders (NPD, HPD) from three current perspectives. The categorical approach is exemplified in the DSM-5 Section II chapter on personality disorders. The categorical/dimensional hybrid approach is characterized by the DSM-5 Section III Alternative Model for Personality Disorders. Finally, both personality disorders are also conceptualized by purely dimensional and multidimensional models (e.g., pathological narcissism, histrionism). Integrative, interdisciplinary research and theory on NPD and pathological narcissism is expanding rapidly, providing novel clinical insights into classification, etiology, maintenance, patient presentation, and treatment. The clinical science of narcissism is robust, and its future appears quite promising. In contrast, contemporary research and theory on HPD and histrionism is scant and declining. Some have called for its elimination as a diagnostic entity. If the current trend of waning empirical and clinical interest persists, it is unlikely that HPD will be retained in future revisions of the DSM and other personality disorder classification systems.
The two commentaries reflect a long-standing dichotomy between clinically-experienced researchers who believe clinical personality science should reciprocally inform and be informed by the clinical enterprise (Ronningstam and Russell) and academic researchers who are dismissive of clinical complexity, eschew clinical contexts, and promote their preferred trait model (Weiss and Campbell). The commentary by Ronningstam and Russell reminds us that the clinical presentation and treatment of narcissism is complex and serious. The authors of this rejoinder fully agree. The commentary by Weiss and Campbell is anti-clinical in its stance and fails to effectively connect with the realities of clinical practice. The authors encourage these academic researchers to stop avoiding clinical complexity and clinical contexts, and instead, take advantage of advances in research methods, analytics, and technology to build a truly meaningful bridge between clinical personality science and practice.
Fluid motion has two well-known fundamental processes: the vector transverse process characterized by vorticity, and the scalar longitudinal process consisting of a sound mode and an entropy mode, characterized by dilatation and thermodynamic variables. The existing theories for the sound mode involve the multi-variable issue and its associated difficulty of source identification. In this paper, we define the source of sound inside the fluid by the objective causality inherent in dynamic equations relevant to a longitudinal process, which naturally favours the material time-rate operator $D/Dt$ rather than the local time-rate operator $\unicode[STIX]{x2202}/\unicode[STIX]{x2202}t$, and describes the sound mode by inhomogeneous advective wave equations. The sources of sound physical production inside the fluid are then examined at two levels. For the conventional formulation in terms of thermodynamic variables at the first level, we show that the universal kinematic source can be condensed to a scalar invariant of the surface deformation tensor. Further, in the formulation in terms of dilatation at the second level, we find that the sound mode in viscous and heat-conducting flow has sources from rich nonlinear couplings of vorticity, entropy and surface deformation, which cannot be disclosed at the first level. Preliminary numerical demonstration of the theoretical findings is made for two typical compressible flows, i.e. the interaction of two corotating Gaussian vortices and the unsteady type IV shock/shock interaction. The results obtained in this study provide a new theoretical basis for, and physical insight into, understanding various nonlinear longitudinal processes and the interactions therein.
Dopamine D2 receptors (D2R) are the primary target of antipsychotic drugs and have been shown to regulate Akt/glycogen synthase kinase-3b (GSK-3b) signaling through scaffolding protein b-arrestin 2.
Objective
In the present study, we researched the effects of saikosaponin B1 on the b-arrestin 2-mediated Akt/GSK-3b pathway in human neuroblastoma cell lineSH-SY5Y cells.
Aims
To determine whether saikosaponin B1 affected neuronal morphology in human neuroblastoma cell line SH-SY5Y cells.
Methods
We investigated the effects of saikosaponin B1 on neurite outgrowth using immunostaining. We examined the effects of saikosaponin B1 on Akt and GSK-3b and its well-known downstream regulators, cAMP response element-binding protein (CREB), brain-derived neurotrophic factor (BDNF), and Bcl-2 levels using Western blot analysis.
Results
Saikosaponin B1 was found to enhance neurite outgrowth. Small interfering RNA (siRNA) for b-arrestin 2 knockdown blocked the increase in saikosaponin B1-induced neurite outgrowth. Furthermore, saikosaponin B1 increased the levels of Akt and GSK-3b phosphorylation. The elevation of Akt phosphorylation induced by saikosaponin B1 was reduced by b-arrestin 2 siRNA. Moreover, saikosaponin B1 effectively increased the levels of phospho-CREB, BDNF, and Bcl-2.
Conclusion
Together, these results suggest that regulation of the b-arrestin 2-dependent pathway via blockade of the D2R in SH-SY5Y cells is one mechanism underlying the neuroprotective effect of saikosaponin B1.
Many MRI studies have cited major depression, with or without anti-depressive treatment, associated with structural plasticity changing in several brain regions. Few of these studies researched the effect of the anti-depressive treatment, electroconvulsive therapy (ECT), on depression.
Objective
To assess the influence of ECT on the brain structure change during the treatment process by utilizing the voxel-based morphometry (VBM) analysis.
Aims
To determine whether ECT alter brain structure.
Methods
We performed HAMD ratings and MRI scans on 12 depressive patients during ECT, analyzing the data by VBM with SPM8 software's family-wise error correction (FWE).
Results
The researchers found volumes changes in white matter in 37 regions between pre-ECT and post-ECT1, but only one region changing between pre-ECT and post-ECT8. Seven regions changing in grey matter between pre-ECT and post-ECT 1⌧but none regions changing between pre-ECT and post-ECT8.
Conclusions
The density changes in several brain regions after a single ECT stimuli, but return to the original level after completing the eighth ECT. Our finding supports that ECT may play a temporary role in treating major depression but do not permanently alter the structures of brain.
Saikosaponin B is one of the main ingredients of Bupleurum. Among the many effects of Bupleurum, saikosaponin B may be contributing molecules.human neuroblastoma cell line SH-SY5Y is a tumor cells of low degree of differentiation. Its cell morphology, physiology and biochemical functions similar to normal nerve cells, are widely used to study the mechanism of diseases and drug, of the nervous system.
Objective
To investigate the effect of Saikosaponin B on SH-SY5Y cells.
Methods
Cultured SH-SY5Y cells and drawed cell growth curve. Then based on the cell growth curve, using hydrogen peroxide of different doses(110?120?130?140?150?160?180?200?220μmol/L) to treated SH-SY5Y cells. At same time, volume fraction 0.05 serum contained Saikosaponin B was added. Cultured SH-SY5Y cells were observed by morphology and tested by the MTT assay.
Results
Less than 140μmol/L hydrogen peroxide, SH-SY5Y cells does not be caused damage. Saikosaponin B of volume fraction 0.05 can relieve the damage of SH-SY5Y cells treated with 140μmol/L hydrogen peroxide, also can increase the survival of the SH-SY5Y cells.
Conclusion
Saikosaponin B can strongly protect the cultured SH-SY5Y cells from damage induced by hydrogen peroxide.
The aim of this study was to develop and externally validate a simple-to-use nomogram for predicting the survival of hospitalised human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) patients (hospitalised person living with HIV/AIDS (PLWHAs)). Hospitalised PLWHAs (n = 3724) between January 2012 and December 2014 were enrolled in the training cohort. HIV-infected inpatients (n = 1987) admitted in 2015 were included as the external-validation cohort. The least absolute shrinkage and selection operator method was used to perform data dimension reduction and select the optimal predictors. The nomogram incorporated 11 independent predictors, including occupation, antiretroviral therapy, pneumonia, tuberculosis, Talaromyces marneffei, hypertension, septicemia, anaemia, respiratory failure, hypoproteinemia and electrolyte disturbances. The Likelihood χ2 statistic of the model was 516.30 (P = 0.000). Integrated Brier Score was 0.076 and Brier scores of the nomogram at the 10-day and 20-day time points were 0.046 and 0.071, respectively. The area under the curves for receiver operating characteristic were 0.819 and 0.828, and precision-recall curves were 0.242 and 0.378 at two time points. Calibration plots and decision curve analysis in the two sets showed good performance and a high net benefit of nomogram. In conclusion, the nomogram developed in the current study has relatively high calibration and is clinically useful. It provides a convenient and useful tool for timely clinical decision-making and the risk management of hospitalised PLWHAs.