To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
We report on a high-repetition-rate, high-power continuously pumped Nd:GdVO4 regenerative amplifier. Numerical simulations successfully pinpoint the optimum working point free of bifurcation instability with simultaneous efficient energy extraction. At a repetition rate of 100 kHz, a maximum output power of 23 W was obtained with a pulse duration of 27 ps, corresponding to a pulse energy of
. The system displayed an outstanding stability with a root mean square power noise as low as 0.3%. The geometry of the optical resonator and the pumping scheme enhanced output power in the
mode with a single bulk crystal. Accordingly, nearly diffraction-limited beam quality was produced with
at full pump power.
The pathophysiology of cognitive impairment in patients with the major depressive disorder (MDD) may involve neuroinflammation mediated by cytokines.
The aim of this study was to examine the serum interleukin-6 (IL-6) levels, sustained attention, and their association in patients with MDD.
Thirty patients with MDD and 30 healthy controls were enrolled in this case-control study. Sustained attention was measured using the Rapid Visual Information Processing (RVP) task in the Cambridge Neuropsychological Tests Automated Battery. The serum IL-6 levels of all subjects were assessed by sandwich enzyme-linked immunosorbent assays.
There were significant differences in the log10RVP total hits, log10RVP total misses, and log10RVP mean latency between patients with MDD and healthy controls (F = 6.04, p = 0.017; F = 19.77, p < 0.0001; F = 14.42, p < 0.0001, respectively). The serum levels of Log10IL-6 were significantly higher in patients with MDD than in healthy controls (F = 192.27, p < 0.0001). The log10IL-6 levels were also positively correlated with the log10RVP mean latency in patients with MDD (r = 0.45, p = 0.013). A further stepwise multivariate regression analysis indicated that the log10IL-6 levels were significantly associated with the log10RVP mean latency in patients with MDD (β = 0.31, t = 2.41, p = 0.025).
Our data suggested that increased IL-6 levels were associated with the psychopathology of MDD, and that abnormal IL-6 levels were implicated in the impairment of sustained attention in patients with MDD.
Babesiosis is an emerging tick-transmitted zoonosis prevalent in large parts of the world. This study was designed to determine the rates of Babesia microti infection among small rodents in Yunnan province, where human cases of babesiosis have been reported. Currently, distribution of Babesia in its endemic regions is largely unknown. In this study, we cataloged 1672 small wild rodents, comprising 4 orders, from nine areas in western Yunnan province between 2009 and 2011. Babesia microti DNA was detected by polymerase chain reaction in 4·3% (72/1672) of the rodents analyzed. The most frequently infected rodent species included Apodemus chevrieri and Niviventer fulvescens. Rodents from forests and shrublands had significantly higher Babesia infection rates. Genetic comparisons revealed that Babesia was most similar to the Kobe- and Otsu-type strains identified in Japan. A variety of rodent species might be involved in the enzootic maintenance and transmission of B. microti, supporting the need for further serological investigations in humans.
We study a special class of quasi-cyclic codes, obtained from a cyclic code over an extension field of the alphabet field by taking its image on a basis. When the basis is equal to its dual, the dual code admits the same construction. We give some examples of self-dual codes and LCD codes obtained in this way.
The effects of boron and zirconium contents from 0 to 0.049 wt% on the casting fluidity, as-cast microstructure and mechanical properties of IN718C superalloy are systematically investigated. The results show that as the B or Zr content increases, the fluidity firstly increases and then decreases. The optimum fluidity is obtained at the pouring temperature of 1470 °C when the content of B is 0.0059 wt% or Zr is 0.042 wt%, respectively. The addition of Zr can lead to the formation of blocky laves phase, but B has no influence on microstructure morphology. Furthermore, the addition of B or Zr can effectively improve the tensile and stress life properties as well as casting fluidity of IN718C superalloy. As compared with IN718C master alloys, the tensile strength can increase 6.2–8.6% and stress life can be improved by 1.3 times when B content is 0.0059 wt%. In addition, when the alloy contains 0.042 wt% Zr, the tensile strength can increase 5.6–7% and stress life can increase 1.076 times than that of the master alloy.
Building on the growing literature on interfirm links and limited attention, we find evidence of return predictability across alliance partners. A long–short portfolio sorted on lagged returns of strategic alliance partners provides a return of 89 basis points per month that is robust to a number of specifications. Investor inattention and limits to arbitrage may be the source of the underreaction of a firm’s returns to that of its partners.
We investigate theoretically the field-free orientation of CO molecules induced by a single-cycle THz laser pulse train. It is shown that the molecular orientation can be obviously enhanced by applying the pulse train. The laser intensity and pulse number have some effects on the molecular orientation. The high degree of field-free molecular orientation |⟨cosθ⟩|max=0.9246 is obtained at temperature T=0 K. The variations of the maximum orientation degree with the experimentally available pulse number and peak intensity are given. Temperature T has a considerable influence on the field-free molecular orientation. The maximal field-free molecular orientation at T=0, 10, 20 and 30 K for N=14 and E0=1.8 MV/cm are |⟨cosθ⟩|max=0.9188, 0.7338, 0.6055 and 0.5154 in order, and the corresponding effective duration times of molecular orientation are Δt=0.759, 0.432, 0.297 and 0.117 ps.
This investigation addresses the dynamics of annular viscoelastic films flowing down a flexible tube. The fluid viscoelasticity is assumed to be weak in order to obtain approximate explicit expressions for the stresses. Based on Shkadov’s integral boundary layer method (Fluid Dyn., vol. 2(1), 1967, pp. 29–34), a set of nonlinear evolution equations is derived that is valid for flows with moderate Reynolds numbers. The linear stability property of the system is examined by using normal-mode analysis, which is verified by comparing the results with those resulting from the linearization of the full Navier–Stokes equations. The results indicate that the fluid viscoelasticity plays an unstable role in the stability of the annular film flow. The tube flexibility, which includes wall damping and wall tension, plays a dual role. A bifurcation analysis is performed, and the families of steady travelling waves are catalogued. It is found that the stiffness of the tube tends to stimulate the interfacial capillary ripples. The fluid viscoelasticity acts to strengthen the dispersion of the interfacial waves but weakens the interfacial capillary ripples. The spatio-temporal evolutions of the system are also solved numerically. When the tube radius is small enough, tube closure can be observed due to the Plateau–Rayleigh instability. The fluid viscoelasticity acts to promote tube closure while the tube radius is relatively small. However, it plays a role in postponing the closure of the tube with a large radius.
Here we report on the photocurrent response of two-dimensional (2D) heterostructures of sputtered MoS2 on boron nitride (BN) deposited on (001)-oriented Si substrates. The steady state photocurrent (Iph) measurements used a continuous laser of λ = 658 nm (E = 1.88 eV) over a broad range of laser intensities, P (∼1 μW < P < 10 μW), and indicate that Iph obtained from MoS2 layers with the 80 nm BN under layer was ∼4 times higher than that obtained from MoS2 layers with the 30 nm BN under layer. We also found super linear dependence of Iph on P (Iph ∝ Pγ, with γ > 1) in both the samples. The responsivities obtained over the range of laser intensity studied were in the order of mA/W (∼12 and ∼2.7 mA/W with 80 nm BN and 30 nm BN under layers, respectively). These investigations provide crucial insight into the optical activity of MoS2 on BN, which could be useful for developing a variety of optoelectronic applications with MoS2 or other 2D transition metal dichalcogenide heterostructures.
Navigational software often lacks official standardisation of the methods used and their accuracy due to commercial confidentiality. The “black box solutions” used by navigational systems are unknown, thus a logical and simple method to solve navigational problems must be presented. This paper presents new meridian arc formulae by the least squares method. As the traditional meridian arc formulae cannot be expressed as a closed form, they are often truncated to the first few terms for practical use and in doing so neglect the values not used. By forming an overdetermined system with known components of the traditional meridian arc formula and actual length of the meridian arc, the least squares method can be used to approximate the best fitting coefficients for the traditional meridian arc formulae and forms the new compact formulae. The new formulae are based on highly accurate values of the meridian arc for the WGS-84 ellipsoid datum, and are perfect for the computational algorithms implemented in navigational software such as Geographic Information Systems (GIS), Electronic Chart Display and Information Systems (ECDIS) and other Electronic Chart Systems (ECS). Their accuracy is compared with other methods and shows that the new proposed formulae are shorter and accurate with negligible errors. The new formulae can be adapted to the accuracy needed and imply different numbers of coefficients. This can also shorten the calculations in navigation such as rhumb-line or great elliptic sailing on the ellipsoid because the meridian arc length is essential for these calculations.
In this study, we present a new numerical model for crystal growth in a vertical solidification system. This model takes into account the buoyancy induced convective flow and its effect on the crystal growth process. The evolution of the crystal growth interface is simulated using the phase-field method. A semi-implicit lattice kinetics solver based on the Boltzmann equation is employed to model the unsteady incompressible flow. This model is used to investigate the effect of furnace operational conditions on crystal growth interface profiles and growth velocities. For a simple case of macroscopic radial growth, the phase-field model is validated against an analytical solution. The numerical simulations reveal that for a certain set of temperature boundary conditions, the heat transport in the melt near the phase interface is diffusion dominant and advection is suppressed.
Meningiomas account for approximately 24-30% of primary intracranial neoplasms. Histopathologic grade and degree of resection are two major prognostic factors. The aim of this study was to determine the factors associated with the prognosis of meningioma.
We used immunohistochemistry to analyze the expression levels of Vav3, SPARC, p-Akt, cyclin D1, and Ki-67 in 287 meningiomas of all grades.
The expression of Vav3, SPARC, p-Akt, cyclin D1, and Ki- 67 significantly increased with meningioma grade (p<0.01), and was higher in brain-invasive meningiomas compared to non-invasive meningiomas (WHO grade I) (p<0.05). Furthermore, the expression of Vav3, p-Akt, and Ki-67 was higher in recurrent meningiomas compared to non-recurrent meningiomas (WHO grade I) (p<0.05).
The expression of Vav3, SPARC, p-Akt, cyclin D1, and Ki-67 in meningiomas appears to correlate with meningioma invasiveness, aggressiveness, and recurrence.
Neurosyphilis (NS) may present with neuropsychiatric disorders characterized by cognitive impairment, personality disorders, and confusion, among others. Very few studies have focused on neuropsychiatric disorders secondary to NS in elderly people.
A retrospective chart review was performed to characterize the psychiatric findings, clinical signs and symptoms, laboratory findings, and brain magnetic resonance imaging results of ten elderly inpatients with NS.
In these ten patients, the most common presenting symptoms included a wide variety of psychiatric manifestations. The serum rapid plasma regain (RPR) and Treponema pallidum particle agglutination assay (TPPA) of the ten patients were positive, with positive CSF TPPA and RPR rates of 100% and 60%, respectively. In addition, 90% of the patients demonstrated abnormal imaging, including cerebral atrophy, infarct ischemic stroke, and hydrocephalus.
Our findings support the importance of serological tests for syphilis as a routine component of the evaluation of patients with clinically evident neurological or psychiatric symptoms. If the serology is positive, all of the patients should be examined with a lumbar puncture. Moreover, psychiatric illnesses secondary to NS in the elderly also deserve medical attention.
The driving mechanism of solar flares and coronal mass ejections is a topic of ongoing debate, apart from the consensus that magnetic reconnection plays a key role during the impulsive process. While present solar research mostly depends on observations and theoretical models, laboratory experiments based on high-energy density facilities provide the third method for quantitatively comparing astrophysical observations and models with data achieved in experimental settings. In this article, we show laboratory modeling of solar flares and coronal mass ejections by constructing the magnetic reconnection system with two mutually approaching laser-produced plasmas circumfused of self-generated megagauss magnetic fields. Due to the Euler similarity between the laboratory and solar plasma systems, the present experiments demonstrate the morphological reproduction of flares and coronal mass ejections in solar observations in a scaled sense, and confirm the theory and model predictions about the current-sheet-born anomalous plasmoid as the initial stage of coronal mass ejections, and the behavior of moving-away plasmoid stretching the primary reconnected field lines into a secondary current sheet conjoined with two bright ridges identified as solar flares.
Pearlitic transformation in an ultrafine-grained (UFG) hypereutectoid steel was investigated. The steel was a plain carbon steel containing 1.0 wt% C and very few other elements. The UFG samples were prepared by thermomechanical treatment, and an average grain size of approximately 1 μm was achieved. The pearlitic transformation was conducted by heating the UFG samples at 1023 K for different times and then cooling in air. A new pearlitic transformation phenomenon was observed: traditional lamellar pearlite can be observed only when the grain size increases to a dimension larger than approximately 4 μm, which is a critical value. When grain size is smaller than this value, the pearlitic transformation occurs in the form of divorced eutectoid, and the microstructure is the ferrite matrix with granular cementite. This research indicates that grain size has a great influence on pearlitic transformation by shortening the diffusion distance and increasing the diffusion rate of carbon atoms in the UFG steel.
To study coronary artery haemodynamics in adolescents with homozygous familial hypercholesterolaemia and aortic supravalvular stenosis.
Patients diagnosed with familial hypercholesterolaemia who were younger than 16 years and who had undergone transthoracic echocardiography from 2007 to 2010 were included in this study. We included patients with homozygous familial hypercholesterolaemia and aortic supravalvular stenosis and those with heterozygous familial hypercholesterolaemia. All patients underwent stress echocardiography, and left anterior descending coronary artery flow was successfully detected. Coronary flow velocity reserve was calculated as the ratio of hyperaemic mean diastolic flow velocity after injection of adenosine to basal mean diastolic flow velocity. Changes in coronary haemodynamics and the relationship between lipid concentrations were determined.
A total of 11 patients with homozygous familial hypercholesterolaemia were enrolled in this study. Lipid concentrations were measured, and the mean coronary flow velocity reserve was 1.97 plus or minus 0.51. Seven children were included in the group of patients with heterozygous familial hypercholesterolaemia. In these children, the mean coronary flow velocity reserve was 3.08 plus or minus 0.84.
The coronary flow velocity reserve of homozygous familial hypercholesterolaemic patients is lower than that of heterozygous familial hypercholesterolaemic patients, and it is associated with a high concentration of low-density lipoprotein cholesterol. Aortic stenosis and plaques compromised the ostia of the coronary artery and caused increased basal mean diastolic coronary velocity with blunted increase in peak velocity, which decreased the coronary flow velocity reserve.