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排序方式: 共有125条查询结果,搜索用时 15 毫秒
61.
Löhle S Eichhorn C Steinbeck A Lein S Herdrich G Röser HP Auweter-Kurtz M 《Applied optics》2008,47(11):1837-1845
Estimation of the local dissociation degree and the local mass-specific enthalpy of a pure oxygen plasma flow determined mainly from laser-induced fluorescence measurements are reported. Measurements have been conducted for several generator parameters in an inductively heated plasma wind tunnel. Additional probe measurements of total pressure together with the deduced translational temperature are used to estimate the local mass-specific enthalpy. For a reference condition, full dissociation has been measured. The measured translational temperature of atomic oxygen for this condition is T = 3500 K. Subsequently, the local mass-specific enthalpy has been derived using these local density and temperature measurements. For the reference condition the estimated value of h = 27 MJ/kg is in good agreement with the probe measurements and results from diode laser absorption spectroscopy. 相似文献
62.
Jui-Hao Lee Si-Yin Lin Jen-Wei Liu Shinn-Zong Lin Horng-Jyh Harn Tzyy-Wen Chiou 《International journal of molecular sciences》2021,22(12)
Spinocerebellar ataxia type 3 (SCA3), a hereditary and lethal neurodegenerative disease, is attributed to the abnormal accumulation of undegradable polyglutamine (polyQ), which is encoded by mutated ataxin-3 gene (ATXN3). The toxic fragments processed from mutant ATXN3 can induce neuronal death, leading to the muscular incoordination of the human body. Some treatment strategies of SCA3 are preferentially focused on depleting the abnormal aggregates, which led to the discovery of small molecule n-butylidenephthalide (n-BP). n-BP-promoted autophagy protected the loss of Purkinje cell in the cerebellum that regulates the network associated with motor functions. We report that the n-BP treatment may be effective in treating SCA3 disease. n-BP treatment led to the depletion of mutant ATXN3 with the expanded polyQ chain and the toxic fragments resulting in increased metabolic activity and alleviated atrophy of SCA3 murine cerebellum. Furthermore, n-BP treated animal and HEK-293GFP-ATXN3-84Q cell models could consistently show the depletion of aggregates through mTOR inhibition. With its unique mechanism, the two autophagic inhibitors Bafilomycin A1 and wortmannin could halt the n-BP-induced elimination of aggregates. Collectively, n-BP shows promising results for the treatment of SCA3. 相似文献
63.
A Physical Model for the Drying of Gelcast Ceramics 总被引:4,自引:0,他引:4
Sarbajit Ghosal Abbas Emami-Naeini Ywh-Pyng Harn Barry S. Draskovich John P. Pollinger 《Journal of the American Ceramic Society》1999,82(3):513-520
Gelcasting is a promising new technology for manufactur-ing advanced structural ceramic components. The process involves drying of the "green" gelcast part before densifi-cation. The physical mechanisms that control this relatively long drying process are not well understood. In this study, several controlled experiments have been performed to elu-cidate the key mechanisms. A one-dimensional drying model has been formulated, based on evaporation and gas-eous diffusion through the part. Experimental data have been used to obtain correlations for model parameters. This model predicts the instantaneous moisture content of a gelcast sample with an accuracy of better than 10% when the dryer humidity, dryer temperature, and sample thick-ness are specified. 相似文献
64.
One of the functions of von Willebrand factor (vWF) is to serve as a carrier of clotting factor VIII (FVIII). Deficiency of this function results in the von Willebrand disease (vWD) variant type 2N, which resembles hemophilia A. We describe a new sandwich enzyme-linked immunosorbent assay (ELISA) to study the ability of vWF to bind exogenous recombinant FVIII (rFVIII), in which anti-vWF-coated plates are incubated with plasma vWF, followed by exogenous FVIII and a peroxidase-coupled anti-FVIII antibody. Dose-response curves obtained using normal plasma vWF and purified normal vWF revealed a hyperbolic relationship between the optical density and the vWF concentration. The assay allows the quantification of FVIII binding with values expressed in U/dL; 100 U/dL was the amount present in normal plasma. The sensitivity and specificity of the method are demonstrated by its ability to measure binding levels as low as 1 to 2 U/dL and the fact that no FVIII binding was observed using plasma known to contain less than 1 U/dL vWF. To verify the accuracy of the assay, three patients with type 2N vWD with characterized vWF gene mutations were studied using an existing chromogenic assay and our ELISA. A patient who was homozygous for the R53W mutation and had no FVIII binding capacity according to the chromogenic method showed undetectable FVIII binding by ELISA. The remaining two patients, one who was homozygous for the R91Q mutation and one with compound heterozygosity for the R91Q and R53W mutations, showed markedly decreased FVIII binding by the chromogenic method and yielded ELISA values ranging from 4 to 8 U/dL. Therefore, although the two methods produce qualitatively similar results, the ELISA method offers the advantage of allowing quantification of the FVIII binding function. FVIII binding was also analyzed in 20 patients with type 1 vWD; we found a decrease of FVIII binding that was proportionate to the decrease in vWF levels, showing a normal FVIII binding activity/vWF molecule ratio. We define the binding activity measured by this assay as vWF:FVIII binding activity and propose its use in the functional analysis of vWF. 相似文献
65.
D Maes H Deluyker M Verdonck F Castryck C Miry A Lein B Vrijens A de Kruif 《Canadian Metallurgical Quarterly》1998,45(8):495-505
An inactivated Mycoplasma hyopneumoniae vaccine was evaluated in five pig herds clinically infected with enzootic pneumonia and practising a continuous production system in the growing/finishing unit. In each herd, a vaccinated and control group of approximately 47 pigs each were individually monitored from birth until slaughter. Vaccinated pigs received the first dose at about 1 week of age and the second approximately 3 weeks later. During all production stages, an equal number of vaccinated and control pigs was present in the same pen. Both groups were compared with respect to zootechnical parameters (major variables) and by means of serological, pathological, and bacteriological parameters (ancillary variables). Daily weight gain was improved by 14 gr/day during the period from 8 days of age until slaughter (P = 0.0486) and by 25 gr/day during the growing/finishing period (P = 0.0067). Mortality rate, and the costs for curative medication were not significantly improved by vaccination. The results of the ancillary variables are presented and discussed. 相似文献
66.
Recurrent ascending myelitis: an unusual presentation of herpes simplex virus type 1 infection 总被引:1,自引:0,他引:1
We report on a healthy female with a unique relapsing transverse myelitis accompanied by herpes simplex virus type 1 (HSV-1) infection. Magnetic resonance imaging showed cord enlargement and increased signal intensity on T1-weighted image with gadolinium enhancement from T-4 to T-10 during the first attack and from C-1 to C-2 during the second episode. She was not diagnosed during the first attack. During the second episode, laboratory studies disclosed IgM and IgG antibodies to HSV at the outset with greater than fourfold increases in antibody levels in the serum and cerebrospinal fluid (CSF). Cells cultured from the CSF were positive for HSV-1 according to the immunofluorescence method. The presence of HVS-1 DNA in CSF was documented by polymerase chain reaction (PCR) technique. Acyclovir was given with a partial recovery. We anticipate that PCR assay of CSF will assist early diagnosis of herpetic central nervous system disorders. 相似文献
67.
Secure communication has become more and more important for many modern communication applications. In a secure communication, every pair of users need to have a secure communication channel (each channel is controlled by a server) In this paper, using monotone span programs we devise an ideal linear multi-secret sharing scheme based on connectivity of graphs. In our proposed scheme, we assume that every pair of users, \(p\) and \(q\) , use the secret key \(s_{pq} \) to communicate with each other and every server has a secret share such that a set of servers can recover \(s_{pq} \) if the channels controlled by the servers in this set can connect users, \(p\) and \(q\) . The multi-secret sharing scheme can provide efficiency for key management. We also prove that the proposed scheme satisfies the definition of a perfect multi-secret sharing scheme. Our proposed scheme is desirable for secure and efficient secure communications. 相似文献
68.
Design of generalised ElGamal type digital signature schemes basedon discrete logarithm 总被引:2,自引:0,他引:2
The ElGamal type digital signature schemes have received wide attention recently. ElGamal type signature schemes can provide `subliminal' channel, message recovery, multisignature, etc. The authors investigate the design criteria of ElGamal type signature scheme and develop a complete list of all variations 相似文献
69.
An epiperikaryal synaptophysin immunoreactivity has been regarded as an indicator of neoplastic or otherwise abnormal neurons and this staining property serves as an important criterion to distinguish between normal and abnormal neurons. In the present study we have investigated the epiperikaryal synaptophysin reactivity in various regions of the normal human central nervous system by using autopsy materials from 11 subjects aged 3 months-86 years. We found a definite but variable staining of the brainstem and spinal cord motor neurons as well as the cerebellar Purkinje cells. A particular strong and consistent reactivity was seen in neurons of the cerebellar nuclei in which also axons and dendrites were labelled to a variable extent. This type of neuronal staining was never observed in the cerebrum. We therefore conclude that the employment of this staining property as a criterion for abnormal neurons should be used with caution in the cerebellum, brainstem, and spinal cord whereas it may be used more safely in the cerebrum. 相似文献
70.
Pt catalyst supported on a novel engineered CNT support which preserves the advantageous morphology and porosity of as-made CNTs agglomerates exhibits lower C?CCl hydrogenolysis activity in hydrogenation of p-chloronitrobenzene than commercial Pt catalyst supported on activated carbon. This is attributed to the open ended pore structure and meso/macro porosity of the CNT support. 相似文献