Search

In this paper, a new field-modulated permanent magnet (FMPM) machine with an improved rotor is proposed and analyzed. The proposed FMPM machine enjoys the advantages of high PM utilization and better heat dissipation. For a fair comparison, the proposed FMPM machine is designed with the same geometrical parameters based on the existing FMPM machine. The electromagnetic performances of existing FMPM (E-FMPM) machine and proposed FMPM (P-FMPM) are compared and analyzed by using finite element method, verifying that the proposed FMPM machine with an improved rotor can obtain high torque density and high PM utilization.

To increase the airgap flux density, this paper proposes a new magnetic-field-modulated permanent magnet (FMPM) machine. The proposed FMPM machine has the compound magnets in the rotor, which is composited by the spoke PMs (SPM) and Halbach PMs (HPM). The proposed SH-FMPM machine facilitates better use of space for armature winding and PMs and combines the benefits of high torque density and high torque/loss. The formation process, operation principle, and electromagnetic performance of the SH-FMPM machine are introduced. It is demonstrated that the SH-FMPM machine has the high torque density and low torque ripple compared to the S-FMPM machine and the H-FMPM machine.

The present study aimed to examine the associations between the protein and mRNA expression levels of ovarian cancer gene 1 (OVCA1), cyclin D1 and p16 and high-risk human papillomavirus (HR-HPV) infection in cervical lesions. The protein expression levels of OVCA1, cyclin D1 and p16 in 66 cases of cervical cancer, 64 cases of cervical intraepithelial neoplasia (CIN) and 34 normal cervix tissues were detected using immunohistochemistry. The mRNA expression levels of OVCA1, cyclin D1 and p16 in cervical cancer and normal cervix cells were detected using real-time polymerase chain reaction. The results revealed that the protein expression levels of OVCA1 increased gradually, whereas its mRNA expression levels decreased gradually, in the progression from normal cervix tissue to CIN and cervical cancer (P<0.01). In addition, significant differences in the protein expression levels of OVCA1 between low-and high-level CIN, as well as between the early and advanced stages of cervical cancer, were observed (P<0.05). No significant associations were detected between the protein and mRNA expression levels of OVCA1 and the pathological type of cervical cancer or the presence of lymph node metastasis (P>0.05). The expression levels of OVCA1 mRNA and protein were positively correlated with the levels of p16 expression (P<0.01). Significant differences were also observed in the OVCA1 protein and mRNA expression levels between the HR-HPV (+) and HR-HPV (-) groups (P<0.05). Therefore, aberrant expression of OVCA1 protein and mRNA may be important during the development of cervical lesions, particularly in the early stages. In addition, the mechanisms underlying the effects of OVCA1 during cervical cancer development may involve p16 and HPV, as the levels of OVCA1 in cervical lesions were correlated with abnormal expression of p16 and HR-HPV infection. [ABSTRACT FROM AUTHOR]

Previous studies have demonstrated an association between neurological diseases and oxidative stress (OS). Naphthoflavone is a synthetic derivative of naturally occurring flavonoids that serves an important role in the treatment and prevention of OS-related diseases. The current study was designed to apply α- and β-Naphthoflavone individually and in combination to counteract the detrimental effects of OS on neurons in vitro. Neuronal SH-SY5Y cells were subjected to 20 μM H2O2, followed by exposure to 20 μM α-Naphthoflavone and/or 10 μM β-Naphthoflavone. Results indicated that α- and β-Naphthoflavone effectively antagonized the apoptosis-promoting effect of H2O2 on neuronal SH-SY5Y cells, and that β-Naphthoflavone significantly (P<0.05) reversed H2O2-inhibited cell viability. Notably, co-treatment of α- and β-Naphthoflavone reversed the H2O2-induced apoptosis rate elevation and cell viability reduction. Further analysis demonstrated that H2O2 inhibited the activities of antioxidant enzymes including catalase, superoxide dismutase and glutathione peroxidase, but this was reversed by the co-treatment with α- and β-Naphthoflavone and selectively enhanced by the treatment with α- or β-Naphthoflavone. H2O2-stimulated p38 mitogen-activated protein kinase activation was repressed following treatment with α- and/or β-Naphthoflavone, along with a decreased expression of the apoptosis-related factors and inhibited caspase-3 activation. In conclusion, co-treatment with α- and β-Naphthoflavone minimized H2O2-led neuron damage compared with treatment with α- or β-Naphthoflavone, suggesting a synergetic effect between α- and β-Naphthoflavone. This indicates that utilizing α- and β-Naphthoflavone together in the clinical setting may provide a novel therapeutic for neurological disease. [ABSTRACT FROM AUTHOR]

Glial reaction is a common feature of neurodegenerative diseases. Recent studies have suggested that reactive astrocytes gain neurotoxic properties, but exactly how reactive astrocytes contribute to neurotoxicity remains to be determined. Here, we identify lipocalin 2 (lcn2) as an inducible factor that is secreted by reactive astrocytes and that is selectively toxic to neurons. We show that lcn2 is induced in reactive astrocytes in transgenic rats with neuronal expression of mutant human TAR DNA-binding protein 43 (TDP-43) or RNA-binding protein fused in sarcoma (FUS). Therefore, lcn2 is induced in activated astrocytes in response to neurodegeneration, but its induction is independent of TDP-43 or FUS expression in astrocytes. We found that synthetic lcn2 is cytotoxic to primary neurons in a dose-dependent manner, but is innocuous to astrocytes, microglia, and oligodendrocytes. Lcn2 toxicity is increased in neurons that express a disease gene, such as mutant FUS or TDP-43. Conditioned medium from rat brain slice cultures with neuronal expression of mutant TDP-43 contains abundant lcn2 and is toxic to primary neurons as well as neurons in cultured brain slice from WT rats. Partial depletion of lcn2 by immunoprecipitation reduced conditioned medium-mediated neurotoxicity. Our data indicate that reactive astrocytes secrete lcn2, which is a potent neurotoxic mediator. [ABSTRACT FROM AUTHOR]

Pristella maxillaris is known as the X-ray fish based on its translucent body. However, the morphological characteristics and the molecular regulatory mechanisms of these translucent bodies are still unknown. In this study, the following three phenotypes, a black-and-gray body color or wild-type (WT), a silvery-white body color defined as mutant I (MU1), and a fully transparent body with a visible visceral mass named as mutant II (MU2), were investigated to analyze their chromatophores and molecular mechanisms. The variety and distribution of pigment cells in the three phenotypes of P. maxillaris significantly differed by histological assessment. Three types of chromatophores (melanophores, iridophores, and xanthophores) were observed in the WT, whereas MU1 fish were deficient in melanophores, and MU2 fish lacked melanophores and iridophores. Transcriptome sequencing of the skin and peritoneal tissues of P. maxillaris identified a total of 166,089 unigenes. After comparing intergroup gene expression levels, more than 3,000 unigenes with significantly differential expression levels were identified among three strains. Functional annotation and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of the differentially expressed genes (DEGs) identified a number of candidates melanophores and iridophores genes that influence body color. Some DEGs that were identified using transcriptome analysis were confirmed by quantitative real-time PCR. This study serves as a global survey of the morphological characteristics and molecular mechanism of different body colors observed in P. maxillaris and thus provides a valuable theoretical foundation for the molecular regulation of the transparent phenotype.

This paper proposes a new electromechanical energy conversion system, called Field Modulated Magnetic Screw (FMMS) as a high force density linear actuator for artificial heart. This device is based on the concept of magnetic screw and linear magnetic gear. The proposed FMMS consists of three parts with the outer and inner carrying the radially magnetized helically permanent-magnet (PM), and the intermediate having a set of helically ferromagnetic pole pieces, which modulate the magnetic fields produced by the PMs. The configuration of the newly designed FMMS is presented and its electromagnetic performances are analyzed by using the finite-element analysis, verifying the advantages of the proposed structure.

This paper proposes a novel permanent magnet (PM) motor for high torque performance, in which hybrid PM material and asymmetric rotor design are applied. The hybrid PM material is adopted to reduce the consumption of rare-earth PM because ferrite PM is assisted to enhance the torque production. Meanwhile, the rotor structure is designed to be asymmetric by shifting the surface-insert PM (SPM), which is used to improve the torque performance, including average torque and torque ripple. Moreover, the reasons for improvement of the torque performance are explained by evaluation and analysis of the performances of the proposed motor. Compared with SPM motor and V-type motor, the merit of high utilization ratio of rare-earth PM is also confirmed, showing that the proposed motor can offer higher torque density and lower torque ripple simultaneously with less consumption of rare-earth PM.

This paper proposed an analytical method, based on conformal mapping (CM) method, for the accurate evaluation of magnetic field and eddy current (EC) loss in fault-tolerant permanent-magnet (FTPM) machines. The aim of modulation function, applied in CM method, is to change the open-slot structure into fully closed-slot structure, whose air-gap flux density is easy to calculate analytically. Therefore, with the help of Matlab Schwarz-Christoffel (SC) Toolbox, both the magnetic flux density and EC density of FTPM machine are obtained accurately. Finally, time-stepped transient finite-element method (FEM) is used to verify the theoretical analysis, showing that the proposed method is able to predict the magnetic flux density and EC loss precisely.

Vernier permanent-magnet (VPM) machine offers the advantage of high torque density. However, the existing VPM machines usually suffer from relatively low power factor. To solve the problem, this paper proposes a new high power factor fault-tolerant VPM machine. Compared with the existing one, the proposed VPM machine has higher power factor and higher torque density. Also, the fault-tolerant capability is provided. The electromagnetic characteristics of the proposed machine are analyzed by using the finite element method.

In this paper, a new dual stator linear permanent-magnet (PM) vernier (LPMV) machine with toroidal winding is proposed and analyzed. The proposed machine enjoys the advantages of less copper usage and copper loss without sacrificing the thrust force performance. For a fair comparison, the proposed machine is designed with the same geometrical parameters based on the conventional dual stator LPMV machine with concentrated winding. Finally, the electromagnetic performances of the proposed machine and the conventional one are compared and analyzed by using finite element method, verifying that the proposed machine with the low copper loss can obtain high force density.

Amyotrophic lateral sclerosis (ALS) is characterized by progressive motor neuron degeneration, which ultimately leads to paralysis and death. Mutation of TAR DNA binding protein 43 (TDP-43) has been linked to the development of an inherited form of ALS. Existing TDP-43 transgenic animals develop a limited loss of motor neurons and therefore do not faithfully reproduce the core phenotype of ALS. Here, we report the creation of multiple lines of transgenic rats in which expression of ALS-associated mutant human TDP-43 is restricted to either motor neurons or other types of neurons and skeletal muscle and can be switched on and off. All of these rats developed progressive paralysis reminiscent of ALS when the transgene was switched on. Rats expressing mutant TDP-43 in motor neurons alone lost more spinal motor neurons than rats expressing the disease gene in varying neurons and muscle cells, although these rats all developed remarkable denervation atrophy of skeletal muscles. Intriguingly, progression of the disease was halted after transgene expression was switched off; in rats with limited loss of motor neurons, we observed a dramatic recovery of motor function, but in rats with profound loss of motor neurons, we only observed a moderate recovery of motor function. Our finding suggests that mutant TDP-43 in motor neurons is sufficient to promote the onset and progression of ALS and that motor neuron degeneration is partially reversible, at least in mutant TDP-43 transgenic rats. [ABSTRACT FROM AUTHOR]

Objective: To compare and analyze the clinical, radiological, and pathological features of solitary or/and multiple CNS tuberculomas (CNSTs)., Methods: The study was conducted at Central South University, First Xiangya Hospital, Changsha, Hunan, China between 1998-2008. Forty-two subjects with diagnosed CNSTs were compared and analyzed by multiple or solitary lesions seen on enhanced MRI. The final diagnosis of tuberculomas was confirmed by histopathology., Results: From the 42 subjects, 64.3% multiple CNSTs were observed, out of which, 55.6% were with meningitis and 44.4% without meningitis. Of the CNSTs, solitary lesions were present in 35.7%, 80% of which were without meningeal involvement, and 20% with meningeal involvement. In multiple CNSTs, 55.6% were noncaseating granulomas, and 74.1% caseating granulomas with a solid center, while in solitary CNSTs, 80% were caseating granulomas with a solid center. For multiple lesions, temporal lobe, frontal lobe, cerebella, and brain stem were predilection sites. While for solitary lesions, apical lobe, and cerebellum were predilection sites. The histopathological features were the same in all multiple and solitary lesions., Conclusion: Multiple CNSTs are more often associated with meningitis, while solitary CNSTs particularly occur with less or atypical clinical manifestation. Difference in the predilection sites between multiple and solitary CNSTs were observed.