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Variants of the coilgun are considered for use in microgravity experimental research. Subscale point designs are described for a payload of 50kg and muzzle velocity of 30 to 40m/s. A multiphase linear induction coilgun (LIL) (one stage with six coils and constant pitch) and a 4 - stage reconnection coilgun were designed and analyzed. The results show that the requirement of very low acceleration is difficult, because the acceleration fluctuation of both designs is large. But differences between them are revealed. The induced current in the armature of the reconnection gun distributes much more unevenly than in the LIL. and this will cause mechanical and thermal problems. The efficiency of energy transformation in the reconnection gun is better than LIL of this specific design. Mechanical structural analysis results of the reconnection coilgun are also presented. The results show the coils are structurally sound. The armature is a nonlinear problem of both material and geometry so the available code Super SAP is adopted. However, the armature requires structural reinforcement. Index Terms - Armature currents, Coilgun, Low acceleration. Structural analysis.

For the principle test a 3 - stage reconnection coilgun was built. It has a 64mm bore, length of 330mm and a projectile weight of 1kg. The muzzle velocity is about 100m/s. The value of the capacitors of the driver coils are 4480, 3000 and 715[[micro]farad] with initial voltages 3.3, 3.6 and 6.0 kV respectively. The agreement of the results between the test and the analysis is good. The performances of AC and DC work modes are compared. DC mode means that a shunt circuit is inserted into each driver coil circuit to prevent current reveral. In the test, visible plastic deformations of the armature occur and it was confirmed by computer simulation. Index Terms - AC and DC work modes, Coilgun, Plastic deformations, System analysis.

The establishment of "moral bank" is considered an original way for the promotion of moral construction; in terms of the ethical basis, it depends heavily on the utilitarian incentives to facilitate moral construction. Thus, the implementation of the policy for building moral banks is faced with theoretical and practical difficulties: theoretically, the construction of moral banks is in conflict with our understanding of virtues; practically, it will foster moral hypocrisy. The predicament of building moral banks, however, can bring us a series of ethical implications. [ABSTRACT FROM AUTHOR]

Objective: To study the correlation of the gene expressions of Chk1 and Chk2 with sperm concentration and motility., Methods: According to sperm concentration and motility (percentage of progressively motile sperm), we divided 80 semen samples into four groups of equal number: normal control, oligozoospermia (OS), asthenospermia (AS), and oligoasthenozoospermia (OAS). We detected the sperm DNA fragmentation index (DFI) and viability and determined the expressions of Chk1 and Chk2 in the sperm by RT-PCR and Western blot., Results: Statistically significant differences were not found in sperm DFI among the control, OS, AS, and OAS groups (21.24±6.93, 19.67±7.64, 21.52±6.92, and 19.28±11.55, P>0.05), but observed in sperm concentration, progressive motility, and viability between the DFI >30% and DFI ≤30% groups (P<0.01). Compared with the normal control, sperm viability was remarkably decreased in the OS, AS, and OAS groups (［83.48±9.87］% vs ［63.86±9.16］%, ［50.45±16.99］%, and ［39.21±15.74］%, P<0.05). RT-PCR showed remarkable differences among the control, OS, AS, and OAS groups in the relative expression level of Chk1 mRNA (0.73±0.22, 0.62±0.14, 1.03±0.39, and 0.92±0.071, P<0.01), which was correlated positively with sperm concentration (b = 80.661, P<0.01) but negatively with sperm motility (b = －19.275, P < 0.01), as well as in that of Chk2 mRNA (0.66±0.30, 0.27±0.09, 0.59±0.19, and 0.42 ± 0.11, P<0.01), which was correlated negatively with sperm concentration (b = －90.809, P<0.01) but positively with sperm motility (b = 27.507, P <0.01). The relative expression levels of the Chk1 protein were significantly different among the four groups (0.63±0.05, 0.42±0.03, 1.13±0.08, and 0.87±0.07, P<0.01), which was correlated positively with sperm concentration (b = 55.74, P<0.01) but negatively with sperm motility (b =－22.649, P<0.01), and so were those of the Chk2 protein (1.23±0.36, 0.37±0.16, 0.87±0.08, and 0.68±0.12, P<0.01), which was correlated negatively with sperm concentration (b =－53.001, P<0.01) but positively with sperm motility (b = 16.676, P < 0.01)., Conclusions: Chk1 and Chk2 are significantly expressed in human sperm. In case of sperm DNA damage, up-regulated Chk1 expression may enhance sperm apoptosis and lead to asthenospermia, while increased Chk2 expression may inhibit spermatogenesis and result in oligospermia.

Objective: To study the effect of tea polyphenols (TP) on the apoptosis of germ cells in rats with experimental varicocele., Methods: Thirty-two adolescent male Wistar rats were randomly and equally divided into groups A (sham-operation), B (high-dose TP), C (low-dose TP), and D (experimental left varicocele). Experimental varicocele was induced by partial ligation of the left renal vein in the latter three groups of rats. The animals in groups A and D were fed with normal saline, while those in B and C with TP at 40 and 10 mg per kg per d, respectively, all for 4 weeks. Then, all the rats were sacrificed and the left testes harvested for determination of the expression of HIF-1, Bcl-2, Bax, CytC, and caspase-3 by immunohistochemistry and measurement of the apoptosis index (AI) of spermatogenic cells., Results: The expression of Bcl-2 was higher in groups B and C than in D but lower than in A (P < 0.05), and lower in C than in B (P < 0.05). However, the expressions of HIF-1, Bax, CytC, and caspase-3 were lower in groups B and C than in D but higher than in A (P < 0.05), and higher in C than in B (P < 0.05). The AI of spermatogenic cells was the lowest in group A, higher in D than in the other groups but lower in B than in C (P < 0.05)., Conclusion: TP can reduce the apoptosis of spermatogenic cells in a dose-dependent manner in varicocele rats.

Enantioselective total synthesis of (-)-(S)-stepholidine, a drug candidate for the treatment of schizophrenia and/or drug abuse, is described. Asymmetric transfer hydrogenation of imines with use of Noyori's catalyst was used as the key step and (-)-(S)-stepholidine was synthesized in 6 steps, with 42% overall yield and >99% ee.

Background & Objective: Cerebral hypoxia is known to be involved in many neurodegenerative diseases such as Alzheimer's and cerebrovascular dementia. The present study was designed to investigate the effects of flavonoids from aerial part of Scutellaria baicalensis Georgi (SSF) on potassium cyanide (KCN) -induced hypoxic cytotoxicity in rat pheochromocytoma cell line PC12, and to understand the probable mechanism., Methods: The rat pheochromocytoma cell line PC12 was subjected to hypoxia by 200 microM KCN for 30 min. The cytotoxicity of KCN was assessed by cell viability assay, morphological observation, lactate dehydrogenase (LDH) release, malondialdehyde (MDA) production, and the activities of superoxide dismutase (SOD) and Na+-K+-ATPase measurements. The effects of SSF on the changes induced by KCN in PC12 cells were detected., Results: Treatment of PC12 cells with 200 micriM KCN for 30 min increased cell death when compared with control, as assayed by MTT reduction, morphological observation and lactate dehydrogenase release measurement. These cell lesions were accompanied by disorders in SOD and Na+-K+-ATPase activities as well as MDA production. In contrast, the PC12 cells pre-treated with SSF for 24 h prior to 200 microM KCN exposure have shown protection against hypoxic toxicity. The KCN - induced decreased cell viability and activities of SOD and Na+-K+-ATPase, as well as increased MDA production were reversed by SSF pre-treatment., Interpretation & Conclusion: SSF exerted neuroprotections against KCN - induced hypoxic cytotoxicity in PC12 cells and the probable mechanisms involved free radicals and energy metabolism. Our findings may have implications in future in the treatment of neurodegenerative diseases.