AN ATTRIBUTION OF CAVITATION RESONANCE： VOLUMETRIC OSCILLATIONS OF CLOUD

In order to further verify the proposed theory of cavitation resonance, as well as to proceed the investigations into microscopic level, a series of studies are being carried out on the Warwick venturi. The analysis of the oscillation characteristics of the cavitation resonance has conclusively verified the macro-mechanism proposed through previous studies on other cavitating flows by the authors. The initial observations using high-speed photographic approach have revealed a new attribution of cavitation resonance. That is, the volumetric oscillation of cavitation cloud is associated with the cavitation resonance, which is a collective behaviour of the bubbles in the cloud.     

基于广义哈密顿系统理论的汽轮调速器分散无源控制

提出了一种预置功角反馈的方法，推导出多机系统汽轮机调速系统的广义受控哈密顿系统模型，进而在哈密顿结构的基础上进行无源化控制器的设计。控制策略的所有变量都是本地可量测的，只与本机组的状态量有关，与其他机组的状态量和输电网络的参数无关，因而具有分散性。4机系统仿真结果表明，该控制规律可以提高电力系统的暂态稳定性和动态性能。     

Olfactory dysfunction in Guamanian ALS, parkinsonism, and dementia

OBJECTIVES: To assess whether olfactory deficits are present in the general Guamanian Chamorro population and to evaluate olfaction in each of the four neurodegenerative disease syndromes of Guam: ALS, pure parkinsonism, pure dementia, and the combined parkinsonism-dementia complex (PDC). BACKGROUND: Olfactory dysfunction was previously reported in patients with PDC of Guam. METHODS: We developed a culturally adjusted olfactory test battery, derived from the original University of Pennsylvania Smell Identification Test (UPSIT), and administered this to Chamorro residents with ALS (n=9), pure parkinsonism (n=9), pure dementia (n=11), PDC (n=31), and 53 neurologically normal Chamorro and 25 North American control subjects. RESULTS: Similar, marked olfactory dysfunction was found in all four syndromes of Guamanian neurodegenerative disease. This correlated poorly with measures of parkinsonism and cognition. In the neurologically normal Chamorro control group, six subjects (11%) had very low olfactory scores; these were less than the lowest North American score, raising a question of subclinical neurodegenerative disease. CONCLUSIONS: Marked olfactory deficits are common to all four Guamanian neurodegenerative syndromes, and suggest the possibility of similar central neuropathologic substrates. The deficit in the Guamanian ALS group contrasts with idiopathic ALS, in which olfactory function has been reported to be only slightly compromised.     

Retroviral transfer of a bacterial alkyltransferase gene into murine bone marrow protects against chloroethylnitrosourea cytotoxicity

The chloroethylnitrosoureas (CENUs) are important antineoplastic drugs for which clinical utility has been restricted by the development of severe delayed myelosuppression in most patients. To investigate the potential of DNA repair proteins to reduce bone marrow sensitivity to the CENUs, we transferred the Escherichia coli ada gene, which encodes a Mr 39,000 O6-alkylguanine-DNA alkyltransferase (ATase), into murine bone marrow cells by the use of a high-titer ecotropic retrovirus. The ada-encoded ATase is resistant to O6-benzylguanine (O6-BG), a potent inhibitor of the mammalian ATases, thus affording the bone marrow an additional level of protection against CENUs. In methylcellulose cultures, ada-infected hematopoietic progenitor cells were twice as resistant as uninfected cells to the toxic effects of 1, 3-bis(2-chloroethyl)-1-nitrosourea (BCNU) following treatment with O6-BG. Although showing no obvious protective effects against leukopenia, overexpression of the bacterial ATase activity reduced the severity of anemia and thrombocytopenia in mice treated with O6-BG and BCNU. These effects, which were maximal at a BCNU dose of 12.5 mg/kg, were associated with improved survival when BCNU was given at this dose. At lower BCNU doses cytotoxicity was limited in both transduced and control mice, and at higher doses the protective effect was saturated due to cytotoxicity. These results suggest that ada gene therapy may be a feasible approach to amelioration of delayed myelosuppression following O6-BG plus CENU combination chemotherapy.     

Effect of chronic cadmium exposure on VEP and EEG spectral components

Pregnant swiss albino rats were divided to three groups as control (C), cadmium (Cd) and non-cadmium (NCd) groups. Control animals were received tap water while the rats of Cd group were received Cd as CdC12 in their drinking water during the experimental period. On the other hand, the NCd group was given Cd during pregnancy, but given tap water after birth. Twenty-two days after birth, fourteen rats (for each group) were taken from their mothers and continued to be treated with Cd (Cd group) or tap water (C and NCd groups) for an additional 38 days. After the experimental period, flash VEPs and EEGs of three groups were recorded and amplitude spectral analysis was computed by Transient Response-Frequency characteristics (TRFC) method. The mean amplitude (dB) of 1-3.5 and 14-20 Hz frequency bands for right response whereas 1-3.5, 4-7, 8-13 and 14-20 Hz frequency bands for left response of VEPs were decreased in Cd group compared with control group. On the other hand, significant differences were observed between Cd and control groups in all the frequency bands of EEGs except 6-8 Hz.     

Cholesterol (thermodynamic) activity determinations in bile salt-lecithin-cholesterol systems and cholesterol-rich liquid crystalline mesophase formation

Previous in vitro studies have shown that tauroursodeoxycholate (TUDC)-lecithin (L) micellar solutions solubilize cholesterol (Ch) poorly compared to its 7 alpha-epimer, taurochenodeoxycholate (TCDC). However, in clinical studies ursodeoxycholic acid (UDC) has been found to be as effective as chenodeoxycholic acid (CDC) in Ch gallstone dissolution, and it has been suggested that, during UDC therapy, liquid crystalline mesophase formation may be involved in enhancing micellar Ch dissolution and dispersion. The purpose of the present study was to investigate whether measurements of the Ch thermodynamic activity (A(T) would provide new insights into the problem of Ch solubilization and mesophase formation in bile salt-lecithin-Ch systems. Using the silicone polymer uptake method developed in this laboratory, A(T) was measured as a function of Ch concentration in the TUDC-L-Ch and TCDC-L-Ch model bile systems. In the TCDC systems Henry's law was obeyed almost up to unit activity (i.e., A(T) was proportional to Ch concentration almost up to A(T) = 1.0). However, in many of the TUDC-containing systems negative deviations from Henry's law were observed well below unit activity and these systems became visibly turbid before saturation with respect to cholesterol monohydrate (ChM) was reached. The effects of varying the TCDC/TUDC ratio upon the A(T) behavior were also studied. With increasing TCDC/TUDC ratio, the onset of mesophase formation was shifted to higher A(T) values. A(T) measurements were also conducted in BS-L-Ch mixtures simulating biles of patients undergoing UDC therapy. The results obtained suggest that mesophase formation may not always occur in biles of patients undergoing UDC therapy.(ABSTRACT TRUNCATED AT 250 WORDS)     

二氧化碳在York地层中埋存的地球化学模拟(英文)

In this paper, we build up a three-dimensional model for CO2 storage in the deep reservoir. And this paper gives the mathematical formalism of combined geochemical and multi-phase flow. The results give us the information about geochemical changing caused by CO2 injection into aqueous, the dissolution or precipitation of reservoir minerals caused by aqueous components change, the change of water density, also the differences between this model and the simulation model without considering geochemical. The basic data for simulation is from York Reservoir.     

A comparative study on the use of fly ash and phosphogypsum in the brick production

Over 15 million tons of fly ash (FA) and 3 million tons of phosphogypsum (PG) are produced in Turkey every year. The utilization of these industrial by-product materials is important in terms of environmental and economical issues are concerned. The main purpose of this study is to evaluate the technical possibilities of incorporating FA and PG in production of building blocks. Various mixtures were prepared by incorporating these industrial wastes by replacing clay with seven different weight proportions (0%, 5%, 10%, 15%, 20%, 25% and 30%). All specimens were fired at 1000°C peak temperature. The physical and mechanical properties of all specimens such as; unit weight, compressive strength, flexural strength, dimensional stability and water absorption values were recorded. The effect of PG incorporation on the properties of samples seems to be more dominant than the effect of FA incorporation. The test results showed that; PG incorporation increased the unit weight and mechanical strength values while lowering the water absorption values. Utilization of these wastes additives is not only for conservation of clay resources, but also an alternative solution to a difficult and expensive waste disposal problems.     

Diminished insulin clearance during late pregnancy in patients with type I diabetes mellitus

OBJECTIVE: Published data on bone metabolism in diabetes mellitus are conflicting. We have measured pyridinium crosslinks, biochemical markers of bone resorption, in order to evaluate bone resorption in diabetes mellitus. We also wished to investigate whether, as a consequence of chronic hyperglycaemia, pyridinoline is glycosylated to a greater extent in patients with diabetes mellitus. DESIGN AND PATIENTS: This cross sectional study included 142 patients (64 males, 78 females) with insulin dependent and non-insulin dependent diabetes mellitus (IDDM and NIDDM). These patients were compared to a healthy control group of 99 individuals (39 males and 60 females). MEASUREMENTS: Pyridinium crosslinks, glycosylated, free and total pyridinoline (gPYD, fPYD, tPYD) and free and total deoxypridinoline (fDPD, tDPD) were measured in a spot urine sample by high performance liquid chromatography (HPLC). Urinary creatinine, albumin and glucose were also measured. RESULTS: In the diabetic group, values of urinary gPYD and tDYD were significantly lower than in controls. gPYD excretion was lowest in patients with severe glycosuria. Free pyridinium crosslinks, both fPYD and fDPD, were excreted to a significantly lower extent. The molar ratio of tPYD to tDPD was significantly increased in diabetes mellitus. CONCLUSIONS: Decreased excretion of tDPD suggests low bone resorption in IDDM and NIDDM. Pyridinoline is not glycosylated to a greater extent in diabetes mellitus and tends to be decreased in proportion to the degree of glycosuria. Excretion of gPYD, fPYD and fDPD is depressed in severe glycosuria. Diminshed degradation to the final products, fPYD and fDPD, might represent increased resistance to enzymatic activity or diminished enzymatic activity. The increased molar ratio tPYD/tDPD in urine suggests an increased ratio in bone collagen in diabetes mellitus.