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Two reduced simulation approaches are exploited to predict the parametric boundary of dominant instability regime with global effects and the characteristics of corresponding turbulent particle fluxes in tokamak plasmas. One is usual numerical simulation of coexisting ion temperature gradient (ITG) mode and trapped electron mode (TEM) turbulence employing an extended fluid code (ExFC) based on the so-called Landau–Fluid model including the trapped electron dynamics. Here the density gradient (i.e. R/L n ) driven TEM (∇n-TEM) is emphasized. The other one is a surrogate turbulence transport model, taking a neural network (NN) based approach with speeding calculation. It is shown that the turbulent particle flux, particularly their directions depend on the type of micro-instability as ITG and/or TEM. On the other hand, the density gradient may govern the direction of the turbulent particle fluxes in general circumstances. Specifically, in the parameter regime explored here, the ITG and the electron temperature gradient driven TEM (∇T e-TEM) are destabilized for flat density profile, generally causing an inward particle flux, i.e. particle pinch. Contrarily, for steep density profile, the ∇n-TEM or coexisting ITG and TEM turbulence are dominant so that the particle always diffuses outwards. An empirical criterion is obtained to predict the dominant instability and the direction of particle flux for medium density gradients, involving the gradients of both ion and electron temperature as well as the density. These two transport models are applied to analyze the spontaneous excitation of a quasi-coherent mode in the turbulence modulation discharge by MHD magnetic island observed on tokamak HL-2A, clearly showing a dynamic transition from ITG to TEM. Furthermore, the ExFC-NN model can predict and speed up the analysis of the turbulence transport in tokamak experiments.

Mechanism of combustion synthesis (CS) of ZrB 2 –Al 2 O 3 composite powders was systematically analyzed by a combustion front quenching method (CFQM). The microstructural evolution during the CS process was investigated by field-emission scanning electron microscopy (FESEM) equipped with energy dispersive X-ray spectrometer (EDS). The combustion temperature and wave velocity were measured by the data acquisition system. Moreover, the phase constituents of the final product were examined by X-ray diffraction (XRD). The thermal behaviors of the stoichiometic powders under the thermal exposure were characterized using differential scanning calorimetry (DSC) and thermogravimetric (TG). The results showed that the combustion reaction started from the melting of the B 2 O 3 and Al particles, which was followed by the formation of ZrO 2 –B 2 O 3 –Al solution. The ignition temperature of this system was determined to be around 800 °C. B and Al 2 O 3 were then precipitated from the solution. As the CS reaction proceeded, Zr and Al 2 O 3 were produced by the reaction between ZrO 2 particles and Al and precipitated from the solution. ZrB 2 could then be formed by the direct reaction between Zr and B. Finally, the ZrB 2 –Al 2 O 3 composite powders were obtained. Furthermore, a model corresponding to the dissolution–precipitation mechanism was proposed.

A new unsymmetrical photochromic diarylethene 1-[2-methyl-5-(4-chlorophenyl)- 3-thienyl]-2-[2-methyl-5-formyl-3-thienyl]perfluorocyclopentene (1o) has been synthesized . In the meantime, its photochromic, kinetics and fluorescence properties were investigated in detail. This diarylethene had good thermal stability and exhibited reversible photochromism. What is more, the kinetic experiments illustrated that the cyclization/cycloreversion process of this compound was determined to be the zeroth/first reaction. The fluorescence intensity of diarylethene decreased dramatically along with the photochromism from open-ring isomer to closed-ring isomer upon irradiation with UV light in acetonitrile solution.

To the Editor: In the past 10 years, chikungunya virus (CHIKV) has caused global epidemics of fever, rash, and arthralgia affecting millions of humans, most recently in the Americas (1). CHIKV is an alphavirus transmitted by Aedes spp. mosquitoes. This virus has been isolated from wild vertebrates, particularly nonhuman primates (NHPs), in Africa (2). This sylvatic cycle might maintain the virus during interepidemic periods. The role of sylvatic cycles in Asia is less clear. Encroachment of human settlements into forests has caused increased conflict between humans and macaques for space and resources in urban and rural areas. This interface exposes humans to zoonotic pathogens found in monkeys, such as CHIKV, dengue virus, and Plasmodium knowlesi. The most common macaque species in Peninsular Malaysia is the long-tailed macaque (Macaca fascicularis); an estimated population of >130,000 monkeys live in human-populated areas (3). We determined the potential role of long-tailed macaques in conflict with humans as a reservoir of CHIKV in Malaysia. In response to reports of long-tailed macaques in human-populated areas, the Malaysian Department of Wildlife and National Parks traps monkeys in these areas and relocates them to forest areas. As part of the Wildlife Disease Surveillance Program conducted by Outbreak Response Team of this department, with assistance from the EcoHealth Alliance, serum samples were collected from 147 long-tailed macaques at >20 sites in the states of Selangor (88 monkeys), Negeri Sembilan (21), Perak (18), Pahang (17), and Penang (3) (Figure). Samples were collected in October–November 2009 and October 2010, just after a nationwide outbreak of CHIKV that affected >13,000 persons in 2008–2009 (4). These samples represent 0.05%–0.29% of estimated populations of long-tailed macaques in human-populated areas in these 5 states (3). Figure Cases of human infection with chikungunya virus (CHIKV) per 100,000 persons in 5 states in Peninsular Malaysia, 2008–2009, and sites where monkeys were sampled in 2009–2010. Published CHIKV case numbers were used (4), and published estimated ... A seroneutralization assay was performed by using baby hamster kidney cells to screen for neutralizing antibodies against CHIKV in heat-inactivated monkey serum samples. Samples at a 1:20 dilution that neutralized CHIKV in 3 months, infectious CHIKV is not detectable beyond 44 days (10), and long-term neutralizing immunity is present for >180 days (5). However, there is no evidence for long-term active CHIKV infection and its recrudescence in macaques or humans. A limitation of our study was the relatively small number of monkeys sampled. Although we found no overall significant correlation between incidence of human cases of infection with CHIKV and estimated number of long-tailed macaques per 100,000 persons in each state (r2 = 0.05, p = 0.49), we cannot exclude the involvement of long-tailed macaques in a local outbreak at a specific site. Long-term dynamics of antibodies against CHIKV in long-tailed macaques are not known, which might affect sensitivity of detection assays. We conclude that long-tailed macaques in conflict with humans in specific areas probably played a small part in transmission of CHIKV during recent large outbreaks in humans in Malaysia. Human–mosquito–human transmission and travel by infected humans were probably the major factors involved in spread of this virus. If a true sylvatic reservoir that effectively maintains CHIKV is present in Malaysia, long-tailed macaques might play only a minor role. In addition, involvement of other NHPs and mammals remains to be elucidated.

This study aimed to investigate human papilloma virus (HPV) genotypes among women with cervical lesions in Shaanxi Province, China, to obtain information regarding cervical lesion prevention and treatment. The study included 4508 HPV-positive subjects; cervical swab specimens were collected and tested for HPV infection status and HPV genotypes using polymerase chain reaction and reverse dot-blot hybridization. Women positive for HPV with cervical lesions, including chronic cervicitis, cervical intraepithelial neoplasia, and cervical squamous cell carcinoma (SCC), were examined; HPV-positive women with no cervical lesions were controls. Data were pooled and weighted estimates have been presented. For women with no cervical lesions and positive for one HPV genotype, HPV 52, 16, 58, 81, 33, and 56 were the most common; for multiple-HPV genotype infection, HPV 16, 52, 6, 18, 58, and 66 were the most common. Collectively, HPV 16, 58, 52, 18, 33, and 81 were the most common in women with cervical lesions. HPV 16 comprised 26.71% of single-genotype and 15.64% of multiple-genotype infections. The proportion of HPV-16-positive cases was 29.15%, which was the highest among all HPV genotypes (P < 0.01). Single-HPV genotype infection was the most common in cervical HPV infection (77.48%); infection with two HPV genotypes comprised 72.22% of multiple-genotype infections. The proportion of single-low-risk HPV genotype infections decreased with increase in cervical lesion severity; there were no single- or multiple-low-risk genotype HPV infections in cervical SCC patients. The proportion of multiple-genotype HPV infections with at least one high-risk genotype increased with cervical lesion severity.

The aim of this study was to examine the subtype distribution of human papilloma virus (HPV) in women in the Shaanxi Province of China. A DNA chip, along with polymerase chain reaction amplification and reverse dot blot technology, was adopted to analyze the HPV genotypes of 22,937 cases of cervical cell specimens. The HPV infection rate was 18.70%, wherein high-risk, low-risk, and high- and low-risk multiple infection rates were 15.75, 2.96 and 1.91%, respectively. High-risk infections accounted for 84.20% of total infections. The rate of HPV infection in women with rural residence, high school education or less, a low income, or age over 40 years was significantly higher than that in the control group (negative HPV infection women). Of the 18 detected high-risk HPV subtypes, the most common in single infections were, in the order of prevalence, HPV16, 58, 18, 52, 33, and 56. For multiple high-risk infections, the most common subtypes in the order of prevalence were HPV16, 52, 58, 18, 56, and 33. Age was a factor in the rate of infection, as the 41-50-year age group had a significantly higher risk of infection than the other groups (P < 0.05). In multiple infections, double infections were common, accounting for 77.10% of multiple infections, and triple or more infections were more common in women aged 51-60 years. In Shaanxi Province, high-risk HPV infection in women was mainly attributed to rural residence, age over 40 years, low income, and low education level.

A new unsymmetrical photochromic diarylethene 1(3,5-dimethyl-4-isoxazolyl)-2-{2-methyl-5-[4-(1,3-dioxolane)phenyl]-3-thienyl}perfluorocyclopentene (1o) has been synthesized. Its properties have been discussed systematically, including photochromic, fluorescence switch and kinetics experiments in acetonitrile solution. The result indicated that this diarylethene had good thermal stability and exhibited reversible photochromism, changing the color from colorless to pink in acetonitrile solution upon appropriate irradiation with 297 nm UV light, respectively. What is more, the kinetic experiments illustrated that the cyclization/cycloreversion process of this compound was determined to be the zeroth/first reaction. The fluorescence intensity of diarylethene decreased dramatically along with the photochromism from open-ring isomer to closed-ring isomer upon irradiation with UV light in acetonitrile solution. Keywords-diarylethene; photochromic; fluorescence; kinetics

In the present paper, a new type of DC arc plasma torch is disclosed. The principles of the new magnetic and fluid dynamic controlled large orifice long discharge tunnel plasma torch is discussed. Large area uniformity is achieved through the externally applied magnetic field which stabilizes the arc jet and the proper magnetic and fluid dynamic control which guarantees the dynamic mixing of gases before impinging on to the substrate. The 100 kW high power jet which is newly developed based on the experience of the low power model is equipped with a Φ120 mm orifice torch, and is capable of depositing diamond films over a substrate area of Φ110 mm at a growth rate as high as 40 μm/h, and can be operated in gas recycling mode, which allows 95% of the gases to be recycled. It is demonstrated that the new type DC plasma torch can be easily scaled-up to an even higher power jet. It is estimated that even by the 100 kW Jet, the cost for tool grade diamond films can be as low as less than $4/carat.

The ball-on-ring method was used to investigate the fracture behavior of thick diamond film samples prepared by high-power DC plasma jet CVD method. Both as-grown and polished samples were tested. Great efforts were made to correlate the data obtained to the microstructural features of the tested samples, particularly to the grain size and the pre-existing defects. For as-grown samples, the data were widely scattered such that it was hard to find any grain size dependence on fracture strength and toughness. Whilst for polished samples, a linear relationship of fracture strength to the inverse of the square root of the grain size (the well-known Petch-Hall equation) was found to fit the data reasonably well. This suggests that grain refinement is also an effective way for improving the mechanical properties of CVD diamond films. Pre-existing micro-cracks are also an important factor affecting the mechanical properties of thick CVD diamond films.

Middle ear fluids (MEE) and matched sera (S) were obtained from 50 patients with serous otitis media and magnesium levels were measured to determine if magnesium concentration was distinctly varied in otitis media with effusion (OME). The MEE/S ratio was considerably raised along with transient sensory hearing loss in chronic OME when compared with acute OME. The higher magnesium level found in the MEE implies that it is probably produced locally by the middle ear mucosa and may contribute to the hearing loss found. We also regard the MEE/S ratio as a prognostic factor in OME.

R.A. Sharma, I. Kavai, Y .L. Fu%nd M. Bobek* Department of Experimental Therapeutics, Grace Cancer Drug Center, Roswell Park Memorial Institute, Buffalo, NY 14263. (Received ir. TJS& 17 Juzze 1977; received ir. m for >IlbliCati@n 11 k:l:Xt 15’77) The biological properties of fluorinated saccharides and nucleosides have, in recent years, prompted the development of several useful methods for their synthesis l-3 . In contrast to the considerable interest directed towards the synthesis and chemistry of fluorosugars in which a single fluorine atom becomes attached to carbon, the synthesis of e-diflurosugars has not been extensively investigated. The first e-difluorosaccharide, 2-deoxy-2, 2-difluoro-D-arabino-hexose4, has recently -been prepared by addition of fluoroxytrifluromethane to 3,4,6-tri-g-acetyl-2-fluoro-I&glucal, followed by hydrolysis. Some B-difluoromethylene sugar derivatives have been prepared 596 by treatment of sugar aldehydes and ketones with (difluoromethylene) triphenylphosphorane . In connection with our efforts towards the synthesis of potential antitumor nucleosides, it became apparent that a general procedure for the preparation of gem-difluorosaccharides would be of considerable value. We now wish to report such a method based on the fluorination of sugar carbonyl groups. Sugar aldehydes and ketones can readily be prepared by oxidation7 of the corresponding alcohols. While aromatic and aliphatlc gem-difluorides have been prepared by fluorination of the corresponding carbonyl derivatives, using reagents such as, SF 8 4 ’ Se F4 * pyridineg , and dialkylaminosulfur trifluoride 10,ll , an earlier attempt to replace the carbonyl oxygen in a sugar derivative, 1,6anhydro-2,4-dideoxy-2,4-difluoro-P-D-rib0 -hexopyranos-3-ulose, by fluorination with PhSF3 failed=. We have found that diethylaminosuliiz trifluoride 10,11,.15 IS a useful reagent for the replacement of the carbonyl oxygen in sugars and glycosides protected with the isopropylidene groups. The reaction appears to be general for sugar aldehydes and ketones in the pyranosyl form.

Pyrolysis of cellulose under vacuum and atmospheric pressure gave a tar containing various amounts of 1,6-anhydro-β-D-glucopyranose, 1,6-anhydro-β-D-glucofuranose, α- and β-D-glucose, 3-deoxy-D-erythro-hexosulose, oligo- and polysaccharides, and some dehydration products. The polysaccharide fraction had no reducing end-group, was randomly linked, contained some furanoid rings, and was very similar to the polysaccharide condensation-product of 1,6-anhydro-β-D-glucose. These results are consistent with a series of inter- and intra-molecular transglycosylation and dehydration and rehydration reactions.