Tunable dual-band perfect absorbers based on extraordinary optical transmission and Fabry-Perot cavity resonance

Magnetic resonance is considered to be a necessary condition for metamaterial perfect absorbers, and dual-band absorbers can be composed of a pair of metallic layers with anti-parallel surface currents. We designed and fabricated a tunable dual-band perfect absorber based on extraordinary-optical-transmission (EOT) effect and Fabry-Perot cavity resonance. The idea and the mechanism are completely different from the absorber based on the near-field interaction. The important advantage of our structure is that we can switch a single-band absorber to a dual-band absorber by changing the distance between two metallic layers and/or incident angle. The peak originating from the EOT effect becomes significantly narrower, resulting in an increase of the Q-factor from 16.88 to 49. The dual-band absorber can be optimized to be insensitive to the polarization of the incident electromagnetic wave by slightly modifying the absorber structure.

Influence of the material removal mechanisms on hole integrity in ultrasonic machining of structural ceramics

Micro-chipping via micro-cracks, due to rapid mechanical indentations by abrasive grits, is the fundamental mechanism of material removal during ultrasonic machining (USM) of hard-brittle materials like ceramics and glass. This study aims mainly to investigate the adverse effects of this inherent removal phenomena on the hole integrity such as entrance chipping, wall roughness and subsurface damage. It also presents the material removal mechanism happens in the gap between the tool periphery and the hole wall (called 'lateral gap'). To do so, experiments were conducted for drilling holes on three advanced structural ceramics, namely, silicon carbide, zirconia, and alumina. Earlier published basic studies on the initiation of different crack modes and their growth characteristics are employed to explain the experimental findings in this USM study. It is realized that the radial and the lateral cracks formed due to adjacent abrasives, which are under the tool face, extends towards radial direction of the hole resulting in entrance chipping. Additionally, the angle penetration and the rolling actions of the abrasives, which are at the periphery of the tool, contribute to the entrance chipping. Later on, in the 'lateral gap', the sliding (or abrasion) and the rolling mechanisms by the larger abrasives take part to material removal. However, they unfavorably produce micro-cracks in the radial direction resulting in surface and subsurface damages, which are ultimately responsible for higher wall-surface roughness. Since the size of micro-cracks in brittle materials is grit size dependent according to the earlier studied physics, it is realized that such nature of the hole integrity during USM can only be minimized by employing smaller grit size, but cannot fully be eliminated.

Jarisch-Herxheimer reaction among syphilis patients in China

BACKGROUND/AIM

The Jarisch-Herxheimer reaction (JHR) is an acute systemic event that can occur during the treatment of spirochetal infections, especially Treponema pallidum in patients with syphilis. JHR has clinical characteristics of an inflammatory reaction to antibiotic treatment and can occur with many medications as long as the antitreponemal concentrations are sufficiently high.

METHODS

The incidence of and risk factors for JHR were investigated retrospectively among 1125 patients with syphilis. A total of 357 patients (32%) had secondary syphilis, 129 (12%) primary, 178 (16%) early latent, 174 (15%) late latent and 285 (25%) latent unknown duration; two patients had tertiary syphilis.

RESULTS

Sixteen patients (1.4%) developed JHR. All JHRs occurred in patients with secondary and latent syphilis treated with penicillin.

CONCLUSIONS

JHR occurred much less frequently than in previously reported studies. It is important that dermatologists recognize the clinical characteristics of JHR so that it is not misinterpreted as an allergic reaction to treatment.

Investigation on CO(2) laser irradiation inducing glass strip peeling for microchannel formation

The study investigates the use of CO(2) laser to induce glass strip peeling off to form microchannels on soda lime gass substrate. The strip peeling exhibits a strong dependence on the energy deposition rate on the glass surface. In spite of the vast difference in the combination of laser power and scanning speed, when the ratio of the two makes the energy deposition rate in the range 3.0-6.0 J/(cm(2) s), the temperature rising inside glass will be above the strain point and reach the softening region of the glass. As a result, glass strip peeling is able to occur and form microchannels with dimensions of 20-40 μm in depth and 200-280 μm in width on the glass surface. Beyond this range, higher energy depsotion rate would lead to surface melting associated with solidification cracks and lower energy deposition rate causes the generation of fragment cracks.

Detection of the Treponema pallidum gene and variation of treponemal DNA load before and after therapy

We explored a genetic detection method for Treponema pallidum (TP) in the peripheral blood of infected patients to compare the loads of treponemal DNA before and after therapy and to see if this new technique enabled assessment of therapeutic effect and detection of serum resistance. Polymerase chain reaction was used for a qualitative detection of TP DNA in peripheral blood and then a semiquantitative method was adopted to estimate the load of TP DNA in blood, both before and after treatment of syphilis. Among 30 untreated patients, three cases were TP DNA-positive. Among 42 treated patients with demonstrated serum resistance, three cases were TP DNA-positive. Five cases in which the rapid plasma reagin had become negative had no detectable TP DNA in their peripheral blood. The TP DNA load in blood after treatment was significantly lower than that before therapy. We conclude that the detection of TP DNA in peripheral blood of TP-infected patients is not yet sufficiently sensitive, but we observed that TP DNA load declines significantly after treatment.

An inter-subspecies cloned buffalo (Bubalus bubalis) obtained by transferring of cryopreserved embryos via somatic cell nuclear transfer

The aim of this study was to explore the feasibility of cryopreservation of inter-subspecies cloned embryos in buffalo. In our experiment, river buffalo ear fibroblast nucleus was fused into swamp buffalo oocyte cytoplasm. The blastocyst formation rate for nuclear transfer of freshly thawed cells was not different from those of growing cells, confluent or serum-starved cells. A total of 122 cloned blastocysts derived from cryopreserved fibroblasts were cryopreserved and thawed, 37 were survived, the cryosurvival rate was 30.3%. The survived blastocysts were transferred into 15 recipient buffalos. Five of the recipients established pregnancy, but four of them aborted on day 53, 59, 145 and 179 of gestation respectively. One cross-bred buffalo (Murrah × Swamp buffalo (2n = 49) received three embryos delivered a 40.5 kg female calf by natural delivery on day 320 of gestation. Up to now (13-month old), the cloned calf has been growing well with no abnormity observed. These results demonstrated that cryopreservation of inter-subspecies cloned embryos is feasible to produce buffalo offspring.

RAPD-based genetic diversities and correlation with morphological traits in Camellia (Theaceae) cultivars in China

Camellia is an economically important ornamental plant that has many uses, such as in beverages, foods and medicines. We examined 15 Camellia cultivars in Wenzhou, China, using RAPD markers and measurements of three traits (petal color, flower diameter, blooming period). PCR amplification with 15 random primers produced 1935 bands, observed at 88 amplification loci; 77% of the amplified loci were polymorphic, with a mean of 4.5 polymorphic loci per primer. The similarity coefficient ranged from 0.5419 to 0.7933 among the 15 samples; the lowest value was between Manao (C. reticulata) and Feibai FR (C. japonica), and the largest value was between Chidan (C. japonica) and Yuanyang FG (C. japonica). Cluster analysis divided the 15 cultivars into two groups at the similarity coefficient of 0.65. A correlation was found between RAPD markers and petal color in the first group. No correlation was found between RAPD markers and the other traits (flower diameter, blooming period). This study provides information useful for the identification, classification, phylogenesis, and breeding of Camellia cultivars.

Femtosecond laser induced surface nanostructuring and simultaneous crystallization of amorphous thin silicon film

Ultrafast pulsed laser irradiation is demonstrated to be able to produce surface nano-structuring and simultaneous crystallization of amorphous silicon thin film in one step laser processing. After fs laser irradiation on 80 nm-thick a-Si deposited on Corning 1737 glass substrate, the color change from light yellow to dark brown was observed on the sample surface. AFM images show that the surface nano-spike pattern was produced on amorphous-Si:H film by fs laser irradiation. Furthermore, micro-Raman results indicate that the a-Si has been crystallized into nanocrystalline Si. Also, the absorptance of the fs laser treated Si thin film was found to increase in the spectrum range of below bandgap compared to original untreated a-Si. The developed process has a potential application in fabrication of high efficiency Si thin film solar cells.

Direct patterning in sub-surface of stainless steel using laser pulses

This paper reports for the first time on the direct creating microcavities in sub-surface of stainless steel using a single Nd:YAG laser pulse. The low peak power density is used in the process, which is in the order of 1 MW/cm(2). The formation of the microcavities in the sub-surface of stainless steel is an evidence of volume expulsion during laser-metal interaction. Direct patterning in the sub-surface of stainless steel is demonstrated by realizing a series of microcavities to form a pre-designed pattern. Potential applications of sub-surface patterning in metal, such as security marking, micro-heater, micro-insulator and micro-sensor, are discussed.

Study on the inter-subspecies nuclear transfer of river buffalo somatic cell nuclei into swamp buffalo oocyte cytoplasm

The objective of this study was to explore the feasibility of inter-subspecies somatic cell nuclear transfer (SCNT) of river buffalo (50 chromosomes) somatic cell nuclei into swamp buffalo (48 chromosomes) oocyte cytoplasm. The enucleated swamp buffalo oocytes were fused with four different types of river buffalo cells: freshly thawed ear fibroblasts, serum-starved ear fibroblasts, cumulus cells and ear fibroblasts from a cloned buffalo calf. As a result, the developmental competence of embryos reconstructed with freshly thawed ear fibroblasts was the poorest (P<0.01), while those of the other three types were not different from each other. Furthermore, the efficiency of swamp-swamp buffalo, swamp-river buffalo and bovine-buffalo SCNT were also compared. The results showed that the blastocyst rate of swamp-river reconstructed embryos was not different from swamp-swamp embryos, while significantly higher than that of bovine-buffalo embryos (P<0.01). A total of thirty cloned blastocysts derived from freshly thawed ear fibroblasts were transferred into thirteen recipient buffaloes, four recipients established pregnancy, while three of them aborted on Days 65, 75 and 90 of gestation, respectively. One cross-bred buffalo (Murrah x swamp, 49 chromosomes) receiving three embryos delivered a 39 kg female calf on Day 335 of gestation. These results indicate that the inter-subspecies SCNT is feasible to produce swamp-river buffalo embryos, and these can develop to full term and result in live buffalo calves.

Cloning the swamp buffalo SRY gene for embryo sexing with multiplex-nested PCR

The polymerase chain reaction (PCR) is an efficient method for sexing embryos. The objective of this study was to develop an accurate and reliable method for sexing swamp buffalo (Bubalus bubalis) embryos. The SRY gene from swamp buffalo genomic DNA was amplified by PCR, using primers based on the sequence of the Holstein SRY gene. This fragment was sequenced based on a BLAST search; the SRY gene was highly conserved. Using a Southern blot, there was a strong signal in genomic DNA only from male swamp buffalo. Two pairs of nested primers, targeted to amplify the swamp buffalo SRY conserved region, were designed for sex identification. Simultaneously, the G3PDH gene was co-amplified to serve as an internal control. A multiplex-nested PCR system was optimized by varying the following individually: concentrations of Mg(2+) and dNTPs, ratio of concentrations of primers and numbers of cycles. Biopsies of 27 IVF-derived embryos and 24 embryos fertilized with Y-chromosome-bearing sperm were examined. Using optimized procedures, clear signals following PCR amplification were obtained from all embryo samples; PCR amplification accuracy was further verified by comparing PCR and dot blots. We concluded that this PCR technique was highly reliable for sexing swamp buffalo embryos.

Even distribution of BK polyomavirus subtypes and subgroups in the Japanese Archipelago

BK polyomavirus (BKV) is ubiquitous among humans, infecting children asymptomatically and then persisting in renal tissue. BKV has four subtypes (I-IV) that can be identified by serological and genotyping methods. Subtypes I and IV are most prevalent in all countries examined to date. Based on nucleotide sequence variation, subtype I is further classified into four subgroups (Ia, Ib-1, Ib-2 and Ic), each of which have a close relationship to a particular human population. To clarify the relationships between BKV and human populations, we investigated the distribution patterns of BKV subtypes and subgroups in the modern Japanese population, which was formed from two distinct ethnic groups. Urine samples were collected from immunocompetent elderly patients in six regions along the Japanese Archipelago. The 287-bp VP1 region of the viral genome from these samples was amplified using the polymerase chain reaction. The amplified VP1 regions were sequenced and a neighbor-joining phylogenetic tree was reconstructed to classify the BKV isolates. We observed a similar pattern of subtype distribution throughout the Japanese Archipelago, with subtype I always detected at high rates (67-75%), followed by subtype IV (19-31%), with rare or no detection of subtypes II and III. Based on phylogenetic and single nucleotide polymorphism analyses, the subtype I isolates were divided into subgroups; the percentage of the Ic subgroup was high in all geographic regions (88-100%). These results suggest that BKV subtypes and subgroups are evenly distributed in the Japanese Archipelago. We discuss the implications of these findings for the relationships between BKV and human populations.

Effect of femtosecond laser irradiation on structure of UV grade fused silica

A p-polarized femtosecond laser beam was used to irradiate a UV grade fused silica to create microchannels, which are useful for producing optical gratings or micro fluidics devices. The laser irradiated surface was characterized using optical microscope, stylus profiler, SEM, XRD and TEM. A special technique was used to protect the laser irradiated surfaces in preparing cross-sectional TEM samples. The XRD spectra and TEM observation reveal that structure of the fused silica remain amorphous after the femtosecond laser irradiation.

Quantification of thermal energy deposited in silicon by multiple femtosecond laser pulses

We report our study of deposited thermal energy in silicon induced by multiple-pulse femtosecond laser irradiation. Using infrared thermography, we quantified through in situ direct measurement of temperature fields that a significant portion of laser power (two-thirds or more) was deposited into the silicon substrate instead of being reflected or carried away with the ablated material. This is believed to be the first reported study of direct in situ measurement of temperature fields as the result of deposited thermal energy from multiple femtosecond laser pulses. Our simulation results support the measured data.

Characterisation of an isolate of Narcissus degeneration virus from Chinese narcissus (Narcissus tazetta var. chinensis)

A potyvirus from Chinese narcissus was transmitted mechanically to three species of Narcissus and to Lycoris radiata but not to 22 other test species. In western blot, the coat protein reacted strongly with Narcissus degeneration virus (UK isolate) antiserum. Antiserum raised to the Chinese virus did not react with eighteen other potyviruses. The complete nucleotide sequence (9816 nt) had the typical genome organisation for a member of the genus Potyvirus. Sequence comparisons and phylogenetic analysis showed that the Chinese virus was different from all previously sequenced potyviruses but distantly related to onion yellow dwarf and shallot yellow stripe viruses.

Subtype IV of the BK polyomavirus is prevalent in East Asia

BK polyomavirus (BKV) is ubiquitous in human populations, infecting children asymptomatically and then persisting in the kidney. Using either serological or genotyping methods, BKV isolates have been classified into four subtypes (I-IV), with subtype I mainly detected in all countries studied so far. To elucidate the subtype of BKV prevalent in East Asia, we examined BKV-positive urine samples collected from immunocompetent elderly patients in Mongolia, Northeast China, Northwest China, Southeast China, Southwest China, Vietnam and Japan. The 287-bp typing region of the viral genome in each of these samples was PCR-amplified and sequenced, and a phylogenetic tree was constructed. According to the tree, BKV isolates in East Asia were unambiguously classified into subtype I or IV (subtypes II and III were not detected). In Japan, subtype I was mainly detected and subtype IV was rare, whereas in the other regions subtype IV was detected frequently, at rates ranging from 24 to 100%. Thus, East Asia (excluding Japan) is a region in which subtype-IV BKV is prevalent, a finding that requires the view of the geographic distribution of BKV subtypes to be revised. Furthermore, we present evidence that the immunological states of urine donors do not affect the pattern of BKV subtypes.

Complete nucleotide sequence and affinities of the genomic RNA of Narcissus common latent virus (genus Carlavirus)

The complete sequence of an isolate of Narcissus common latent virus (NCLV) from Zhangzhou city, Fujian, China was determined from amplified fragments of purified viral RNA. Excluding the poly(A) tail, the genomic RNA of NCLV was 8539 nucleotides (nt) long and had the typical organization for a member of the genus Carlavirus. The most closely related species were Potato virus M, Hop latent virus and Aconitum latent virus, which had 58-59% nt identity to NCLV in their entire genomes. These relationships were confirmed by a phylogenetic analysis using a composite nucleotide alignment of all the open reading frames.

Detection and characterisation of a second potyvirus from Thunberg fritillary in China

Plants of Thunberg fritillary (Fritillaria thunbergii Miq.) from Zhejiang Province, were found to be co-infected with two distinct potyviruses. One was an isolate of the recently reported Thunberg fritillary mosaic virus (TFMV; Wei et al., (2005) Arch Virol 150: 1271-1280), while the other was a distinct virus that did not react with TFMV antiserum nor with antisera to 17 other potyviruses, except for a weak reaction with antibodies produced to soybean mosaic virus (SMV) Pinellia strain. Both viruses could be transmitted mechanically to their original host but not to any of a range of commonly used indicator plants. No local lesion host was identified that would enable the viruses to be propagated independently. The complete sequences of both viruses were determined; that of the new virus (9656 nt) had the typical genome organisation and recognised sequence motifs of a potyvirus, encoding a putative polyprotein of 351 kDa. Phylogenetic analysis, sequence comparisons, and the pattern of polyprotein cleavage sites all indicated that it was a member of the Bean common mosaic virus subgroup. The most closely related species are Soybean mosaic virus and Wisteria vein mosaic virus, with 68-69% amino acid identity between their polyproteins. This is sufficiently different for the new virus to be regarded as a distinct species, which we have tentatively named Fritillary virus Y.

Characterisation of the welsh onion isolate of Shallot yellow stripe virus from China

The host range and nucleotide sequence of shallot yellow stripe virus (SYSV) from welsh onion in Shandong province, China is described. Of the plants tested, only shallot and welsh onion became infected but most shallot plants were symptomless. The complete sequence of one isolate (10429 nt) and the 3'-terminal 3540 nts of a second isolate were determined. They had c. 90% nt identity to one another and to published (partial) sequences of SYSV. SYSV was most closely related to onion yellow dwarf virus (OYDV) and resembled it in having a much larger P3 protein than other species in the genus.

A new potyvirus from Thunberg fritillary (Fritillaria thunbergii Miq.) in Zhejiang, China

A potyvirus causing mosaic symptoms in Thunberg fritillary (Fritillaria thunbergii) was found at two sites in Zhejiang province, China. The virus was readily mechanically transmitted to its original host but not to any of 17 other widely used plant virus indicators. A polyclonal antiserum raised to purified virus particles reacted with its homologous virus but not with a range of other viruses (including 16 potyvirus species). In electron microscopy, virus particles and inclusion bodies typical of a potyvirus were seen. The complete nucleotide sequence of an isolate from Ningbo was determined. It was 9723 nt long and sequence analyses predicted the standard potyvirus organisation. The partial sequence (1664 nts at the 3'-terminus) of an isolate from Panan was also determined; the two sequences had 96.9% nt identity. In sequence comparisons and phylogenetic analyses with completely sequenced potyviruses, the new virus was most closely related to Lily mottle virus (53.0% aa identity) and Leek yellow stripe virus. The most closely related incomplete sequence in the international databases was for Lycoris mild mottle virus (72.8% nt identity in their coat proteins). These results suggest that the virus studied is a new species in the genus Potyvirus, which we have tentatively named Thunberg fritillary mosaic virus.

Enhanced human osteoblast cell adhesion and proliferation on 316 LS stainless steel by means of CO2 laser surface treatment

An effective and novel technique for improving the biocompatibility of a biograde 316 LS stainless steel through the application of CO(2) laser treatment to modify the surface properties of the material is described herein. Different surface properties, such as surface roughness, surface oxygen content, and surface energy for CO(2) laser-treated 316 LS stainless steel, untreated, and mechanically roughened samples were analyzed, and their effects on the wettability characteristics of the material were studied. It was found that modification of the wettability characteristics of the 316 LS stainless steel following CO(2) laser treatment was achieved. This improvement was identified as being mainly due to the change in the polar component of the surface energy. One-day cell adhesion tests showed that cells not only adhered and spread better, but also grew faster on the CO(2) laser-treated sample than on either the untreated or mechanically roughened sample. Further, compared with the untreated sample, MTT cell proliferation analysis revealed that the mechanically roughed surface resulted in a slight enhancement, and CO(2) laser treatment brought about a significant increase in cell proliferation. An increase in the wettability of the 316 LS stainless steel was observed to positively correlate with the cell proliferation.

Further molecular characterisation of potyviruses infecting aroid plants for medicinal use in China

Degenerate primers were used to detect and amplify 3'-terminal genome fragments of potyviruses from medicinal aroid plants growing at 16 sites in China. Virus was detected in 7 samples of which six, all of Pinellia ternata, contained a strain of soybean mosaic virus (SMV) similar to that previously reported from this host in China. The complete sequence of one isolate and the P1 protein coding region of the other isolates were also sequenced. In all cases, the P1 proteins resembled isolates of Dasheen mosaic virus (DsMV) more closely than SMV, confirming earlier suggestions of recombination in this region. In a phylogenetic analysis of SMV, DsMV and related sequences, the aroid sequences of SMV formed a distinct group which also included a sequence published as Zantedeschia symptomless virus (AF469171). One of the P. ternata samples was also infected with a second potyvirus, the 3'-terminal sequence of which was similar to DsMV and to some sequences published as Vanilla mosaic virus. The seventh infected sample was Typhonium flagelliforme and the virus from it was identified from its sequence as zantedeschia mosaic virus (ZaMV), providing the first report of this virus from mainland China.

The formation of a hydroxyl bond and the effects thereof on bone-like apatite formation on a magnesia partially stabilized zirconia (MgO-PSZ) bioceramic following CO2 laser irradiation

For the purpose of improving the bioactivity of a magnesia partially stabilized zirconia (MgO-PSZ) and to explore a new technique for inducing OH group and apatite formation, a CO(2) laser has been used to modified the surface properties. The bioactivity of the CO(2) laser modified MgO-PSZ has been investigated in stimulated human fluids (SBF) with ion concentrations almost equal to those in human blood plasma. Some hydroxyl groups were found on the MgO-PSZ following CO(2) laser treatment with selected power densities. The surface melting on the MgO-PSZ induced by CO(2) laser processing provides the Zr(4+) ion and OH(-) ion, in turn, the incorporation of the Zr(4+) ion and the OH(-) ion creates the Zr-OH group on the surface. After 14 days of SBF soaking, the apatites formed on the MgO-PSZ with relatively high amount of hydroxyl groups generated by the CO(2) laser treatment, while no apatite was observed on the untreated with few hydroxyl groups. It exhibits that the Zr-OH groups on the MgO-PSZ surface is the functional groups to facilitate the apatite formation. The increased surface roughness provides more active sites, meantime, increased surface energy benefits to the adsorption and reaction on the surface.

A new potyvirus from tuberose ( Polianthes tuberosa) in China

Tuberose plants with mild mottle symptoms, growing in a glasshouse in Hangzhou, China, contained virions and inclusion bodies typical of a potyvirus. The virus was mechanically transmitted to tuberose but not to 14 other test plant species. A fragment of 4607 nucleotides, corresponding to the 3'-half of a typical potyvirus was amplified by RT-PCR using degenerate primers and sequenced. The most similar sequence in the databases was that of Tuberose mild mosaic virus (TuMMV) from Taiwan and this was the only virus significantly related to it in phylogenetic analyses. The new sequence had 71.1% nt and 76.6% aa identity to TuMMV in the coat protein. Western blot analyses using antisera raised to expressed coat protein showed that the two viruses were serologically related. Although there are no substantial biological data to distinguish the Hangzhou isolate from TuMMV, the molecular difference between the two virus isolates is similar to, or slightly greater than, that between several pairs of well-established potyvirus species. These results therefore suggest that the Hangzhou isolate should be regarded as a new member of the genus Potyvirus, and we have tentatively named it Tuberose mild mottle virus.