Green, facile and fast synthesis of silver nanoparticles by using solution plasma techniques and their antibacterial and anticancer activities.

We herein present a simple, fast, efficient and environmentally friendly method for preparing silver nanoparticles (AgNPs) using the solution plasma method in the presence of extracts from Paramignya trimera (P. trimera). The effects of P. trimera extract concentrations and the applied voltage on the formation of AgNPs were investigated. Surface plasmon resonance spectra show a strong peak at 413 nm for the prepared samples. The Fourier-transform infrared spectroscopy measurement results indicated the presence of possible functional groups in the prepared AgNPs. Morphological analysis revealed that the AgNPs were spherical with an average size of 8 nm. The prepared AgNPs exhibited good stability in solution compared to that of AgNPs prepared by the solution plasma technique without P. trimera extract. The formation mechanism of AgNPs is also proposed. The prepared AgNPs exhibited high antibacterial ability against Gram (+) Staphylococcus aureus, Gram (-) Pseudomonas aeruginosa bacteria and strong anticancer activity for the AGS gastric cancer cell line. The obtained results demonstrated that this is a simple, rapid, environmentally friendly method for preparing AgNPs instead of conventional methods using chemical reducing agents for potential applications.

Optical properties and stability of small hollow gold nanoparticles.

In the current work, small hollow Au nanoparticles (d ≈ 16 nm) with excellent thermal stability and high photo-thermal conversion efficiency, which have great potential for use in photo-thermal cancer therapy, were prepared through galvanic replacement reaction between Ag nano-templates and gold salt. The position of surface plasmon resonance (SPR) bands for these nanoparticles could be tuned by varying the amount of gold salt. The hydrophobic hollow nanostructures were made water-dispersible by being encapsulated with poly(maleic anhydride-alt-1-octadecene) - PMAO. The obtained nanostructures were stable in an aqueous solution of NaCl with concentration up to 280 mM. The hollow gold nanoparticles (HGNPs) were then heated using an 808 nm laser at different power densities, the obtained data showed that they are highly photo-thermal stable under a high power density laser up to 1.6 W cm-2 after three circles of irradiation at 20 min per circle (20 min continuous irradiation for each circle). The facile synthesis of small size HGNPs with a plasmon peak in the near infrared range, colloidal and photo-thermal stability, and high capacity of conversion of photon energy into heat makes them a promising material for photo-thermal and imaging applications.

Tracking Objects Based on Multiple Particle Filters for Multipart Combined Moving Directions Information.

Object tracking is an important procedure in the computer vision field as it estimates the position, size, and state of an object along the video's timeline. Although many algorithms were proposed with high accuracy, object tracking in diverse contexts is still a challenging problem. The paper presents some methods to track the movement of two types of objects: arbitrary objects and humans. Both problems estimate the state density function of an object using particle filters. For the videos of a static or relatively static camera, we adjusted the state transition model by integrating the movement direction of the object. Also, we propose that partitioning the object needs tracking. To track the human, we partitioned the human into N parts and, then, tracked each part. During tracking, if a part deviated from the object, it was corrected by centering rotation, and the part was, then, combined with other parts.

Five monogenean species (Allodiscocotylidae, Heteromicrocotylidae, Microcotylidae) from the Pacific seabream Acanthopagrus pacificus (Perciformes: Sparidae) in the Gulf of Tonkin off Vietnam, with descriptions of three new species.

A total of 52 specimens of the Pacific seabream Acanthopagrus pacificus Iwatsuki, Kume et Yoshino from the Gulf of Tonkin off Vietnam were examined for monogeneans. Twenty fish were parasitised by 101 individuals of five monogenean species, including two known species Allodiscocotyla diacanthi Unnithan, 1962 and Heterapta chorinemi (Tripathi, 1956), as well as three new species, Polylabroides tienyenensis sp. n., Polylabroides tonkinensis sp. n. and Metacamopia lebedevi sp. n. Polylabroides tienyenensis and P. tonkinensis are morphologically more similar to Polylabroides guangdongensis Zhang et Yang, 2001 in comparison with other species within the genus, based on the absence of small spines on the cirrus. However, P. tonkinensis is distinguished from P. guangdongensis by fewer clamps on the haptor and by the different shapes of the large spines on the cirrus. Similarly, P. tienyenensis differs from P. guangdongensis by vaginal ducts with fewer branches, fewer clamps and smaller egg size. Metacamopia lebedevi is distinguished from Metacamopia chorinemi (Yamaguti, 1953) by the arrangement of testes (one row vs two rows), diverticula absent in the oesophagus, and the number of anchor pairs (one vs two); it differs from Metacamopia oligoplites Takemoto, Amato et Luque, 1996 by the smaller haptor, shape and absence of small sclerotised hooks, the number of ribs in their clamps, and the position of the testes; it can be separated from Metacamopia indica (Unnithan, 1962) by having fewer testes and lacking sclerotised structures in the vagina. The present study also provides the measurements for A. diacanthi, H. chorinemi, and proposes a new key to all species of Polylabroides.

In situ observation of phase transformation in iron carbide nanocrystals.

This paper reports on the in situ observation of phase transformation in an iron carbide nanocrystal encapsulated in a graphitic shell by means of high resolution transmission electron microscopy (HR-TEM). A Fe7C3 nanocrystal in orthorhombic (o-Fe7C3) structure with carbon graphitic cover is captured at the initial time of the experiment. Under the projection of a high-energy electron beam (200kV), the graphitic carbon layer evaporates gradually and structural changes in orthorhombic (o-Fe7C3) crystal manifests simultaneously. Specifically, changes in crystal direction happens first and then the crystal structure switching between orthorhombic and hexagonal (h-Fe7C3) follows. Details analysis and conclusive evidences of the phase structure and transformation are presented and discussed. The appearance of o-Fe7C3 structure is captured for about 92min over 100min of observation, indicating the preference of o-Fe7C3 form over h-Fe7C3 form.

Association of Microvascular Function and Endothelial Biomarkers With Clinical Outcome in Dengue: An Observational Study.

BACKGROUND: The hallmark of severe dengue is increased microvascular permeability, but alterations in the microcirculation and their evolution over the course of dengue are unknown. METHODS: We conducted a prospective observational study to evaluate the sublingual microcirculation using side-stream dark-field imaging in patients presenting early (<72 hours after fever onset) and patients hospitalized with warning signs or severe dengue in Vietnam. Clinical findings, microvascular function, global hemodynamics assessed with echocardiography, and serological markers of endothelial activation were determined at 4 time points. RESULTS: A total of 165 patients were enrolled. No difference was found between the microcirculatory parameters comparing dengue with other febrile illnesses. The proportion of perfused vessels (PPV) and the mean flow index (MFI) were lower in patients with dengue with plasma than those without leakage (PPV, 88.1% vs 90.6% [P = .01]; MFI, 2.1 vs 2.4 [P = .007]), most markedly during the critical phase. PPV and MFI were correlated with the endothelial activation markers vascular cell adhesion molecule 1 (P < .001 for both) and angiopoietin 2 (P < .001 for both), negatively correlated. CONCLUSIONS: Modest microcirculatory alterations occur in dengue, are associated with plasma leakage, and are correlate with molecules of endothelial activation, angiopoietin 2 and vascular cell adhesion molecule 1.

Revision of Metahaliotrema Yamaguti, 1953 (Monogenoidea: Dactylogyridae), with new and previously described species from the spotted scat Scatophagus argus (Linnaeus) (Perciformes: Scatophagidae) in Vietnam.

An emended diagnosis of Metahaliotrema Yamaguti, 1953 (Monogenoidea: Dactylogyridae) is provided based on specimens of six species collected from the spotted scat Scatophagus argus (Linnaeus) (Scatophagidae) in Vietnam: M. scatophagi Yamaguti, 1953 (type-species); M. cf. yamagutii Mizelle & Price, 1964; M. mizellei Venkatanarasaiah, 1981; M. kulkarnii Venkatanarasaiah, 1981; M. ypsilocleithrum n. sp.; and M. similis n. sp. Methaliotrema filamentosum Venkatanarasaiah, 1981 from the whipfin silver-biddy Gerres filamentosus Cuvier (Gerreidae) is included as the only other valid member of the genus. Metahaliotrema arii Yamaguti, 1953 from an ariid catfish is considered incertae sedis within the Dactylogyridae; and Metahaliotrema srivastavai Singh & Agarwal, 1994 from a bagrid catfish is transferred to Chauhanellus Bychowsky & Nagibina, 1969 as Chauhanellus srivastavai (Singh & Agarwal, 1994) n. comb. Metahaliotrema geminatohamula Pan, Ding & Zhang, 1995 from spotted scat in China is determined to be a junior subjective synonym of M. scatophagi. The two new species and M. scatophagi, M. mizellei, and M. kulkarnii are described or redescribed based on specimens from Vietnam.

Two new axinid species (Monogenea: Axinidae) from the Pharao flyingfish Cypselurus naresii (Günther) (Beloniformes: Exocoetidae) in the Gulf of Tonkin off Vietnam.

A total of 21 Pharao flyingfish Cypselurus naresii (Günther) from the Gulf of Tonkin off Vietnam was examined for monogeneans. Ten individuals were parasitised by 72 specimens of two new axinid species of two rare and little known genera, Unnithanaxine Price, 1962 containing only one species, U. parawa (Unnithan, 1957), and Loxuroides Price, 1962 containing two species, L. sasikala (Unnithan, 1957) and L. fungilliformis Zhang, Ding, Liu & Wang, 1999. Unnithanaxine naresii n. sp. and Loxuroides pricei n. sp. are described and differentiated from the related species. Unnithanaxine naresii n. sp. is morphologically similar to U. parawa but is distinguished by the size of the clamps and reproduction organs, the number of spines in the lateral groups of the genital atrium, and in parasitism in a host fish species of a different genus. Loxuroides pricei n. sp. differs from L. fungilliformis in the greater size of the body, the number of clamps, testes, spines on cirrus and genital atrium, and in parasitism in a different host family. Similarly, L. pricei can be separated from L. sasikala in having a shorter distance from the anterior extremity to genital atrium or vaginal region, fewer testes, and a slightly greater number of spines on cirrus and genital atrium.

A simple bridging flocculation assay for rapid, sensitive and stringent detection of gene specific DNA methylation.

The challenge of bringing DNA methylation biomarkers into clinic is the lack of simple methodologies as most current assays have been developed for research purposes. To address the limitations of current methods, we describe herein a novel methyl-protein domain (MBD) enrichment protocol for simple yet rapid and highly stringent selection of highly methylated DNA from limiting input samples. We then coupled this with a DNA-mediated flocculation assay for rapid and low cost naked-eye binary evaluation of highly methylated genes in cell line and blood DNA. The low resource requirements of our method may enable widespread adoption of DNA methylation-based diagnostics in clinic and may be useful for small-scale research.

Single phase Si1-xGex nanocrystals and the shifting of the E1 direct energy transition.

We report preparation and characterization of Si1-xGex alloys with varied composition x of a large range from 0-1. The materials have been obtained by co-sputtering, followed by a heat treatment process at 600, 800, and 1000 °C for 30 min in a nitrogen gas atmosphere. X-ray diffraction data have revealed the formation of single-phase nanoparticles in the face-centered cubic (FCC) structure of Si1-xGex alloys. We found that lattice constant a of the Si1-xGex alloys increased linearly with the composition parameter x. Average diameters of the single-phase nanoparticles were estimated to be between 3-10 nm. Further evidence of FCC single-phase [Formula: see text] nanoparticles has been obtained by high resolution transmission electron microscopy. From absorption spectra, the gradual shift of the direct phononless transition identified for the E1 point in the Brillouin zone of bulk Ge is observed in single-phase Si1-xGex nanoparticles as a function of the composition parameter x.

Epidemiology, clinical manifestations, and outcomes of Streptococcus suis infection in humans.

Streptococcus suis, a bacterium that affects pigs, is a neglected pathogen that causes systemic disease in humans. We conducted a systematic review and meta-analysis to summarize global estimates of the epidemiology, clinical characteristics, and outcomes of this zoonosis. We searched main literature databases for all studies through December 2012 using the search term "streptococcus suis." The prevalence of S. suis infection is highest in Asia; the primary risk factors are occupational exposure and eating of contaminated food. The pooled proportions of case-patients with pig-related occupations and history of eating high-risk food were 38.1% and 37.3%, respectively. The main clinical syndrome was meningitis (pooled rate 68.0%), followed by sepsis, arthritis, endocarditis, and endophthalmitis. The pooled case-fatality rate was 12.8%. Sequelae included hearing loss (39.1%) and vestibular dysfunction (22.7%). Our analysis identified gaps in the literature, particularly in assessing risk factors and sequelae of this infection.

Standardization of the methylation­specific PCR method for analyzing BRCA1 and ER methylation.

The significant differences in DNA methylation that are considered to be a biomarker for the diagnosis of cancer are a barrier to the application of biomarkers in the clinical field. In the present study, new primers were designed and further standard controls were set up to validate the accuracy of the methylation­specific PCR (MSP), a method widely used to analyze DNA methylation. By analyzing the methylation pattern of breast cancer 1 (BRCA1) and estrogen receptor (ER) in 60 patients with breast cancer, the number of cases of methylated BRCA1 and ER detected by the primer was 7/60 and 21/60, respectively, whereas that detected by the previous widely used primers was 25/60 and 47/60, respectively. Sequencing of the MSP products indicated that the 18 and 26 false-positive methylations of BRCA1 and ER, respectively, were due to insufficient validation of the previously used primers. Thus, the present study proposes that all studies based on the MSP approach should incorporate more controls to validate the precision of the MSP primers.

Methylation profile of BRCA1, RASSF1A and ER in Vietnamese women with ovarian cancer.

DNA methylation is considered a promising biomarkers for diagnosis of cancer in general and of ovarian cancer in particular. In our study, we validated the accuracy of methylation specific polymerase chain reaction (MSP) to analyze the methylation pattern of BRCA1, RASSF1A and ER in 59 and 10 Vietnamese patients with epithelial ovarian cancer (EOC) and benign ovarian tumors, respectively. We found methylation of BRCA1, RASSF1A and ER in 11/59 (18.6%), 40/59 (67.8%) and 15/59 (25.4%) of EOC cases, while methylation of BRCA1 was only detected in 2/10 (20%) benign ovarian patients. Forty five out of the 59 EOCs (78%) demonstrated methylation at one or more genes. The methylation frequency of RASSF1A was significantly associated with EOC (p<0.0005). No significant association was observed between methylation status of these genes and the clinical and pathological parameters of tumors collected from Vietnamese women suffering from ovarian cancer.

Straightforward procedure for laboratory production of DNA ladder.

DNA ladder is commonly used to determine the size of DNA fragments by electrophoresis in routine molecular biology laboratories. In this study, we report a new procedure to prepare a DNA ladder that consists of 10 fragments from 100 to 1000 bp. This protocol is a combination of routinely employed methods: cloning, PCR, and partial digestion with restriction enzymes. DNA fragments of 100 bp with unique restriction site at both ends were self-ligated to create a tandem repeat. Once being cloned, the tandem repeat was rapidly amplified by PCR and partially digested by restriction enzymes to produce a ladder containing multimers of the repeated DNA fragments. Our procedure for production of DNA ladder could be simple, time saving, and inexpensive in comparison with current ones widely used in most laboratories.