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Melioidosis is a fatal infectious disease in the tropics and subtropics. Currently, bacterial culture is the gold standard for diagnosis of the disease, but its sensitivity is relatively low. In this study, we evaluated four ELISAs using sera collected from culture-confirmed cases of melioidosis (n = 63), cases with other bacterial infections (n = 62), and healthy donors (n = 60). Antigens used for ELISAs were the whole-cell (WC) antigens and recombinant proteins of hemolysis co-regulated protein 1 (Hcp1), chaperonin GroEL1, and alkyl hydroperoxide reductase subunit C (AhpC). Using the cutoff values for optical density at 490 nm defined at a specificity of > 95%, the sensitivity of the WC, Hcp1, GroEL1, and AhpC ELISAs was 93.7%, 87.3%, 61.9%, and 57.1%, respectively. The combined WC/Hcp1 ELISA showed the greatest sensitivity and specificity of 98.4% and 95.1%, respectively. Of 511 and 500 sera collected from clinically suspected febrile patients admitted to the General Hospital of Ha Tinh Province and the Hue Central Hospital, respectively, combined WC/Hcp1 ELISAs showed 52 (10.2%) and 41 (8.2%) patients positive for melioidosis, respectively. The assay detected 14 of 14 (100%) and 21 of 23 (91.3%) culture-confirmed cases of melioidosis at Ha Tinh and Hue, respectively. A follow-up study of 38 patients positive for melioidosis by combined WC/Hcp1 ELISAs but negative for Burkholderia pseudomallei by culture method or not assigned to examine for bacterial culture resulted in 2 (5.3%) culture-reconfirmed patients with melioidosis, 9 (23.7%) deaths, 17 (44.7%) unhealthy patients, and 10 (26.3%) healthy persons. Combined WC/Hcp1 ELISA was a reliable serological method to detect underdiagnosed cases of melioidosis. Further investigations are needed to estimate the true sensitivity and specificity of the assay and the true number of cases of melioidosis.

Morphological data and the first molecular data are provided for four species of the trematode family Bucephalidae Poche, 1907 from marine and freshwater teleost fish species of East Asia. A new species, Rhipidocotyle husi n. sp., was isolated from Huso dauricus from the Amur River, Russia. Adult worms of this species were distinguished from their congeners Rhipidocotyle illense and Rhipidocotyle kovalai by morphological analysis. Three other known species were identified: Bucephalus skrjabini and Prosorhynchus cf. squamatus were detected in Siniperca chuatsi from the Amur River and in Myoxocephalus spp. from the Okhotsk Sea, Russia, respectively, while Prosorynchoides karvei was extracted from Strongylura strongylura from Halong Bay, Vietnam. The 28S ribosomal DNA (rDNA)-based phylogenetic analysis showed that the new species formed a shared polytomy clade with Rhipidocotyle fennica. Phylogenetic analysis of all available molecular data showed that four genera, namely Rhipidocotyle, Bucephalus, Prosorynchoides and Prosorhynchus, are para- or polyphyletic. Molecular-based phylogenetic analysis of morphologically validated bucephalid species indicated that three genera – Rhipidocotyle, Bucephalus and Prosorynchoides – were monophyletic. The genus Prosorhynchus maintained paraphyly, and P. cf. squamatus was more closely related to Dollfustrema spp. than to other Prosorhynchus spp. These findings do not exclude the possibility that representatives of Dollfustrema and P. cf. squamatus belong to the same genus.

Intraspecific variation of Parasaccocoelium mugili collected from mullet fish of the south of Russian Far East and Vietnam has previously been estimated on the basis of two molecular markers: ribosomal internal transcribed spacer 1 (ITS1) rDNA and mitochondrial cytochrome oxidase I (COI) gene sequences. In the present study, molecular identification of this species from the Kievka River, Primorye and from Vietnam was performed by analysis of 28S rDNA sequences. Analysis of ITS1 rDNA sequences variation revealed two highly differentiated main groups, representing trematode specimens from the two regions. Genetic variation within each region was relatively low. Mitochondrial COI gene sequence data analysis revealed fixed nucleotide and amino acid substitutions, and supported the existence of two genetically different groups associated with geographical origin. Analysis of the COI gene fragments showed extremely high variation within Russian and Vietnamese P. mugili samples. Our results for P. mugili most probably represent a case of initial step of allopotric speciation for this trematode, caused by living strategy of its definitive host at evolutionary scale. Mitochondrial DNA sequence data show that existence of gene flow between local populations of P. mugili in the Primorye Region caused by definitive hosts can be proposed.

In this paper, we present a real-time hardware implementation of spectrum sensing based energy detection (SS-ED) with reception diversity techniques. The paper mainly focused on selection combining (SC) and equal gain combining (EGC) to improve the probability of detection for spectrum sensing purpose in cognitive radio network (CRN). The performance of system is evaluated in real-time over Rayleigh environment based FPGA (field programmable gate array) platform. The DVB-T (digital video broadcasting - terrestrial) signal in 2k mode is considered as primary signal as specified in IEEE 802.22 WRAN (wireless regional area network) draft standard for re-using the very high frequency and ultra high frequency bands. The empirical results showed that performances of SS-ED with reception diversity techniques enhanced significantly, and they also matched with theoretical analysis. Therefore, these techniques should be utilized to overcome disadvantage of ED over Rayleigh fading channel.

Spectrum sensing (SS) plays a significant role in cognitive radio network. In our work, we focused on FPGA (Field Programmable Gate Array) implementation of SS applying for DVB-T (Digital Video Broadcasting - Terrestrial) signal detection because TV band has been considered for the operation of cognitive users (unlicensed users) by Federal Communications Commission (FCC). The OFDM signal (Orthogonal Frequency Division Multiplexing) - 1024 subcarriers in 2k mode of DVB-T system is considered as primary transmitter as specified in IEEE 802.22 WRAN standard for reusing the TV frequency band. The system is synthesized and implemented on Stratix II EP2S180 board. The fixed point 32 bits (fraction: 22.10) is chosen for calculation in FPGA model. Numerical results showed that detection effectiveness of ED based on FPGA platform matched well with theoretical analyses. They also indicated that system performances degraded dramatically in Rayleigh fading environment. Thus, longer sensing time should be considered and and higher probability of false alarm should be accepted to improve sensing efficiency in fading condition.

In cognitive radio network (CR), spectrum sensing (SS) is regarded as a critical component. Several local SS schemes have been studied well in the literature to locate spectrum holes for reusing it. However, the system's performance will be degraded seriously over the fading environment. The cooperative spectrum sensing techniques were proposed to improve performances of signal sensing. In this paper, we mainly focus on the close form mathematical expressions and present simulation comparisons of cooperative SS based soft decision (Selection Combining - SC, Equal Gain Combining - EGC) and hard decision (k-out-of-n, OR, AND, and MAJORITY rule). The numerical results shown that the performance of cooperative SS were improved significantly and matched well with the theory analysis.

The phenylhydrazone of 2-tetralone was dilithiated with excess lithium diisopropylamide followed by condensation with several aromatic esters, and the resulting intermediates were acid cyclized to 4,5-dihydro-2H-benz[e]indazoles.

The phenylhydrazone of 2-tetralone was dilithiated with excess lithium diisopropylamide followed by condensation with several aromatic esters, and the resulting intermediates were acid cyclized to 4,5-dihydro-2H-benz[e]indazoles.