激光多普勒振动计用于水下声光通信

介绍了激光多普勒振动计(LDV)用于水下声光通信的应用背景,阐述了激光多普勒振动计的工作原理和两种相干检测方式。采用零差的相干探测方式,设计并实现了一套光纤结构的激光多普勒振动计。为了证明系统能够应用于水下声光通信,进行了对水下声源发出的声波频率和强度的探测实验。通过对实验数据的分析得出：第一,系统能够检测出水下声源发出的声波频率,对7 kHz附近的10个声波频率的测量标准偏差小于8 Hz; 第二,系统探测信号强度与水下声源发声的声压级成指数关系,对于水下目标通信所用的3.5 kHz和7 kHz声波频段的

Direct detection of Yersinia pestis from the infected animal specimens by a fiber optic biosensor

The FOB-3, anew type fiber optic biosensor, is designed to rapidly detect a variety of biological agents or analytes with better stability, sensitivity and specificity. In order to detect Y. Pestis, a sandwich immunoassay was developed by using the purified antibody against antigen FI immobilized on polystyrene probes as the capture antibody and the monoclonal antibody-Cy5 conjugate as the detector. After a series of optimization for the stability, sensitivity and specificity of the FOB-3, 50-1000 ng/ml of antigen FI and 6 x 10(1)-6 x 10(7) CFU/ml Y. pestis could be detected constantly in about 20 min, and Y pestis could be detected specifically from Y. pseudotuberculosis, Y. enterocolitica, B. anthracis and E. coli. Then, 39 blind samples, including 27 tissues of mice infected with Y pestis and 12 tissues of healthy mice as negative control, were detected with the FOB-3. 92.6% infected tissues were identified from the tissues of healthy mice and the tissues containing more than 100 CFU/ml bacteria could be detected by the biosensor. The results demonstrated the feasibility of the FOB-3 as an effective method to detect Y. pestis rapidly and directly from the infected animal specimens with the advantage of portability, simple-operation as well as high sensitivity and specificity. (c) 2006 Elsevier B.V. All rights reserved.

Studies of magnetic interactions in Mn-doped β-Ga2O3 from first-principles calculations

The magnetic behavior of Mn-doped beta-Ga2O3 is Studied from first-principles calculations within the generalized gradient approximation method. Calculations show that ferromagnetic ordering is always favorable for configurations in which two Mn ions substitute either tetrahedral or octahedral sites, and the ferromagnetic ground state is also sometimes favorable for configurations where one Mn ion substitutes a tetrahedral site and another Mn ion substitutes an octahedral site. However, the configurations of the latter case are less stable than those of the former. (c) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Studies of magnetic interactions in Ni-doped ZnO from first-principles calculations

The magnetic interactions in Ni-doped ZnO are calculated using GGA and GGA + U method of density functional theory. The following three cases: (i) Ni-doped ZnO, (ii) (Ni, Al)-codoped ZnO, and (iii) (Ni, Li)-codoped ZnO are studied. The ferromagnetic ordering is always favorable for the three cases within GGA method. However, the ferromagnetic state is sometimes favorable after treating within the method of GGA + U. The GGA underestimates the correlated interactions especially when the Ni ions align directly to each other. (C) 2007 Elsevier B.V. All rights reserved.

First-principles study of the electronic structures and absorption spectra for the PbMoO4 crystal with lead vacancy

The electronic structures and absorption spectra for the perfect PbMoO4 crystal and the crystal containing lead vacancy V-Pb(2-) with lattice structure optimized are calculated using density functional theory code CASTEP. The calculated absorption spectra of the PbMoO4 crystal containing V-Pb(2-) exhibit three absorption bands peaking at 2.0 eV (620 nm), 3.0 eV (413 run) and 3.3 eV (375 nm), which are in good agreement with experimental values. The theory predicts that the 390 nm, 430 nm and 580 run absorption bands are related to the existence of V-Pb(2-) in the PbMoO4 crystal.

First-principles calculations of electronic structures and absorption spectra of YAlO3 crystals with F center

National Nature Science Foundation of China (Grant No. 60607015)

The first report of kininogen from invertebrates

The hornet possesses highly toxic venom, which is rich in toxin, enzymes, and biologically active peptides. Several bradykinin-like peptides, vespakinins, have been found in wasp venoms since 1970s, but the mode of biosynthesis of these peptides is unknow

The first antimicrobial peptide from sea amphibian

The crab-eating frog, Rana cancrivora, is one of only a handful of amphibians worldwide that tolerates saline waters. It typically inhabits brackish water of mangrove forests of Southeast Asia. A large amount of antimicrobial peptides belonging to different families have been identified from skins of amphibians inhabiting freshwater. No antimicrobial peptide from sea amphibians has been reported. In this paper, we firstly reported the antimicrobial peptide and its cDNA cloning from skin secretions of the crab-eating frog R. cancrivora. The antimicrobial peptide was named cancrin with an amino acid sequence of GSAQPYKQLHKVVNWDPYG. By BLAST search, cancrin had no significant similarity to any known peptides. The cDNA encoding cancrin was cloned from the cDNA library of the skin of R. cancrivora. The cancrin precursor is composed of 68 amino acid residues including a signal peptide, acidic spacer peptide, which are similar to other antimicrobial peptide precursors from Ranid amphibians and mature cancrin. The overall structure is similar to other amphibian antimicrobial peptide precursors although mature cancrin is different from known peptides. The current results reported a new family of amphibian antimicrobial peptide and the first antimicrobial peptide from sea amphibian. (c) 2007 Elsevier Ltd. All rights reserved.

The First Gene-encoded Amphibian Neurotoxin

Many gene-encoded neurotoxins with various functions have been discovered in fish, reptiles, and mammals. A novel 60-residue neurotoxin peptide (anntoxin) that inhibited tetrodotoxin-sensitive (TTX-S) voltage-gated sodium channel (VGSC) was purified and c

Cloning and characterization of the first amphibian bradykinin gene

More than ten bradykinin-related peptides and their cDNAs; have been identified from amphibians, but their genes are unknown. In present study, four cDNAs encoding one, two, four and six copies of bradykinin-related peptides were cloned from the frog (Odorrana grahami) skin cDNA library, respectively. Three bradykinin-related peptides (bradykinin, Thr6-bradykinin, Leu5Thr6-bradykinin) were deduced from these four cDNA sequences. Based on the cDNA sequence, the gene sequence encoding an amphibian bradykinin-related peptide from O. grahami was determined. It is composed of 7481 base pairs including two exons and two introns. The first exon codes signal peptide and the second exon codes acidic spacer peptide and Thr6-bradykinin. The promoter region of the bradykinin gene contains several putative recognition sites for nuclear factors, such as SRY, GATA-1, LYF-1, DeltaE, CDXA, NKX-2.5, MIF1 and S8. The current work may facilitate to understand the regulation and possible functions of amphibian skin bradykinin-related peptides. (C) 2009 Elsevier Masson SAS. All rights reserved.

Mitochondrial DNA Haplogroups M7b1 ' 2 and M8a Affect Clinical Expression of Leber Hereditary Optic Neuropathy in Chinese Families with the m.11778G -> A Mutation

Leber hereditary optic neuropathy (LHON) is the most extensively studied mitochondrial disease, with the majority of the cases being caused by one of three primary mitochondrial DNA (mtDNA) mutations. Incomplete disease penetrance and gender bias are two

Molecular characterization of six Chinese families with m.3460G > A and Leber hereditary optic neuropathy

The primary mutation m.3460G > A occurs with a very low frequency (similar to 1%) in Chinese patients with Leber hereditary optic neuropathy (LHON). Up to now, there is no comprehensive study of Chinese patients harboring this mutation. We characterized six unrelated probands with m.3460G > A in this study, which were identified from 1,626 patients with LHON or suspected with LHON. The overall penetrance of LHON (25.6% [10/39]) in four pedigrees with m.3460G > A was substantially lower than those families with m.11778G > A (33.3% [619/1859]) as reported in our previous study. Intriguingly, family Le688 with a heteroplasmic m.3460G > A presented a lower penetrance (12.5%) than the other three families with a homoplasmic mutation. There is an elevated gender bias (affected male to affected female = 4:1) in the four families with m.3460G > A compared to those LHON families with m.11778G > A (2.4:1). Complete mtDNA sequencing indicated that the six matrilines belonged to haplogroups B4d1, F2, A5b, M12a, D4b2b, and D4b2, respectively. We did not identify any potential secondary mutation(s) that will affect or be associated with the penetrance of LHON in the six probands by using an evolutionary analysis and protein secondary-structure prediction. Taken together, our results suggested that the m.3460G > A mutation occurred multiple times in Chinese LHON patients. The heteroplasmic status of mutation m.3460G > A might influence the penetrance of LHON in family Le688.