超连续谱激光可见谱段致人眼眩目效应研究

本文采用超连续谱激光光源滤除其红外部分仅输出可见谱段部分,在不超过国家安全标准允许的最大辐照量条件下,以正入射方式照射人眼后,记录并分析在明、暗适应条件下中心极限视力恢复时间、中心近极限视力恢复时间和视觉后像持续时间,明确超连续谱激光可见谱段对人眼的眩目效果。明适应下激光照射0.1 s导致人眼中心极限视力恢复时间为31~119 s,中心近极限视力恢复时间为19~76 s;暗适应下激光照射0.1 s导致人眼中心极限视力恢复时间为26~223 s,中心近极限视力恢复时间为13~123 s;明、暗适应下导致人眼眩目效应的最小功率密度值分别为0.055 mW/cm^2和0.005 mW/cm^2。结果表明,超连续谱激光可见谱段对人眼有良好的眩目效果,可导致数十秒至数百秒的中心视力下降,随着照射功率密度增高,眩目效应增强,显示出较好的量效关系,且相同功率密度时暗适应下人眼的眩目效果优于明适应。该研究探究了明、暗适应条件下超连续谱激光对人眼眩目效应,明确了超连续谱激光与人眼眩目的量效关系。     

Sequencing and annotated analysis of full genome of Holstein breed bull

In the present study, we describe the deep sequencing and structural analysis of the Holstein breed bull genome. Our aim was to receive a high-quality Holstein bull genome reference sequence and to describe different types of variations in its genome compared to Hereford breed as a reference. We generated four mate-paired libraries and one fragment library from 30 μg of genomic DNA. Colour space fasta were mapped and paired to the reference cow (Bos taurus) genome assembly from Oct. 2011 (Baylor 4.6.1/bosTau7). Initial sequencing resulted in the 4,864,054,296 of 50-bp reads. Average mapping efficiency was 71.7 % and altogether 3,494,534,136 reads and 157,928,163,086 bp were successfully mapped, resulting in 60 × coverage. This is the highest coverage for bovine genome published so far. Tertiary analysis found 6,362,988 SNPs in the bull’s genome, 4,045,889 heterozygous and 2,317,099 homozygous variants. Annotation revealed that 4,330,337 of all discovered SNPs were annotated in the dbSNP database (build 137) and therefore 2,032,651 SNPs were novel. Large indel variations accounted for the 245,947,845 bp of the variation in entire genome and their number was 312,879. We also found that small indels (number was 633,310) accounted for the total variation of 2,542,552 nucleotides in the genome. Only 106,768 small indels were listed in the dbSNP. Finally, we identified 2,758 inversions in the genome of the bull covering in total 23,099,054 bp of genome’s variation. The largest inversion was 87,440 bp in size. In conclusion, the present study discovered different types of novel variants in bull’s genome after high-coverage sequencing. Better knowledge of the functions of these variations is needed.     

Dose distribution comparison in volumetric-modulated arc therapy plans for head and neck cancers with and without an external body contour extended technique

AimThis study compared volumetric-modulated arc therapy (VMAT) plans for head and neck cancers with and without an external body contour extended technique (EBCT).BackgroundDose calculation algorisms for VMAT have limitations in the buildup region.Materials and methodsThree VMAT plans were enrolled, with one case having a metal artifact from an artificial tooth. The proper dose was calculated using Eclipse version 11.0. The body contours were extended 2 cm outward from the skin surface in three-dimensional space, and the dose was recalculated with an anisotropic analytical algorithm (AAA) and Acuros XB (AXB). Monitor units (MUs) were set, and the dose distributions in the planning target volume (PTV), clinical target volume, and organ at risk (OAR) and conformity index (CI) with and without an EBCT were compared. The influence of a metal artifact outside of the thermoplastic head mask was also compared.ResultsThe coverage of PTV by the 95% dose line near the patient’s skin was increased drastically by using an EBCT. Plan renormalization had a negligible impact on MUs and doses delivered to OARs. CI of PTV with a 6-MV photon beam was closer to 1 than that with a 10-MV photon beam when both AAA and AXB were used in all cases. Metal artifacts outside the head mask had no effect on dose distribution.ConclusionsAn EBCT is needed to estimate the proper dose at object volumes near the patient’s skin and can improve the accuracy of the calculated dose at target volumes.     

Effect of ionic strength, serum albumin and other macromolecules on the maintenance of motility and the surface of mammalian spermatozoa in a simple medium

The seminal plasma in sperm suspensions from boar, bull, rabbit, ram and stallion was replaced with simple defined media as completely as possible by a combination of centrifugation through Ficoll and dilution. After this process, motility declined and the cells showed a tendency to agglutinate and/or stick to glass. Varying the ionic strength of the medium had little effect upon these parameters but sperm motility was preserved better in the presence of serum albumin. When a number of purified proteins and other macromolecules were tested individually in this way for their motility-preserving ability, bovine or human serum albumin was consistently the most effective. Defatting the albumin or altering its nature by mild reduction, oxidation or alkylation had little detectable effect on its motility-preserving ability; the protein did not appear to be acting as a chelator of metal ions, for it could not be replaced by EDTA. The response of the spermatozoa to replacemrnt of seminal plasma varied between species: bull spermatozoa were particularly sensitive and serum albumin had little effect upon their subsequent motility.     

Resonant TE Transmission Through a Continuous Metal Film: Perspectives for Low-Loss Plasmonic Elements

Whereas resonant transverse magnetic transmission across an undulated continuous metal film is achieved with the mediation of plasmon modes excited by the undulation, it is shown here that transverse electric (TE) resonant transmission through a continuous metal film can also be achieved with the mediation of the second-order TE₁ mode of a dielectric slab waveguide having the metal film sandwiched at its middle. The demonstration is made by using the materials currently used in the domain of optical security and counterfeit deterrence: ZnS is shown to possibly be a lossless interface/adhesion layer between a polymer and a noble metal for plasmonic resonant elements.     

Thymic Hyperplasia and Graves Disease: Management of Anterior Mediastinal Masses in Patients with Graves Disease

ObjectiveTo describe a case of an anterior mediastinal mass (AMM) in a patient with Graves disease.MethodsWe report the clinical presentation, diagnosis, management, and outcome of a 34-year-old man with dyspnea on exertion.ResultsInitial evaluation of the patient’s complaints revealed a large AMM on chest radiography and then chest computed tomography. After occurrence of additional symptoms, the patient was diagnosed as having Graves disease and treated with antithyroid medications. Despite an appropriate biochemical response, he continued to experience severe dyspnea on exertion. A repeated computed tomographic scan 8 weeks after initiation of therapy showed no appreciable decrease in size of the AMM. He elected to undergo thymectomy. An intraoperative phrenic nerve injury resulted in a paralyzed left hemidiaphragm, leaving the patient with considerable difficulties in his career and profoundly decreased exercise tolerance.ConclusionThe differential diagnosis of an AMM includes several malignant lesions with a risk often warranting early surgical excision. In light of the association of benign thymic hyperplasia with Graves disease, thymectomy may be delayed in expectation of thymic regression with medical therapy. The timing of regression is variable, and very few reports exist in the literature. In our current case, the patient opted for thymectomy relatively early and had an unfortunate complication. The lack of clinical evidence regarding management of an enlarged thymus in patients with Graves disease, however, makes management decisions more difficult. (Endocr Pract. 2009;15: 534-539)     

Maternity validation using sire‐only BovineSNP50 BeadChip data

Based on pairwise identity‐by‐state (IBS) distances and whole‐genome SNP data, kinship was investigated in the Israeli Holstein population. A total of 789 bulls, including most of the artificial insemination sires in service since 1987, were genotyped by the BovineSNP50 BeadChip. This sample included up to five generations. For each bull‐by‐bull combination, three states are possible for each marker: no match, a single match and both alleles match. Summing over all markers, the 932 598 IBS scores (three match frequencies*310 866 bull‐by‐bull combinations) were visualized using three‐dimensional coordinates that corresponded to the frequencies of the three possible states. Results were reduced to two dimensions using the transformations x’ = 0.7071(1 + freq1?freq2) and y’ = 1.2247freq0. Bull‐by‐bull pairs were grouped according to their level of kinship, and canonical scores were calculated using discriminant analysis and the x’ and y’ features. Of the 474 pairs of recorded maternal grandsire–grandson with both individuals genotyped, the probability for 28 pairs to belong to this level of kinship was low (P < 0.05), suggesting an error rate of around 3% per generation in pedigree determination.     

Sperm nuclei analysis of 1/29 Robertsonian translocation carrier bulls using fluorescence in situ hybridization

In 1964, Gustavsson and Rockborn first described the 1/29 Robertsonian translocation in cattle. Since then, several studies have demonstrated the negative effect of this particular chromosomal rearrangement on the fertility of carrier animals. During the last decade, meiotic segregation patterns have been studied on human males carrying balanced translocations using FISH on decondensed sperm nuclei. In this work, we have applied the 'Sperm-FISH' technique to determine the chromosomal content of spermatozoa from two bulls heterozygous for the 1/29 translocation and one normal bull (control). 5425 and 2702 sperm nuclei were scored, respectively, for the two heterozygous bulls, using whole chromosome painting probes of chromosomes 1 and 29. Very similar proportions of normal (or balanced) spermatozoa resulting from alternate segregation were observed (97.42% and 96.78%). For both heterozygous bulls, the proportions of nullisomic and disomic spermatozoa did not follow the theoretical 1:1 ratio. Indeed, proportions of nullisomic spermatozoa were higher than those of disomic sperma tozoa (1.40% vs 0.09% (bull 1) and 1.29% vs 0.15% (bull 2) for BTA1, and 0.65% vs 0.40% (bull 1) and 1.11% vs 0.63% (bull 2) for BTA29). The average frequencies of disomic and diploid spermatozoa in the normal bull were 0.11% and 0.05%, respectively.     

Individual identification of Chinese Holstein Bull by 10 STR loci

With the premium bull plays a growing important role in cattle industry, semen detection technology based on individual identification and phylogenetic relationship is paid more and more attention. In order to lay the foundation for the establishment of the China Holstein bull identification method, this research takes 20 Chinese Holstein dairy bull’s blood and their corresponding semen, and then extracts the DNA both from the blood and semen, analysis the genetic polymorphisms of 10 microsatellite loci (TGLA227, INRA23, TGLA122, BM2113, SPS115, ETH3, ETH225, MCM158, MAF45 and UMN0108) by microsatellite marker, discuss the feasibility of this method used to individual identification. The results showed that Chinese Holstein dairy bull genetic diversity in the ten microsatellite loci were both high, and the average polymorphic information content of TGLA227, which highest, is 0.8162, ETH225 has the lowest, which is 0.6224. Use STR loci to identify the bull’s semen, the cumulative individual identification capacity is 99.99 %, which indication that 10 STR loci can be used to the frozen semen quality test and cows individual identification.     

Comparative x-ray diffraction study of the crystalline lens in a number of vertebrates including man

X-ray diffraction method has been applied for comparative investigation of native structure of eye lens proteins (crystallins). X-ray diffraction patterns of the whole lenses and/or their nuclear parts were obtained for man and vertebrate animals. Crystalline lenses of the fishes Acerina cernua and Pelmatochromis kribensis, frog Rana temporaria, bull and man contain crystallins with a very similar secondary and tertiary structure, whereas lenses of chicks and the tortoise Testudo horsfieldi contain mainly crystallins with other structure. The results obtained reveal evolutionary conservatism of crystallin structure in fishes, amphibians and mammals. It was also concluded that there is no correlation between crystallin structure of the lens, elasticity of the latter and accommodation mechanism.     

Combined use of eBeam irradiation and the potential probiotic Lactobacillus rhamnosus Vahe for control of foodborne pathogen Klebsiella pneumoniae

The implementation of electron beam radiation coupled with the use of probiotics is one of the newest food processing technologies that may be used to ensure food safety and improve shelf life of food products. The purpose of this study was to evaluate the effect of 50–150-Gy electron beam irradiation on the antimicrobial activity of the putative probiotic strain Lactobacillus rhamnosus Vahe. Low-dose electron beam irradiation of lactobacilli cells was performed using the Advanced Research Electron Accelerator Laboratory’s electron accelerator, and the agar well diffusion method and Verhulst logistic function were used to evaluate the effect of radiation on anti–Klebsiella pneumoniae activity of the cell free supernatant of L. rhamnosus Vahe cells in vitro. Our results suggest that 50–150-Gy electron beam irradiation decreases the viability of the investigated lactobacilli, but does not significantly change the probiotic’s activity against K. pneumoniae. Results indicate that the combined use of irradiation and L. rhamnosus Vahe might be suggested for non-thermal food sterilizing technologies.     

Acidic residues and a predicted,highly conserved α‐helix are critical for the endonuclease/strand separation functions of bacteriophage λ’s TerL

Complementation, endonuclease, strand separation, and packaging assays using mutant TerL^λ’s, coupled with bioinformatic information and modeling of its endonuclease, identified five residues, D401, E408, D465, E563, and E586, as critical acidic residues of TerL^λ’s endonuclease. Studies of phage and viral TerL nucleases indicate acidic residues participate in metal ion‐binding, part of a two‐ion metal catalysis mechanism, where metal ion A activates a water for DNA backbone hydrolysis. Modeling places D401, D465, and E586 in locations analogous to those of the metal‐binding residues of many phage and viral TerLs. Our work leads to a model of TerL^λ’s endonuclease domain where at least three acidic residues from a ~185 residue segment (D401 to E586) are near each other in the structure, forming the endonuclease catalytic center at cosN, the nicking site. DNA interactions required to bring the rotationally symmetric cosN precisely to the catalytic center are proposed to rely on an ~60 residue region that includes a conserved α‐helix for dimerization. Metal ion A, positioned by TerL^λ’s acidic D401 and E586, would be placed at cosN for water activation, ensuring high accuracy for DNA backbone hydrolysis.     

Consistency of mate choice in eye and hair colour: Testing possible mechanisms

Partner preferences are formed by several mechanisms, including an imprinting-like effect (parent-similarity) and homogamy (self-similarity). It is still unknown, however, whether these preferences remain stable throughout an individual’s lifetime. We have therefore tested the consistency of mate choice in eye and hair colour both in a shortand long-term context. In other words, we tested whether people systematically choose partners with a particular eye and hair colour. We asked 1,048 respondents to indicate the eye and hair colour of themselves, their opposite-sex and same-sex parent, and all the romantic partners they had in their lives. Our results show that people consistently choose partners of a particular eye and hair colour in both short- and long-term contexts, which suggests that people do have their ‘types’. Nevertheless, the consistency was significantly higher in a long-term context than in a short-term context. Furthermore, the eye colour of one's partner was predicted by the eye colour of one's opposite-sex as well as same-sex parent, but the strongest parental effect was found when both parents had same eye colour. There were no significant results for hair colour. Our results thus suggest that preferences for eye colour are determined by the imprinting-like effect rather than by homogamy, and that they remain stable over time. These findings also indirectly support an assumption of stability of this imprinting-like effect in humans, since people consistently choose partners with their opposite-sex parent's eye-colour.     

Modification of a laser-based flow cytometer for high-resolution DNA analysis of mammalian spermatozoa

Modification of a Coulter EPICS V orthogonal laser-based flow cytometer/cell sorter allows resolution of X and Y mammalian sperm populations based on DNA content. The modification consists of beveling the sample injection tube situated in the flow chamber, adding a second fluorescence detector directly forward along the laser beam axis, and routing the collected fluorescence through an optical fiber bundle to one of the existing photomultiplier tubes. The X and Y chromosome-bearing spermatozoa from the bull, boar, and ram can be resolved using this system.     

Laser light-scattering studies of bull spermatozoa. I. Orientational effects.

Calculations based on the known dimensions of bull spermatozoa show that the scattered light intensity is strongly dependent upon the relative orientation of the particle to the incident beam. The magnitude of this effect of apparently much greater than for other systems where motility has been investigated by dynamic light scattering. The calculations show that the scattering source can be approximated by a small spinning mirror, and consequently the greatest light intensity at the detector results from cells swimming in a direction perpendicular to the scattering vector. The calculations are in substantial agreement with photographic observations, as well as direct measurements of the scattered intensity. Previous treatments of dynamic light scattering from swimming bull spermatozoa based on point scattering models are shown to be incorrect.     

Enzymatic unpacking of bull sperm chromatin.

When isolated bull sperm chromatin is incubated with 0.1 M 2-mercaptoethanol at pH 8, an extensive proteolytic degradation of sperm histone occurs, being accompanied by a marked swelling of the chromatin masses. The degradation of sperm histone is strongly inhibited by monovalent or divalent metal ions. The protease found in isolated bull sperm chromatin possesses properties indistinguishable from those of an acrosomal protease of trypsin-type, acrosin (EC 3.4.21.10), and requires a combination of NaCl, urea and 2-mercaptoethanol for its extraction. Evidence suggests that the protease travels along chromatin strands and hydrolyzes essentially all the sperm histone molecules within the chromatin masses.     

Two Genomic Loci Control Three Eye Colors in the Domestic Pigeon (Columba livia)

The iris of the eye shows striking color variation across vertebrate species, and may play important roles in crypsis and communication. The domestic pigeon (Columba livia) has three common iris colors, orange, pearl (white), and bull (dark brown), segregating in a single species, thereby providing a unique opportunity to identify the genetic basis of iris coloration. We used comparative genomics and genetic mapping in laboratory crosses to identify two candidate genes that control variation in iris color in domestic pigeons. We identified a nonsense mutation in the solute carrier SLC2A11B that is shared among all pigeons with pearl eye color, and a locus associated with bull eye color that includes EDNRB2, a gene involved in neural crest migration and pigment development. However, bull eye is likely controlled by a heterogeneous collection of alleles across pigeon breeds. We also found that the EDNRB2 region is associated with regionalized plumage depigmentation (piebalding). Our study identifies two candidate genes for eye colors variation, and establishes a genetic link between iris and plumage color, two traits that vary widely in the evolution of birds and other vertebrates.