[Clinical analysis of 4 cases of acute nitrite food poisoning].

Nitrite has high toxicity and is commonly found in food poisoning. Poisoned patients may experience cyanosis of the skin and lips, nausea, vomiting, and difficulty breathing or coma may occur in severe cases. Four cases of nitrite poisoning patients who were transferred from primary hospitals to the Third Affiliated Hospital of Gansu University of Chinese Medicine, the First People's Hospital of Baiyin were reported. After symptomatic supportive treatment with special antidote methylene blue, oxygen inhalation, blood purification, etc., the patients recovered and were discharged after 4 days of treatment.

[Report on a case of significant increase in urine mercury due to excessive mercury in cosmetics].

Mercury is highly toxic and can be absorbed through skin contact. From December 5, 2020 to February 16, 2021, occupational disease laboratory of the First People's Hospital of Baiyin received 30 urine mercury test samples from a beauty salon in Lanzhou City. The test results showed that 28 samples exceeded the normal value (normal value: 4 µg/g Cr) . 15 patients were treated with sodium dimertopropyl sulfonate for mercury removal and tiopron for liver protection, and the prognosis was good.

[Study of local application of CpG-oligodeoxynucleotide combined with 4-1BB monoclonal antibody to treat hepatoma- bearing mice].

Objective: To investigate the curative effect of local application of CpG-oligodeoxynucleotide (CpG-ODN) combined with 4-1BB monoclonal antibody in hepatoma-bearing mice, and to evaluate the effect of 4-1BB monoclonal antibody on CpG-ODN immunotherapy. Methods: H22 single cell suspension was injected subcutaneously into the axilla and four limbs of the BALB/c male mice to establish a tumor-bearing mice model. After 7 days, 30 mice with corresponding tumor-bearing volume were screened and randomly divided into model control group, CpG group and CpG+4-1BB group, and the drug was injected into the tumors of left lower extremity. The same batch of normal mice was selected as normal control group. Survival of mice was recorded. Tumor-bearing volume and organ index were calculated. Serum levels of interleukin (IL) - 12 and interferon (IFN) gamma and spleen CD8(+)T lymphocyte ratio were measured. The measurement data were analyzed by analysis of variance. The survival rate of each group of mice was analyzed by log-rank test. Results: Mice in the model control group with tumor-bearing volume had a sustained growth before the execution. CpG group and the CpG+4-1BB group [(976.08 ± 29.55) mm(3), (47.25 ± 0.93) mm(3))] tumor-bearing volume was decreased than model group [(1 336.52 ± 39.40) mm3] (F = 5 329.273, P < 0.05). CpG+4-1BB group distant tumor-bearing volume [(611.83 ± 113.02) mm3] was decreased than model group and CpG group [(1 406.62 ± 51.09) mm(3), (1 380.01 ± 51.44) mm3] (F = 247.160, P < 0.05), but there was no significant difference between the CpG group and the model group (P > 0.05). Serum IL-12 concentration (23.90 ± 2.33 pg/ml), IFN-γ concentration (103.02 ± 6.10 pg/ml) and spleen CD8(+)T cell ratio (4.54 ± 0.62%) in the model group were lower than those in the normal group (P < 0.05). Serum IL-12 concentration in CpG group and CpG+4-1BB group (29.21 ± 2.23 pg/ml, 37.04 ± 1.49 pg/ml), IFN-γ concentration (116.12 ± 4.08 pg/ml, 138.65 ± 1.72 pg/ml), CD8(+)T cell ratio (6.65 ± 0.64%, 12.73 ± 0.88%) were higher than the model group, while CpG+4-1BB group was higher than the CpG group (P < 0.05). The survival rate of CpG+4-1BB group was higher than that of model group and CpG group (χ(2) = 25.544, P < 0.05), but there was no significant difference between CpG group and model group (P > 0.05). There was no significant difference in organ index between the four groups (P > 0.05). Conclusion: 4-1BB monoclonal antibody combined with CpG-ODN therapy can shrink hepatoma-bearing capacity, inhibit the growth of distant tumors and significantly prolong the survival time of mice.

[Loop-mediated isothermal amplification for visual detection of hepatitis B virus].

OBJECTIVE: To investigate the method of loop-mediated isothermal amplification (LAMP) using boiled serum for visual detection of hepatitis B virus (HBV). METHODS: Specific LAMP primers were designed according to the conservative region compared with the sequence of S genes in GenBank, and DNA of the samples was extracted by kit and boiling methods. The reaction conditions of LAMP were optimized, and HBV standard strains and clinical samples were examined to evaluate the specificity, sensitivity, and anti-interference ability of LAMP. Visual detection was performed for the results of LAMP, and SPSS 17.0 was used for consistency test. RESULTS: The optimal reaction conditions of LAMP were established. LAMP had a high specificity, and there was no nonspecific amplification. The sensitivity of LAMP was 10 copies/tube, regardless of the method for nucleic acid extraction. Hydroxynaphthol blue (HNB) had a comparable sensitivity to electrophoresis and SYBR Green I, and, unlike SYBR Green I, did not cause aerosol pollution easily. In addition, with fluorescent quantitative PCR (FQ-PCR) as the gold standard, LAMP using the boiling method and FQ-PCR were in good consistency (Kappa = 0.762, P > 0.05). However, PCR using boiling method was not well consistent with FQ-PCR (Kappa = 0.186, P < 0.05). CONCLUSION: LAMP has certain advantages over PCR in detecting HBV infection, and LAMP can be used to detect HBV in the field or primary hospitals.

[Establishment of a cell co-culture system in accordance with the immunological characteristics of chronic HBV infection].

Objective: To investigate whether the co-culture of Huh7.93 cells and peripheral blood mononucleated cells from chronic hepatitis B patients (cPBMCs) can simulate the replication features of hepatitis B virus (HBV) and immune function in chronic hepatitis B (CHB) patients, and to provide an in vitro cell co-culture system for the research on immune clearance in chronic HBV infection. Methods: Huh7.93 cells were cultured alone or co-cultured with peripheral blood mononucleated cells from healthy people who underwent physical examination (nPBMCs) or cPBMCs for 7 days. The CCK8 assay was performed to measure the proliferative activity of Huh7.93 cells, and quantitative real-time PCR and Southern blot were used to measure HBV replication in cPBMCs and co-cultured cells. The independent samples t-test was used for comparison between two groups. Results: When Huh7.93 cells were co-cultured with peripheral blood mononucleated cells (PBMCs) at a certain ratio, Huh7.93 cells had a high proliferative activity and good cell growth. HBV could not infect or replicate in cPBMCs. HBV DNA in the supernatant of Huh7.93 cells co-cultured with cPBMCs showed significant increases and significantly higher than that in the supernatant of Huh7.93 cells cultured alone on day 4 (6.01 ± 0.20 log10copies/ml vs 4.99 ± 0.08 log10copies/ml, P = 0.000) and day 7 (7.82 ± 0.24 log10copies/ml vs 6.96±0.09 log10copies/ml, P = 0.000). On day 7 of culture, the cell lysis buffer of Huh7.93 cells co-cultured with cPBMCs had a significant increase in the level of HBV replicative intermediate compared with that of Huh7.93 cells cultured alone. After HepG2.2.15 cells were co-cultured with cPBMCs, there was no significant increase in HBV replication. Conclusion: The co-culture of Huh7.93 cells and cPBMCs produces similar viral replication as human body infected with HBV and can well simulate the liver microenvironment and immune function in CHB patients, which provides a new method for the research on immune clearance in chronic HBV infection.

Effect of polymorphisms in the CSN3 (κ-casein) gene on milk production traits in Chinese Holstein Cattle.

This study was designed to evaluate significant associations between single nucleotide polymorphisms (SNPs) and milk composition and milk production traits in Chinese Holstein cows. Six SNPs were identified in the κ-casein gene using pooled DNA sequencing. The identified SNPs were genotyped by Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) methods from 507 individuals. Out of six, we identified three non-synonymous SNPs (g.10888T>C, g.10924C>A and g.10944A>G) that changed in the protein product. SIFT (Sorting_Intolerant_From_Tolerant) prediction score (0.01) demonstrated that protein changed Isoleucine > Threonine (g.10888T>C) will affect the phenotypes. Significant associations between identified SNPs and three yield traits (milk, protein and fat) and two composition traits (fat and protein percentages) were found whereas it did not reach significance for fat percentage in haplotypes association. Importantly, the significant SNPs in our results showed a large proportion of the phenotypic variation of milk protein yield and concentration. Our results suggest that CSN3 is an important candidate gene that influences milk production traits, and identified polymorphisms and haplotypes could be used as a genetic marker in programs of marker-assisted selection for the genetic improvement of milk production traits in dairy cattle.

Protective effect of an egg yolk-derived immunoglobulin (IgY) against Prevotella intermedia-mediated gingivitis.

AIMS: To investigate the effects of an egg yolk-derived immunoglobulin (IgY) specific to Prevotella intermedia in vitro and in vivo. METHODS AND RESULTS: An IgY specific to P. intermedia was produced by immunizing hens with formaldehyde-inactivated P. intermedia and showed high titres when subjected to an ELISA. The obtained IgY inhibited the growth of P. intermedia in a dose-dependent manner at concentrations from 1 to 20 mg ml(-1) in Center for Disease Control and Prevention liquid medium. Forty rats were challenged with P. intermedia on gingivae and then randomly divided into four groups, which were syringed respectively with phosphate-buffered saline, 1 mg ml(-1) of tinidazole, 20 mg ml(-1) of nonspecific IgY and 20 mg ml(-1) of the IgY specific to P. intermedia at a dosage of 300 µl per day. Gingival index (GI), plaque index (PI), bleeding on probing (BOP), counts of white blood cell (WBC) and histopathological slide of the gums were measured after treatment for 15 days. The gingivitis rats treated with the IgY specific to P. intermedia showed significantly decreased GI, PI, BOP and WBC (P < 0·05). Gum histopathology of the treated rats demonstrated a superior protective effect of the specific IgY on P. intermedia-mediated gingivitis. CONCLUSIONS: A new immunoglobulin specific to P. intermedia was developed from egg yolk. This specific IgY can dose-dependently inhibit the growth of P. intermedia and protect rats from gingivitis induced by P. intermedia. SIGNIFICANCE AND IMPACT OF THE STUDY: The new IgY has potential for the treatment of P. intermedia-mediated gingivitis.

Effect of FASN gene on milk yield and milk composition in the Chinese Holstein dairy population.

Fatty acid synthase (FASN) is a multifunctional protein that catalyzes de novo synthesis of fatty acids in cells. It plays a key role in the lipid biosynthesis as well as in the general metabolism of all living animals. We herein investigated polymorphisms of FASN. As a result, six single nucleotide polymorphisms (SNPs) were found and then genotyped in 752 Chinese Holstein cows. It was found that g.17924A>G was non-synonymous, g.13965 C>T, g.16907 T>C and g.18663T>C were synonymous mutations and two other two SNPs, g.8948 C>T (ss491228481) and g.14439T>C (rs133498277), were in intronic sequences of the gene. All such identified SNPs were found to be associated with milk yield and composition traits (P = 0.0441 to <0.0001). Significant additive and allele substitution effects were observed for three yield traits at all six loci as well (P < 0.05 to <0.01). Complete linkage disequilibrium among the five SNPs, with the exception of g.8948 C>T, was observed.

Inheritance of cytosine methylation patterns in purebred versus hybrid chicken lines.

We used methylation-sensitive amplified polymorphism to examine DNA methylation levels and CCGG patterns in parents and offsprings of 3 groups of adult chickens, purebred White Leghorn (AA), White Plymouth Rock (EE), and crossbred individuals (EA) using 10 primer combinations. We found that about 66% of the cytosines at CCGG sites were not methylated. Fully methylated sites were less frequent than hemi-methylated sites in the chicken genome; these frequencies were different from those of plants. We observed that the probability that the offspring would inherit the methylation pattern for any given site from the parents was 88%; consequently, unexpected methylation patterns in offspring occurred at a rate of about 12%. The methylation degree in offspring was lower than in parents, and there were more sites with altered methylation patterns in EA crossbreds compared with AA and EE purebreds. Seven differentially methylated fragments between parental lines and their offspring were isolated, sequenced, and characterized, 4 of which were located in the coding regions. We conclude that most of the methylation status is transferred from parents to offspring in chickens, and that there are differences in the inheritance of methylation status in purebred versus crossbred offspring. We also concluded that methylation-sensitive amplified polymorphism is highly efficient for large-scale detection of cytosine methylation in the chicken genome.

Aberrant promoter methylation of the CD4 gene in peripheral blood cells of mastitic dairy cows.

Bovine mastitis is the most common and costly disease of dairy cattle. Cluster of differentiation 4 (CD4) is closely related to the immune response in mastitis. We quantified promoter CpG methylation levels of the CD4 gene in Chinese Holsteins with clinical mastitis (CM) and in healthy controls; these levels were quantitatively detected with bisulfite pyrosequencing assays and confirmed by cloning sequencing. We found that the bovine CD4 promoter had 16% more methyl groups in the cows with CM (75.0 ± 5.8%) compared to the controls (59.0 ± 8.5%). The decreased expression level of CD4 in CM cows may be downregulated by the increased DNA methylation levels in the CD4 promoter. Two-dimensional hierarchical clustering analyses showed large differences in promoter CD4 methylation between mastitic and healthy cows; the dendrogram clearly distinguished the cows with clinical mastitis from healthy controls based on methylation levels. The DNA methylation level of the CD4 gene was strongly influenced by mastitis status in all comparisons. We suggest that the DNA methylation level of the CD4 promoter can be used as a molecular marker for clinical mastitis in dairy cows.

Identification of four novel alleles of the BoLA-DRB3 upstream regulatory region in Chinese yellow cattle.

The sequence of upstream regulatory region (URR) of BoLA-DRB3 gene was amplified with polymerase chain reaction followed by DNA sequencing from six animals of Chinese yellow cattle. A total of five alleles including four newly identified ones, named BoLA-DRB3*R-03-U2, BoLA-DRB3*R-06-U2, BoLA-DRB3*R-07-U and BoLA-DRB3*R-12-U for the BoLA-DRB3 URR were found. Result of sequence analysis showed that the regulatory elements W, X, Y, CCAAT and TATA-like boxes existed in such URRs and 16 polymorphic sites (11 transitions, 3 transversions, 1 deletion and 1 insertion) located in the spacers between the conserved consensus boxes and 1 insertion within X box, while no new polymorphic site within the consensus boxes.

Genetic effects of stearoyl-coenzyme A desaturase (SCD) polymorphism on milk production traits in the Chinese dairy population.

Stearoyl-CoA desaturase (SCD) is a multifunctional complex enzyme important in the cellular biosynthesis of fatty acids. The present study was to investigate the association of the SCD gene with milk production traits in dairy cattle. Two single nucleotide polymorphisms (SNPs) (g.6926A>G and g.8646A>G) in introns 3 and 4, and three SNPs (g.10153A>G, g.10213T>C and g.10329C>T) in exon 5 were identified with pooled DNA sequencing and genotyped using matrix-assisted laser desorption/ionization time of flight mass spectrometry assay in 752 Chinese Holstein cows. Polymorphism g.10329C>T was predicted to result in an amino acid replacement from alanine to valine in the SCD protein. With a mixed animal model, the significant associations of the five SNPs with 305-day milk, fat and protein yields and protein percentage were determined. We further demonstrated cows with heterozygous genotypes (A/G or C/T) had highest 305 day milk yield, fat yield, protein yield and lowest protein percentage. Heterozygous cows with genotype AG at the g.6926A>G locus showed the greatest milk yield (P < 0.0001), fat yield (P < 0.0001) and protein yield (P < 0.0001) among other heterozygous genotypes at any of the loci. Dominance effects of all identified SNPs on milk, fat and protein yields and protein percentage were significant. Moreover, significant allele substitution effects at g.6926A>G locus on milk yield and at g.10213T>C on protein yield were observed. Five-locus haplotypes and strong linkage disequilibrium (D' > 0.9) between the five SNPs were also observed. The results suggest that identified polymorphisms could be potential genetic markers to improve the production performance of Chinese Holstein.

Short communication: Distribution of recessive genetic defect carriers in Chinese Holstein.

In dairy cattle, 4 important recessive hereditary diseases exist: complex vertebral malformation (CVM), bovine leukocyte adhesion deficiency (BLAD), citrullinemia (CTLN), and deficiency of uridine monophosphate synthase (DUMPS). Holstein Associations in developed countries have established monitoring systems for such disorders in Holstein bulls for decades. Over the past decades, China has continuously imported Holstein semen and embryos, mainly from North America but also from Europe. The dissemination of such genetic defects was undetermined until now, although efforts were taken to develop molecular techniques and detect carriers for CVM and BLAD in small populations of Chinese dairy cattle. Thus, herein we extensively screened 732 proven bulls participating in artificial insemination programs and 136 young bulls entering progeny test from 15 bull stations in China for CVM, BLAD, CTLN, and DUMPS. The proportion of carriers of the defects was found to be 7.72, 1.38, 0.23, and 0.12%, respectively. Given our findings, early diagnostic and monitoring systems on recessive inherited disorders among proven and young bulls entering the national genetic improvement programs for dairy cattle of China should be established immediately, in which a series of measures will be taken to prevent further spreading of such disorders and gradually eliminate them in the dairy cattle population in China.

Genetic effect of the follicle-stimulating hormone receptor gene on reproductive traits in Beijing You chickens.

We analyzed the effects of the polymorphisms of the follicle-stimulating hormone receptor (FSHR) gene on egg production in a Beijing You chicken population divergently selected for egg number, egg weight, and BW across 3 generations. The FSHR gene encodes the receptor of follicle-stimulating hormone, which controls follicular development and recruitment in the ovary. Seven SNP of the FSHR gene were investigated in 768 pedigreed hens from the G2 generation. Association analysis revealed that g.-310A > G, g.-181A > T, and g.159C > T were associated with egg number at different weeks of age (P < 0.05) and that g.75470A > G and g.75860G > A were associated with egg weight at first egg (P < 0.05). The favorable allele of g.-181A > T and g.159C > T had increased frequencies not only in the high line but also over the 2 generations (G2 vs. G1) within the high line. To confirm the association study, we tested for FHSR mRNA expression level in the chicken ovaries. The results showed that the homozygous favorable genotypes of g.-181A > T and g.-310A > C increased the FSHR mRNA expression level compared with the other genotypes (P = 0.001 and P = 0.026, respectively). Hence, our findings implied that the SNP g.-181A > T could be a potential genetic marker for egg performance in the Beijing You chicken, but further replications of our study in other chicken populations are needed to verify such effects detected here.

CYP3A catalyses schizandrin biotransformation in human, minipig and rat liver microsomes.

Schizandrin is recognized as the major absorbed effective constituent of Fructus schisandrae, which is extensively applied in Chinese medicinal formula. The present study aimed to profile the phase I metabolites of schizandrin and identify the cytochrome P450 (CYP) isoforms involved. After schizandrin was incubated with human liver microsomes, three metabolites were isolated by high-performance liquid chromatography (HPLC) and their structures were identified to be 8(R)-hydroxyl-schizandrin, 2-demethyl-8(R)-hydroxyl-schizandrin, 3-demethyl-8(R)-hydroxyl-schizandrin, by liquid chromatography-mass spectrometry (LC-MS), (1)H-nuclear magnetic resonance (NMR), and (13)C-NMR, respectively. A combination of correlation analysis, chemical inhibition studies, assays with recombinant CYPs, and enzyme kinetics indicated that CYP3A4 was the main hepatic isoform that cleared schizandrin. Rat and minipig liver microsomes were included when evaluating species differences, and the results showed little difference among the species. In conclusion, CYP3A4 plays a major role in the biotransformation of schizandrin in human liver microsomes. Minipig and rat could be surrogate models for man in schizandrin pharmacokinetic studies. Better knowledge of schizandrin's metabolic pathway could provide the vital information for understanding the pharmacokinetic behaviours of schizandrin contained in Chinese medicinal formula.

Association of Janus kinase 2 polymorphisms with growth and reproduction traits in chickens.

Growth and reproduction are 2 economically important traits in the poultry industry. Janus kinase 2 (JAK) participates in the JAK2/signal transducer and activator of transcription 5 growth hormone signaling pathway, which plays important roles in the processes of growth and reproduction. The present study was designed to investigate the association of JAK2 SNP and haplotypes with growth as well as with reproductive traits in chickens. Fourteen JAK2 SNP were identified by pooled DNA sequencing, and 5 of these were genotyped for 768 Beijing You hens by using a matrix-assisted laser desorption/ionization-time of flight mass spectrometry assay. For 5 growth traits, BW at 17 wk of age was significantly associated with JAK2 C28109928T and A28135099G (P < 0.05). The 2 SNP were strongly related to BW at first egg, egg weight at first egg, and egg weight at 36 wk of age (P < 0.05). The SNP JAK2 C28122751T was found to be associated with BW at first egg and egg weight at 36 wk of age (P = 0.041 and P = 0.046, respectively), whereas JAK2 G28132240C was related to egg number at 40 wk of age (P < 0.01). Further haplotype analyses showed that 4 haplotypes checked in the population had no distinct influence on growth traits but were associated with 7 reproductive traits, namely, age at first egg; BW at first egg; egg weight at first egg; egg weight at 36 wk of age; and egg numbers at 32, 36, and 40 wk of age (P < 0.05). The results indicated that the JAK2 polymorphisms could be potential molecular markers to improve laying performance and growth traits in chickens.

Polymorphisms of three neuroendocrine-correlated genes associated with growth and reproductive traits in the chicken.

The identification and utilization of potential candidate genes for QTL with significant effects on economically important traits are becoming increasingly important in poultry breeding programs. Chicken insulin-like growth factor binding protein 1 and 3 and signal transducers and activators of transcription 5B (STAT5B) genes are 3 essential nodes for signaling pathways and gene networks of growth and reproduction. The pooled DNA sequencing approach was used for identification of 9 SNP of the 5' upstream region of the 3 genes. A total of 826 individuals from Beijing You chicken were genotyped for 5 SNP using a modified PCR-RFLP method and the association with chicken growth and reproductive traits was studied using the GLM procedure. The T56039403C (T-808C) SNP of the insulin-like growth factor binding protein 1 gene was associated with BW at 10 wk of age (P = 0.0061), and the C56072547T (C-968T) SNP of the insulin-like growth factor binding protein 3 gene was associated with BW at 8 and 10 wk of age (P = 0.0056 and P = 0.0016, respectively). The C4535156T (C-1591T), G4533815A (G-250A), and G4533675C (G-110C) SNP of the STAT5B gene were associated with age at first egg (P = 0.0143, P = 0.0088, and P = 0.0114, respectively). Moreover, Lewontin's D' (|D'|) and r(2) of C4535156T and G4533815A SNP, C4535156T and G4533675C SNP, and G4533815A and G4533675C SNP of the STAT5B gene were 0.939 and 0.852, 0.967 and 0.858, and 0.971 and 0.896, respectively. The 3 SNP were strong-linked with each other and lay within a haplotype block. Our results suggest that these SNP were significantly associated with early growth or with sexual maturation in chickens, or both, and may be potential molecular markers for MAS.

[Excision of thyroglossal cyst in children by transverse submentum incision].

Objective:To explore the application of transverse submentum incision in thyroglossal duct cyst surgery. Method:Submentum transverse incision for thyroglossal duct cyst removal in 14 children with thyroglossal duct cyst from January 2014 to December 2017. All cases were performed submentum dermatoglyphic incision, skin incision, subcutaneous tissue, platysma muscle incision, down lifting flap, along the white line incision and separation of banded muscle on both sides, see the mass along the wall of the capsule separated to the attachment of the hyoid bone, ablation of the mucosa of the capsule wall of the hyoid bone attachment, electrotome to break the hyoid bone. The cavity is indeed stopped after bleeding, and the skin is sutured continuously for continuous intradermal suture. The operation time, bleeding volume, severe complications, wound healing time and severe surgical scars were recorded. Close follow-up was performed to observe whether there was infection or recurrence of incisional wound. Parents were informed by telephone to go back to the outpatient clinic. RUTTER Children's Behavior Questionnaire was used to assess the children's psychological status. Vancouver Scar Rating Scale was used to evaluate the children's surgical scars, and to investigate whether parents satisfactory surgical methods. Result:Fourteen cases of thyroglossal duct cyst underwent transverse incision thyroglossal duct cyst excision successfully. The average operative time was 55 minutes, and the standard deviation was 10.5 min, bleeding was less than 10 ml, postoperative hoarseness and weakness of voice, silence became low, wound healing time averaged one week, no serious surgical scars, no wound infection and recurrence. Among the normal children of the same age group, 14 parents were satisfied with the operation. Conclusion:Excision of thyroglossal duct cyst under transverse incision is safe, reliable and satisfactory in appearance.

Evolution analysis of EUV radiation from laser-produced tin plasmas based on a radiation hydrodynamics model.

One of fundamental aims of extreme ultraviolet (EUV) lithography is to maximize brightness or conversion efficiency of laser energy to radiation at specific wavelengths from laser produced plasmas (LPPs) of specific elements for matching to available multilayer optical systems. Tin LPPs have been chosen for operation at a wavelength of 13.5 nm. For an investigation of EUV radiation of laser-produced tin plasmas, it is crucial to study the related atomic processes and their evolution so as to reliably predict the optimum plasma and experimental conditions. Here, we present a simplified radiation hydrodynamic model based on the fluid dynamic equations and the radiative transfer equation to rapidly investigate the evolution of radiation properties and dynamics in laser-produced tin plasmas. The self-absorption features of EUV spectra measured at an angle of 45° to the direction of plasma expansion have been successfully simulated and explained, and the evolution of some parameters, such as the plasma temperature, ion distribution and density, expansion size and velocity, have also been evaluated. Our results should be useful for further understanding of current research on extreme ultraviolet and soft X-ray source development for applications such as lithography, metrology and biological imaging.

Corticofugal influences on the responses of bat inferior collicular neurons to sound stimulation.

Corticofugal influences on the responses of inferior collicular neurons (IC) to acoustic stimulation were studied by electrical stimulation of the auditory cortex. Among 471 IC neurons isolated, about 26% were affected by cortical stimulation. Responses of 103 (22%) IC neurons were inhibited and 17 (3.6%) were facilitated. The degree of inhibition was dependent upon the amplitude of both auditory and electrical stimuli. Corticofugal inhibition of the response of an IC neuron was likely due to an increase in the neuron's minimum threshold. Inhibitory latency varied with the interstimulus interval. The shortest inhibitory latency of most IC neurons was between 1 and 2 ms. The localization of the point of cortical stimulation was crucial in determining the responses of IC neurons. It is assumed that corticofugal influences on IC neurons are a part of regulatory mechanism in the centrifugal pathway for frequency analysis and acoustic orientation.