白内障超声乳化联合IOL植入术治疗PACG的有效性及影响因素分析

目的:分析白内障超声乳化联合人工晶状体(IOL)植入术治疗原发性闭角型青光眼(PACG)的有效性及影响因素。方法:回顾性分析2017-01/2018-12在本院接受白内障超声乳化联合IOL植入术治疗的PACG患者75例75眼的临床资料,统计其眼压、最佳矫正视力(BCVA)、眼前节参数及并发症发生情况,并采用多因素Logistic回归分析影响PACG患者白内障超声乳化联合IOL植入术疗效的危险因素。结果:与术前比较,PACG患者术后眼压均下降,BCVA均改善(P<0.05);术后中央前房深度(ACD)、房角开放距离(AOD500)、小梁虹膜夹角(TIA500)、房角隐窝面积(ARA)较术前显著上升(P<0.05);多因素Logistic回归分析显示,慢性PACG、术前眼压是PACG患者白内障超声乳化联合IOL植入术疗效的危险因素(P<0.05)。结论:白内障超声乳化联合IOL植入术治疗PACG疗效及安全性俱佳,但需重视术前眼压控制,对慢性PACG患者或应慎重考虑是否需行该术式。

Different roles of capsule endoscopy and double-balloon enteroscopy in obscure small intestinal diseases

AIM: To compare the roles of capsule endoscopy(CE)and double-balloon enteroscopy(DBE) in the diagnosis of obscure small bowel diseases.METHODS: From June 2009 to December 2014, 88 patients were included in this study; the patients had undergone gastroscopy, colonoscopy, radiological small intestinal barium meal, abdominal computed tomography or magnetic resonance imaging scan and mesenteric angiography, but their diagnoses were still unclear. The patients with gastrointestinal obstructions,fistulas, strictures, or cardiac pacemakers, as well as pregnant women, and individuals who could not accept the capsule-retention or capsule-removal surgery were excluded. Patients with heart, lung and other vital organ failure diseases were also excluded. Everyone involved in this study had undergone CE and DBE. The results were divided into:(1) the definite diagnosis(the diagnosis was confirmed at least by one of the biopsy,surgery, pathology or the drug treatment effects with follow-up for at least 3 mo);(2) the possible diagnosis(a possible diagnosis was suggested by CE or DBE,but not confirmed by the biopsy, surgery or follow-up drug treatment effects); and(3) the unclear diagnosis(no exact causes were provided by CE and DBE for the disease). The detection rate and the diagnostic yield of the two methods were compared. The differencein the etiologies between CE and DBE was estimated,and the different possible etiologies caused by the age groups were also investigated.RESULTS: CE exhibited a better trend than DBE for diagnosing scattered small ulcers(P = 0.242, Fisher's test), and small vascular malformations(χ 2 = 1.810,P = 0.179, Pearson χ 2 test), but with no significant differences, possible due to few cases. However,DBE was better than CE for larger tumors(P =0.018, Fisher's test) and for diverticular lesions with bleeding ulcers(P = 0.005, Fisher's test). All three hemangioma cases diagnosed by DBE in this study(including sponge hemangioma, venous hemangioma,and hemangioma with hamartoma lesions) were all confirmed by biopsy. Two parasite cases were found by CE, but were negative by DBE. This study revealed no obvious differences in the detection rates(DR) of CE(60.0%, 53/88) and DBE(59.1%, 52/88). However,the etiological diagnostic yield(DY) difference was apparent. The CE diagnostic yield was 42.0%(37/88),and the DBE diagnostic yield was 51.1%(45/88).Furthermore, there were differences among the age groups(χ 2 = 22.146, P = 0.008, Kruskal Wallis Test). Small intestinal cancer(5/6 cases), vascular malformations(22/29 cases), and active bleeding(3/4cases) appeared more commonly in the patients over50 years old, but diverticula with bleeding ulcers were usually found in the 15-25-year group(4/7cases). The over-25-year group accounted for the stromal tumors(10/12 cases).CONCLUSION: CE and DBE each have their own advantages and disadvantages. The appropriate choice depends on the patient's age, tolerance, and clinical manifestations. Sometimes CE followed by DBE is necessary.

Phylogenetic placement of Cynomorium in Rosales inferred from sequences of the inverted repeat region of the chloroplast genome

Cynomorium is a herbaceous holoparasite that has been placed in Santalales, Saxifragales, Myrtales, or Sapindales. The inverted repeat （IR） region of the chloroplast genome region is slow evolving and, unlike mitochondrial genes, the chloroplast genome experiences few horizontal gene transfers between the host and parasite. Thus, in the present study, we used sequences of the IR region to test the phylogenetic placements of Cynomorium. Phylogenetic analyses of the chloroplast IR sequences generated largely congruent ordinal relationships with those from previous studies of angiosperm phylogeny based on single or multiple genes. Santalales was closely related to Caryophyllales and asterids. Saxifragales formed a clade where Peridiscus was sister to the remainder of the order, whereas Paeonia was sister to the woody clade of Saxifragales. Cynomorium is not closely related to Santalales, Saxifragales, Myrtales, or Sapindales; instead, it is included in Rosales and sister to Rosaceae. The various placements of the holoparasite on the basis of different regions of the mitochondrial genome may indicate the heterogeneous nature of the genome in the parasite. However, it is unlikely that the placement of Cynomorium in Rosales is the result of chloroplast gene transfer because Cynomorium does not parasitize on rosaceous plants and there is no chloroplast gene transfer between Cynomorium and Nitraria, a confirmed host of Cynomorium and a member of Sapindales.

Radiation dose distribution of liquid fueled thorium molten salt reactor

A liquid fueled thorium molten salt reactor(TMSR-LF),one of the Generation IV reactors,was designed by the Shanghai Institute of Applied Physics,Chinese Academy of Sciences.This study uses the‘rt code to calculate the neutron and gamma dose rate distributions around the reactor.Multiple types of tallies and variance reduction techniques were employed to reduce calculation time and obtain convergent calculation results.Based on the calculation and analysis results,the TMSR-LF1 radiation shield with a 60-cm serpentine concrete layer and a 120-cm ordinary concrete layer is able to meet radiation requirements.The gamma dose rate outside the reactor biological shield was 16.1 mSv h-1;this is higher than the neutron dose rate of 3.71×10^(–2)mSv h^(-1).The maximum thermal neutron flux density outside the reactor biological shield was 1.899103 cm^(-2)s^(-1),which was below the 19105 cm^(-2)s^(-1)limit.

Analysis of tritium production in a 2 MW liquid-fueled molten salt experimental reactor and its environmental impact

Tritium release is one of the most concerning topics in nuclear power plants. Here, the tritium production in a 2 MW liquid-fueled molten salt experimental reactor(TMSR-LF1) was calculated by ORIGEN-S with an updated cross-section library generated by TRITON in SCALE 6.1.3 code system. The results show that the tritium production rate and normalized tritium production rate of TMSR-LF1 are 8.90x10^(11)Bq/day and4.45x10^(11)Bq/(MW day), respectively. The environmental impact of tritium was analyzed via PC-CREAM 08 with an assumed 36 % release rate of tritium referring to the molten salt reactor experiment. During normal operations, the maximum tritium concentration is 1.4 Bq/m^3 under normal condition, and the corresponding individual dose to the public is about 1 μSv/a; under extreme conditions, the maximum concentration and corresponding individual doses are 11.8 Bq/m^3 and 9 μSv/a, respectively.Ingestion is the main exposure pathway and accounts for62 % of the total dose. Of this, 35 % is from organically bound tritium.

Radiological environmental impact analysis of a 2-MW thorium molten salt reactor during an accident

The thorium molten salt reactor–liquid fuel(TMSR-LF1) has inherent safety features. The accident occurrence possibility and their consequences are much lower for the TMSR-LF1 than that of traditional reactors.Based on accident analysis, the maximum credible accident and the radioactive source terms of the TMSR-LF1 were first estimated. Then, the total effective dose of the maximum credible accident was calculated. Based on calculations, the cover gas flow rate can significantly affect the radiation consequences of the maximum credible accident when it changes from 0 to 10 L/min. If no cover gas is flowing, a site-area emergency would be required within the range of 50–73 m from the reactor. In the case of cover gas flow, only an abnormal notification and an alert two emergency class would be required within the range of 50 m.

A Novel ATM Antisense Transcript ATM-AS Positively Regulates ATM Expression in Normal and Breast Cancer Cells

Objective:The ataxia telangiectasia mutated(ATM)gene is a master regulator in cellular DNA damage response.The dysregulation of ATM expression is frequent in breast cancer,and is known to be involved in the carcinogenesis and prognosis of cancer.However,the underlying mechanism remains unclear.The bioinformatic analysis predicted a potential antisense transcript ATM-antisense(AS)from the opposite strand of the ATM gene.The purpose of this study was to identify ATM-AS and investigate the possible effect of ATM-AS on the ATM gene regulation.Methods:Single strand-specific RT-PCR was performed to verify the predicted antisense transcript ATM-AS within the ATM gene locus.qRT-PCR and Western blotting were used to detect the expression levels of ATM-AS and ATM in normal and breast cancer cell lines as well as in tissue samples.Luciferase reporter gene assays,biological mass spectrometry,ChIP-qPCR and RIP were used to explore the function of ATM-AS in regulating the ATM expression.Immunofluorescence and host-cell reactivation(HCR)assay were performed to evaluate the biological significance of ATM-AS in ATM-mediated DNA damage repair.Breast cancer tissue samples were used for evaluating the correlation of the ATM-AS level with the ATM expression as well as prognosis of the patients.Results:The ATM-AS significantly upregulated the ATM gene activity by recruiting KAT5 histone acetyltransferase to the gene promoter.The reduced ATM-AS level led to the abnormal downregulation of ATM expression,and impaired the ATM-mediated DNA damage repair in normal breast cells in vitro.The ATM-AS level was positively correlated with the ATM expression in the examined breast cancer tissue samples,and the patient prognosis.Conclusion:The present study demonstrated that ATM-AS,an antisense transcript located within the ATM gene body,is an essential positive regulator of ATM expression,and functions by mediating the binding of KAT5 to the ATM promoter.These findings uncover the novel mechanism underlying the dysregulation of the ATM gene in breast cancer,and enrich our understanding of how an antisense transcript regulates its host gene.

Impact of consolidation pressure on contaminant migration in clay liner

Consolidation deformation occurs in clay liners under the self-weight of wastes at a simple garbage dump or dredged sediment dump, which leads to a decrease in the porosity. However. the migration of contaminants in clay liners is influenced by the porosity. Thus, the impact of consolidation deformation of clay liners on the migration of contaminants cannot be ignored. Based on Biot＇s consolidation theory, the contaminant migration theory, and consideration of the three kinds of migration mechanisms of convection, diffusion, and adsorption, a one-dimensional migration model of contaminants in deforming porous media was established, and the finite difference method was adopted to obtain the numerical solutions for an established initial-boundary value problem. The impact of consolidation pressure on the migration law of a contaminant was studied. The results show that, regardless of adsorption modes, different consolidation pressures have similar impacts on the migration law of the contaminant. Namely, over a certain migration time, the greater the consolidation pressure is, the smaller the migration depth of the contaminant. The results also show that, while the migration time increases, the impact of a certain increment of consolidation pressure on the variation of contaminant concentration with the depth increases gradually and, while the migration depth increases, the impact of a certain increment of consolidation pressure on the variation of the contaminant concentration with time increases gradually.

A one-dimensional transport model for multi-component solute in saturated soil

A modified multi-component solute diffusion equation described with diffusion flux was derived in detail based on the classical MaxwellStefan diffusion theory. The friction between the solute species and the soil skeleton wall, which is proportional to the relative velocity between the solute species and the soil skeleton, is introduced. The chemical potential gradient is considered the driving force. A one-dimensional model for transport of multi-component solute in saturated soil was developed based on the modified diffusion equation and the modified competitive Langmuir adsorption equation. Numerical calculation of a case of two heavy metal ion species, which was chosen as an example, was carried out using the finite element software COMSOL Multiphysics. A comparative analysis was performed between the multi-component solute transport model developed in this study and the convection-diffusion transport model of single-component solute based on Fick's law. Simulation results show that the transport behavior of each species in a multi-component solute system is different from that in a single-component system, and the friction characteristics considered in the developed model contribute to obstructing the movement of each solute component. At the same time,the influence of modified competitive Langmuir adsorption on solute transport was investigated. These research results can provide strong theoretical support for the design of antifouling barriers in landfills and the maintenance of operation stability.

Effect of surgical procedures on prostate tumor gene expression profiles

Current surgical treatment of prostate cancer is typically accomplished by either open radical prostatectomy （ORP） or robotic-assisted laparoscopic radical prostatectomy （RALRP）. Intra-operative procedural differences between the two surgical approaches may alter the molecular composition of resected surgical specimens, which are indispensable for molecular analysis and biomarker evaluation. The objective of this study is to investigate the effect of different surgical procedures on RNA quality and genome-wide expression signature. RNA integrity number （RIN） values were compared between total RNA samples extracted from consecutive LRP （n= 11） and ORP （n= 24） prostate specimens. Expression profiling was performed using the Agilent human whole-genome expression microarrays. Expression differences by surgicat type were analyzed by Volcano plot analysis and gene ontology analysis. Quantitative reverse transcription （RT）-PCR was used for expression validation in an independent set of LRP （n=8） and ORP （n=8） samples. The LRP procedure did not compromise RNA integrity. Differential gene expression by surgery types was limited to a small subset of genes, the number of which was smaller than that expected by chance. Unexpectedly, this small subset of differentially expressed genes was enriched for those encoding transcription factors, oxygen transporters and other previously reported surgery-induced stress-response genes, and demonstrated unidirectional reduction in LRP specimens in comparison to ORP specimens. The effect of the LRP procedure on RNA quality and genome-wide transcript levels is negligible, supporting the suitability of LRP surgical specimens for routine molecular analysis. Blunted in vivo stress response in LRP specimens, likely mediated by CO2 insufflation but not by longer ischemia time, is manifested in the reduced expression of stress-response genes in these specimens.

Electronic structure and optical properties of the scintillation material wurtzite ZnS(Ag)

In order to investigate the effect of Ag doping(ZnS(Ag)) and Zn vacancy(V_(Zn)) on the alpha particle detection performance of wurtzite(WZ) ZnS as a scintillation cell component, the electronic structure and optical properties of ZnS, ZnS(Ag), and V_(Zn)were studied by firstprinciple calculation based on the density functional theory. The results show that the band gaps of ZnS, ZnS(Ag),and V_(Zn)are 2.17, 1.79, and 2.37 eV, respectively. Both ZnS(Ag) and V_(Zn)enhance the absorption and reflection of the low energy photons. A specific energy, about 2.9 eV,leading to decrease of detection efficiency is observed. The results indicate that Ag doping has a complex effect on the detection performance. It is beneficial to produce more visible light photons than pure WZ ZnS when exposed to the same amount of radiation, while the increase of the absorption to visible light photons weakens the detection performance. Zn vacancy has negative effect on the detection performance. If we want to improve the detection performance of WZ ZnS, Ag doping will be a good way,but we should reduce the absorption to visible light photons and control the number of Zn vacancy rigorously.

Concentration-Dependent Inuence of Silver Nanoparticles on Amyloid Fibrillation Kinetics of Hen Egg-White Lysozyme

Understanding the inuence of nanoparticles on the formation of protein amyloid brillation is cru-cial to extend their application in related biological diagnosis and nanomedicines.In this work,Ra-man spectroscopy was used to probe the amyloid brillation of hen egg-white lysozyme in the pres-ence of silver nanoparticles(Ag-NPs)at di erent concentrations,combined with atomic force mi-croscopy and thioavin T(ThT)uorescence assays.Four representative Raman indicators were utilized to monitor transformation of the protein tertiary and secondary structures at the molecular level:the Trp doublet bands at 1340 and 1360 cm^(-1),the disul de stretching vibrational peak at 507 cm^(-1),the N-Cα-C stretching vibration at 933 cm^(-1),and the amide I band.All experimental results con rmed the concentration-dependent inuence of AgNPs on the hen egg-white lysozyme amyloid brillation kinetics.In the presence of AgNPs at low concentration(17μg/mL),electrostatic interaction of the nanoparticles stabilizes disul de bonds,and protects the Trp residues from exposure to hydrophilic environment,thus leading to formation of amorphous aggregates rather than brils.However,with the action of AgNPs at high concentration(1700μg/mL),the native disul de bonds of hen egg-white lysozyme are broken to form Ag-S bonds owing to the competition of electrostatic interaction from a great deal of nanoparticles.As for providing functional surfaces for protein to interact with,AgNPs play a bridge role in direct transformation from-helices to organized-sheets.The present investigation sheds light on the controversial e ects of AgNPs on the kinetics of hen egg-white lysozyme amyloid brillation.

Primary small cell neuroendocrine carcinoma of the right posterior tongue

Small cell neuroendocrine carcinoma(SNEC)is an extremely aggressive tumor and mainly occurs in the lung.Primary extra-pulmonary SNEC is rare.To date,only 11 primary SNECs occurring in the oral cavity have been reported in the English literature.We describe a case of primary SNEC of the right posterior tongue in a 46-year-old man.The patient had stage IVA disease and received adjuvant chemotherapy,followed by radical surgery and radiotherapy.He remained tumor-free for 20 mo before death due to gastrointestinal metastasis.The relevant literature on the 11 previously reported patients was reviewed,and the clinical features,histopathological characteristics,differential diagnosis and therapeutic strategies of this rare tumor were analyzed.

Effect of hyperthermia perfusion chemotherapy combined with systemic chemotherapy on the expression and secretion of malignant molecules in advanced bladder cancer

Objective: To study the effect of hyperthermia perfusion chemotherapy combined with systemic chemotherapy on the expression and secretion of malignant molecules in advanced bladder cancer. Methods: Patients who were diagnosed with advanced bladder cancer in Gongan County People's Hospital between March 2015 and December 2017 were chosen and randomly divided into two groups, experimental group accepted hyperthermia perfusion chemotherapy combined with systemic chemotherapy, and control group accepted routine infusion chemotherapy combined with systemic chemotherapy. The expression levels of proliferation and invasion genes in the lesions as well as the secretion of cytokines in the urine were measured before chemotherapy and 3 months after chemotherapy. Results: Livin, Bcl-2, TRAP1 and MMP9 mRNA expression in lesions as well as VEGF, TGF-β1, MCP-1 and CEACAM1 secretion in urine of both groups after chemotherapy were lower than those before chemotherapy whereas Bad, LRIG3, Beclin1, KLF4, CHD13 and E-cadherin mRNA expression in lesions as well as IFN-γ and IL-2 secretion in urine were higher than those before chemotherapy, and Livin, Bcl-2, TRAP1 and MMP9 mRNA expression in lesions as well as VEGF, TGF-β1, MCP-1 and CEACAM1 secretion in urine of experimental group were significantly lower than those of control group whereas Bad, LRIG3, Beclin1, KLF4, CHD13 and E-cadherin mRNA expression in lesions as well as IFN-γ and IL-2 secretion in urine were significantly higher than those of control group. Conclusion: Hyperthermia perfusion chemotherapy combined with systemic chemotherapy can be more effective than routine infusion chemotherapy combined with systemic chemotherapy to regulate the expression and secretion of malignant molecules in advanced bladder cancer.

Comparison of epidemiological characteristics COVID-19 Delta variant infection among children in Xi'an and Baoji

Objective:To explore the epidemiological characteristics of Corona Virus Disease 2019(COVID-19)Delta variant infection in children in Xi'an and Baoji.Methods:According to the official information released by Shaanxi Province,the information of confirmed cases in Xi'an(December 20,2021 to January 8,2022)and Baoji(March 8 to March 27,2022)were collected respectively.Records include age,sex,residential address,community and other basic information.Isolation mode,isolation time,morbidity and positive time of viral nucleic acid test,vaccination,clinical typing,close contact personnel,cluster incidence situation and the social activity tracking of the confirmed cases were collected,and the data were statistically analyzed.Results:In 20 days,there were 281 infected children in Xi'an,accounting for 14.48%of the total cases(1,940 cases),including 154 boys(54.8%)and 127 girls(45.20%).The number of diagnosed children in Baoji City(55 cases)is 19.57%of that in Xi'an(55/281),but accounts for 23.31%of the total number of cases(236 cases)in Baoji(this ratio is higher than that of 14.48%in Xi'an).Among the 55 cases of children,there are 33 males(60.00%)and 22 females(40.00%).The proportion of male children in both cities is higher.The median age of diagnosed children in Xi'an was 7.0 years(IQR:1.0-13.0 years old),and the age range was 4 d-18 years old,while the median age of Baoji children was 9.0 years old(IQR:5.0-17.0 years old),ranging from 3 months to 18 years old.The number of children vaccinated in Xi'an and Baoji was positively correlated with the number of infected children.The vaccination rates of children in Xi'an and Baoji were 64.06%and 52.73%,respectively.The vaccination rates of infants(≤1 year old)in both cities were 18.52%and 14.29%,respectively.On the whole,the number of new child cases in the two cities increased first and then decreased.The peak number of new child cases in Xi'an was 39(10th day of statistics),while that of Baoji was 13(6th day of statistics).The peak in Xi'an comes later and the epidemic lasts longer.Among the children in Xi'an,201(71.53%)had a history of close contact,55(19.57%)had no clear history of COVID-19 infection,and were positive after actively participating in the nucleic acid test of all members of the community,of which 54(98.18%)were primary and middle school students.54 cases(98.18%)of Baoji children had a history of close contact,of which 20 cases were infected by the confirmed case number 62 officially announced on March 10.The time to be positive for viral nucleic acid test in children after isolation was 1-14 days.The positive rate of children in Xi'an reached 85.41%(240/281)after 7 days of isolation,and the highest peak of positive detection was on the third day of isolation(84 cases).After 7 days of isolation,45 cases were positive in Baoji,accounting for 81.82%(45/55).The highest peak of positive detection was on the 5th day of isolation(11 cases).The regional distribution of infected children in Xi'an was the highest in Yanta District(137 cases),followed by High-tech Zone(42 cases)and Lianhu District(29 cases).The main manifestations of COVID-19 in Xi'an were light(278 cases,98.93%),common type(3 cases,1.07%),light in Baoji(54 cases,98.18%),and common type(1 case,1.82%).Through general clinical treatment(including traditional Chinese medicine treatment and symptomatic treatment),all were cured.Conclusion:Delta variant increases the susceptibility of children to infection,which spreads rapidly mainly through close family contact and community concealment,so it is necessary to study better early diagnosis and prevention and control measures.

Whole process prediction model of silicon steel strip on transverse thickness difference based on Takagi-Sugeno fuzzy network

The hot rolling and cold rolling control models of silicon steel strip were examined.Shape control of silicon steel strip of hot rolling was a theoretical analysis model,and the shape control of cold rolling was a data-based prediction model.The mathematical model of the hot-rolled silicon steel section,including the crown genetic model,inter-stand crown recovery model,and hot-rolled strip section prediction model,is used to control the shape of hot-rolled strip.The cold rolling shape control is mainly based on Takagi-Sugeno fuzzy network,which is used to simulate and predict the transverse thickness difference of cold-rolled silicon steel strip.Finally,a predictive model for the transverse thickness difference of silicon steel strips is developed to provide a new quality control method of transverse thickness of combined hot and cold rolling to improve the strip profile quality and increase economic efficiency.The qualified rate of the non-oriented silicon steel strip is finally obtained by applying this model,and it has been steadily upgraded to meet the needs of product quality and flexible production.

Perovskite single-pixel detector for dual-color metasurface imaging recognition in complex environment

Highly efficient multi-dimensional data storage and extraction are two primary ends for the design and fabrication of emerging optical materials.Although metasurfaces show great potential in information storage due to their modulation for different degrees of freedom of light,a compact and efficient detector for relevant multi-dimensional data retrieval is still a challenge,especially in complex environments.Here,we demonstrate a multi-dimensional image storage and retrieval process by using a dual-color metasurface and a double-layer integrated perovskite single-pixel detector(DIP-SPD).Benefitting from the photoelectric response characteristics of the FAPbBr2.4l0.6 and FAPbl3 films and their stacked structure,our filter-free DIP-SPD can accurately reconstruct different colorful images stored in a metasurface within a single-round measurement,even in complex environments with scattering media or strong background noise.Our work not only provides a compact,filter-free,and noise-robust detector for colorful image extraction in a metasurface,but also paves the way for color imaging application of perovskite-like bandgap tunable materials.

Genome-wide Characterization of Long Terminal Repeat-retrotransposons in Apple Reveals the Differences in Heterogeneity and Copy Number between Ty1-copia and Ty3-gypsy Retrotransposons

The conserved domains of reverse transcriptase （RT） genes of Tyl-copia and Ty3-gypsy groups of long terminal repeat （LTR） retrotransposons were isolated from the Malus domestica genome using degenerate oligonucleotide primers. Sequence analysis showed that 45% of Ty1-copia and 63% of Ty3-gypsy RT sequences contained premature stop codons and/or indels disrupting the reading frame. High heterogeneity among RT sequences of both Ty1-copia and Ty3-gypsy group retrotransposons was observed, but Ty3-gypsy group retrotransposons in the apple genome are less heterogeneous than Ty1-copia elements. Retrotransposon copy number was estimated by dot blot hybridizations for Ty1-copia （-5000） and Ty3-gypsy （-26000）. All elements of the two types of LTR retrotransposons comprise approximately 38% of the M. domestica genome, with the Ty3-gypsy group contribution being higher （33.5%） than the Tyl.copia one （4.6%）. Transcription was not detected by reverse transcription-polymerase chain reaction for either Ty1-copia or Ty3-gypsy retrotransposons in the leaves of plants in vitro or in leaf explants cultured on medium supplemented with high concentration benzylaminopurine. This research reveals the differences in heterogeneity and copy number between Ty1-copia and Ty3-gypsy retrotransposons in the apple genome. Ty1-copia retrotransposon has higher heterogeneity than Ty3-gypsy retrotransposon, but the latter has a higher copy number, which implies that Ty3-gypsy retrotransposons may play a more important role in the apple genome evolution.

Relationship between La and Ce additions on microstructure and corrosion resistance of hot-dip galvanized steel

Scanning electron microscopy,X-ray diffraction,a neutral salt spray test,and electrochemical methods were applied to observe the microstructure and test the corrosion resistance of hot-dip galvanized steel before and after the addition of La and Ce.La/Ce mixture existed in the form of(La,Ce)Zn13 on the coated surface,decreased the coating thickness and accelerated the zinc dendritic growth.The corrosion current density of Zn-0.1La-0.1Ce coating was 63%less than that of pure Zn coating.This phenomenon can be explained that La/Ce mixture inhibited the transformation of Zn5(OH)8Cl2·H2O into Zn5(CO3)2(OH)6 or ZnO,reduced the time for appearance of red rust,and thus enhanced the stability of corrosion products and delayed the oxidation and corrosion processes of galvanized coating.La/Ce mixture improved the corrosion resistance compared to a single La or a single Ce addition.A competitive relationship between La and Ce was observed in the corrosion resistance improvement of hot-dip galvanized steel.

Bainite Transformation of Low-carbon and Boron-containing Steel under Continuous Cooling

The effects of deformation temperature and strain on bainite transformation of low carbon steel and boron- containing steel were investigated under continuous cooling conditions by means of dilatometric measurement and mi- crostructure observation. The results show that with decreasing the deformation temperature from 1000 to 800 ℃ and increasing strains, bainite start temperature for boron-containing low carbon steel increases, whereas it decreases for low carbon steel under the same condition. The bainite microstructures are easily obtained for boron-containing steel deformed at different temperatures and different strains compared with plain low carbon steel. With increasing the continuous cooling rate, the bainite start temperature under deformed condition is about 20 ℃ higher than that under undeformed condition for boron-containing steel, but it changes slightly when the cooling rate is 20 ℃/s or more.