Magnetic and other physical properties of X 52, X 60, X 70, and X 80 grade linepipe steels

The following magnetic properties were determined for X 52, X 60, X 70, and X 80 grade linepipe steels: magnetic induction as a function of magnetic field strength in the form of hysteresis loops, coercive force and saturation magnetisation. In addition, the following physical properties were determined: coefficient of thermal expansion between -180 and 400°C, elastic constants between -180 or 20 and 300°C, electrical resistivity, thermal conductivity and thermal diffusivity between -180 and 300°C. The crystallographic textures of the materials were represented by pole figures.     

Ring chromosome in Turner''s syndrome with a 45,X/46,X,Xr mosaic

Expanding the "journey test", the author recommends a simple diagnostic test by which the physician can gain a quick information on the psycho-motoric-somatic status of the old patients--as evidenced by 100 cases examined. To make a journey is recommended by the physician even to old people provided the following conditions are fulfilled: I. intact capacity of reasoning; II. satisfactory somatic condition; III. ability of harmonic (co-ordinated) locomotion; IV. financial (objective) resources available for the journey.     

Structure and properties of weld joints in X80, X90, and K70 pipe steel

The phase transformations of austenite in the thermal-influence zone of pipe steel (strength classes X80, X90, and K70) are studied by plotting thermokinematic diagrams that simulate the thermal cycle of welding. The influence of the maximum temperature and cooling rate on the structure and properties of sections in the thermal-influence zone is established. The risk of cold crack formation and softening in the steel is assessed by means of the dependence of the hardness on the cooling rate. The results are confirmed by the correlation of the hardness and the type of structural components in laboratory and industrial samples.     

Fluorescene in situ hybridization establishes homology between human and silvered leaf monkey chromosomes, reveals reciprocal translocations between chromosomes homologous to human Y/5, 1/9, and 6/16, and delineates an X1X2Y1Y2/X1X1X2X2 sex-chromosome system

The adhesive core of the desmosome is composed of cadherin-like glycoproteins of 2 families, desmocollins and desmogleins. The desmosomal cadherins show distinct patterns of expression in adult epidermis, and we have suggested that the desmocollins have a functional role in regulating the differentiation and/or morphogenesis of that epithelium (North et al. [1996] Proc. Natl. Acad. Sci. USA 93:7701-7705.). To examine this hypothesis, we cloned murine desmocollins and examined the induction patterns of desmocollins 1 and 3 during skin and skin appendage development. Desmocollins 3 and 1 were first expressed in epidermis in highly regional patterns at embryonic days 13.0 and 13.5, respectively, and both were up-regulated in general body epidermis at day 14.5. At this stage, epidermis is undifferentiated and the desmocollins showed an unexpected expression pattern. However, by day 18.5 when skin had undergone terminal differentiation, desmocollin 1 and 3 expression resembled that found in the adult. Thus, the establishment of the adult pattern of desmocollin expression corresponds to the adult pattern of epidermal stratification. We suggest that it is the ratio of desmocollin 1 to desmocollin 3 expression at different levels in the epidermis that is fundamental in establishing this pattern of differentiation.     

Pathogenetics of 45,X/46,XY gonadal mosaicism

Five patients with 45,X/46,XY mosaicism ranging from 8% to 66% of 46, XY lymphocytes in the peripheral blood were studied. Their age when chromosome studies were performed ranged from a few days to 37 yr. The phenotypic presentations were two females with gonadal dysgenesis and Turner syndrome features (cases 1 and 2), two males with ambiguous genitalia and mixed gonadal dysgenesis (cases 3 and 4), and an infertile male with an atrophic testis (case 5). Fluorescence in situ hybridization (FISH) using dual-color X and Y probes on paraffin-embedded sections of the gonads was performed to assess mosaicism. A mosaic cell line with a Y chromosome was present in the streak ovary, dysgenetic gonad, and testis. In the mixed gonadal dysgenesis cases (cases 3 and 4), the testis had a higher percentage (greater than two fold) of XY cells than the ovary had. However, the highest ratio of cells with a Y chromosome was in the atrophic testis of the infertile male (case 5). The distribution of mosaic clones in the different gonadal cell types was examined. Both females (cases 1 and 2) with dysgenetic gonads had scant ovarian stroma and nests of Leydig or hilus cells. In FISH studies, the coelomic epithelial cells were predominantly 46,XY; in comparison, the Leydig and hilus cells had a lower percentage and the ovarian stroma the least number of cells with a Y signal. A mixed gonadal dysgenesis case (case 3) possessed a right testis with an XY complement in approximately 21% of Sertoli cells and approximately 14% of Leydig cells. The infertile male had an atrophic testis with interstitial hyperplasia (case 5). His testis contained Sertoli cells but no evidence of spermatogenesis. FISH detected a Y signal in about 50-60% of the Sertoli and Leydig cells.     

Comparative molecular phylogeography of two Xenopus species, X. gilli and X. laevis, in the south-western Cape Province, South Africa

Xenopus gilli is a vulnerable anuran with a patchy distribution along the south-western coast of the Cape Province, South Africa. This species is sympatric with Xenopus laevis laevis, a widespread relative found over much of southern Africa. We examined the molecular phylogeography and population structure of the contact zone between these species to obtain information about historical biogeography and conservation management of this region. Analyses of the distribution, frequency, and cladistic and phenetic relationships among mitochondrial DNA haplotypes indicate that population subdivision is present in both taxa but that long-term isolation of sets of populations has occurred in X. gilli only. Haplotype and nucleotide diversity are also considerably higher within and among X. gilli ponds than X. l. laevis ponds in this region. We attribute the genetic segregation of X. gilli populations to ancient habitat fragmentation by ocean transgression into X. gilli habitat and to continued habitat alteration by human activity. The lower level of genetic diversity in X. L. laevis in this region is likely a result of a recent arrival of this taxon to the south-western Cape region relative to X. gilli. Population structure in X. l. laevis may be a result of isolation by distance. Clear evidence exists for at least two management units within X. gilli and strongly supports the establishment of protective measures east of False Bay in order to conserve a substantial portion of this species' extant genetic diversity.     

Evidence for a cryptic 46,XX cell line in a 45,X/46,X,psu idic(Xq) patient with normal reproduction

During a period between April 1, 1986 and December 31, 1996, a total of 3190 cardiothoracic operations were performed in our Department. The overall mortality was 4.1% The prerequisite for successful accomplishment of clinical research was discussed in detail.     

Prenatal identification of mos 45,X/46,X,+mar in a normal male baby by cytogenetic and molecular analysis

We report a case of mos 45,X/46,X,+mar, diagnosed prenatally by amniocentesis, whose physical examination, including external and internal organs, along with serum testosterone values were normal five years after delivery. The mosaic karyotype was seen in 146 of 240 cells examined (amniotic fluid cells, 110/65; placental chorionic villi: 5/4; cord blood, 21/81; cultured skin fibroblasts, 10/90) from 386 metaphases, and the marker chromosome appeared as a small non-fluorescent acrocentric chromosome. All autosomes appeared normal, and no normal Y chromosome could be demonstrated. Analysis of 26 Y-chromosome loci by molecular techniques such as PCR, Southern analysis using multiple Y-specific DNA probes, and Hae III restriction endonuclease assessment of male-specific repeated DNA in the heterochromatic region of the Y chromosome, and fluorescence in situ hybridization (FISH), revealed the marker was derived from a Y chromosome including p terminal to q11.23, and paracentric inversion in the remaining Y long arm. The formation of testes can be considered as existence of SRY (sex-determining region of Y) as a testis-determining factor. The present report illustrates the importance of FISH and molecular techniques as a complement to cytogenetic methods for accurate identification and characterization of chromosome rearrangements in prenatal diagnosis.     

Mosaicism for a small supernumerary ring X chromosome in a dysmorphic, growth-retarded male: mos47,XXY/48,XXY, +r(X)

Supernumerary ring X [r(X)] chromosomes are often found in patients with Turner syndrome. The phenotypic effects of the r(X) chromosome are variable, and largely depend on the presence or absence of the X inactivation (XIST) locus. Ring(X) chromosomes in males are rare and have been previously reported in only four cases, with 47,XY, + r(X) or mos47,XY, +r(X)/46,XY karyotypes. These patients all had developmental delay and dysmorphic features. We describe a 2.5-year-old male patient with facial dysmorphia, growth retardation, microcephaly, global developmental delay, and microphallus. Cytogenetic analysis from peripheral blood lymphocytes and fibroblasts identified mosaicism for two cell lines: mos48,XXY, + r(?X)/47,XXY. Fluorescence in situ hybridization (FISH) with an X chromosome paint showed the ring chromosome to be X chromosome derived. This is the first case of an r(X) chromosome described in a 47,XXY patient. FISH analysis of the r(X) chromosome with an XIST probe showed that the XIST locus was absent. Functional disomy of genes in the r(X) chromosome most likely accounts for the abnormal phenotype in the proband.     

Effects of alloying elements X (X=Zr,V, Cr,Mn, Mo,W, Nb,Y) on ferrite/TiC heterogeneous nucleation interface: first-principles study

The segregation behavior of alloying elements X (X=Zr,V,Cr,Mn,Mo,W,Nb,Y) on the ferrite (100)/TiC(100) interface has been investigated using first principles method,and the work of separation and interface energy of ferrite/TiC interfaces alloyed by these elements were also analyzed.The results indicated that all these alloying additives except Y were thermodynamically favorable because of the negative segregation energy,showing that they have the tendency to segregate to the ferrite/TiC interface.When the Fe atom in the ferrite/TiC interface is replaced by Y,Zr,or Nb,the adhesive strength of the interface will be weakened due to the lower separation work,larger interfacial energy,and weaker electron effects.However,the introduction of Cr,Mo,W,Mn and V will improve the stability of the ferrite/TiC interface through strong interaction between these elements and C,and Crdoped interface is the most stable structure.Therefore,the Cr,Mo,W,Mn and V in ferrite side of the interface can effectively promote ferrite heterogeneous nucleation on TiC surface to form fine ferrite grain.