Notes: Nd-Fe-B as-cast alloys in the form of small ingots 4–5 mm thick and with composition Nd2.1Fe14B were transformed into high coercivity magnets using the hydrogenation disproportionation desorption (HDD) process without decrepitation of the blocks taking place. Magnetic measurements revealed that it was possible to produce blocks with coercivity of ∼780 kA m−1, remanence of ∼680 mT and a BHmax of ∼68 kJ m−3 (8.6 MGOe). The high coercivities in these samples were attributed to the disproportionation and subsequent recrystallization process. SEM metallographs of the samples processed at optimum temperature revealed an absence of the original large (∼200 μm) grains of Nd2Fe14B containing areas of free iron; instead an extremely fine grained, submicron, microstructure of single phase Nd2Fe14B grains was observed. In samples processed at temperatures higher than that found to be the optimum, larger Nd2Fe14B grains with extremely rectangular morphologies could be observed growing from surrounding submicron matrix grains. Domain patterns observed on these larger grains, using the Kerr effect, indicated that Nd2Fe14B matrix grains appear to grow predominantly with rectangular morphologies from the disproportionated material with the a and c crystal axis running parallel to the edges of the rectangle.

Notes: Several versions of Mevva ion sources have been developed in our institute since 1988. It operates in a pulsed mode with a pulse length of 1.2 ms and a repetition rate of up to 50 pps. A time-averaged beam current of 10 or 50 mA has been extracted at 30–80 kV from Mevva IIA-H and Mevva IIB, respectively. In order to develop surface modification of materials by ion implantation we have constructed three kinds of Mevva ion source implantation systems. High dose (3–5×1017 cm−2) implantation with Ti, Ce, Y, and Ti+C, etc. has been carried out for improving the lifetime of metal cutting tools, relay contacts, dies, and some sophisticated components.

Notes: The charge density and the charge state distribution of ions extracted from metal vapor vacuum arc ion source have been measured by single, double probe, and time of flight systems, and the ion beam density distributions near the extracting electrode have been measured with and without a cusped magnetic field in order to improve the performance of ion beams. The charge state distributions as a function for many operational cathode materials were investigated.

Notes: Dyschromatosis symmetrica hereditaria (DSH) is a pigmentary genodermatosis of autosomal dominant inheritance characterized by a mixture of hyperpigmented and hypopigmented macules distributed on the dorsal aspects of the hands and feet. It is caused by mutations of the RNA-specific adenosine deaminase gene. We report the identification of a Chinese family with a three-generation pedigree of DSH, in whom a novel tyrosine substitution mutation in DSRAD was demonstrated: a heterozygous nucleotide A→G transition at position 2879 in exon 10 of the DSRAD gene was detected.

Notes: Marie Unna hereditary hypotrichosis (MUHH) is a rare autosomal dominant disorder with progressive hair loss starting in early childhood and aggravating at puberty. Several studies have mapped the MUHH gene to chromosome 8p21. Here we report a Chinese MUHH family with variable phenotypes. All affected individuals have anomalies affecting both hair density and hair shafts. Major clinical characteristics, disease history and histological examination support the diagnosis of MUHH, but the features of scarring in this kindred are modest and none of the patients have vertex hair loss, which is in contrast with typical MUHH. We now report genotyping and linkage analysis using 11 polymorphic microsatellite markers spanning the MUHH locus at 8p. Two-point linkage analysis using these markers revealed significant exclusion of this locus (log of the odds scores 〈 − 2) at θ = 0 indicating that there is a range of clinical presentations in MUHH, and that more than one genetic locus is responsible for the disorder.

Notes: Haplotype associations of the major histocompatibility complex (MHC) with psoriasis vulgaris (PV) have been demonstrated in different racial or ethnic populations. The objective of this study was to demonstrate the different haplotype associations of the MHC in Chinese patients with psoriasis according to the type of onset and their sex. One hundred and thirty-eight patients with PV and 149 normal control subjects without psoriasis were typed for HLA-A, -B, -C, -DQA1, -DQB1 and -DRB1 by using the PCR with sequence-specific primers. The results showed: (i) HLA-A*26 (26.1% vs. 12.1%, Pc 〈 1 × 10−5), -B*27 (17.03% vs. 1.01%, Pc 〈 1 × 10−7), -Cw*0602 (15.58% vs. 5.03%, Pc 〈 1 × 10−2), -DQA1*0104 (19.93% vs. 9.40%, Pc 〈 1 × 10−3), -DQA1*0201 (22.40% vs. 10.74%, Pc 〈 1 × 10−3), -DQB1*0303 (18.12% vs. 9.73%, Pc 〈 1 × 10−7), and -DRB1*0701/02 (26.09% vs. 9.73%, Pc 〈 1 × 10−7) were significantly increased in PV patients, while HLA-B*57, -DQB1*0201 were slightly increased in PV patients. HLA-Cw*0304 (5.07% vs. 14.43%, Pc 〈 1 × 10−3), -DQA1*0501 (5.79% vs. 14.09%, Pc 〈 0.05) were found to be negatively associated with PV, but HLA-A*2 (2.54% vs. 6.38%, Pc 〈 0.5) was decreased in PV patients without statistical significance. (ii) HLA-A*26-B*27 [P 〈 0.0001, odds ratio (OR) = 48.38], -A*26-Cw*0602 (P 〈 0.0001, OR = 11.84), -B*27-Cw*0602 (P 〈 0.0001, OR = undefined), -DRB1*0701/02-B*27 (P 〈 0.0001, OR = 22.62), -DRB1*0701/02-DQA1*0104 (P 〈 0.0002, OR = 3.59), -DRB1*0701/02-DQB1*0303 (P 〈 0.0001, OR = 5.63), -DQA1*0201-DQB1*0303 (P 〈 0.0002, OR = 7.77), -A*26-B*27-Cw*0602 (P 〈 0.0004, OR = undefined), -A*26-DRB1*0701/02-DQA1*0201-DQB1*0303 (P 〈 0.01, OR = undefined) were identified as risk haplotypes for patients with PV in China. (iii) HLA-A*26 -B*27 (P 〈 0.0001, OR = 58.47), -DQA1*0201-DQB1*0303 (P 〈 0.0001, OR = 8.62), -DRB1*0701/02 -DQA1*0104 (P 〈 0.0002, OR = 4.13), -DRB1*0701/02-DQB1*0303 (P 〈 0.0001, OR = 6.68) and -A*26-DRB1*0701-DQA1*0201 -DQB1*0303 (P 〈 0.006, OR = undefined) were only significantly associated with type I psoriasis compared with controls, while others showed no differences in either type I or type II psoriasis. (iv) These associated haplotypes with PV were not different by sex, except that the frequency of DRB1*0701/02-DQB1*0303 (P 〈 0.0001, OR = 10.14) was higher in male patients with psoriasis. To summarize, this study demonstrated a differential association of HLA and identified some special risk haplotypes in Chinese patients with PV compared with other ethnic or racial populations.

Notes: Very few articles have aimed to illuminate the clinical profiles of vitiligo in China. We conducted this retrospective survey involving 4118 outpatients with vitiligo in order to identify the differences among various clinical types of vitiligo and their associated disorders. Completed questionnaires (3742) were validated and analysed. Of this large cohort, 1565 (41.8%) individuals presented vitiligo vulgaris, followed by focal, segmental, acrofacial, and universal, in that order. The mean age of vitiligo onset was 18.88 years. More than 60% of the patients were affected before 20 years of age. Patients with segmental vitiligo were affected earlier than those with other types of vitiligo (15.55 years; (P 〈 0.001). More than 74% of the patients presented with focal vitiligo at onset. After 3–5 years, 99% of active vitiligo was worse and shifted from one clinical type to another. However, there was no transformation between acrofacial vitiligo and segmental vitiligo. Compared with the general population, the patients with vitiligo were more likely to be affected by rheumatoid arthritis (P 〈 0.01), ichthyosis (P 〈 0.01), chronic urticaria (P 〈 0.01), or alopecia areata (P 〈 0.01).

Notes: Summary Dystrophic epidermolysis bullosa (DEB) is caused by mutations in the COL7A1 gene encoding type VII collagen, the major component of anchoring fibrils. The characteristic genetic lesion in dominant DEB (DDEB) is a glycine substitution in the collagenous domain of the protein. In this study, we identified a Chinese family with a four-generation pedigree of DDEB, in whom a novel glycine substitution mutation in COL7A1 was demonstrated. A heterozygous nucleotide G→A transition at position 6208 in exon 74 of COL7A1 was detected, which resulted in a glycine to arginine substitution (G2070R) in the triple-helical domain of type VII collagen. This substitution was not found in 110 unrelated normal alleles. This report emphasizes the predominance of glycine substitution mutations in DDEB and contributes to the expanding database on COL7A1 mutations.

Notes: A new approach of growing thick Ge layers on Si substrates by molecular beam epitaxy is presented. A 30–80 A(ring) thick Ge overlayer is first deposited on the Si(100) substrate at room temperature. By thermally annealing the sample to 300 or 500 °C for 10 min, the Ge atoms cluster into randomly distributed islands which would play a role in releasing the mismatch stress at the interface. The Ge film of 10 000 A(ring) thickness epitaxially grown on this surface at 550 °C shows a better crystalline quality than that grown by a conventional method. A full width at half maximum of 262 s for the Ge (400) x-ray diffraction peak has been achieved.