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The effects of Si substitution for Al on the glass forming ability, Curie temperature T(C), magnetocaloric effect, and refrigeration capacity (RC) of melt-spun Gd-based Gd(65)Fe(20)Al(15-x)Si(x) (x = 0-7) glassy ribbons have been investigated. The small amounts of Si substitution for Al in the Gd(65)Fe(20)Al(15-x)Si(x) glassy ribbons with high T(x)/T(m) (>0.70) and small Delta T(m) (Delta T(m) = T(m)-T(x)) promote the formation of high thermal stability of these alloys. The Si addition leads to an increase of Curie temperature T(C) of glassy ribbons from 181 K for x = 0 to 227 K for x = 7. The maximal magnetic entropy changes -Delta S(M) and RC values for magnetic field change of 50 kOe are about 4.70-5.20 J/kg K and 710-760 J/kg, respectively. The large RC values are due to the broad temperature range of the half maximum of Delta S(M) peak (similar to 200 K), which is caused by the change of the amorphous disorder structure. The moderate Delta S(M) and large RC values jointly make the Gd(65)Fe(20)Al(15-x)Si(x) glassy ribbons promising candidates for magnetic refrigeration materials working at temperature range of 100-300 K. (C) 2011 American Institute of Physics. [doi:10.1063/1.3540666]

Gd-based Gd65−xRExFe20Al15 (x = 0–20, RE = Tb, Dy, Ho, and Er) alloys in ribbon form have been prepared by rapid quenching technology. It is found that the Gd65−xTbxFe20Al15 ribbons are in amorphous state. However, for the Gd65−xRExFe20Al15(RE = Dy, Ho, and Er) ribbons, in addition to a diffuse diffraction band, peaks from hexagonal rare-earth-rich phases are present indicating a mixture of amorphous and crystalline phases. This indicates that the heavier rare-earth elements (Dy, Ho, and Er) will decrease glass formability in the Gd-based Gd65−xRExFe20Al15 (RE = Dy, Ho, and Er) ribbons. The magnetic entropy changes of these ribbons increase with increasing the contents of the heavier rare-earth elements. The maximal magnetic entropy changes of the Gd45RE20Fe20Al15 (RE = Tb, Dy, Ho, and Er) ribbons are located in the range of 4.46–5.57 J/kg K under 50 kOe. Refrigerant capacity values are obtained to be about 580–720 J/kg under 50 kOe. These values are comparable to or even higher than those of Gd-based bul...

Ab initio density functional calculations, transmission electron microscope, and x-ray diffraction (XRD) were used to study the dominant factor of increased coercivity for the doping effect in SmCo7−xZrx (x = 0 to 0.3). Simulated values of saturated magnetization are 940 emu/cm3 for SmCo7 and 799 emu/cm3 for SmCo6.7Zr0.3, which agree with experimental results within 6%. The calculated anisotropy constant (for 2e) increases from 1.151 × 107 erg/cm3 for SmCo7 to 1.934 × 107 erg/cm3 for SmCo6.7Zr0.3. The grain sizes remain almost the same by adding ∼4% (atomic percent) Zr through the analyses of XRD. The increased anisotropy is the dominated factor for enhancing the coercivity in SmCo6.7Zr0.3. In addition, both results of Rietveld refinements of XRD data and ab initio calculations show that Zr situating at 2e/3g positions are more stable than 2e/2e locations, which were suggested conventionally.

alpha 1-Acid glycoprotein (AGP) is a major acute phase protein synthesized primarily by the liver. The AGP gene is transcriptionally activated in hepatocytes during the acute phase response to bacterial lipopolysaccharide. In this study, we analyzed an acute phase responsive element (APRE) located between nucleotide residues -127 to -104 relative to the transcription initiation site of the mouse AGP gene. Binding studies show that several trans-acting factors interact with the APRE. Using monospecific antibodies we demonstrate that three isoforms of the CCAAT/enhancer-binding protein (C/EBP) family, namely C/EBP alpha, C/EBP beta, and C/EBP delta, bind to the APRE. Furthermore, with liver nuclear protein from control animals, C/EPB alpha is the predominant form that binds to the APRE, whereas with nuclear proteins from acute phase-induced animals, C/EBP alpha is replaced by C/EBP beta. The mechanism of activation of the AGP gene during the acute phase response appears to involve an exchange of C/EBP alpha by C/EBP beta. C/EBP delta does not play a role in this reaction. Interestingly, the C/EBP binding site of the APRE partially overlaps a functional glucocorticoid responsive element. We present evidence that both purified C/EBP alpha and glucocorticoid receptor bind strongly to the APRE. By site-specific mutation, we have identified the C/EBP and glucocorticoid receptor binding sites in the APRE. These mutants were used in expression vectors to demonstrate that both C/EBP and glucocorticoid receptor are essential for maximal response to interleukin-6 and dexamethasone. These results demonstrate that the APRE is a composite binding site for multiple factors that are responsible for the transcriptional control of the mouse AGP. Finally, functional analyses indicate that C/EBP alpha, C/EBP beta, and C/EBP delta are strong transcriptional trans-activators of the AGP APRE in hepatoma cells. These data suggest that the regulatory activity of the C/EBP with the APRE in the liver may require interactions with adjacent proteins.

It is generally accepted that improper preparation of the post space in endodontically treated teeth may damage sealing of the filling and cause treatment failure. Conventional method of detecting the sealing ability of endodontically treated teeth are quite complicated and inconvenient. To avoid the shortcomings of these traditional methods, the law of diffusion was adopted in this experimental design, and the results were compared with those of the traditional dye penetration method. Fifty sound molar teeth were treated by routine endodontic procedures, and were instrumented to 35# endodontic file. In 20 teeth in the control group, half were treated as a positive control by leaving the apical foramen open, and the remaining half were used as a negative control by sealing the foramen with two layers of nail polish. The other 30 experimental teeth were filled with gutta-percha points and sealer Canals by the lateral condensation method. Two weeks later, the filling material was removed to apical 3 mm, then 60 microL 2915 mM KCl solution was placed into the pulp cavity. The root was immersed into 1 mL 24.17 mM KCl solution. During the following 30 days, the concentration of the potassium ions in the outer solution was monitored by an ion-selective electrode. Finally, all 50 teeth were immersed in 1% methylene blue for 24 hours, sectioned with Isomet, and the extent of dye penetration was measured under a stereomicroscope with a digital caliper. The results of both methods were compared by means of regression analysis. There was a good correlation between the dye penetration method and the newly designed ion-diffusion method (r = 0.812).(ABSTRACT TRUNCATED AT 250 WORDS)

The causation of breast cancer in certain strains of mice by a virus that can be transmitted vertically, through the milk produced during lactation, has led to the hypothesis that a similar phenomenon could exist in humans. There have been laboratory-based studies in humans suggesting that a virus may be involved in the etiology of female breast cancer although other investigations did not support this hypothesis. Descriptive data and epidemiologic evidence of ecologic nature do not indicate a role of lactation in the causation of human breast cancer, but the hypothesis has not been adequately assessed in analytic epidemiologic studies. A nested case-control study undertaken in Sweden to examine the role of prenatal factors on breast cancer risk in the offspring, allowed the evaluation of the importance of breast-feeding in the causation of this disease. Standardised records concerning women born at the Uppsala University Hospital from 1874 to 1954 were linked with invasive breast cancer incident cases, identified through their unique national registration number in the Swedish Cancer Registry during 1958-1990. For each case with breast cancer, the females born to the first three mothers admitted after the case's mother were selected as potential matching controls. Only controls living in Sweden and free from breast cancer until the time of diagnosis of breast cancer in the corresponding case were eventually included in the study. The analysis was based on 458 cases of breast cancer born in singleton pregnancies and 1,197 singleton age- and birth date-matched controls. Breast-feeding was not a significant or suggestive risk factor for breast cancer in the offspring; compared to women who at discharge were wholly or partly breastfed, women who as newborn were not breastfed had a relative risk of breast cancer of 0.97 with 95% confidence interval 0.44-2.17 (P = 0.95).

Abnormal contractile responses of blood vessels are observed widely in several hypertension models and are assumed to play a role in the etiology of essential hypertension. Inconsistent reports also exist due to different animals, preparations, and experimental techniques employed. In this investigation, we compared vascular response of normotensive Wistar-Kyoto rat (WKY) with that of spontaneously hypertensive rat (SHR) employing two experimental methods. Thoracic aorta obtained from age-matched animals were contracted by norepinephrine (NE) with either--single-dose method or cumulative-dose method. Differences in both reactivity (maximal tension) and sensitivity (ED50) to NE were observed. Although no significant differences were found between WKY and SHR with either method, the choice of the method employed could affect the outcome. For aorta from WKY, the reactivity to NE was similar for both methods; however, for aorta from SHR, the reactivity obtained by cumulative-dose method was significantly higher. Furthermore, the cumulative-dose method yielded higher sensitivity in both WKY and SHR when compared with that obtained by single-dose method. Taken together, the cumulative-dose method appeared to be a more sensitive method to determine contractile response. Nevertheless, no significant difference in either reactivity or sensitivity to NE in aorta was detected between WKY and SHR when cumulative-dose method was employed. These data indicate that aorta do not exhibit abnormal response to NE in SHR, consistent with earlier findings that not all tissue preparations behave similarly.

The effect of Ta addition on the structure and magnetic properties of melt-spun SmCo7−xTax (x=0–0.6) ribbons has been investigated. The intrinsic coercivity increases dramatically from 1.9 kOe for Ta-free ribbon to 9.8 kOe for SmCo6.7Ta0.3 ribbon, while further increasing Ta results in little enhancement of the coercivity. XRD patterns reveal that SmCo7−xTax ribbons crystallize in the pure TbCu7-type structure for low Ta substitution of x≤0.3 and a minor phase of TaCo3 appears when x>0.3. According to Rietveld structure refinement, the ternary alloying element Ta prefers to occupy the 2e site of TbCu7-type structure. The mechanism of the coercivity enhancement has been discussed based on crystal structure and microstructure.

Magnetic properties, phase evolution, and microstructure of melt spun Sm(Co0.97M0.03)xCy (M=Hf and Zr; x=5–9; y=0–0.15) ribbons quenched at the wheel speed of 40 m/s have been investigated. X-ray diffraction analysis show that the main phases exist in Sm(Co0.97M0.03)x ribbons are 1:5 for x=5 and 5.5, 1:5 and 1:7 for x=6 and 6.5, 1:7 for x=7 and 7.5, 1:7 and 2:17 for x=8, and 2:17 for x=8.5 and 9. The grain size of 200–500 nm for these two series of ribbons is almost unchanged when x is increased from 5 to 9. Accordingly, the magnetic properties of Sm(Co0.97M0.03)x ribbons (M=Hf and Zr) are mainly dominated by their phase constitutions. Furthermore, a slight addition of C to Sm(Co0.97M0.03)x ribbons refines the grain size down to 10–50 nm, resulting in the improvement of magnetic properties. Sm(Co0.97Hf0.03)7.5C0.1 ribbons show the optimal magnetic properties of Br=6.9 kG, Hic=9.2 kOe, and (BH)max=10.0 MGOe. For the Sm-lean Sm(Co,Hf)xCy (x=8.5–9) ribbons, higher Hf and C content are required to improve the...

Magnetic properties and microstructure of directly quenched Nd9.5Fe72.5−yTi2.5Zr0.5CryB15−xCx (x=0–1; y=0–3) magnets with a diameter of 1.1 mm and a length of 15 mm have been investigated. The thermomagnetic analysis show that the bulk magnets with x≦0.5 and y=0–3 mainly consist of magnetically hard 2:14:1 phase. Besides, a slight substitution of C for B and Cr for Fe in Nd9.5Fe72.5Ti2.5Zr0.5B15 can effectively refine the grain size of the bulk magnet with larger diameter, resulting in the remarkable enhancement of the magnetic properties. The optimal magnetic properties of Br=5.9 kG, Hic=8.2 kOe, and (BH)max=7.2 MGOe could be attained in Nd9.5Fe71.5Ti2.5Zr0.5Cr1B14.5C0.5 magnet.

The crystal structure and magnetic properties of melt spun SmCo7−xMx (M=Ta, Cr, and Mo; x=0–0.6) ribbons have been investigated. Based on x-ray diffraction analysis, it is found that a pure TbCu7-type structure is formed in the melt spun SmCo7−xTax (x=0–0.3) ribbons, while minor amount of additional 2:17 phase appears for the SmCo7−xMx (M=Cr and Mo; x=0.1–0.6) ribbons, implying that the elements in VIB group (Cr and Mo) are inferior to the element in VB group (Ta) in stabilizing metastable 1:7 phase. The result, analyzed by Rietveld refinement method, shows that Ta, Cr, and Mo may occupy the 2e site of 1:7 phase, which leads to the enhancement of the magnetic anisotropy field of 1:7 phase, just like Ti, Zr, Hf, Nb, or V did. From the magnetic performance point of view, with increasing the content of doping element x from 0 to 0.6, the maximum coercivity of SmCo7−xMx ribbons is enhanced from 1.9 kOe for binary SmCo7 to 11.3 kOe for M=Ta, 6.6 kOe for M=Cr, and 7.5 kOe for M=Mo, respectively, while the reman...

Little is known about the cause of uveal melanoma, the most common primary intraocular malignant lesion in adults. This population-based case-control study evaluated occupational exposures.One hundred ninety-seven newly diagnosed cases of uveal melanoma participated. Approximately two control subjects matched for age, sex, and telephone exchange area were selected for each case by random-digit dialing. Data were collected by a structured telephone interview. Two systems of occupational coding were used: an occupation-exposure linkage system and the Bureau of Census data. Conditional logistic regression for matched studies was used to examine various occupational exposures while controlling for previously reported potential confounders and for family income. The occupation-exposure matrix was used to define clusters of cases exposed to a particular chemical group from various occupations.Odds ratios were elevated for agriculture and farming work for both industry and occupation; this was consistent across both classification systems. Elevated odds ratios also were found for occupations involving machine operations, fabrication, assembling, equipment cleaning, and exposure to metal industries. Exposure to alkylating agents and phenols was associated with a lower risk compared with all other exposures. Several self-reported exposures also were studied. Exposures associated with elevated odds ratios were inks, insecticides, gases, radioactive substances, polybromated biphenyls, and chemical solvents.This exploratory study suggests various occupational associations for uveal melanoma and areas for future research.

From January 1987 to December 1990 at Chang Gung Memorial Hospital, the fetal membrane ruptured in 47 singleton pregnancies at the 20th to the 28th gestational weeks. Sixty-six percent of the patients delivered within three days and 91.5% within one week. Only six (12.8%) patients carried their pregnancies over the 28th week. Of the 47 patients, 16 (34.0%) developed clinical evidence of chorioamnionitis during the latent period. The development of chorioamnionitis was not related to any of clinical factors [gestational age at rupture of the membranes, duration of rupture of the membranes before admission, positive endocervical culture, tocolysis, latent period or the presence of oligohydramnios (p0.05)]. The neonatal survival rate was 12.7% (six out of 47). Neonatal death was mainly attributable to prematurity. Gestational age beyond the 28th week and body weight greater than 1000 gm are two factors contributing to fetal survival. When fetal lung maturity has not occurred expectant management in the absence of infection is an alternative treatment.

It is frequently assumed that the risk of hepatocellular carcinoma related to hepatitis B virus is higher when chronic hepatitis B virus infection is acquired early in life. This hypothesis has never been directly evaluated. However, firstborn and secondborn children are exposed to common infections after their school enrollment, whereas laterborn children are exposed much earlier, through their older siblings. The authors analyzed sibship size and birth order data from a large case-control study of patients admitted to Athens, Greece, hospitals between April 1976 and October 1984. The analyses included 185 patients with hepatocellular carcinoma, 35 patients with metastatic liver cancer, and 432 other hospital controls. There was a tendency for cases of hepatocellular carcinoma to concentrate at higher birth orders. When the analysis was restricted to cases and controls who were positive for hepatitis B surface antigen, this tendency was even more notable. These results are compatible with the hypothesis that establishment of chronic hepatitis B virus infection at an early age increases the risk of hepatocellular carcinoma substantially more than does chronic infection with this virus established at a later age.

Intrauterine exposure to high concentrations of endogenous pregnancy oestrogens may be important in the aetiology of breast cancer. In a nested case-control study we have assessed the relation between breast cancer risk and indicators of pregnancy oestrogen concentrations; pre-eclampsia/eclampsia is negatively related and measures of fetal size are positively related to oestrogen concentrations. Standard records for women born at Uppsala University Hospital between 1874 and 1954 were linked with records of invasive breast cancer cases, identified through their unique national registration numbers in the Swedish Cancer Registry during 1958-90. For each breast cancer case, we selected as potential controls female offspring of the first three mothers admitted to the hospital after the case's mother; only controls still living in Sweden and free from breast cancer when it was diagnosed in the case were finally included. Conditional logistic regression analysis was done for 458 breast cancer cases and 1197 matched controls. Pre-eclampsia/eclampsia was associated with a breast cancer rate ratio of 0·24 (95% confidence interval 0·09-0·70, p=0·01). Linear trends for breast cancer incidence with increasing birth weight, birth length, and placental weight were positive but not significant. Thus, prenatal factors are important in breast carcinogenesis. Concentrations of pregnancy oestrogens may be one such factor, but other prenatal or perinatal factors cannot be excluded.

The authors studied the prevalence and risk determinants for human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) in female prostitutes from Dakar (1985-1990), Ziguinchor (1987-1990), and Kaolack (1987-1990), Senegal, West Africa. Each cohort showed a distinct distribution of HIVs: 10.0% HIV-2 and 4.1% HIV-1 in Dakar, 38.1% HIV-2 and 0.4% HIV-1 in Ziguinchor, and 27.4% HIV-2 and 1.3% HIV-1 in Kaolack. In 1,275 female prostitutes from Dakar, increase years of sexual activity and a history of scarification were associated with HIV-2 seropositivity. In contrast, HIV-1 seroprevalence was associated with a shorter duration of prostitution and a history of hospitalization. In 278 female prostitutes from Ziguinchor, HIV-2 seroprevalence was associated with women of Guinea-Bissau nationality and increased years of sexual activity. In 157 female prostitutes from Kaolack, HIV-2 seroprevalence was associated with increased years of sexual activity and a history of never using condoms. The authors also studied the risk determinants for HIV-2 in the 1,280 Senegalese prostitutes pooled from all three sites. Controlling for ethnic group, women from Ziguinchor and Kaolack were more likely to be HIV-2 seropositive as compared with women from the Dakar site. Increased years of sexual activity were associated with HIV-2 seropositivity, while a history of excision and BCG vaccinations decreased the risk of HIV-2 infection.

Meconium peritonitis is usually the result of prenatal bowel obstruction with subsequent perforation, then the contents spread into the peritoneal cavity, which results in a sterile inflammatory reaction. The incidence ranges from 1/1500 to 1/2000, if without prenatal diagnosis and planned postnatal treatment, the mortality rate is as high as 62%. We describe three children, two with surgically, one with autoptically confirmed meconium peritonitis. All had abnormally prenatal ultrasonographic examinations. The first fetus showed a large 10 x 11 cm intra-abdominal mass with floating echogenic substances inside and with an echogenic rim. The second showed increased echogenicity with dilated bowel in abdominal cavity in one of the twin, and the third had an intra-abdominal cyst with several echogenic bands inside, fetal ascites was also noted. It is remarkable that the ultrasonographic findings were different in the three children. Two of the three children survived postoperation, one died 3 hours later after induction out at 31 weeks of gestational age due to multiple congenital anomalies.

For many infectious agents, seroprevalence rate is low but has serious consequences and must therefore be kept out of donated blood supplies. However, screening to ensure the safety of blood supplies has an associated very high cost. For example, in blood banks, detection of all the harmful items in a large number of samples is an expensive and tedious process. The laboratory and statistical approaches to obtain significant savings by the pooling method were discussed from 1943, recently, there have been further discussions of pooling sera as a means to determining the HIV seroprevalence rate in the general population or the weed out all HIV-positive individuals in blood screening. Here we describe a simple mathematical method to weed out all HIV, and HCV seropositive units. The method is designed to maximize possible savings. Two examples illustrate the application of this method in determining the number to be pooled in each stage, and the resulting savings. When the prevalence rate is lower than 2 percent. our method offers savings of over 80 percent.

In a case-control study probing the role of diet on the occurrence of colorectal cancer and undertaken in Athens, Greece, sera were collected from 100 cases and 100 controls, and serum total cholesterol, high-density-lipoprotein (HDL) cholesterol and triglycerides were determined. The biochemical results were analyzed in conjunction with nutrient intakes and a dietary score that summarizes in a linear way the dietary contrast between high-risk (high protein, saturated fat and dietary cholesterol; low vegetable) and low-risk (low protein, saturated fat and cholesterol; high vegetable) patterns. Cases with colorectal cancer had significantly (p less than 0.001) and substantially lower values of serum total cholesterol and particularly HDL cholesterol, but these associations did not reflect dietary practices, since protein intake and, to a lesser (and nonsignificant) extent, saturated fat and dietary cholesterol intake were higher among cases than among controls. In absolute terms, the dietary effect (as summarized in the linear dietary score) is more evident among persons with low serum total cholesterol and HDL cholesterol than among those with high levels of these serum lipids. These results indicate that a diet beneficial with respect to the risk of coronary heart disease is also likely to reduce the risk of colorectal cancer, even though low levels of serum total cholesterol and particularly HDL cholesterol represent important independent correlates of clinically overt colorectal cancer.

We have compared the activities of mouse alpha-fetoprotein (AFP) enhancers I, II, and III with their minimal enhancer fragments (Mers) I, II, and III and with the entire 7-kilobase pair enhancer domain by transient expression assay in primary fetal mouse liver cells. The level of expression directed by the AFP promoter [p(-1009)AFPcat] alone is stimulated at least 10-fold by the entire AFP enhancer domain (-1009 to -6983). Enhancer I can drive the level of chloramphenicol acetyltransferase activity equivalent to that of the entire enhancer domain, whereas the increase in activity by enhancers II and III is significantly lower (1.5-fold). MersI, II, and III all mediate a greater increase in activity than their corresponding enhancer regions. The increase with MerI is 16-fold. Using DNase I protection analyses we identified 3 protein-binding regions in MerI; site Ia binds liver and brain nuclear proteins; site Ib binds liver, kidney, and brain nuclear proteins as well as purified C/EBP; site Ic binds liver and kidney nuclear proteins. Site-specific mutation of Ia, Ib, or Ic showed a 10-25% reduction in chloramphenicol acetyltransferase expression; deletion of the C/EBP-binding site in Ib showed a 45% reduction in activity and mutation of all 3 sites (Ia, Ib, and Ic) resulted in a 75% reduction in activity. Our studies indicate no single trans-acting factor is absolutely essential for enhancer activity, and that the enhancer activity of MerI is mediated via a combinatorial and additive mechanism.

We present a case of non-mosaic trisomy 20 in amniotic fluid associated with major congenital anomalies. A detailed prenatal ultrasonic examination was performed, and revealed dilatation of the cisterna magna and the fourth ventricle with hypoplasia of the vermis of the cerebellum. Fetal echocardiography showed overriding aorta and ventricular septal defects with pulmonary atresia. However, the karyotype of the lymphocyte in the cord blood was normal female 46, XX. The occurrence of the Dandy-Walker malformation in non-mosaic trisomy 20 has not been reported before, and the clinical significance of this major defect for prenatal diagnosis is discussed.

An association between low maternal serum alpha-fetoprotein (MSAFP) and fetal trisomy has now been thoroughly documented. The mechanisms resulting in low MSAFP are still unclear. In order to determine whether the low values of MSAFP in autosomal trisomies are associated with smaller fetal weights, we compared 11 fetuses with Down syndrome (trisomy 21), 4 with trisomy 18, with 45 normal fetuses. All of them are aborted in the second trimester of pregnancy. No significant difference in the weight distribution between fetuses with Down syndrome and control fetuses was found. In contrast, as compared with the control fetuses, fetuses with trisomy 18 had a significant lower weight distribution. The mean value of MSAFP was 0.72 +/- 0.26 MoM for those with Down syndrome and 0.51 +/- 0.33 MoM for fetuses with trisomy 18; both results being significantly lower than that of normal control (1.01 +/- 0.28). The mean value of amniotic fluid AFP was 0.63 +/- 0.23 MoM for fetuses with Down syndrome. This value was significantly lower than those of the fetuses with trisomy 18 and normal controls (1.02 +/- 0.09 and 1.02 +/- 0.30). A linear relationship between MSAFP and fetal weight was found in normal fetuses at a given gestational age but was not found in trisomy pregnancy. Fetal weight cannot be used to explain the reason for low MSAFP in Down syndrome pregnancy but may partially account for the lower levels noted in fetuses with trisomy 18.

The phase evolution, microstructure, and magnetic properties of melt spun SmCo7−xNbx (x=0–0.6) ribbons have been investigated using powder x-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer, respectively. SmCo7−xNbx ribbons could crystallize in TbCu7-type structure only for low Nb substitution of x=0–0.3 at high wheel speed of 30–40 m/s. According to the structure refinement, the doping element Nb prefers to occupy the 2e site. The intrinsic coercivity increases dramatically from 1.9 kOe for SmCo7 ribbon to 10.2 kOe for SmCo6.8Nb0.2 ribbon at wheel speed of 40 m/s. The mechanism of the coercivity enhancement has been discussed. The optimal magnetic properties of σr=54.4 emu/g and Hic=10.2 kOe were obtained in SmCo6.8Nb0.2 ribbon.

Effect of B content on the magnetic properties, phase evolution, magnetic after effect, and the activation energy (Ea) for the melt-spun [(Fe0.7Co0.3)0.725Pt0.275]100−xBx (x=14–18) ribbons has been investigated. Sufficient amount of boron addition effectively decreases the activation energy of ordering transformation, and also refines the grain size of the studied ribbons after thermal annealing, resulting in the improvement of Hic from 3.4 kOe for x=14 to 6.2 kOe for x=18. The highest permanent magnetic properties of Br=10.1 kG, Hic=5.4 kOe, and (BH)max=15.7 MGOe can be achieved in [(Fe0.7Co0.3)0.725Pt0.275]85B15 ribbons. Meanwhile, the magnetic after effect study evidences that the activation volume is reduced with the increase in B content from V=41.33×10−19 cm3 for x=14 to V=21.71×10−19 cm3 for x=18, arisen from the lower volume fraction of magnetically soft phases and the stronger exchange-coupling effect between magnetic grains.

Magnetic properties and microstructure of directly quenched Nd9.5Fe72.5Ti3−xMxB15 (M=Nb and Zr; x=0–3) bulk magnets in rod form with a diameter of 0.9 mm have been studied. Proper Nb or Zr substitution for Ti has been found to well modify phase constitution and to refine the grain size from 200 to 50–100 nm effectively. Accordingly, the magnetic properties of the rods are enhanced remarkably from Hic=6.2 kOe and (BH)max=5.6 MG Oe for Nd9.5Fe72.5Ti3B15 to Hic=6.7–15.4 kOe and (BH)max=6.0–8.2 MG Oe for Nd9.5Fe72.5Ti3−xMxB15. The optimum magnetic properties of Br=6.6 kG, Hic=9.6 kOe, and (BH)max=8.2 MG Oe can be achieved for Nd9.5Fe72.5Ti2.5Zr0.5B15 alloy, while the highest coercivity of Hic=15.4 kOe [Br=5.9 kG and (BH)max=7.0 MG Oe] is obtained for Nd9.5Fe72.5Nb3B15. Their high permanent magnetic property arises mainly from the existence of a large volume fraction of 2:14:1 phase, finer grain size, and the existence of grain boundary phase.

The magnetocaloric effect (MCE) of the amorphous Fe–Zr–B–M (M=Mn, Cr, and Co) ribbons has been investigated. The MCEs of the Fe90−xZr10Bx (x=5, 10, 15, and 20) ribbons are enhanced with small amounts of boron addition. Furthermore, the Curie temperature of the specimens can be decreased to be about room temperature with appropriate Mn and Cr substitutions, but the MCE performance of the specimens drops only slightly. It is also found that the magnetic entropy change of the Co-substitution series of Fe85−yZr10B5Coy ribbons almost remains constant although the Curie temperature is increased to be about 400K for y=5. Therefore, for the application of MCE refrigeration at above room temperature, the Fe85−yZr10B5Coy ribbons are preferred due to the constant MCE and the high refrigeration capacity of about 90J∕kg at the magnetic field change of 10kOe. Moreover, the field dependence of the magnetic entropy change exhibits power dependence for all the studied specimens. In the ferromagnetic range, the exponent is...

Magnetic properties, phase constitution, and microstructure of melt spun R-lean and B-enriched Mischmetal (MM)–Fe–Co–Ti–B nanocomposites have been investigated. The thermal magnetic analysis show that only 2:14:1 and α-Fe [α-(Fe,Co)] phases appear for MM(A)9.5Fe78.5Ti2B10 and MM(A)9Fe79.5Co2.5Ti1B8 ribbons, while an additional Fe3B phase is present for R9.25Fe79.25Co2.5Ti1B8 [R=MM(A), MM(B), and MM(C)] ribbons. The magnetic properties of the above nanocomposites are determined not only by the phase constitution of MM–Fe–Co–Ti–B nanocomposites but also by the composition of MMs. Besides, fine grain size of 15–40 nm is almost unchanged for the ribbons with various MMs, giving rise to the strong exchange coupling effect between magnetic grains and the improved magnetic performance. In this study, the optimum magnetic properties of Br=9.6 kG, Hic=8.6 kOe, and (BH)max=18.2 MG Oe can be achieved for MM(B)9.25Fe79.25Co2.5Ti1B8 nanocomposites.

The crystal structure and magnetic properties of melt spun Sm(Co,V)7 ribbons have been investigated. It was found that SmCo7−xVx ribbons may crystallize in pure TbCu7-type structure for x=0.1–0.3 spun at a high wheel speed of 40 m/s. The structure refinement results show that the doping element V prefers to occupy the 2e site of TbCu7-type structure. Besides, transmission electron microscopy images show that with increasing V content, the grain size was refined from 200–400 nm for x=0.1 to 40–100 nm for x=0.3. As a result, the intrinsic coercivity enhances effectively from 1.9 kOe for SmCo7 ribbon to 11.5 kOe for SmCo6.7V0.3 ribbon. It is also verified that a slight addition of C to SmCo7−xVx could further refine the microstructure, resulting in the improvement of the magnetic properties of SmCo7−xVx ribbons. The optimal magnetic properties of σr=58.7 emu/g, Hic=13.5 kOe, and (BH)max=9.3 MG Oe can be obtained for SmCo6.9V0.1C0.1 ribbon.

The photoinduced changes in reflectivity (ΔR/R) at energies closed to the Mn d-d optical transition of HoMnO3 single crystal have been systematically measured from 300 K to 30 K by time-resolved optical pump-probe spectroscopy. The oscillation induced by the propagation of strain pulse was clearly observed in the ΔR/R signal with various probing wavelength. Moreover, the different relaxation processes of photoexcited carriers with in various wavelengths may be led by the blue shift of Mn3+ d level.

Thermodynamically YMnO3 (YMO) can only exist with hexagonal structure at ambient conditions. In this study, we demonstrate that the stain between film and substrate can play an important role in forming orthorhombic YMO (o-YMO). o-YMO films with nearly perfect crystallographic orientation alignment were obtained on LaAlO3(110) substrates. These films allow us to unambiguously disclose the intrinsic magnetic property and electronic structure anisotropies along different crystallographic orientations. The antiferromagnetic (AFM) phase transition was around 42 K. Moreover, we observed a signature of spin reordering at lower temperatures when the applied field was parallel to the a- or c-axis. On the other hand, only the AFM transition was observed when the field is parallel to the b-axis. By comparing the X-ray absorption spectroscopy (XAS) results to standard manganese oxides, YMnO3 exhibits the dominant Mn+3 characteristics as that obtained from the standard Mn2O3 powder. The polarization dependent XAS also revealed anisotropic bonding behavior along each crystalline axis.

The orthorhombic phase HoMnO3 (o-HMO in Pbnm symmetry setting) thin films were prepared on LaAlO3(110) (LAO(110)) substrates by pulsed laser deposition. While for films grown on LAO(110) substrates, the compressive strain along the b-axis was resulted from the tensile strain in the a-c plane. The films provide the opportunity of investigating the effects of strain, hence lattice elasticity, on the physical properties of this material. For o-HMO films an antiferromagnetic ordering with TN~42 K, irrespective to the direction of applied field was clearly observed. However, an additional magnetic ordering occurring around 26.4 K was observed when the field was applied along the c-axis of o-HMO. This transition, however, was absent when the field was applied along a- and b-axis. These results indicate that the second magnetic ordering observed along the c-axis could be more relevant to the Mn moments lying along the partially strained b direction of the o-HMO which has been theoretically expected to result in incommensurate-commensurate lock-in transition.

The design, fabrication, and performance characterization of a passive gas-liquid separation system is presented in this paper. The gas-liquid separation system is silicon-based and its fabrication is compatible with the existing CMU design of the microscale direct methanol fuel cell (DMFC). Both gas and liquid separators consist of staggered arrays of etched-through holes fabricated by deep reactive ion etching (DRIE). The gas separator is coated with a thin layer of hydrophobic polymer to substantiate the gas-liquid separation. To visually characterize the system performance, the gas-liquid separation system is made on a single wafer with a glass plate bonded on the top to form a separation chamber with a narrow gap in between. Benzocyclobutene (BCB) is applied for the low-temperature bonding. The maximum pressure for the liquid leakage of the gas separators is experimentally determined and compared with the values predicted theoretically. Several successful gas-liquid separations are observed at liquid pressures between 14.2 and 22.7 cmH2 O, liquid flow rates between 0.705 and 1.786 cc/min, and CO2 flow rates between 0.15160 to 0.20435 cc/min.Copyright © 2006 by ASME

Two hundred and fifty-five patients underwent forceps deliveries in Chang Gung Memorial Hospital from January 1, 1985 to June 30, 1990. There was neither maternal nor perinatal mortality related to this procedure during this period; and the perinatal outcome was good without sequela. In the past three years, cesarean section took the place of forceps delivery in some cases with acute fetal distress and malposition. As a result, maternal problems became the most common indication for forceps delivery during that period. Fourth degree laceration of the perineum was the major maternal complication, occurring in 22.4% of total forceps deliveries. Postpartum voiding problems continued to be another complication after forceps delivery, accounting for 7.0%. Either fourth degree laceration of the perineum or postpartum voiding difficulty could be prevented to a certain extent if the forceps were handled delicately in an experienced hand and there was early diagnosis with prompt management of voiding dysfunction.

From June 1978 to June 1990, there were 41,989 deliveries, 13,396 cesarean sections and 15 emergency obstetric hysterectomies at Taipei Chang Gung Memorial Hospital. The incidence of emergency obstetric hysterectomy is 36/100,000 deliveries. The mean age of patients is 31.7 years old. The indications for hysterectomy were placental disorder (60.0%), uterine atony (26.7%), and uterine rupture (13.3%). The present series showed that 14 cases had total abdominal hysterectomy, while only one case had a subtotal hysterectomy. Total hysterectomy should generally be performed unless maternal instability mandates a more expeditious subtotal hysterectomy. The most common postoperative complication included unknown fever and urinary tract infection. For those four cases of post-cesarean hysterectomy, conservative treatment was tried but failed. All cases presented with hypotension (less than 80/60 mmHg), tachycardia (greater than 100 times/min) and with a mean hemoglobin of 9 mg% during the observation period. In these patients, blood loss, operating time and length of hospitalization was increased when compared with a group of 7 patients undergoing cesarean hysterectomy. In patients with placenta accreta, who are candidates for cesarean hysterectomy, initial hypotension, tachycardia and shock developed during cesarean section. It must be emphasized that conservative aggressive measures to control obstetric hemorrhage remain the mainstay of therapy, but emergency hysterectomy played the life-saving role with which every practitioner of obstetrics must be familiar and keep in mind.

Three elderly patients, (an 80-year-old female, 78-year-old female and 78-year-old male) suffering from renal cell carcinoma with pancreatic metastasis were reported. In all cases, renal cell carcinoma had been diagnosed previously. Pancreatic tumors were revealed by computed tomography and ultrasonic study during subsequent admission in all cases. In the first case, laparotomy and histological examination proved that pancreatic tumor was metastatic from renal cell carcinoma. In the other cases, according to their clinical course and other laboratory data, we considered the pancreatic tumors to be metastatics from renal cell carcinoma though histological diagnosis was not obtained.

Serum taken from patients in a case-control study in Athens, Greece, was used to examine the interactive roles of hepatitis B virus (HBV) and hepatitis C virus (HCV) in the origin of hepatocellular carcinoma (HCC). An enzyme immunoassay for anti-HCV was used to test serum taken from 185 cases with HCC, 35 cases with metastatic liver cancer (MLC), and 432 hospital controls. Weakly positive anti-HCV results were more strongly related to MLC than to HCC, implying that these anti-HCV results are false positive. By contrast, strongly positive anti-HCV results were significantly related to HCC (relative risk [RR], 6.3), whereas no significant association was evident for MLC (RR, 0.6). The association of anti-HCV with HCC was substantially higher among subjects whose radioimmunoassay was positive for hepatitis B surface antigen (RR, 20.0) than among those whose radioimmunoassay was negative for this marker (RR, 4.8). These findings indicate that HCV infection has an interactive role in the origin of HCC.

Peripartum cardiomyopathy is defined as the development of heart failure during the later part of pregnancy or during the first three to six postpartum months, without an obvious underlying cause or prior evidence of cardiac disease. We present one case of peripartum cardiac failure which occurred in a 25-year-old primigravida with twin gestation. The patient underwent an emergency Cesarean section followed by successful medical treatment. An endomyocardial biopsy was performed 12 days after delivery and the pathological changes were consistent with the diagnosis of peripartum cardiomyopathy.

Appropriate interpretation of monitored fetal growth throughout pregnancy in individual patients and populations is dependent upon the availability of adequate standards. Previously published standards either were based on small samples, data decades old or were characteristic of foreign subpopulations. We have reviewed the data on a series of 46,575 singleton live births at Chang Gung Memorial Hospital from 1979 to 1989. The ratio of males to females was 1.08. The fetal growth pattern in the third trimester of pregnancy approximates a sigmoid curve. Fetal growth was most rapid from the 32nd to the 37th week of gestation with an average increase of 240 g per week. The birth weight declined beyond 42 weeks' gestation. There were significantly greater weight gains amongst male fetuses as compared to female fetuses from the 34th to the 42nd week of gestation. The mean birth weight recorded at 40 weeks' gestation in male and female newborns was 3,381 g and 3,262 g, respectively. Comparing the birth weight of term pregnancies using our data, with those of a previous, two-decade old report (1945-1967) by Chen, we found that birth weight were slightly higher in this study. The derived fetal growth curves are useful for clinical, public health, and investigational purposes.

Magnetic properties and microstructure of directly quenched Nd9.5Fe75.5−xMxB15 (M=Mo, Nb, Ta, Ti, V, and Zr; x=0–4) bulk magnets in rod form with a diameter of 0.7mm have been studied. The substitution of the selected refractory elements for Fe in the Nd9.5Fe75.5MxB15 alloy can suppress the formation of the soft phases, including Nd2Fe23B3 and one unknown phase, leading to the presence of a large amount of the Nd2Fe14B phase. Besides, the grain size at the core side of the rods is refined from a micrometer scale for a ternary magnet to 50–120nm for the magnets with refractory element substitution. As a result, the magnetic properties are improved remarkably from Br=5.0kG, Hci=1.0kOe, and (BH)max=1.7MGOe for a ternary magnet to Br=5.7–6.5kG, Hci=2.0–14.6kOe, and (BH)max=3.1–8.7MGOe for refractory element substituted magnets. The optimal magnetic properties of Br=6.5kG, Hci=10.3kOe, and (BH)max=8.7MGOe can be achieved in the Nd9.5Fe72.5Ti3B15 magnet, while the highest coercivity of Hci=14.6kOe, with Br=5.9k...

Magnetic properties, phase evolution, and microstructure of melt-spun (Sm1−xPrx)Co7−yHfyCz ribbons have been investigated. For (Sm1−xPrx)Co7−yHfy (x=0–1; y=0.1–0.3) ribbons, the magnetization increases, but coercivity decreases, with increasing Pr content. However, the phase constitution and microstructure have not been influenced by modifying Pr content x. The attractive magnetic properties of Br=6.5kG, Hci=6.1kOe, and (BH)max=7.2MGOe could be obtained for (Sm0.8Pr0.2)Co6.9Hf0.1 ribbons. A slight addition of C in (Sm0.8Pr0.2)Co6.9Hf0.1Cz (z=0.06–0.14) ribbon not only refines the microstructure, but also induces nanoscale fcc-Co precipitation in the matrix, leading to the stronger exchange-coupling effect between magnetic grains and the enhancement of remanence and magnetic energy product. As a result, the improved magnetic properties of Br=7.1kOe, Hci=8.5kOe, and (BH)max=11.2MGOe can be achieved for (Sm0.8Pr0.2)Co6.9Hf0.1C0.12 ribbons.

Effects of Co content on the magnetic properties and microstructure of melt-spun [(Fe1−xCox)0.675Pt0.325]84B16 (x=0–0.5) and [(Fe1−yCoy)0.725Pt0.275]85B15 (y=0 and 0.3) nanocomposite ribbons have been investigated. The substitution of Co for Fe in [(Fe1−xCox)0.675Pt0.325]84B16 ribbons enhances the coercivity (Hci) from 7.5kOe for x=0to10kOe for x=0.3, due to the formation of ordered L10-(Fe,Co)Pt phase with higher anisotropy field. The effect of Co substitution for Fe in [(Fe1−yCoy)0.725Pt0.275]85B15 series ribbons is similar to that in [(Fe1−xCox)0.675Pt0.325]84B16 system. Interestingly, larger magnetization could be obtained by decreasing the boron and Pt content simultaneously. Moreover, L10-(Fe,Co)Pt phase provides [(Fe0.7Co0.3)0.725Pt0.275]85B15 ribbons sufficient high coercivity Hci=5.4kOe, resulting in a remarkable enhancement of energy product from 10.0MGOe for Co-free ribbons to 15.7MGOe for ribbons with y=0.3.

This study was undertaken to estimate the cesarean delivery rate in Chang Gung Memorial Hospital (CGMH) and to determine whether the reasons for the rising rate have changed during the past 6 years. Since 1984, 43% of the rise in the cesarean rate was due to repeat cesareans, 29% due to dystocia, and 15% due to fetal distress. At the same time, the cesarean delivery rates due to abnormality of position and placentation dropped by 2% in either condition. The rate of cesarean delivery among those with a previous cesarean was 98%. In the future, if the number of vaginal deliveries after cesarean increases, then the overall cesarean delivery rate will decrease or stabilize.

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The prevalence of mottled enamel (dental fluorosis) was investigated among children, aged 6 to 15 years, in Chung-hsing New Village and in Tsao-tun Village. The drinking water in Chung-hsing New Village has been fluoridated for 12 years at a level of 0.6 ppm, while the drinking water in Tsao-tun contains a negligible level of 0.08 ppm. The degree of mottled enamel was assessed by using Dean's Index and the Community Fluorosis Index (CFI), the latter being derived from Dean's Index for the purpose of comparison. In Dean's Index, 6 classes based on the severity of the mottling, are identified: normal, questionable, very mild, mild, moderate, and severe. The results showed that children in Chung-hsing had whiter teeth than those in Tsao-tun Village. In the fluoridated group, 5.8% of children fell into the "very mild" mottling category, as compared to 0.9% in Taso-tun, the control area. For the "mild" class, the rate was 1.9% for Chung-hsing New Village and 0.4% for Tsao-tun. With only one exception in Tsao-tun, none of the children in the two groups showed mottling in the "moderate" or "severe" classes. The Community Fluorosis Index (CFI) was 0.15 for the Chung-hsing group, indicating that the occurrence of mottled enamel is very low when compared with data from fluoridation programs in other countries. It is concluded that in Taiwan, a 0.6 ppm fluoride concentration in drinking water, which has previously been reported to be effective in prevention of dental caries, is associated with only negligible mottling of enamel. Even when mottling does occur, the degree is very mild and only small chalky spots can be seen on the teeth.

We have fabricated Na_xCoO_2 thin films via lateral diffusion of sodium into Co_3O_4 (111) epitaxial films (reactive solid-phase epitaxy: Ref. 4). The environment of thermal diffusion is key to the control of the sodium content in thin films. From the results of x-ray diffraction and in-plane resistivity, the epitaxial growth and the sodium contents of these films were identified. The thermoelectric measurements show a large thermoelectric power similar to that observed in single crystals. The quasiparticle scattering rate is found to approach zero at low temperatures, consistent with the small residual resistivity, indicating high quality of the Na_xCoO_2 thin films., 16 pages. 4 figures. To appear in Applied Physics Letters

A method for the synthesis of multi-walled carbon nanotubes (MWCNTs) using paraffin wax candles is reported. The MWCNTs were grown on a cobalt-coated silicon wafer with a combustion rate of 80 s at a flame temperature of 700°C. The MWCNTs are 15–20 nm in diameter and ∼1–3 µm in length. Raman spectroscopy revealed that the IG/ID ratio is 0.88. The growth of the MWCNTs was studied using different combustion times. The amount of MWCNTs decreased for experiments longer than 80 s, presumably because the MWCNTs were burned off with a long stay in the flame.

Background The incidence of adenocarcinoma in the distal esophagus and at the gastroesophageal junction (GEJ) has been increasing in the last decades. It has been suggested that patients in whom Barrett mucosa can be identified in the surgical specimen have a better prognosis compared with those without. This has led to the belief that patients with and without Barrett mucosa may represent 2 distinct cancer types. Hypothesis Distal esophageal–GEJ adenocarcinoma with and without Barrett mucosa share the same origin, but differ only in clinical presentation and outcome. Design and Setting Retrospective cohort study in a university tertiary referral center. Patients and Methods Between 1992 and 2002, 215 patients (173 men and 42 women; median age, 66 years; age range, 26-91 years) had esophagogastrectomy for adenocarcinoma of the distal esophagus-GEJ. Patients receiving neoadjuvant chemotherapy or radiation therapy were excluded. Main Outcome Measures Clinical presentation, tumor characteristics, and survival were compared in patients with Barrett mucosa (n = 140) and those without (n = 75). Results Patients with Barrett mucosa in the specimen had tumors that were diagnosed earlier; were smaller in size; earlier in stage, with fewer node metastases; and had a better 5-year survival. Conclusions Observed differences in survival between patients with distal esophageal–GEJ adenocarcinoma with and without Barrett mucosa can be explained by earlier diagnosis. Patients without Barrett mucosa have their tumors detected later, when the disease is more advanced. This suggests the possibility that tumors without Barrett mucosa are not of a different origin, but rather are larger tumors that may have overgrown areas of Barrett mucosa.

Background: Evidence suggests that intestinal metaplasia develops in acquired cardiac mucosa at the gastroesophageal junction (GEJ). The aim of this study was to compare the luminal pH exposure to the histology of the mucosa at the GEJ. Methods: 251 symptomatic patients with increased esophageal acid exposure on 24 h pH monitoring were grouped according to the histology based on three biopsies of the GEJ: 1.squamous mucosa (SQ), 2.oxyntocardiac mucosa (OC), 3.cardiac mucosa (C) and 4.intestinal metaplasia (IM). All patients were free of Helicobacter pylori infection and off acid suppression therapy. Acid exposure was measured as the percentage time the luminal pH was at intervals of 0–1, 1–2, 2–3, 3–4, 4–5, 5–6 and 6–7 over a 24 h period. The relationship between each luminal pH interval and the various types of histology was compared using a one-way ANOVA and post hoc analysis with adjustments made for multiple comparisons. Results: Of the 251 patients, 31 had SQ mucosa; 40 OC mucosa; 125 C mucosa and 55 IM. Patients with intestinal metaplasia spent significantly more time at pH intervals of 2–3, 3–4 and significantly less time at the pH interval 5–6. Table 1. Mucosal histology at the GEJ and percentage time exposure at various pH intervals pH interval SQ OC C IM P-value* (IM vs others) * One-way ANOVA significant P-value < 0.05; † post hoc significant difference P < 0.0167. pH 0–1 0.01 0.03 0.01 0.01 0.58 pH 1–2 0.58 0.62 0.57 1.83 0.14 pH 2–3 2.29 1.84 2.16 4.18 0.00*† pH 3–4 5.59 4.98 6.08 9.30 0.00*† pH 4–5 10.47 9.08 10.90 13.70 0.02* pH 5–6 30.77 35.59 30.17 19.79 0.00*† pH 6–7 46.77 43.67 45.95 43.07 0.53 Conclusions: Patients with intestinal metaplasia of the cardia is associated with a significantly longer exposure time at the pH interval of 2–4 compared to those with cardiac mucosa, oxyntocardiac mucosa and squamous epithelium. This strongly suggests that the development of intestinal metaplasia may be secondary to stem cell stimulation by prolonged exposure to a luminal pH between 2 and 4.