A case study of Fe2TaZ (Z = Al,Ga, In) Heusler alloys: hunt for half-metallic behavior and thermoelectricity

We have computed the electronic structure and transport properties of Fe₂TaZ (Z = Al, Ga, In) alloys by the full-potential linearized augmented plane wave (FPLAPW) method. The magnetic conduct in accordance with the Slater–Pauling rule classifies them as non-magnetic alloys with total zero magnetic moment. The semiconducting band profile and the density of states in the post DFT treatment are used to estimate the relations among various transport parameters such as Seebeck coefficient, electrical conductivity, thermal conductivity, and figure of merit. The Seebeck coefficient variation and band profiles describe the p-type behavior of charge carriers. The electrical and thermal conductivity plots follow the semiconducting nature of bands along the Fermi level. The overall measurements show that semi-classical Boltzmann transport theory has well-behaved potential in predicting the transport properties of such functional materials, which may find the possibility of their experimental synthesis for future applications in thermoelectric technologies.

Crystal structure in conventional unit cell for Fe₂TaZ (Z = Al, Ga, In) in Fm$\bar{3}$m configuration.     

Prenatal care and subsequent birth intervals

CONTEXT: Prenatal care generally includes contraceptive and health education that may help women to control their subsequent fertility. However, research has not examined whether receipt of prenatal care is associated with subsequent birthspacing. METHODS: Longitudinally linked birth records from 113,662 New Jersey women who had had a first birth in 1996–2000 were used to examine associations between the timing and adequacy of prenatal care prior to a woman’s first birth and the timing of her second birth. Multinomial logistic regression analyses adjusted for social and demographic characteristics, hospital and year of birth. RESULTS: Most women (85%) had initiated prenatal care during the first trimester. Women who had not obtained prenatal care until the second or third trimester, or at all, were more likely than those who had had first‐trimester care to have a second child within 18 months, rather than in 18–59 months (odds ratios, 1.2–1.6). Similarly, women whose care had been inadequate were more likely than those who had had adequate care to have a short subsequent birth interval (1.2). The associations were robust to alternative measures of prenatal care and birth intervals, and were strongest for mothers with less than 16 years of education. CONCLUSIONS: Providers should capitalize on their limited encounters with mothers who initiate prenatal care late or use it sporadically to ensure that these women receive information about family planning.     

Randomized controlled trial comparing the Franseen needle with the Fork-tip needle for EUS-guided fine-needle biopsy

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Prevalence and natural history of subclinical hepatic encephalopathy in cirrhosis

BACKGROUND AND AIMS: The natural history of subclinical hepatic encephalopathy (SHE) is unknown. The present study was conducted to study the prevalence and the natural history of SHE in patients with cirrhosis of the liver. METHODS: One hundred and sixty-five patients with cirrhosis of the liver were studied. A total of nine psychometric tests (trail making and Wechsler adult intelligence scale-performance (WAIS-P) tests) were administered. Subclinical hepatic encephalopathy was present if two or more psychometric tests were abnormal. Seventy-two patients (SHE 40, without SHE 32) also underwent serial psychometric testing on follow-up visits at 6-8 week intervals. RESULTS: Subclinical hepatic encephalopathy was present in 103 (62.4%) patients. The number and figure connection, block design and picture completion tests were the most useful in the detection of SHE. Severity of SHE, as assessed by the number of abnormal tests, was greater in patients with more severe liver disease. During follow up, SHE tended to persist or worsen in patients with poorer liver function. Although other clinical complications were similar in different groups, overt hepatic encephalopathy developed more commonly in those patients who had SHE at entry compared to those who did not (22.6 vs 5.6%, P = 0.044). Among the patients with SHE, the development of overt hepatic encephalopathy was more common in patients with Child's score of > 6 than with Child's score of 相似文献   

Diagnostic accuracy of transient elastography in diagnosing clinically significant portal hypertension in patients with chronic liver disease: a systematic review and meta-analysis

Purpose

Liver stiffness measurement using transient elastography (TE-LSM) is a promising noninvasive alternative to hepatic venous pressure gradient (HVPG) for diagnosing clinically significant portal hypertension (CSPH). However, previous studies have yielded conflicting results. We evaluated the correlation between TE-LSM and HVPG and the performance of TE-LSM in diagnosing CSPH (HVPG?≥?10 mmHg).

Methods

We conducted a systematic review and meta-analysis by searching PubMed and Scopus databases for relevant literature evaluating the clinical usefulness of TE for diagnosing CSPH in patients with chronic liver disease.

Results

Twenty-six studies (4337 patients with valid TE and HVPG) met our inclusion criteria. The median correlation coefficient of TE with HVPG was 0.70 (range 0.36–0.86). The weighted mean of optimal cut-off of liver stiffness value for diagnosing CSPH was 22.8 kPa (95% CI 22.7–23.0 kPa). The summary sensitivity and specificity were 79% (95% CI 74–84%) and 88% (95% CI 84–91%), respectively. The area under the hierarchical summary receiver operating characteristic (HSROC) curve was 0.91 (95% CI 0.88–0.93) according to the bivariate model. One limitation of the study was significant heterogeneity in the results of summary sensitivity and specificity (I² 83 and 74%, respectively). The heterogeneity could be explained by the variable liver stiffness cut-offs used in studies. The meta-regression plot revealed that as the optimal cut-off increased, the sensitivity decreased, the specificity increased, and vice versa.

Conclusions

Liver stiffness measurement using TE correlates well with HVPG, and a liver stiffness cut-off value of 22.8 kPa shows a high accuracy for diagnosing CSPH. Thus, use of TE should be integrated into clinical practice for noninvasive diagnosis of CSPH.

     

Synthesis of microtubule-interfering halogenated noscapine analogs that perturb mitosis in cancer cells followed by cell death

We have previously identified the naturally occurring non-toxic antitussive phthalideisoquinoline alkaloid, noscapine as a tubulin-binding agent that arrests mitosis and induces apoptosis. Here we present high-yield efficient synthetic methods and an evaluation of anticancer activity of halogenated noscapine analogs. Our results show that all analogs display higher tubulin-binding activity than noscapine and inhibit proliferation of human cancer cells (MCF-7, MDA-MB-231 and CEM). Surprisingly, the bromo-analog is ∼40-fold more potent than noscapine in inhibiting cellular proliferation of MCF-7 cells. The ability of these analogs to inhibit cellular proliferation is mediated by cell cycle arrest at the G₂/M phase, in that all analogs except 9-iodonoscapine, caused selective mitotic arrest with a higher efficiency than noscapine followed by apoptotic cell death as shown by immunofluorescence and quantitative FACS analyses. Furthermore, our results reveal the appearance of numerous fragmented nuclei as evidenced by DAPI staining. Thus, our data indicate a great potential of these compounds for studying microtubule-mediated processes and as chemotherapeutic agents for the management of human cancers.     

Comparison of single-segment and double-segment Intacs for keratoconus and post-LASIK ectasia

PURPOSE: To evaluate the efficacy of single-segment Intacs and compare with double-segment Intacs in subjects with post-LASIK ectasia and keratoconus. DESIGN: Retrospective comparative analysis. METHODS: setting: Boxer Wachler Vision Institute, Beverly Hills, California, USA. study population: Thirty-seven eyes of 28 patients with keratoconus and post-LASIK ectasia classified into two groups: single-segment group (17 eyes, 11 patients) and double-segment group (20 eyes, 17 patients). Both groups were matched for age, visual acuity (uncorrected, UCVA; best spectacle-corrected, BSCVA), refractive error (sphere, cylinder, spherical equivalent), and keratometry (K) value (flat, steep, average) by t test for equality of means. intervention: Single- or double-segment Intacs procedure with axis of incision for insertion in the steep axis of manifest refraction. main outcome measure: Improvement of acuity, refractive error, K values, and inferior-superior (I-S) ratio. RESULTS: There was more improvement in UCVA in the single-segment group (nine lines) than the double-segment group (2.5 lines), P < .01; in BSCVA in the single-segment group (2.5 lines) than the double-segment group (<1 line), P < .01; in steep K values in the single-segment group (2.76 diopters +/- 2.68) than the double-segment group (0.93 diopters +/- 2.01), P = .02; and in I-S ratio in the single-segment group (9.51 +/- 7.49) than the double-segment group (4.22 +/- 4.82), P = .01; and greater cylinder decrease after Holladay vector analysis in the single-segment group (5.69 diopters +/- 3.10) than the double-segment group (1.58 diopters +/- 3.09), P < .01. CONCLUSIONS: Single-segment Intacs improved both UCVA and BSCVA by differential flattening of inferior meridian and steepening of superior meridian as reflected by change in I-S ratio.