173 research outputs found
Screening of suitable cationic dopants for solar absorber material CZTS/Se: A first principles study
The earth abundant and non-toxic solar absorber material kesterite Cu2ZnSn(S/Se)(4) has been studied to achieve high power conversion efficiency beyond various limitations, such as secondary phases, antisite defects, band gap adjustment and microstructure. To alleviate these hurdles, we employed screening based approach to find suitable cationic dopant that can promote the current density and the theoretical maximum upper limit of the energy conversion efficiency (P(%)) of CZTS/Se solar devices. For this task, the hybrid functional (Heyd, Scuseria and Ernzerhof, HSE06) were used to study the electronic and optical properties of cation (Al, Sb, Ga, Ba) doped CZTS/Se. Our in-depth investigation reveals that the Sb atom is suitable dopant of CZTS/CZTSe and also it has comparable bulk modulus as of pure material. The optical absorption coefficient of Sb doped CZTS/Se is considerably larger than the pure materials because of easy formation of visible range exciton due to the presence of defect state below the Fermi level, which leads to an increase in the current density and P(%). Our results demonstrate that the lower formation energy, preferable energy gap and excellent optical absorption of the Sb doped CZTS/Se make it potential component for relatively high efficient solar cells
Construction of large-volume tissue mimics with 3D functional vascular networks
We used indirect stereolithography (SL) to form inner-layered fluidic networks in a porous scaffold by introducing a hydrogel barrier on the luminal surface, then seeded the networks separately with human umbilical vein endothelial cells and human lung fibroblasts to form a tissue mimic containing vascular networks. The artificial vascular networks provided channels for oxygen transport, thus reducing the hypoxic volume and preventing cell death. The endothelium of the vascular networks significantly retarded the occlusion of channels during whole-blood circulation. The tissue mimics have the potential to be used as an in vitro platform to examine the physiologic and pathologic phenomena through vascular architecture.ope
Clinical significance of soft markers in second trimester ultrasonography for pregnant Korean women: a multicenter study and literature review
OBJECTIVE: To evaluate the clinical significance of soft markers for aneuploidy screening in Korean women. METHODS: We retrospectively reviewed the medical records of 5,428 singleton pregnant women who underwent sonography during the second trimester at seven institutions in South Korea. We evaluated the prevalence of the following soft markers: intracardiac echogenic focus, choroid plexus cysts, pyelectasis, echogenic bowel, and mild ventriculomegaly. We developed best-fitted regression equations for the fetal femur and humerus length using our data and defined a short femur and humerus as both long bones below the fifth centile. The results of genetic testing and postnatal outcomes were investigated in patients who had been diagnosed with aforementioned soft markers. RESULTS: The median maternal age of our study population was 33 years, and the median gestational age at the time of ultrasonographic examination was 21 weeks. We detected soft markers in 10.0% (n=540) of fetuses: 9.3% (n=504) were isolated cases and 0.7% (n=36) of cases had two or more markers. We identified only two aneuploides (trisomy 18, 46,XX,t[8;10][q22.1;p13]), of which one was clinically significant. We presented the neonatal outcomes of the fetuses with the respective soft markers. Preterm delivery, low birth weight, and small-for-gestational-age (SGA) were significantly more common in women with a shortened fetal femur (P<0.001, all). However, the presence of a shortened fetal humerus was not associated with those outcomes excluding SGA. CONCLUSION: Soft markers in second-trimester ultrasonography have limited use in screening for fetal aneuploidy in Korean women. However, these markers can be used as a screening tool for adverse outcomes other than chromosomal abnormality
Summary of clinically diagnosed amniotic fluid embolism cases in Korea and disagreement with 4 criteria proposed for research purpose
Objective: This study aimed 1) to investigate the clinical characteristics of amniotic fluid embolism (AFE) cases clinically diagnosed by maternal fetal medicine (MFM) specialists in Korea, 2) to check the disagreement with 4 recently proposed criteria by the Society for Maternal-Fetal Medicine (SMFM) for research purpose, and 3) to compare maternal outcomes between cases satisfying all 4 criteria and cases with at least 1 missing criterion. Methods This study included 12 patients clinically diagnosed with AFE from 7 referral hospitals in Korea. We collected information, including maternal age, symptoms of AFE, the amount of transfusion, and maternal mortality. Results The median maternal age was 33 years (range, 28-40 years). Regarding symptoms, cardiovascular arrest, hypotension, respiratory compromise, clinical coagulopathy, and neurologic signs were observed in 41.7%, 83.3%, 83.3%, 100%, and 66.7% of the cases, respectively. Among the 12 cases, 5 women died and 2 suffered severe neurologic disability, showing an intact survival rate of 41.7%. Disagreement with all 4 criteria proposed by the SMFM was found in 66.7% of the cases, due to the lack of criteria for disseminated intravascular coagulation or strict onset time (<30 minutes after delivery). There was no difference in maternal mortality and the amount of transfusion between cases satisfying all 4 criteria and cases with at least 1 missing criterion. Conclusion Two-thirds of clinically confirmed AFE cases did not satisfy all 4 criteria proposed by the SMFM, despite similar rates of maternal mortality with cases satisfying all 4 criteria. Our study suggests that there may be some discrepancy between the clinical diagnosis of AFE and the recent diagnostic criteria proposed by the SMFM for research purpose
The Genetic Effect of Copy Number Variations on the Risk of Type 2 Diabetes in a Korean Population
BACKGROUND: Unlike Caucasian populations, genetic factors contributing to the risk of type 2 diabetes mellitus (T2DM) are not well studied in Asian populations. In light of this, and the fact that copy number variation (CNV) is emerging as a new way to understand human genomic variation, the objective of this study was to identify type 2 diabetes-associated CNV in a Korean cohort. METHODOLOGY/PRINCIPAL FINDINGS: Using the Illumina HumanHap300 BeadChip (317,503 markers), genome-wide genotyping was performed to obtain signal and allelic intensities from 275 patients with type 2 diabetes mellitus (T2DM) and 496 nondiabetic subjects (Total n = 771). To increase the sensitivity of CNV identification, we incorporated multiple factors using PennCNV, a program that is based on the hidden Markov model (HMM). To assess the genetic effect of CNV on T2DM, a multivariate logistic regression model controlling for age and gender was used. We identified a total of 7,478 CNVs (average of 9.7 CNVs per individual) and 2,554 CNV regions (CNVRs; 164 common CNVRs for frequency>1%) in this study. Although we failed to demonstrate robust associations between CNVs and the risk of T2DM, our results revealed a putative association between several CNVRs including chr15:45994758-45999227 (P = 8.6E-04, P(corr) = 0.01) and the risk of T2DM. The identified CNVs in this study were validated using overlapping analysis with the Database of Genomic Variants (DGV; 71.7% overlap), and quantitative PCR (qPCR). The identified variations, which encompassed functional genes, were significantly enriched in the cellular part, in the membrane-bound organelle, in the development process, in cell communication, in signal transduction, and in biological regulation. CONCLUSION/SIGNIFICANCE: We expect that the methods and findings in this study will contribute in particular to genome studies of Asian populations
Randomized, Controlled, Multi-center Trial: Comparing the Safety and Efficacy of DA-9701 and Itopride Hydrochloride in Patients With Functional Dyspepsia.
BACKGROUND/AIMS: Therapies of functional dyspepsia (FD) are limited. DA-9701 is a novel prokinetic agent formulated with Pharbitis semen and Corydalis Tuber. We aimed to assess the efficacy of DA-9701 compared with itopride in FD patients.
METHODS: Patients with FD randomly received either itopride 50 mg or DA-9701 30 mg t.i.d after a 2-week baseline period. After 4 weeks of treatment, 2 primary efficacy endpoints were analyzed: the change from baseline in composite score of the 8 dyspep-tic symptoms and the overall treatment effect. Impact on patients' quality of life was assessed using the Nepean Dyspepsia Index (NDI) questionnaire.
RESULTS: We randomly assigned 464 patients with 455 having outcome data. The difference of the composite score change of the 8 symptoms between the 2 groups was 0.62, indicating that DA-9701 was not inferior to itopride. The overall treatment effect response rate was not different between the groups. When responder was defined as ≥ 5 of the 7 Likert scale, responder rates were 37% of DA-9701 and 36% of itopride group. Patients receiving DA-9701 experienced similar mean percentage of days with adequate relief during the 4-week treatment period compared with those receiving itopride (56.8% vs 59.1%). Both drugs increased the NDI score of 5 domains without any difference in change of the NDI score between the groups. The safety profile of both drugs was comparable.
CONCLUSIONS: DA-9701 significantly improves symptoms in patients with FD. DA-9701 showed non-inferior efficacy to itopride with com-parable safety
Grain Size and Texture of Cu2ZnSnS4 Thin Films Synthesized by Cosputtering Binary Sulfides and Annealing: Effects of Processing Conditions and Sodium
We investigate the synthesis of kesterite Cu2ZnSnS4 (CZTS) polycrystalline
thin films using cosputtering from binary sulfide targets followed by annealing
in sulfur vapor at 500 {\deg}C to 650 {\deg}C. The films are the kesterite CZTS
phase as indicated by x-ray diffraction, Raman scattering, and optical
absorption measurements. The films exhibit (112) fiber texture and preferred
low-angle and Sigma3 grain boundary populations which have been demonstrated to
reduce recombination in Cu(In,Ga)Se2 and CdTe films. The grain growth kinetics
are investigated as functions of temperature and the addition of Na.
Significantly, lateral grain sizes above 1 um are demonstrated for samples
grown on Na-free glass,demonstrating the feasibility for CZTS growth on
substrates other than soda lime glass
Ramosetron versus Palonosetron in Combination with Aprepitant and Dexamethasone for the Control of Highly-Emetogenic Chemotherapy-Induced Nausea and Vomiting
PURPOSE: The purpose of this study was to compare ramosetron (RAM), aprepitant (APR), and dexamethasone (DEX) [RAD] with palonosetron (PAL), APR, and DEX [PAD] in controlling highly-emetogenic chemotherapy (HEC)-induced nausea and vomiting.
MATERIALS AND METHODS: Patients were randomly assigned (1:1) to receive RAD or PAD:RAM (0.3 mg intravenously) or PAL (0.25 mg intravenously) D1, combined with APR (125 mg orally, D1 and 80 mg orally, D2-3) and DEX (12 mg orally or intravenously, D1 and 8 mg orally, D2-4). Patients were stratified by sex, cisplatin-based chemotherapy, and administration schedule. The primary endpoint was overall complete response (CR), defined as no emesis and no rescue regimen during 5 days of HEC. Secondary endpoints were overall complete protection (CP; CR+nausea score < 25 mm) and total control (TC; CR+nausea score < 5 mm). Quality of life was assessed by Functional Living Index Emesis (FLIE) questionnaire on D0 and D6.
RESULTS: A total of 279 patients receiving RAD (n=137) or PAD (n=142) were evaluated. Overall CR rates in RAD and PAD recipients were 81.8% and 79.6% (risk difference [RD], 2.2%; 95% confidence interval [CI], -7.1 to 11.4), respectively. Overall CP and TC rates for RAD and PAD were 56.2% and 58.5% (RD, -2.3%; 95% CI, -13.9 to 9.4) and 47.5% vs. 43.7% (RD, 3.8%; 95% CI, -7.9 to 15.5), respectively. FLIE total score >/= 108 (no impact on daily life) was comparable between RAD and PAD (73.9% vs. 73.4%, respectively). Adverse events were similar between the two groups.
CONCLUSION: In all aspects of efficacy, safety and QOL, RAD is non-inferior to PAD for the control of CINV in cancer patients receiving HEC
Information resource preferences by general pediatricians in office settings: a qualitative study
BACKGROUND: Information needs and resource preferences of office-based general pediatricians have not been well characterized. METHODS: Data collected from a sample of twenty office-based urban/suburban general pediatricians consisted of: (a) a demographic survey about participants' practice and computer use, (b) semi-structured interviews on their use of different types of information resources and (c) semi-structured interviews on perceptions of information needs and resource preferences in response to clinical vignettes representing cases in Genetics and Infectious Diseases. Content analysis of interviews provided participants' perceived use of resources and their perceived questions and preferred resources in response to vignettes. RESULTS: Participants' average time in practice was 15.4 years (2–28 years). All had in-office online access. Participants identified specialist/generalist colleagues, general/specialty pediatric texts, drug formularies, federal government/professional organization Websites and medical portals (when available) as preferred information sources. They did not identify decision-making texts, evidence-based reviews, journal abstracts, medical librarians or consumer health information for routine office use. In response to clinical vignettes in Genetics and Infectious Diseases, participants identified Question Types about patient-specific (diagnosis, history and findings) and general medical (diagnostic, therapeutic and referral guidelines) information. They identified specialists and specialty textbooks, history and physical examination, colleagues and general pediatric textbooks, and federal and professional organizational Websites as information sources. Participants with access to portals identified them as information resources in lieu of texts. For Genetics vignettes, participants identified questions about prenatal history, disease etiology and treatment guidelines. For Genetics vignettes, they identified patient history, specialists, general pediatric texts, Web search engines and colleagues as information sources. For Infectious Diseases (ID) vignettes, participants identified questions about patients' clinical status at presentation and questions about disease classification, diagnosis/therapy/referral guidelines and sources of patient education. For ID vignettes, they identified history, laboratory results, colleagues, specialists and personal experience as information sources. CONCLUSION: Content analysis of office-based general pediatricians' responses to clinical vignettes provided a qualitative description of their perceptions of information needs and preferences for information resource for cases in Genetics and Infectious Diseases. This approach may provide complementary information for discovering practitioner's information needs and resource preferences in different contexts
Addition of Cervical Elastography May Increase Preterm Delivery Prediction Performance in Pregnant Women with Short Cervix: a Prospective Study
BACKGROUND: We investigated whether there is a difference in elastographic parameters between pregnancies with and without spontaneous preterm delivery (sPTD) in women with a short cervix (</= 25 mm), and examined the ability of elastographic parameters to predict sPTD in those women.
METHODS: E-Cervix(TM) (WS80A: Samsung Medison, Seoul, Korea) elastography was used to examine the cervical strain. Elastographic parameters were compared between pregnancies with and without sPTD. Diagnostic performance of elastographic parameters to predict sPTD </= 37 weeks, both alone and in combination with other parameters, was compared with that of cervical length (CL) using area under receiver operating characteristic curve (AUC) analysis.
RESULTS: A total of 130 women were included. Median gestational age (GA) at examination was 24.4 weeks (interquartile range, 21.4-28.9), and the prevalence of sPTD was 20.0% (26/130). Both the elastographic parameters and CL did not show statistical difference between those with and without sPTD. However, when only patients with CL >/= 1.5 cm (n = 110) were included in the analysis, there was a significant difference between two groups in elasticity contrast index (ECI) within 0.5/1.0/1.5 cm from the cervical canal (P /= 1.5 cm, the combination of parameters (CL + pre-pregnancy body mass index + GA at exam + ECI within 0.5/1.0/1.5 cm) showed a significantly higher AUC than CL alone (P < 0.05).
CONCLUSION: An addition of cervical elastography may improve the ability to predict sPTD in women with a short CL between 1.5 and 2.5 cm
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