Charge Transfer Induced Molecular Hole Doping into Thin Film of Metal-Organic-Frameworks

Despite the highly porous nature with significantly large surface area, metal organic frameworks (MOFs) can be hardly used in electronic, and optoelectronic devices due to their extremely poor electrical conductivity. Therefore, the study of MOF thin films that require electron transport or conductivity in combination with the everlasting porosity is highly desirable. In the present work, thin films of Co3(NDC)3DMF4 MOFs with improved electronic conductivity are synthesized using layer-by-layer and doctor blade coating techniques followed by iodine doping. The as-prepared and doped films are characterized using FE-SEM, EDX, UV/Visible spectroscopy, XPS, current-voltage measurement, photoluminescence spectroscopy, cyclic voltammetry, and incident photon to current efficiency measurements. In addition, the electronic and semiconductor property of the MOF films are characterized using Hall Effect measurement, which reveals that in contrast to the insulator behavior of the as-prepared MOFs, the iodine doped MOFs behave as a p-type semiconductor. This is caused by charge transfer induced hole doping into the frameworks. The observed charge transfer induced hole doping phenomenon is also confirmed by calculating the densities of states of the as-prepared and iodine doped MOFs based on density functional theory. Photoluminescence spectroscopy demonstrate an efficient interfacial charge transfer between TiO2 and iodine doped MOFs, which can be applied to harvest solar radiations.Comment: Main paper (19 pages, 6 figures) and supplementary information (15 pages, 10 figures), accepted in ACS Appl. Materials & Interface

A Large Bandgap Shift in InGaAs(P)/InP Multi-Quantum Well Structure Obtained by Impurity-Free Vacancy Diffusion Using SiO2 Capping and its Application to Photodetectors

In this paper, we have investigated the bandgap tuning in the InGaAs (P)/ InP multiquantum well (MQW) structure obtained by impurity-free vacancy diffusion (IFVD) using low temperature photoluminescence (PL). The MQW intermixing was performed in a rapid thermal annealer (RTA) using the dielectric capping materials, Si02 and SiNX. The Si02 capping was successfully used with InGaAs cap layer to cause a large bandgap tuning effect in the InGaAs/InP MQW material. The blue shift of bandgap energy after RTA treatment was as much as 185 and 230 meV at 750 t and 850 t, respectively, with its value controllable using annealing time and temperature. Samples with Si02-InP or SiN-InGaAs cap layer combinations, on the other hand, did not show any significant energy shifts. The absorption spectra taken from the same samples confimed the energy shifts obtained using PL. The process developed can be readily applied to fabrication of photodetectors that are sensitive to wavelength and/or polarization.This work was fmancially supported in part by OERC(Opto-Electronic Research Center) through the grant # 97K3-0809- 02-06-1 and by the SPRC (Semiconductor Physics Research Center) of Korea. The authors thank U. H. Lee and Prof. D. Lee of Chung Nam National Univ. for their help with the absorption measurement

Neonatal Intrahepatic Cholestasis Caused by Citrin Deficiency in Korean Infants

Citrin is a liver-type mitochondrial aspartate-glutamate carrier encoded by the SLC25A13 gene, and its deficiency causes adult-onset type II citrullinemia and neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD). Here, the authors investigated clinical findings in Korean infants with NICCD and performed mutation analysis on the SLC25A13 gene. Of 47 patients with neonatal cholestasis, three infants had multiple aminoacidemia (involving citrulline, methionine, and arginine) and galactosemia, and thus were diagnosed as having NICCD. Two of these three showed failure to thrive. The laboratory findings showed hypoproteinemia and hyperammonemia, and liver biopsies revealed micro-macrovesicular fatty liver and cholestasis. The three patients each harbored compound heterozygous 1,638-1,660 dup/ S225X mutation, compound heterozygous 851del4/S225X mutation, and heterozygous 1,638-1,660 dup mutation, respectively. With nutritional manipulation, liver functions were normalized and catch-up growth was achieved. NICCD should be considered in the differential diagnosis of cholestatic jaundice in Korean infants

Nomograms for Prediction of Disease Recurrence in Patients with Primary Ta, T1 Transitional Cell Carcinoma of the Bladder

We developed nomograms to predict disease recurrence in patients with Ta, T1 transitional cell carcinoma of the bladder. Thirty-eight training hospitals participated in this retrospective multicenter study. Between 1998 and 2002, a total of 1,587 patients with newly diagnosed non-muscle invasive bladder cancer were enrolled in this study. Patients with prior histories of bladder cancer, non-transitional cell carcinoma, or a follow-up duration of less than 12 months were excluded. With univariate and multivariate logistic regression analyses, we constructed nomograms to predict disease recurrence, and internal validation was performed using statistical techniques. Three-year and five-year recurrence-free rates were 64.3% and 55.3%, respectively. Multivariate analysis revealed that age (hazard ratio [HR]=1.437, p<0.001), tumor size (HR=1.328, p=0.001), multiplicity (HR=1.505, p<0.001), tumor grade (HR=1.347, p=0.007), concomitant carcinoma in situ (HR=1.611, p=0.007), and intravesical therapy (HR=0.681, p<0.001) were independent predictors for disease recurrence. Based on these prognostic factors, nomograms for the prediction of disease recurrence were developed. These nomograms can be used to predict the probability of disease recurrence in patients with newly diagnosed Ta, T1 transitional cell carcinoma of the bladder. They may be useful for patient counseling, clinical trial design, and patient follow-up planning

Comparative genomics of Mycoplasma pneumoniae isolated from children with pneumonia: South Korea, 2010–2016

Background Mycoplasma pneumoniae is a common cause of respiratory tract infections in children and adults. This study applied high-throughput whole genome sequencing (WGS) technologies to analyze the genomes of 30 M. pneumoniae strains isolated from children with pneumonia in South Korea during the two epidemics from 2010 to 2016 in comparison with a global collection of 48 M. pneumoniae strains which includes seven countries ranging from 1944 to 2017. Results The 30 Korean strains had approximately 40% GC content and ranged from 815,686 to 818,669 base pairs, coding for a total of 809 to 828 genes. Overall, BRIG revealed 99% to > 99% similarity among strains. The genomic similarity dropped to approximately 95% in the P1 type 2 strains when aligned to the reference M129 genome, which corresponded to the region of the p1 gene. MAUVE detected four subtype-specific insertions (three in P1 type 1 and one in P1 type 2), of which were all hypothetical proteins except one tRNA insertion in all P1 type 1 strains. The phylogenetic associations of 30 strains were generally consistent with the multilocus sequence typing results. The phylogenetic tree constructed with 78 genomes including 30 genomes from Korea formed two clusters and further divided into two sub-clusters. eBURST analysis revealed two clonal complexes according to P1 typing results showing higher diversity among P1 type 2 strains. Conclusions The comparative whole genome approach was able to define high genetic identity, unique structural diversity, and phylogenetic associations among the 78 M. pneumoniae strains isolated worldwide.This research was supported by the 2017 Seoul National University Hospital Research Fund (0320170230) and the Basic Science Research Program through the National Research Foundation of Korea, which is funded by the Ministry of Education, Science and Technology (NRF2018R1D1A1A09082098). The funding bodies played no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript. The study sponsors provided research grants to perform the study which was written by Dr. EH Choi

Whole genome sequence and analysis of the Marwari horse breed and its genetic origin

Background: The horse (Equus ferus caballus) is one of the earliest domesticated species and has played an important role in the development of human societies over the past 5,000 years. In this study, we characterized the genome of the Marwari horse, a rare breed with unique phenotypic characteristics, including inwardly turned ear tips. It is thought to have originated from the crossbreeding of local Indian ponies with Arabian horses beginning in the 12th century. Results: We generated 101 Gb (similar to 30 x coverage) of whole genome sequences from a Marwari horse using the Illumina HiSeq2000 sequencer. The sequences were mapped to the horse reference genome at a mapping rate of similar to 98% and with similar to 95% of the genome having at least 10 x coverage. A total of 5.9 million single nucleotide variations, 0.6 million small insertions or deletions, and 2,569 copy number variation blocks were identified. We confirmed a strong Arabian and Mongolian component in the Marwari genome. Novel variants from the Marwari sequences were annotated, and were found to be enriched in olfactory functions. Additionally, we suggest a potential functional genetic variant in the TSHZ1 gene (p.Ala344&gt;Val) associated with the inward-turning ear tip shape of the Marwari horses. Conclusions: Here, we present an analysis of the Marwari horse genome. This is the first genomic data for an Asian breed, and is an invaluable resource for future studies of genetic variation associated with phenotypes and diseases in horses.open1