Numerical Investigation of Graphene as a Back Surface Field Layer on the Performance of Cadmium Telluride Solar Cell.

This paper numerically explores the possibility of ultrathin layering and high efficiency of graphene as a back surface field (BSF) based on a CdTe solar cell by Personal computer one-dimensional (PC1D) simulation. CdTe solar cells have been characterized and studied by varying the carrier lifetime, doping concentration, thickness, and bandgap of the graphene layer. With simulation results, the highest short-circuit current (Isc = 2.09 A), power conversion efficiency (h = 15%), and quantum efficiency (QE ~ 85%) were achieved at a carrier lifetime of 1 × 103 ms and a doping concentration of 1 × 1017 cm-3 of graphene as a BSF layer-based CdTe solar cell. The thickness of the graphene BSF layer (1 mm) was proven the ultrathin, optimal, and obtainable for the fabrication of high-performance CdTe solar cells, confirming the suitability of graphene material as a BSF. This simulation confirmed that a CdTe solar cell with the proposed graphene as the BSF layer might be highly efficient with optimized parameters for fabrication.

Homogeneously staining region (hsr) on chromosome 11 is highly specific for KMT2A amplification in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS).

AML and MDS are most common myeloid neoplasms that affect mainly older patients. Overexpression of certain proto-oncogenes plays an indispensable role in tumorigenesis and overexpression can be a consequence of gene rearrangement, amplification and/or mutation. Rearrangement and amplification of KMT2A located at chromosome band 11q23 is a well-characterized genetic driver in a subset of AML/MDS cases and is associated with a poor prognosis. The presence of homogeneously staining regions (hsr) also has been correlated with amplification of specific proto-oncogenes. In this study, we correlated hsr(11)(q23) with KMT2A in a large cohort of AML/MDS (n = 54) patients. We identified 37 patients with hsr(11)(q23) in the setting of AML (n = 27) and MDS (n = 10). All patients showed a complex karyotype including 12 cases with monosomy 17. KMT2A FISH analysis was available for 35 patients which showed KMT2A amplification in all patients. Among control cases with hsr involving chromosomes other than 11q [non-11q hsr, n = 17], FISH analysis for KMT2A was available in 10 cases and none of these cases showed KMT2A amplification (p = 0.0001, Fisher's exact test, two-tailed). Mutational analysis was performed in 32 patients with hsr(11)(q23). The most common mutated gene was TP53 (n = 29), followed by DNMT3A (n = 4), NF1 (n = 4), and TET2 (n = 3). Thirty (83%) patients died over a median follow-up of 7.6 months (range, 0.4-33.4). In summary, hsr(11)(q23) in AML/MDS cases is associated with a complex karyotype, monosomy 17, KMT2A amplification, and TP53 mutation.

MYC protein expression is an important prognostic factor in acute myeloid leukemia.

As new drugs targeting MYC show clinical activity in acute myeloid leukemia (AML), understanding MYC expression in AML is of critical importance. We assessed MYC protein expression by immunohistochemistry in bone marrow of patients with untreated AML (n = 265). Overall, 90% of patients demonstrated MYC overexpression and MYC immunopositivity ≤6% was associated with superior complete remission (CR) duration of 23 months versus 12 months for MYC immunopositivity >6% (p = .028). Among 241 patients at higher risk for relapse, including those ≥55 years of age and patients with intermediate- and high-risk AML, MYC immunopositivity ≤6% conferred significantly superior median overall survival (OS) (24 versus 13 months; p = .042), event-free survival (EFS) (14 versus 6 months; p = .048), and relapse-free survival (RFS) (25 versus 12 months; p = .024). The prognostic impact of MYC-immunopositivity was retained on multivariate analysis of OS, EFS, and RFS. We conclude that MYC immunopositivity is an important prognostic factor in patients with untreated AML, particularly those at higher risk for relapse.

Development of a Solar Cell Back Sheet with Excellent UV Durability and Thermal Conductivity.

The back sheet is one of the most important materials in photovoltaic (PV) modules. It plays an important role in protecting the solar cell from the environment by preventing moisture penetration. In the back sheet, the outermost layer is composed of a polyester (PET) film to protect the PV module from moisture, and the opposite layer is composed of a TiO2 + PE material. Nowadays, PV modules are installed in the desert. Therefore, methods to improve the power generation efficiency of PV modules need to be investigated as the efficiency is affected by temperature resulting from the heat radiation effect. Using a back sheet with a high thermal conductivity, the module output efficiency can be increased as heat is efficiently dissipated. In this study, a thermally conductive film was fabricated by mixing a reference film (TiO2 + PE) and a non-metallic material, MgO, with high thermal conductivity. UV irradiation tests of the film were conducted. The thermally conductive film (TiO2 + PE + MgO) showed higher conductivity than a reference film. No visible cracks and low yellowing degree were found in thermally conductive film, confirming its excellent UV durability characteristics. The sample film was bonded to a PET layer, and a back sheet was fabricated. The yellowing of the back sheet was also analyzed after UV irradiation. In addition, mini modules with four solar cell were fabricated using the developed back sheet, and a comparative outdoor test was conducted. The results showed that power generation improved by 1.38%.

Sol-Gel Deposited Double Layer TiO2 and Al2O3 Anti-Reflection Coating for Silicon Solar Cell.

In this work, the deposition of double layer ARC on p-type Si solar cells was carried out by simple spin coating using sol-gel derived Al2O3 and TiO2 precursors for the fabrication of crystalline Si solar cells. The first ARC layer was created by freshly prepared sol-gel derived Al2O3 precursor using spin coating technique and then second ARC layer of TiO2 was deposited with sol-gel derived TiO2 precursor, which was finally annealed at 400 °C. The double layer Al2O3/TiO2 ARC on Si wafer exhibited the low average reflectance of 4.74% in the wavelength range of 400 and 1000 nm. The fabricated solar cells based on double TiO2/Al2O3 ARC attained the conversion efficiency of ~13.95% with short circuit current (JSC) of 35.27 mA/cm2, open circuit voltage (VOC) of 593.35 mV and fill factor (FF) of 66.67%. Moreover, the fabricated solar cells presented relatively low series resistance (Rs) as compared to single layer ARCs, resulting in the high VOC and FF.

Acute lymphoblastic leukemia secondary to myeloproliferative neoplasms or after lenalidomide exposure.

Philadelphia-negative (Ph-) myeloproliferative neoplasms (MPN) do rarely transform to acute lymphoblastic leukemia (ALL). While causality is difficult to establish, a few cases of ALL arising after exposure to lenalidomide for registered indications (multiple myeloma, myelodysplastic syndrome with 5q deletion) have been described in the literature.

Analysis of the cephalometric changes in the first 3 months after spring-assisted cranioplasty for scaphocephaly.

BACKGROUND: Spring-assisted cranioplasty (SAC) has become an accepted treatment for patients with sagittal craniosynostosis; however, the early effects of springs on skull dimensions have never been assessed with objective measurements in the literature. The present study evaluated the changes in skull dimensions and intracranial volume (ICV) during the first 3 months after SAC for sagittal synostosis. METHODS: Sixteen patients with sagittal synostosis underwent SAC. The cephalic index (CI) and the distance between the spring foot plates were chronologically measured until spring removal at 3 months. Pre- and post-treatment CT scans available for 6 patients were used to assess changes in head shape. Thirteen patients underwent objective aesthetic assessment using pre- and post-operative photographs. Statistical analysis was performed using the linear mixed model for chronological data, t-test statistics for normative data comparisons and Wilcoxon's signed rank test for non-parametric data. RESULTS: For scaphocephalic patients, pre-operative and post-operative CIs were 0.70 and 0.74 (p = 0.001), respectively. Cranial widening towards normative values was observed (p = 0.0005). A continuous expansion in the distance between the spring foot plates was observed over the treatment period. Frontal and occipital angles were not affected by SAC despite apparent clinical improvements in frontal bossing and occipital prominence. CT analysis demonstrated relative reduction in the anterior cranial volume (p = 0.01) and relative expansion of the superior occipital volume (p = 0.03). CONCLUSIONS: Spring expansion was most marked in the hours following spring insertion. The expansion rate reduced to the minimum by day 1 post-operatively. Clinical benefits of SAC resulted from an increase in the bi-temporal width that camouflaged the frontal bossing. Improvement in occipital prominence was due to superior occipital volume expansion, allowing the occiput to remodel to a more rounded shape.

Myeloid neoplasms with concurrent BCR-ABL1 and CBFB rearrangements: A series of 10 cases of a clinically aggressive neoplasm.

Chronic myeloid leukemia (CML) is defined by the presence of t(9;22)(q34;q11.2)/BCR-ABL1. Additional chromosomal abnormalities confer an adverse prognosis and are particularly common in the blast phase of CML (CML-BP). CBFB rearrangement, particularly CBFB-MYH11 fusion resulting from inv(16)(p13.1q22) or t(16;16)(p13.1;q22), is an acute myeloid leukemia (AML)-defining alteration that is associated with a favorable outcome. The co-occurrence of BCR-ABL1 and CBFB rearrangement is extremely rare, and the significance of this finding remains unclear. We identified 10 patients with myeloid neoplasms harboring BCR-ABL1 and CBFB rearrangement. The study group included six men and four women with a median age of 51 years (range, 20-71 years). The sequence of molecular alterations could be determined in nine cases: BCR-ABL1 preceded CBFB rearrangement in seven, CBFB rearrangement preceded BCR-ABL1 in one, and both alterations were discovered simultaneously in one patient. BCR-ABL1 encoded for p210 kD in all cases in which BCR-ABL1 preceded CBFB rearrangement; a p190 kD was identified in the other three cases. Two patients were treated with the FLAG-IDA regimen (fludarabine, cytarabine, idarubicin, and G-CSF) and tyrosine kinase inhibitors (TKI); seven with other cytarabine-based regimens and TKIs, and one with ponatinib alone. At last follow up (median, 16 months; range 2-85), 7 of 10 patients had died. The co-existence of BCR-ABL1 and CBFB rearrangement is associated with poor outcome and a clinical course similar to that of CML-BP, and unlike de novo AML with CBFB rearrangement, suggesting that high-intensity chemotherapy with TKI should be considered in these patients.

Optimization of BBr3-Based Co-Diffusion Processes for Bifacial N-Type Solar Cells.

We report on the co-diffused bifacial N-type solar cells based on N-type Si wafers using the process of spin on doping (SOD, phosphorous source) and boron tribromide (BBr3) diffusion by atmospheric pressure chemical vapor deposition (APCVD). For bifacial co-diffusion, a phosphorous layer was deposited by SOD on the rear side of N-type Si wafer and a BBr3 as boron dopant source deposited by APCVD. Co-diffusion process was controlled by changing the flowrate of carrier N2 gas and drive-in temperatures. It was found that the fabricated bifacial co-diffused N-type solar cell with 2% H3PO4 doping, the flowrate of N2 carrier gas of 15 slm and drive-in temperature at 930°C exhibited the highest conversion efficiency of 15.8% with high open circuit voltage (V(oc)) of 593 mV. As compared to high H3PO4 concentrations (5% and 9%), the low H3PO4 concentration of SOD showed the higher sheet resistance and decreased in the thickness of N + emitter layer, resulting in the high V(oc), shunt resistance, fill factor and conversion efficiency of solar cells.

Properties of CuInS2 Nano-Particles on TiO2 by Spray Pyrolysis for CuInS2/TiO2 Composite Solar Cell.

In this letter, for the absorption layer of a CuInS2/TiO2 composite solar cell, I­III­VI2 chalcopyrite semiconductor CuInS2 nano-particles were deposited by using spray pyrolysis method on TiO2 porous film. Their material characteristics including structural and optical properties of CuInS2 nano-particles on TiO2 nanorods were analyzed as a function of its composition ratios of Cu:In:S. Crystalline structure, surface morphology and crystalline size were also investigated by X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), and High-Resolution TEM (HRTEM), respectively. On the other hand, optical property was characterized by an UV-Visible Spectrophotometer. As a result, it was found that the size of CuInS2 nano-particles, which was formed at 300±5 °C, was smaller than 16 nm from HRTEM analyses, and it was identified that the CuInS2 particle size was increased as increasing the heat-treatment temperature and time. However, as the size of CuInS2 nano-particle becomes smaller, optical absorption edge of ternary compound film tends to move to the blue wavelength band. It turns out that the optical energy-band gap of the compound films was ranging from 1.48 eV to 1.53 eV.

Characterization of Boron Diffusion Phenomena According to the Specific Resistivity of N-Type Si Wafer.

This paper is directed to characterize the boron diffusion process according to the specific resistivity of the Si wafer. N-type Si wafers were used with the specific resistivity of 0.5-3.2 omega-cm, 1.0-6.5 omega-cm and 2.0-8.0 omega-cm. The boron tribromide (BBr3) was used as boron source to create the PN junction on N-type Si wafer. The boron diffusion in N-type Si wafer was characterized by sheet resistance of wafer surface, secondary ion mass spectroscopy measurements (SIMS) and surface life time analysis. The degree of boron diffusion was depended on the variation in specific resistivity and sheet resistance of the bare N-type Si wafer. The boron diffused N-Si wafer exhibited the average junction depth of 750 nm and boron concentration of 1 x 10(19). N-type Si wafer with the different specific resistance considerably affected the boron diffusion length and life time of Si wafer. It was found that the lifetime of boron diffused wafer was proportional to the sheet resistance and resistivity. However, optimization process may necessary to achieve the high efficiency through the high sheet resistance wafer, because the metallization process control is very sensitive.

Hydrodechlorination of Silicon Tetrachloride to Trichlorosilane Over Ordered Mesoporous Carbon Catalysts: Effect of Pretreatment of Oxygen and Hydrochloric Acid.

This paper reports on the catalytic reaction for the conversion of silicon tetrachloride (STC) to trichlorosilane (TCS) over pretreated ordered mesoporous carbon (OMC) catalysts by oxygen (denoted as OMC-O2) and hydrochloric acid (denoted as OMC-HCl) at 300 degrees C under N2 atmosphere. The OMC-O2 shows significantly improved the surface area (1341.2 m2/g) and pore volume (1.65 cm3/g), which results in the highest conversion rate of 7.3% as compared to bare OMC (4.3%) and OMC-HCI (5.7%). It is found that the conversion rate of STC to TCS is proportional to the number of Si-O bond over OMC catalysts, which suggests that Si-O-C bond formation is crucial to the reaction as active sites. The O2 pretreatment seems to promote the generation of oxygenated species for the formation of Si-O-C.

Nanoprecursor-Mediated Synthesis of Mg²âº-Doped TiO2 Nanoparticles and Their Application for Dye-Sensitized Solar Cells.

Surface-doping anatase TiO2 nanoparticles with Mg²âº were prepared via a novel synthetic method, and used as photoanodes for dye-sensitized solar cells (DSSCs). X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) image results indicate that the Mg²âº doping has no effect on the crystal phase and morphology of anatase TiO2. The shift in XRD peaks to higher angles, the absorption shift in UV-vis diffuse reflection spectra, and X-ray photoelectron spectroscopy (XPS) results indicate the incorporation of Mg²âº-ions into the TiO2 lattice. The as-prepared TiO2nanoparticles doped with a low concentration of ions is proven a superior photoanode material than pure anatase TiO2. The energy-conversion efficiency (1) of DSSC based on TiO2 nanoparticles doped with Mg²âº is at a maximum of 5.90%, corresponding to an efficiency improvement of 23.4% as compared to DSSC based on un-doped TiO2. This new synthetic approach using a nanoprecursor provides a simple and versatile method for the preparation of excellent photoanode materials for application in solar energy conversion devices.

Isoniazid therapy for Mycobacterium tuberculosis infection in HIV clinics, Los Angeles, California.

SETTING: Publicly funded human immunodeficiency virus (HIV) clinics in Los Angeles County, California, USA. BACKGROUND: HIV-infected persons are a high priority group for targeted testing and treatment for Mycobacterium tuberculosis infection in the United States. OBJECTIVE: To describe rates of isoniazid (INH) initiation and completion among HIV-1 and M. tuberculosis co-infected persons in Los Angeles County. DESIGN: We conducted a cross-sectional study using routinely collected surveillance data from publicly funded HIV clinics. We examined differences in INH treatment initiation and completion between four clinic categories: the three largest clinics (Clinics A, B, and C) and 'Other' clinics (pooled data for the remaining 10 clinics). RESULTS: During 2010-2013, 802 (5.3%) of 15 029 HIV-1-infected persons tested positive for M. tuberculosis infection. INH was initiated in 581 (72.4%) persons, of whom 457 (78.7%) completed treatment. We found significant differences between clinics in terms of treatment initiation (range 59.1-93.4%) and completion (range 58.8-82.3%). Overall, 57% (457/802) of HIV and M. tuberculosis co-infected persons completed the recommended treatment (range across clinics 34.8-76.3%). CONCLUSION: We identified significant gaps in the treatment for M. tuberculosis infection among HIV-infected persons in Los Angeles County. Interventions are needed to improve initiation and completion of treatment for M. tuberculosis infection in this population.

Double minute chromosomes in acute myeloid leukemia, myelodysplastic syndromes, and chronic myelomonocytic leukemia are associated with micronuclei, MYC or MLL amplification, and complex karyotype.

Double minute chromosomes (dmin) are small, paired chromatin bodies that lack a centromere and represent a form of extrachromosomal gene amplification. Dmin are rare in myeloid neoplasms and are generally associated with a poor prognosis. Most studies of dmin in myeloid neoplasms are case reports or small series. In the current study, we present the clinicopathologic and cytogenetic features of 22 patients with myeloid neoplasms harboring dmin. These neoplasms included acute myeloid leukemia (AML) (n = 18), myelodysplastic syndrome (MDS) (n = 3), and chronic myelomonocytic leukemia (CMML) (n = 1). The AML cases consisted of AML with myelodysplasia-related changes (n = 13) and therapy-related AML (n = 5). Dmin were detected in initial pre-therapy samples in 14 patients with AML or CMML; they were acquired during the disease course in 8 patients who had AML or MDS. The presence of dmin was associated with micronuclei (18/18; 100%), complex karyotype (17/22; 77.3%), and amplification of MYC (12/16; 75%) or MLL (4/16; 25%). Immunohistochemical staining for MYC performed on bone marrow core biopsy or clot sections revealed increased MYC protein in all 19 cases tested. Except for one patient, most patients failed to respond to risk-adapted chemotherapies. At last follow up, all patients had died of disease after a median of 5 months following dmin detection. In conclusion, dmin in myeloid neoplasms commonly harbor MYC or MLL gene amplification and manifest as micronuclei within leukemic blasts. Dmin are often associated with myelodysplasia or therapy-related disease, and complex karyotypes.

The clinical significance of 8q24/MYC rearrangement in chronic lymphocytic leukemia.

Chromosome 8q24/MYC rearrangement is associated with Burkitt lymphoma and some aggressive B-cell lymphomas, but is rare in chronic lymphocytic leukemia. We here report a cohort of 20 chronic lymphocytic leukemia patients with 8q24/MYC rearrangement, 3 detected at time of initial diagnosis and 17 acquired after a median interval of 48 months. At the time when 8q24/MYC arrangement was detected, 18 patients had B-symptoms, 17 had lymphadenopathy, and 17 had splenomegaly. Histologically, typical chronic lymphocytic leukemia morphology was seen in six patients, increased prolymphocytes in nine and Richter's transformation in five patients. Eighteen patients had karyotypic information available that showed t(8;v) in a complex karyotype in 12 patients and in a non-complex karyotype in 6 patients. Fluorescence in situ hybridization confirmed MYC rearrangement in 17/17 patients. All patients required therapy after 8q24/MYC rearrangement was detected. At last follow-up, five of six patients with a non-complex karyotype were alive after a median of 74 months (10~143 months) from the detection of 8q24/MYC rearrangement. In contrast, 10 of 12 patients with a complex karyotype died with a median survival of 5.5 months. We conclude that 8q24/MYC rearrangement in chronic lymphocytic leukemia is rare and often acquired during the course of disease. If it is presented in a complex karyotype, it is often associated with Richter's transformation, refractory to therapy and an aggressive clinical course; on the other hand, if it is present in a non-complex karyotype, patients often respond to risk-adapted therapies and achieve remission.