bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficient Organic Tandem Solar Cells based on Small Molecules
Authors: Riede Moritz , Uhrich Christian , Widmer Johannes , Timmreck Ronny , Wynands David , Schwartz Gregor , Gnehr Wolf‐Michael , Hildebrandt Dirk , Weiss Andre , Hwang Jaehyung , Sundarraj Sudhakar , Erk Peter , Pfeiffer Martin , Leo Karl 
Published: June 2011

AbstractIn this paper, two vacuum processed single heterojunction organic solar cells with complementary absorption are described and the construction and optimization of tandem solar cells based on the combination of these heterojunctions demonstrated. The red‐absorbing heterojunction consists of C60 and a fluorinated zinc phthalocyanine derivative (F4‐ZnPc) that leads to a 0.1–0.15 V higher open circuit voltage Voc than the commonly used ZnPc. The second heterojunction incorporates C60 and a dicyanovinyl‐capped sexithiophene derivative (DCV6T) that mainly absorbs in the green. The combination of both heterojunctions into one tandem solar cell leads to an absorption over the whole visible range of the sun spectrum. Thickness variations of the transparent p‐doped optical spacer between both subcells in the tandem solar cell is shown to lead to a significant change in short circuit current density jsc due to optical interference effects, whereas Voc and fill factor are hardly affected. The maximum efficiency η of about 5.6% is found for a spacer thickness of 150‐165 nm. Based on the optimized 165nm thick spacer, effects of intensity and angle of illumination, and temperature on a tandem device are investigated. Variations in illumination intensity lead to a linear change in jsc over three orders of magnitude and a nearly constant η in the range of 30 to 310 mW cm−2. Despite the stacked heterojunctions, the performance of the tandem device is robust against different illumination angles: jsc and η closely follow a cosine behavior between 0° and 70°. Investigations of the temperature behavior of the tandem device show an increase in η of 0.016 percentage points per Kelvin between −20 °C and 25 °C followed by a plateau up to 50 °C. Finally, further optimization of the tandem stack results in a certified η of (6.07 ± 0.24)% on (1.9893 ± 0.0060)cm2 (Fraunhofer ISE), i.e., areas large enough to be of relevance for modules.
Variations in Atomic Disorder in Biogenic Carbonate Hydroxyapatite Using the Infrared Spectrum Grinding Curve Method
Authors: Asscher Yotam , Weiner Steve , Boaretto Elisabetta 
Published: June 2011

AbstractBiogenic carbonate hydroxyapatite crystals are inherently disordered at the atomic level due mainly to the substitutions of various ions in the crystal structure, and, in the case of the bone family of materials, to the fact that these very small crystals have a very large surface‐to‐bulk ratio. Characterization of the extent of disorder is of much interest, as this relates to the stability and hence solubility of the crystals. Here the infrared spectrometry grinding curve approach developed for calcite, is adapted to carbonate hydroxyapatites. The infrared splitting factor is plotted against the full width at half height of the strong phosphate absorption peak as a function of increased grinding of the sample. By doing so, the contribution of particle size to the shape of the peaks is better separated from the contribution of atomic disorder to peak shape. It is shown that differences in disorder exist between dentine, cementum, and bone crystals which could reflect crystal size and/or atomic defects within the crystal. It is als shown that systematic differences exist between enamel samples from different taxa, which we assume only reflects atomic disorder differences within these large crystals. The method can be used to characterize atomic disorder in natural hydroxyapatites, as well as in the many different types of synthetic hydroxyapatites used for biomedical implants.
Oxidative Cleavage of the CarbonCarbon σ‐Bond Using Reusable Copper on Iron
Authors: Song Ren‐Jie , Liu Yu , Hu Rui‐Xiang , Liu Yan‐Yun , Wu Ji‐Cheng , Yang Xu‐Heng , Li Jin‐Heng 
Published: June 2011

AbstractAn efficient and resuble copper on iron catalyst has been prepared for the cleavage of the carbon‐carbon σ‐bond in α‐aminocarbonyl compounds leading to the corresponding formylamides and acids with a maximal TON of up to 51,000. It is noteworthy that the copper on iron catalyst can be easily separated from the reaction mixture, and retains its activity after several reuses.
Silica Nanohybrid Membranes with High CO2 Affinity for Green Hydrogen Purification
Authors: Lau Cher Hon , Liu Songlin , Paul Donald R. , Xia Jianzhong , Jean Yan‐Ching , Chen Hongmin , Shao Lu , Chung Tai‐Shung 
Published: June 2011

AbstractAn effective separation of CO2 from H2 can be achieved using currently known polyethylene oxide (PEO)‐based membranes at low temperatures but the CO2 permeability is inadequate for commerical operations. For commercial‐scale CO2/H2 separation, CO2 permeability of these membranes must be significantly enhanced without compromising CO2/H2 selectivity. We report here exceptional CO2/H2 separation properties of a nanohybrid membrane comprising polyethylene glycol methacrylate (PEGMA) grafts on an organic‐inorganic membrane (OIM) consisting of a low molecular weight polypropylene oxide (PPO)‐PEO‐PPO diamine and 3‐glycidyloxypropyltrimethoxysilane (GOTMS), an alkoxysilane. The CO2 gas permeability of this nanohybrid membrane can reach 1990 Barrer with a CO2/H2 selectivity of 11 at 35 °C for a mixed gas mixture comprising 50% CO2 ‐ 50% H2 at 3.5 atm. The transformation of the inorganic silica phase from a well‐dispersed network of finely defined nanoparticles to rough porous clusters appears to be responsible for this OIM membrane exceeding the performance of other state‐of‐the‐art PEO‐based membranes.
Effects of Side Chains on Thiazolothiazole‐Based Copolymer Semiconductors for High Performance Solar Cells
Authors: Subramaniyan Selvam , Xin Hao , Kim Felix Sunjoo , Shoaee Safa , Durrant James R. , Jenekhe Samson A. 
Published: June 2011

AbstractNew thiazolothiazole‐dithienosilole copolymer semiconductors bearing side chains of different type, size, and topology were synthesized and used to demonstrate the influence of side chains on morphology, charge transport and photovoltaic properties. The field effect mobility of holes varied from 0.01‐0.03 cm2V−1s−1 in PSOTT and PSEHTT to 0.12 cm2V−1s−1 in PSOxTT. The average power conversion efficiency of solar cells under 1.0 sun illumination could be varied from 2.1% in PSOxTT and 4.1% in PSOTT to 5.0% in PSEHTT. The highest photovoltaic efficiency achieved in PSEHTT, that has all‐branched alkyl side chains and face‐on π‐stacking orientation, was corroborated by its enhanced charge photogeneration observed by transient absorption spectroscopy.
Systemic infections mimicking thrombotic thrombocytopenic purpura
Authors: Booth Kristina K. , Terrell Deirdra R. , Vesely Sara K. , George James N. 
Published: June 2011

AbstractThe absence of specific diagnostic criteria, the urgency to begin plasma exchange treatment, and the risk for complications from plasma exchange make the initial evaluation of patients with suspected thrombotic thrombocytopenic purpura (TTP) difficult. Systemic infections may mimic the presenting clinical features of TTP. In the Oklahoma TTP‐HUS (hemolytic‐uremic syndrome) Registry, 1989–2010, 415 consecutive patients have been clinically diagnosed with their first episode of TTP; in 31 (7%) the presenting clinical features were subsequently attributed to a systemic infection. All 31 patients had diagnostic criteria for TTP; 16 (52%) had the complete “pentad” of microangiopathic hemolytic anemia, thrombocytopenia, neurologic abnormalities, renal failure, and fever. Four (16%) of 25 patients who had ADAMTS13 measurements had <10% activity; three patients had a demonstrable ADAMTS13 inhibitor. Compared with 62 patients with severe ADAMTS13 deficiency (<10%) who had no recognized alternative disorders, patients with systemic infections had more frequent fever, coma, renal failure, and the complete “pentad” of clinical features. Seventeen different infectious etiologies were documented. A systematic literature review identified 67 additional patients with a diagnosis of TTP or HUS and also a systemic infection. Among all 98 patients, infections with 41 different bacteria, viruses, and fungi were documented, suggesting that many different systemic infections may mimic the presenting clinical features of TTP. Initial plasma exchange treatment is appropriate in critically ill patients with diagnostic features of TTP, even if a systemic infection is suspected. Continuing evaluation to document a systemic infection is essential to determine the appropriateness of continued plasma exchange. Am. J. Hematol. 86:743–751, 2011. © 2011 Wiley‐Liss, Inc.
Prevalence of monoclonal gammopathy of undetermined significance in an elderly urban Korean population
Authors: Park Hyun‐Kyung , Lee Kyoung‐Ryul , Kim Young‐Jin , Cho Han‐Ik , Eun Kim Jung , Woong Kim Ki , Jung Kim Yu , Lee Keun‐Wook , Hyun Kim Jee , Bang Soo‐Mee , Lee Jong‐Seok 
Published: June 2011

AbstractResearch on the epidemiology of monoclonal gammopathy of undetermined significance (MGUS) is limited in Korea. The aim of this study was to determine the prevalence and characteristics of MGUS in an elderly urban Korean population. A random sample of 1118 Korean elders was selected from residents aged 65 years or older living in Seongnam, Korea 1 year from August 2005. We obtained plasma samples remaining after scheduled tests for the Korean Longitudinal Study on Health and Aging. The mean age of the study population was 72 years (range, 65–97 years). To screen for MGUS, immunofixation and free light‐chain (FLC) assays were performed. Age‐adjusted and gender‐adjusted MGUS prevalence rates in 680 responders were estimated as 3.3% [95% confidence interval (CI) = 2.0–4.6%], and the estimated age‐adjusted prevalence of MGUS was 4.3% in men (95% CI = 1.9–6.6%) and 2.6% in women (95% CI = 1.0–4.2%). Abnormal FLC ratios were detected in 10% of MGUS cases. Multivariate analysis of 945 participants revealed that significant risk factors for MGUS included advanced age, male sex, hyperproteinemia, increased erythrocyte sedimentation rate, and abnormal FLC ratio. MGUS is less prevalent among elderly Koreans (3.3%) than other races. This is the first study to estimate the prevalence of MGUS in the Korean elderly population. Our findings should be confirmed with additional studies analyzing follow‐up samples from 2010. Am. J. Hematol., 2011. © 2011 Wiley‐Liss, Inc.
Two founder mutations in the SEC23B gene account for the relatively high frequency of CDA II in the Italian population
Authors: Russo Roberta , Gambale Antonella , Esposito Maria Rosaria , Serra Maria Luisa , Troiano Annaelena , De Maggio Ilaria , Capasso Mario , Luzzatto Lucio , Delaunay Jean , Tamary Hannah , Iolascon Achille 
Published: June 2011

AbstractCongenital Dyserythropoietic Anemia type II is an autosomal recessive disorder characterized by unique abnormalities in the differentiation of cells of the erythroid lineage. The vast majority of CDA II cases result from mutations in the SEC23B gene. To date, 53 different causative mutations have been reported in 86 unrelated cases (from the CDA II European Registry), 47 of them Italian. We have now identified SEC23B mutations in 23 additional patients, 17 Italians and 6 non‐Italian Europeans. The relative allelic frequency of the mutations was then reassessed in a total of 64 Italian and 45 non‐Italian unrelated patients. Two mutations, E109K and R14W, account for over one‐half of the cases of CDA II in Italy. Whereas the relative frequency of E109K is similar in Italy and in the rest of Europe (and is also prevalent in Moroccan Jews), the relative frequency of R14W is significantly higher in Italy (26.3% vs. 10.7%). By haplotype analysis we demonstrated that both are founder mutations in the Italian population. By using the DMLE+ program our estimate for the age of the E109K mutation in Italian population is ≈2,200 years; whereas for the R14W mutation it is ≈3,000 years. We hypothesize that E109K may have originated in the Middle East and may have spread in the heyday of the Roman Empire. Instead, R14W may have originated in Southern Italy. The relatively high frequency of the R14W mutation may account for the known increased prevalence of CDA II in Italy. Am. J. Hematol. 86:727–732, 2011. © 2011 Wiley‐Liss, Inc.
High‐dose (40,000 IU twice/week) alpha recombinant human erythropoietin as single agent in low/intermediate risk myelodysplastic syndromes: A retrospective investigation on 133 patients treated in a single institution
Authors: Azzarà Antonio , Carulli Giovanni , Galimberti Sara , Baratè Claudia , Fazzi Rita , Cervetti Giulia , Petrini Mario 
Published: June 2011

AbstractWe investigated the efficacy of alpha recombinant human erythropoietin (α‐rHuEPO) administered as single agent to 133 patients affected by myelodysplastic syndromes referring to our Institution in the last 10 years. WPSS score was “very low” in 67%, “low” in 19%, “intermediate” in 14%. The starting schedule was: 40,000 IU bi‐weekly, with reduction or suspension, when necessary, in responsive patients. According to new IWG criteria, response rate (RR) was 75%, 66%, 59% after 8, 16, 24 weeks, respectively. Comparing “very low” and “low/intermediate” risk, RR was 81% vs. 43% (P < 0.001); 70% vs. 45% (P = 0.040); 63% vs. 42% (P = NS) after 8, 16, 24 weeks. RR was significantly influenced by transfusion dependence (P = 0.039) and basal serum EPO level (P < 0.001). Mean Hb value was 94 ± 11 g/l before therapy; 114 ± 19 after 8 weeks (P < 0.001); 116 ± 18 after 16 weeks (P < 0.001); 114 ± 17 after 24 weeks (P < 0.001). Reduction or suspension of therapy significantly affected Hb level after 4 (P < 0.001) and 8 weeks (P < 0.01). Conversely, restart of full dosage significantly enhanced again Hb level after 4 (P < 0.01) and 8 weeks (P < 0.001). 65% patients are alive (mean survival: 74 weeks). Seventy percent are alive in the “very low risk” group and 38% in “low/intermediate risk” group (P < 0.001). Overall mean follow‐up was 69 weeks (range, 8–376): it was 80 weeks in responsive patients (max 376) and 38 weeks in patients who progressively became unresponsive (max 168) (P < 0.01). Median response was 36 weeks, with 33% of patients still responding after one year. Treatment was well tolerated. Am. J. Hematol. 86:762–767, 2011. © 2011 Wiley‐Liss, Inc.
The ancient Egyptian dwarfs of the pyramids: The high official and the female worker
Authors: Kozma Chahira , Sarry El Din Azza Mohamed , El Shafy El Banna Rokia Abd , El Samie Kandeel Wafaa Abd , Lachman Ralph 
Published: June 2011

AbstractThe existence of dwarfism is amply documented in ancient Egypt due to the rich biological and artistic legacies. In previous articles published in this journal, I discussed the roles of people with skeletal dysplasia in ancient Egyptian civilization. In this article I, along with my Egyptian and American colleagues, describe two skeletons of dwarfs that date to 2700–2184 BCE and were unearthed from a funerary complex near the Great Pyramids in Giza. The first skeleton belongs to a high official, Per‐ni‐ankh‐w, who died between 45 and 50 years of age. His statue is on display in the Egyptian Museum of Cairo. The second skeleton belongs to a pregnant female worker found with a fetus in situ. Her estimated age at death was 25–30 years. She most likely died during childbirth due to a small pelvic outlet as supported by her narrow sacrum. The fetal bones appear normal. Radiological examination of both skeletons confirmed the clinical diagnosis of achondroplasia.Ancient Egyptians concerned themselves with the search for spiritual fulfillment through the tradition of moral teachings. Amenemope, a wise man who lived during the reign of Amenhotep III (1391–1354 BCE), advocated respect toward individuals with disabilities:Do not jeer at a blind man nor tease a dwarf,Neither interfere with the condition of a cripple.Do not taunt a man who is in the hand of God,Nor scowl at him if he errs.In summary, artistic, biological, and written resources indicate that dwarfs were well integrated in ancient Egyptian society. © 2011 Wiley‐Liss, Inc.
Effects of crystallinity and molecular weight on crack behavior in crystalline poly(L‐lactic acid)
Authors: Nurkhamidah Siti , Woo Eamor M. 
Published: June 2011

AbstractThe crack behavior and spherulitic morphology in melt‐crystallized poly(L‐lactic acid) (PLLA) were found to be molecular weight (MW) and crystallinity dependent, along with other key factors. With increasing MW in PLLA, the size of spherulites, band spacing of ring‐banded spherulites, and degree of crystallinity decreased, whereas cracks were increasingly less likely to occur. Multiple types of cracks, that is, circumferential and/or radial cracks, were massively present in low‐MW PLLA (PLLA‐11k), which had a high crystallinity. Upon cooling, in PLLA‐11k at most crystallization temperatures (Tc's), cracks formed, and the crack patterns were dependent on the lamellar morphology within the spherulites. Hexagonal, rather than circular, cracks occurred spontaneously during the cooling process of PLLA of a medium‐MW grade (PLLA‐120k) in PLLA film samples crystallized only at high Tc (135–138°C) and cooled to ambient temperature. However, no cracks of any types at all were present in PLLA films of high enough MWs (PLLA‐152k and PLLA‐258k) upon either slow air cooling or quench cooling when the samples were dipped into liquid nitrogen. Apparently, cooling‐induced contraction differences in different directions were invalid or not sufficient to address the complex cracking behavior in PLLA. In addition, for PLLA‐11k with a substantially high crystallinity, cracks were so prone to occur that even cover constraint imposed another factor in determining the crack and ring‐band patterns. More plausible mechanisms and correlations between the cracks, MW, crystallinity, spherulite size, and spherulite lamellar patterns of PLLA were analyzed in detail and proposed in this study. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Facile preparation and potential application of water‐soluble polymeric temperature/pH probes bearing fluorescein
Authors: Guan Xiaolin , Lai Shoujun , Su Zhixing 
Published: June 2011

AbstractAn unsaturated monomer bearing xanthene groups and allyloxyfluorescein (Al‐Flu), was synthesized from fluorescein and allyl bromide by etherification. The structure of the monomer was confirmed by IR and mass spectroscopy and 1H‐NMR, and 13C‐NMR spectroscopy. With azobisisobutyronitrile as a thermal initiator in tetrahydrofuran under 65–70°C, a copolymer of allyloxyfluorescein and acrylamide [poly(Al‐Flu‐co‐AM)] was obtained and was characterized by the methods of IR spectroscopy, ultraviolet–visible spectroscopy, and differential scanning calorimetry. The experimental results show that the fluorescence spectra of water‐soluble poly(Al‐Flu‐co‐AM) was dependent on the pH and temperature in the solution. Moreover, poly(Al‐Flu‐co‐AM) had an excellent linear response between the relative fluorescence intensity and temperature in the range 0–60°C and had a nonlinear response from pH 0.00 to 12.85 between the relative fluorescence intensity and pH. The pH and temperature sensitivities of the fluorescence could be advantageous for it as a multifunctional material to probe pH and temperature. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Water‐based amorphous carbon nanotubes filled polymer nanocomposites
Authors: Yang Xiaoming , Li Liang , Shang Songmin , Tao Xiao‐ming 
Published: June 2011

AbstractA novel method of making water‐based amorphous carbon nanotubes (ACNTs) for advanced polymer nanocomposites is presented. In this approach, sodium dodecyl sulfate (SDS) is introduced onto the amorphous carbon nanotubes to improve the solubility in water and the dispersion in polyvinyl alcohol [PVA] matrix. As a result, the addition of 0.6 wt % ACNTs in the polymer resulted in the significant improvement (167.5 and 175.8%) in the tensile strength and modulus of the polymer, respectively. The improved mechanical property could be ascribed to the load transfer to the nanotubes in the composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Synthesis and characterization of poly(HEMA‐MAA) hydrogel carrier for oral delivery of insulin
Authors: Tyagi Priyanka , Kumar Amit , Kumar Yougesh , Lahiri Sitanshu S. 
Published: June 2011

AbstractPoly(HEMA‐MAA) hydrogel particles were synthesized by redox free‐radical polymerization using 2‐hydroxyethylmethacrylate, different concentration of methacrylic acid as monomer, ethyleneglycol dimethacrylate as crosslinking agent, and APS/TEMED as free‐radical initiator. Fourier transform infrared spectrum of poly(HEMA‐MAA) hydrogels showed intense absorption peak of carbonyl group at ∼ 1700 cm−1 due to carboxylic acid groups of MAA, peak at ∼ 2960 cm−1 due to CH stretching and vinylic peak at 1700 cm−1 independent of MAA concentration. Highest swelling percentage 587% was observed in case of poly(HEMA‐MAA) hydrogel synthesized using 30% of MAA while lowest swelling percentage 413% was observed in hydrogel synthesized 10% of MAA at basic pH (8.0). Scanning electron micrograph of copolymeric particles showed the irregular shape of poly(HEMA‐MAA) particles with conglomeration with each due to ionization of carboxylic groups. Insulin was radiolabeled using technetium‐99m radionuclide and the radiolabeling efficiency was found to be 99%. Poly(HEMA‐MAA) hydrogel having 60% of MAA showed the highest insulin loading efficiency of 68% while lowest 37% was observed in case of 10% MAA hydrogel. Insulin release studies showed only 35–65% of insulin was released into the medium from particles at pH 2.5 in 60 min, while insulin release was significantly higher at pH 7.4. Hypoglycemic effect of the 60 and 80 I.U./kg insulin dose loaded in poly(HEMA‐MAA) copolymeric particles were carried out in fasted diabetic rats and highest decrease in blood glucose level from 506 mg/dL to 170 mg/dL was observed within first 3 h. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Synthesis of controlled thermoresponsive PET track‐etched membranes by ATRP method
Authors: Pan Kai , Ren Ruimin , Dan Yi , Cao Bing 
Published: June 2011

AbstractControlled thermoresponsive PET track‐etched membranes were synthesized by grafting N‐isopropylacrylamide (NIPAAm) onto the membrane surface via atom transfer radical polymerization (ATRP). The initial measurements were made to determine the anchoring of ATRP initiator on PET membrane surface. Thereafter, polymerization was carried out to control the mass of polymer by controlling reaction time grafted from the membrane surface and, ATR‐FTIR, grafting degree measurements, water contact angle measurements, TGA, and SEM were used to characterize changes in the chemical functionality, surface and pore morphology of membranes as a result of modification. Water flux measurements were used to evaluate the thermoresponsive capacity of grafted membranes. The results show the grafted PET track‐etched membranes exhibit rapid and reversible response of permeability to environmental temperature, and its permeability could be controlled by controlling polymerization time using ATRP method. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Preparation and characterization of wood/styrene‐acrylonitrile copolymer/MMT nanocomposite
Authors: Devi R. R. , Maji T. K. 
Published: June 2011

AbstractWood polymer nanocomposite (WPNC) was prepared by impregnating Simul (Salmalia malabarica) wood with styrene‐acrylonitrile copolymer (SAN), glycidyl methacrylate(GMA), and a reactive polymerizable surfactant modified montmorillonite (MMT). The physical and mechanical properties of WPNC were investigated by using XRD, tensile tester, SEM, and FTIR. The polymer loading, dimensional stability, water uptake, mechanical property, and thermal stability were found to improve due to inclusion of MMT. SEM micrographs showed the presence of polymer and MMT into cell wall and cell lumen. FTIR analysis confirmed the presence of MMT and SAN in WPNC. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011