bluuebunny/crossref_metadata_2025 huggingface dataset:
Human papillomavirus in oropharyngeal squamous cell carcinoma: Assessing virus presence in normal tissue and activity in cervical metastasis
Authors: Laborde Rebecca R. , Janus Jeffrey R. , Olsen Steven M. , Wang Vivian W. , Garcia Joaquin J. , Graham Rondell P. , Moore Eric J. , Olsen Kerry D. , Kasperbauer Jan L. , Price Daniel L. , Berres Michael , Halling Geoffrey , Smith David I.
Published: September 2012

Objectives/Hypothesis:

Human papillomavirus (HPV) has been established as an etiologic and prognostic factor in oropharyngeal squamous cell carcinoma (OPSCC). HPV oncogenesis involves expression of E6/E7 oncoproteins, with downstream p53 degradation and pRb inhibition. Although much research has focused on HPV's oncogenic behavior in primary OPSCC, minimal information exists about HPV in adjacent normal and metastatic tissue.

Study Design:

Retrospective cohort study

Methods:

Patient‐matched tumor, normal, and metastatic tissue was gathered from 42 OPSCC patients and tested with real‐time quantitative polymerase chain reaction (RT‐qPCR), in situ hybridization (ISH), and immunohistochemistry (IHC). RT‐qPCR was performed using total RNA from fresh‐frozen tissues and primers for HPV16 E6, E7, and p16 transcripts. HPV ISH was performed to detect the presence of HPV DNA and IHC to detect p16 protein.

Results:

Primary tumor, adjacent normal tissue, and tumor metastasis from 17 OPSCC patients were analyzed. When comparing the presence of HPV16 DNA in tumor, metastatic, and normal tissue by ISH, perfect correlation is found at all subsites (P < .0001). However, active infections determined by HPV16 E6 and E7 expression using quantitative polymerase chain reaction or p16 detection by IHC, were present only in primary and metastatic tissue (P = .0012, E6; P = .02, E7). No such correlation was found in normal tissue when compared to primary or metastatic tissue.

Conclusions:

There is a clear pattern of active HPV expression that correlates to disease course. In HPV‐positive patients, all sites including primary, metastatic, and normal tissues are DNA positive. Transcriptionally active infections were detected in primary and metastatic tissues, whereas normal tissues appear to have latent infections.
Hepatic and Abdominal Carbon Dioxide Measurements Detect and Distinguish Hepatic Artery Occlusion and Portal Vein Occlusion in Pigs
Authors: Pischke Soeren Erik , Tronstad Christian , Holhjem Lars , Line Pål Dag , Haugaa Håkon , Tφnnessen Tor Inge
Published: September 2012

Hepatic artery (HA) occlusion and portal vein (PV) occlusion are the most common vascular complications after liver transplantation with an impact on mortality and retransplantation rates. The detection of severe hypoperfusion may be delayed with currently available diagnostic tools. Hypoperfusion and anaerobically produced lactic acid lead to increases in tissue carbon dioxide. We investigated whether the continuous assessment of the intrahepatic and intra-abdominal partial pressure of carbon dioxide (PCO2) could be used to detect and distinguish HA and PV occlusions in real time. In 13 pigs, the HA and the PV were fully occluded (n = 7) or gradually occluded (n = 6). PCO2 was monitored intrahepatically and between loops of small intestine. The hepatic and intestinal metabolism was assessed with microdialysis and PV as well as hepatic vein blood samples, and the results were compared to clinical parameters for the systemic circulation and blood gas analysis. Total HA occlusion led to significant increases in hepatic PCO2 and lactate, and this was accompanied by significant decreases in the partial pressure of oxygen and glucose. PV occlusion induced a significant increase in intestinal PCO2 (but not hepatic PCO2) along with significant increases in intestinal lactate and glycerol. Gradual HA occlusion and PV occlusion caused steady hepatic and intestinal PCO2 increases, respectively. Systemic clinical parameters such as the blood pressure, heart rate, and cardiac output were affected only by PV occlusion. In conclusion, even gradual HA occlusion affects liver metabolism and can be reliably identified with hepatic PCO2 measurements. Intestinal PCO2 increases only during PV occlusion. A combination of hepatic and intestinal PCO2 measurements can reliably diagnose the affected vessel and depict the severity of the occlusion, and this may emerge as a potential real-time clinical monitoring tool for the postoperative course of liver transplantation and enable early interventions. Liver Transpl, 2012. © 2012 AASLD.
Deceased donation in Asia: Challenges and opportunities
Authors: Lo Chung-Mau
Published: September 2012

Key Points

1. The deceased donation rate is low in Asia, and there is a critical shortage of liver grafts.

2. The number of liver transplants in Asia has increased rapidly during the last decade, mainly because of the rapid increase in the use of living donor liver transplantation (LDLT).

3. Various social, cultural, religious, and economic factors account for the low rate of deceased donation, and there is marked diversity between different countries and even within individual countries.

4. There are excellent opportunities for the actualization of deceased donation through legislation, education, donor actions, and innovations.

5. In the foreseeable future, LDLT will continue to play a crucial role for patients with liver disease in Asia. Liver Transpl, 2012. © 2012 AASLD.
An Efficient Thiol‐Ene Chemistry for the Preparation of Amphiphilic PHA‐Based Graft Copolymers
Authors: Le Fer Gaëlle , Babinot Julien , Versace Davy‐Louis , Langlois Valérie , Renard Estelle
Published: September 2012

We present a straightforward method to prepare amphiphilic graft copolymers consisting of hydrophobic poly(3‐hydroxyalkanoates) (PHAs) backbone and hydrophilic α‐amino‐ω‐methoxy poly(oxyethylene‐co‐oxypropylene) (Jeffamine®) units. Poly(3‐hydroxyoctanoate)‐co‐(3‐hydroxyundecenoate) (PHOU) was first methanolyzed to obtain the desired molar mass. The amino end groups of Jeffamine were converted into thiol by a reaction with N‐acetylhomocysteine thiolactone and subsequently photografted. This “one‐pot” functionalization prevents from arduous and time‐consuming functionalization of the hydrophilic precursor or tedious modifications of PHAs, thus simplifying the process. The amphiphilic nature of modified PHAs leads to water‐soluble copolymers exhibiting thermoresponsive behavior.
Probability Based hERG Blocker Classifiers
Authors: Wang Zhi , Mussa Hamse Y. , Lowe Robert , Glen Robert C. , Yan Aixia
Published: September 2012

The US Food and Drug Administration (FDA) require in vitro human ether‐a‐go‐go related (hERG) ion channel affinity tests for all drug candidates prior to clinical trials. In this study, probabilistic‐based methods were employed to develop prediction models on hERG inhibition prediction, which are different from traditional QSAR models that are mainly based on supervised ‘hard point’ (HP) classification approaches giving ‘yes/no’ answers. The obtained models can ‘ascertain’ whether or not a given set of compounds can block hERG ion channels. The results presented indicate that the proposed probabilistic‐based method can be a valuable tool for ranking compounds with respect to their potential cardio‐toxicity and will be promising for other toxic property predictions.
Harnessing Human N‐type Ca2+ Channel Receptor by Identifying the Atomic Hotspot Regions for Its Structure‐Based Blocker Design
Authors: Pandey Ashish , P Jigneshkumar , Tripathi Satyaprakash , Gopi Mohan C.
Published: September 2012

The voltage dependent N‐type Ca2+ channel (NCC) receptor was identified to have therapeutic potential for the treatment of neuropathic pain and stroke disease. The Ca2+ ion transport through the transmembrane influx is mainly dependent on the closing, opening, or intermediate state gating mechanism of NCC. Harnessing this dynamic gating mechanism at the structural level is an important and challenging physiological phenomenon. The three dimensional (3D) structure of this membrane receptor is not yet experimentally determined to understand its mechanism of action. Based on these observations, we have developed for the first time the structure of the closed state of the NCC receptor at the pore forming domains which mainly involve three transmembrane helices (TMhs) S5, P and S6. Hot‐spot binding site residues of this receptor model were identified by molecular docking technique using amlodipine, cilnidipine and nifedipine compounds known to be potent Ca2+ channel antagonists. Further, the Ca2+ ion permeability and the hydrophobic gating mechanism provided better structural and functional insights on the NCC receptor. These results are in consonance with other Ca2+ channel receptors and would provide guidance for further biochemical investigations.
Serial measurement of hepatic lipids during chemotherapy in patients with colorectal cancer: a 1H MRS study
Authors: Qi Jing , Fong Yuman , Saltz Leonard , D'Angelica Michael I. , Kemeny Nancy E. , Gonen Mithat , Shia Jinru , Shukla‐Dave Amita , Jarnagin William M. , Do Richard K. G. , Schwartz Lawrence H. , Koutcher Jason A. , Zakian Kristen L.
Published: September 2012

Hepatic steatosis is a hallmark of chemotherapy‐induced liver injury. We made serial 1H MRS measurements of hepatic lipids in patients over the time course of a 24‐week chemotherapeutic regimen to determine whether 1H MRS could be used to monitor the progression of chemotherapy‐induced steatosis. Thirty‐four patients with stage III or IV colorectal cancer receiving 5‐fluorouracil, folinic acid and oxaliplatin (n = 21) or hepatic arterial infusion of floxuridine with systemic irinotecan (n = 13) were studied prospectively. 1H MRS studies were performed at baseline and after 6 and 24 weeks of treatment. A 1H MR spectrum was acquired from the liver during a breath hold and the ratio of fat to fat + water (FFW) was calculated to give a measure of hepatic triglycerides (HTGCs). The methodology was histologically validated in 18 patients and the reproducibility was assessed in 16 normal volunteers. Twenty‐seven patients completed baseline, 6‐week and 24‐week 1H MRS examinations and one was censored. Thirteen of 26 patients (50%) showed an increase in FFW after completion of treatment. Six patients (23%) developed hepatic steatosis and two patients converted from steatosis to nonsteatotic liver. Patients whose 6‐week hepatic lipid levels had increased significantly relative to baseline also had a high probability of lipid elevation relative to baseline at the completion of treatment. Serial 1H MRS is effective for the monitoring of HTGC changes during chemotherapy and for the detection of chemotherapy‐associated steatosis. Six of 26 patients developed steatosis during chemotherapy. Lipid changes were observable at 6 weeks. Copyright © 2012 John Wiley & Sons, Ltd.
Layered double hydroxide – montmorillonite – a new nano‐dimensional material
Authors: Yi Deqi , Yang Rongjie , Wilkie Charles A.
Published: September 2012

A new nano‐dimensional material, layered double hydroxide – montmorillonite (LDH‐MMT), has been synthesized by the formation of an LDH in the presence of MMT. The structure is studied using X‐ray diffraction, Fourier transform infrared, scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy analysis. The LDH‐MMT shows a novel layered structure containing negatively charged MMT layers and positively charged LDH layers with some sodium ions required to balance the charge. LDH‐MMT can be ion‐exchanged to obtain organically modified LDH‐MMT, and this material can be well‐dispersed in polystyrene. Copyright © 2012 John Wiley & Sons, Ltd.
Poly(ethylene glycol)‐crosslinked fullerenes for high efficient phototherapy
Authors: Lee Dong Jin , Ahn Yong Sik , Youn Yu Seok , Lee Eun Seong
Published: September 2012

Poly(ethylene glycol)‐crosslinked multimeric C60 was developed for use in photothermal/photodynamic therapy of malignant cells. We showed that: (i) the tumor surface temperature on KB tumor‐bearing nude mice treated with multimeric C60 reached about 44 °C; (ii) this hyperthermic condition and tremendous singlet oxygen generation from multimeric C60 resulted in significant tumor volume regression in KB tumor‐bearing nude mice; and (iii) multimeric C60 also efficiently inhibited arthritic progress in the arthritis‐induced DBA/1 J mice model. This multimeric C60 may be useful for photothermal/photodynamic cell ablation in various malignant cells. Copyright © 2012 John Wiley & Sons, Ltd.
Outcome of patients with localized orbital sarcoma who relapsed following treatment on Intergroup Rhabdomyosarcoma Study Group (IRSG) Protocols‐III and ‐IV, 1984–1997: A report from the Children's Oncology Group
Authors: Raney Beverly , Huh Winston , Hawkins Douglas , Hayes‐Jordan Andrea , Million Lynn , Rodeberg David , Teot Lisa , Anderson James ,   for the Soft Tissue Sarcoma Committee of the Children's Oncology Group, Arcadia, CA
Published: September 2012

Background

We wanted to ascertain patterns of recurrence, re‐treatment, and outcome among 188 eligible patients treated for localized orbital sarcoma on IRSG Protocols III/IV, 1984–1997.

Procedure

Retrospective chart review.

Results

Twenty‐four of 188 patients (12.8%) developed local (n = 22) or distant relapse (n = 2) at 0.057–7.05 years (median, 1.58) after enrollment. Ages at study entry were 0.14–17 years (median, 5 years). Initial tumor operations included biopsy (n = 20) or gross resection with microscopic residual (n = 4). Initial tumor diameters were 0.5–7 cm (median, 3). Pathologic subtypes were embryonal rhabdomyosarcoma (ERMS, n = 19), sarcoma not otherwise specified (n = 2), and alveolar RMS, botryoid ERMS, or undifferentiated sarcoma (n = 1 each). Initial treatment included vincristine/dactinomycin (n = 24) including an alkylator (n = 4) and radiotherapy (RT, n = 21). Twenty patients responded, 14 completely, 6 partially. After recurrence, patients underwent orbital exenteration (n = 10), enucleation (2), tumor excision (3), or biopsy (1); 7 had no operation, and 1 had no data. Post‐relapse chemotherapy included combinations of etoposide (n = 14 patients), doxorubicin (14), ifosfamide (12), cyclophosphamide (7), and dacarbazine (n = 1). Six patients received RT, including four previously treated and two not irradiated initially. Two patients died; one at 1.79 years after contralateral brain metastasis followed by local recurrence, and another at 2.49 years after multiple local recurrences. Twenty‐two patients (91.7%) survived sarcoma‐free for 0.04–17 years (median, 6.9) after relapse, and 18 of 22 (82%) were alive ≥5 years after relapse.

Conclusion

Survival following recurrent localized orbital sarcoma appears likely after vigorous re‐treatment given with curative intent. Pediatr Blood Cancer 2013; 60: 371–376. © 2012 Wiley Periodicals, Inc.
No evidence of increased asparagine levels in the bone marrow of patients with acute lymphoblastic leukemia during asparaginase therapy
Authors: Tong Wing H. , Pieters Rob , Hop Wim C.J. , Lanvers‐Kaminsky Claudia , Boos Joachim , van der Sluis Inge M.
Published: September 2012

Background

Mesenchymal cells (MSCs) in bone marrow (BM) may produce asparagine and form protective niches for leukemic cells. In vitro, this led to high levels of asparagine and conferred asparaginase resistance to acute lymphoblastic leukemia (ALL) cells. The aim of this study was to investigate whether MSCs or other cells in BM indeed produce such significant amounts of asparagine in vivo as to result in clinical asparaginase resistance.

Procedure

Twenty‐six patients with newly diagnosed ALL were enrolled. All children received induction chemotherapy according to the Dutch Childhood Oncology Group (DCOG) ALL‐10 protocol. Asparaginase was administered from days 12–33. Asparaginase, asparagine, aspartic acid, glutamine, and glutamic acid levels were measured in BM and blood at diagnosis, days 15, 33, and 79.

Results

Median asparaginase trough levels were not significantly different at days 15 and 33. Only at diagnosis, asparagine level was significantly higher in BM than in blood (P = 0.001). Asparagine levels were all below the lower limit of quantification in BM and blood at days 15 and 33. However, aspartic acid level in BM was significantly higher than in blood (P < 0.001) at diagnosis, and also at days 15, 33, and 79.

Conclusions

We demonstrate higher aspartic acid levels in BM compared to blood; however, no increased asparagine levels were seen during induction therapy containing asparaginase in BM when compared to blood. Therefore, increased asparagine synthesis by MSCs is of relevance for resistance to asparaginase of leukemic cells in vitro, but it is questionable whether this leads to asparaginase resistance in childhood ALL patients. Pediatr Blood Cancer 2013;60:258–261. © 2012 Wiley Periodicals, Inc.
Food selection for treatment of hypoglycaemia in insulin‐treated diabetes: what happens in real life?
Authors: Vindedzis Sally A , Marsh Beryl , Sherriff Jill L , Dhaliwal Satvinder S , Stanton Kim G
Published: September 2012

Hypoglycaemia is a feared complication of insulin‐treated diabetes. Treatment recommendations vary worldwide and their implementation is poorly documented. The primary study objective was to assess adherence to broad guidelines of hypoglycaemic treatment; initially with quick‐acting carbohydrate and follow up with long‐acting carbohydrate. The secondary objective was to assess if initial treating carbohydrate quantity complied with current worldwide recommendations.

Assessment was by questionnaire, which was validated, piloted and administered to all insulin‐treated individuals attending routine outpatient diabetes clinic appointments over four weeks. The questionnaire response rate, readability and validity were acceptable at 74%, grade 6 level and 0.61 (Cohen's kappa), respectively.

Assessment of broad guidelines for treatment of hypoglycaemia showed 78% of responders reported initial treatment with recommended foods, but only 40.8% of these were quick‐acting carbohydrate. Only 55.8% reported ingesting follow‐up food. Assessment of initial treating carbohydrate quantity showed 20.6% of responders used quantities exceeding all guidelines. Of the remaining, 46.4% used quantities consistent with the most liberal recommendations (European Association for the Study of Diabetes).

Most study participants reported treating with recommended foods in quantities exceeding minimum recommendations, possibly attempting to resolve unpleasant symptoms of hypoglycaemia quickly. Failure of many to ingest follow‐up food is concerning and warrants investigation. Increased patient education and standardisation of guidelines for treatment of hypoglycaemia are indicated. Copyright © 2012 John Wiley & Sons.
Performance management in clinical diabetes: are the Diabetes UK ‘15 health care essentials’ a good enough measure of the standard of diabetes care?
Authors: Grant Paul , Haq Masud , Barnes Dennis
Published: September 2012

Having the right care is essential for the wellbeing of all people with diabetes. There is a minimum level of health care that every person with diabetes should expect. In 2010, Diabetes UK produced a list of 15 essential checks and services that people with diabetes should expect to receive. We wanted to assess whether we were adequately achieving all of these targets in our own diabetes service and assess whether the targets were themselves adequate and appropriate.

We retrospectively reviewed the medical records of 200 randomly selected patients attending the diabetes review clinic in a district general hospital. We recorded whether the parameters outlined in the Diabetes UK ‘15 health care essentials’ had been achieved in the last 12 months and then collated the data.

The data showed that we scored well in terms of monitoring HbA1c, blood pressure, body mass index, retinal screening and cholesterol. However, we scored sub‐optimally in terms of the following parameters: smoking cessation, pregnancy planning, structured education, measurement of waist circumference and psychological assessment.

In conclusion, the Diabetes UK ‘essentials’ checklist may be viewed as mechanistic, but it provides a useful starting point to assess the effectiveness of a diabetes service in providing the basics of patient care in much the same way as the WHO surgical checklist reduces adverse outcomes. We have been able to see where the deficiencies in our own service lie and have made amends to ensure that these areas are covered in future.

One issue that arose is that there are certain other ‘essentials’ that would be good to include in such a checklist, such as: erectile dysfunction (as suggested by the NICE guidelines), obstructive sleep apnoea, vitamin D deficiency, neuropathy screening and monitoring of liver function to rule out incipient steatohepatitis/fatty liver disease. Copyright © 2012 John Wiley & Sons.
Photon absorption and photocurrent in solar cells below semiconductor bandgap due to electron photoemission from plasmonic nanoantennas
Authors: Novitsky A. , Uskov A. V. , Gritti C. , Protsenko I. E. , Kardynał B. E. , Lavrinenko A. V.
Published: September 2012

We model the electron photoemission from metal nanoparticles into a semiconductor in a Schottky diode with a conductive oxide electrode hosting the nanoparticles. We show that plasmonic effects in the nanoparticles lead to a substantial enhancement in photoemission compared with devices with continuous metal films. Optimally designed metal nanoparticles can provide an effective mechanism for the photon absorption in the infrared range below the semiconductor bandgap, resulting in the generation of a photocurrent in addition to the photocurrent from band‐to‐band absorption in a semiconductor. Such structure can form the dais of the development of plasmonic photoemission enhanced solar cells. Copyright © 2012 John Wiley & Sons, Ltd.
Gettering of transition metals by porous silicon in epitaxial silicon solar cells
Authors: Radhakrishnan Hariharsudan Sivaramakrishnan , Ahn Chihak , Van Hoeymissen Jan , Dross Frédéric , Cowern Nick , Van Nieuwenhuysen Kris , Gordon Ivan , Mertens Robert , Poortmans Jef
Published: September 2012

Epitaxial silicon solar cells (“epicells”) are based on an epitaxial active layer (“epilayer”) grown on top of a low‐cost, inactive p+ silicon substrate. A key challenge is to mitigate transition metal out‐diffusion from the low‐purity substrate into the active layer. An embedded porous silicon (PSi) layer can be used to getter metals within the substrate. This was studied theoretically using density functional theory where large binding energies (∼1.9–2.2 eV) for metal segregation to PSi void surface were calculated for Fe and Cu. Incorporating this in a diffusion model yielded large gettering coefficients of ∼104 even at 1000 °C. To verify this experimentally, a test structure consisting of a 2‐µm thick epilayer grown on top of an 8.5 × 8.5 cm2 area of re‐organized PSi etched into the middle of an 8″ Cz, p+ wafer was used. These wafers were surface‐contaminated with metals (Fe, Ni, Cu) to ∼1014–1015 cm−2 and annealed at high temperatures (950–1000 °C) for up to 15 min. This allowed the metals to distribute throughout the wafer and getter to preferential sites. Direct total reflection X‐ray fluorescence mapping of Cu on the front side showed that the embedded PSi reduced the amount of Cu reaching the top surface by ∼103 times, compared to the areas without PSi. Moreover, SIMS depth profiling revealed large metal concentrations (1018–1019 cm−3) in the depth associated with PSi, while the metal concentrations were below detection limits in the surrounding area, suggesting a gettering coefficient of ∼103–104. A slow cooling rate and smaller pore radii were also found to be beneficial for gettering.
Direct growth of vertically aligned single‐walled carbon nanotubes on conducting substrate and its electrochemical performance in ionic liquids
Authors: Azam Mohd Asyadi , Isomura Kazuki , Fujiwara Akihiko , Shimoda Tatsuya
Published: September 2012

We report the fabrication of vertically aligned single‐walled carbon nanotube (VA‐SWCNT) electrodes for a symmetric electrochemical capacitor using a simple, low‐cost ethanol‐based SWCNT growth system. From the CNT direct growth technique, the electrode was easily prepared and consequently assembled with an electrochemically stable ionic liquid as electrolyte. VA‐SWCNTs were directly grown on conducting SUS 310S foils in which the binder material was not incorporated in the capacitor structure. The morphology of as‐grown CNTs was investigated using scanning and transmission electron microscopy. This capacitor demonstrated a gravimetric capacitance of up to 584 F g−1 (at 1 mV s−1 scan rate) and a high‐rate capability, with up to 1000 mV s−1 scan rate being obtained. From the cyclic voltammetric analysis, the capacitance was contributed not only from the ideal double‐layer capacitance, but also from faradaic/redox processes that might have occurred during charge–discharge. Other than the capacitance, the VA‐SWCNT capacitor electrochemical performance was also measured by using frequency response (electrochemical impedance) and charge–discharge analyses.
Multicrystalline silicon solar cells from RST ribbon process
Authors: De Moro Fabrice , Focsa Alexandru , Derbouz Karim , Slaoui Abdelilah , Auriac Nicolas , Lignier Hélène , Keller Philipp
Published: September 2012

The aim of Solarforce is the achievement of high efficiency solar cells made out of ≤100 µm thick multicrystalline silicon wafers produced by the Ribbon on Sacrificial Template (RST) process. For a first evaluation of the RST material, solar cells were fabricated on p‐type RST wafers with different processes. The first conclusion is that the density of silicon carbide inclusions has to be lowered to obtain better FF values, and in turn a better homogeneity in cell performances. Secondly, conversion efficiency is found to be limited around 14% by low bulk minority carrier lifetime values, limiting both Voc and Leff. ICP‐MS analyses on RST material show that this lifetime may be improved with the possible achievement of low metallic impurity content in the wafers, under 1 ppb wt. Further enhancement is also shown to be possible with the n doping of RST material, a well controlled process in ribbon growth (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reduction of surface reflectivity in multi‐crystalline silicon solar cells by wet nano‐texturing
Authors: Cho Young Joon , Chang Hyo Sik
Published: September 2012

The effect of electroless wet treatment on multi‐crystalline silicon solar cells was investigated. We prepared nanostructures on a multi‐crystalline silicon surface via wet nano‐texturing processes to ensure that less light is reflected off the surface. Nano‐texturing can reduce the average reflectance to about 2.5% in the wavelength range of 400‐900 nm. Further, we obtained an effective reflectance of 1.9% with Al2O3/SiNx:H coating. The use of our wet nano‐texturing process resulted in a reflectance value lower than that obtained with conventional acid texturization. Thus, the nano‐texturing of multi‐crystalline silicon via the wet chemical process can further increase the efficiency of silicon solar cells (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Double side multicrystalline silicon passivation by one step stain etching‐based porous silicon
Authors: Mohamed Seifeddine Belhadj , Ben Rabha Mohamed , Bessais Brahim
Published: September 2012

In this paper, we investigate the effect of stain etching‐based porous silicon on the double side multicrystalline silicon. Special attention is given to the use of the stain etched PS as an antireflection coating as well as for surface passivating capabilities. Stain etching of double side multicrystalline silicon leads to the formation of PS nanostructures, that dramatically decrease the surface reflectivity from 30% to about 7% and increase the effective lifetime from 1 µs to 10 µs at a minority carrier density (Δn) of 1015 cm–3. These results let us correlate the rise of the lifetime values to the photoluminescence intensity to the hydrogen and oxide passivation as shown by FTIR analysis. This low‐cost PS formation process can be applied in the photovoltaic cell technology as a standard procedure (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Non‐polar group‐III nitride semiconductor surfaces
Authors: Eisele Holger , Ebert Philipp
Published: September 2012

The intrinsic structural and electronic properties of a surface are important for any further study or application of the material, especially when a high surface‐to‐volume ratio is obtained or the surface gets functionalized, as e.g. during growth. Due to increasing material quality over recent years, the first experimental results are now available for the non‐polar group‐III nitride semiconductor surface, which can be compared with previously reported theoretical calculations. While the reports on AlN and InN surfaces are still small in number, for GaN quite a lot of experimental results on the non‐polar surfaces were published on the intrinsic geometric and electronic properties, the defects, the decomposition, and the effect of impurities. Furthermore, the growth on non‐polar group‐III nitride surfaces is a new concept to reduce undesirable piezoelectric polarization in heterostructures and the side walls of wurtzite‐structured nano‐wires are formed mostly by non‐polar facets. Hence, we review the existing intrinsic structural and electronic properties of non‐polar surfaces of group‐III nitride semiconductors in this contribution.

magnified image

The three different non‐polar surfaces of III–V semiconductors with filled (bright green) and empty (bright red) dangling bonds: left (red) the (10\bar 10) surface of the wurtzite crystal structure, middle (blue) the (11\bar 20) surface of the wurtzite crystal structure, and right (green) the ({110}) surface of the zincblende structure. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mathematical Model for Water Transfer in Multidomain Food Packed in Permeable Packaging
Authors: Chu Zhenhui , Lu Lixin , Wang Jun
Published: September 2012

In terms of composite food systems, the food shelf life is affected by the moisture migration between the package and the external environment as well as among the components. In this paper, the water transfer behaviour in multidomain food packed in permeable packaging was studied, and a mathematical model based on Fick's and Henry's laws was developed to predict the unidirectional moisture transferring in composite food products packed with permeable packages. By using 0.6 water activity (aw) dried slice of pork and 0.7 aw piece of hawthorn as middle aw analogues, the model was validated with a pair of two‐component composite food systems (biscuit with the slice of pork and biscuit with the piece of hawthorn), and the moisture content changing with time in biscuits was tested and compared with the predicted value, showing high correspondence and consistency. Copyright © 2012 John Wiley & Sons, Ltd.
Buffer gas modifiers effect resolution in ion mobility spectrometry through selective ion‐molecule clustering reactions
Authors: Fernández‐Maestre Roberto , Wu Ching , Hill Herbert H.
Published: September 2012

RATIONALE

When polar molecules (modifiers) are introduced into the buffer gas of an ion mobility spectrometer, most ion mobilities decrease due to the formation of ion‐modifier clusters.

METHODS

We used ethyl lactate, nitrobenzene, 2‐butanol, and tetrahydrofuran‐2‐carbonitrile as buffer gas modifiers and electrospray ionization ion mobility spectrometry (IMS) coupled to quadrupole mass spectrometry. Ethyl lactate, nitrobenzene, and tetrahydrofuran‐2‐carbonitrile had not been tested as buffer gas modifiers and 2‐butanol had not been used with basic amino acids.

RESULTS

The ion mobilities of several diamines (arginine, histidine, lysine, and atenolol) were not affected or only slightly reduced when these modifiers were introduced into the buffer gas (3.4% average reduction in an analyte's mobility for the three modifiers). Intramolecular bridges caused limited change in the ion mobilities of diamines when modifiers were added to the buffer gas; these bridges hindered the attachment of modifier molecules to the positive charge of ions and delocalized the charge, which deterred clustering. There was also a tendency towards large changes in ion mobility when the mass of the analyte decreased; ethanolamine, the smallest compound tested, had the largest reduction in ion mobility with the introduction of modifiers into the buffer gas (61%). These differences in mobilities, together with the lack of shift in bridge‐forming ions, were used to separate ions that overlapped in IMS, such as isoleucine and lysine, and arginine and phenylalanine, and made possible the prediction of separation or not of overlapping ions.

CONCLUSIONS

The introduction of modifiers into the buffer gas in IMS can selectively alter the mobilities of analytes to aid in compound identification and/or enable the separation of overlapping analyte peaks. Copyright © 2012 John Wiley & Sons, Ltd.
Combined inverse and gradient iterative learning control: performance, monotonicity, robustness and non‐minimum‐phase zeros
Authors: Owens David H. , Chu Bing
Published: September 2012

Based on recent papers that have demonstrated that robust iterative learning control can be based on parameter optimization using either the inverse plant or gradient concepts, this paper presents a unification of these ideas for discrete‐time systems that not only retains the convergence properties and the robustness properties derived in previous papers but also permits the inclusion of filters in the input update formula and a detailed analysis of the effect of non‐minimum‐phase dynamics on algorithm performance in terms of a ‘plateauing’ or ‘flat‐lining’ effect in the error norm evolution. Although the analysis is in the time domain, the robustness conditions are expressed as frequency domain inequalities. The special case of a version of the inverse algorithm that can be used to construct a robust stable anti‐causal inverse non‐minimum‐phase plant is presented and analysed in detail. Copyright © 2012 John Wiley & Sons, Ltd.
Robust REML estimation fork‐component Poisson mixture with random effects: application to the epilepsy seizure count data and urinary tract infections data
Authors: Yu Dalei , Yau Kelvin K.W.
Published: September 2012

A robust version of residual maximum likelihood estimation for Poisson log‐linear mixed model is developed, and the method is extended tok‐component Poisson mixture with random effects. The method not only provides the robust estimators for the fixed effects and variance component parameters but also gives the robust prediction of random effects. Simulation results show that the proposed method is effective in limiting the impact of outliers under different data contamination schemes. The method is adopted to analyze the epilepsy seizure count data and the urinary tract infections data, which are deemed to contain several potential outliers. The results show that the proposed method provides better goodness of fit to the data and demonstrate the effect of the robust tuning mechanism. Copyright © 2012 John Wiley & Sons, Ltd.
The Identification of Inner Tube Defects in Double‐Wall Carbon Nanotubes
Authors: Allen Christopher S. , Robertson Alex W. , Kirkland Angus I. , Warner Jamie H.
Published: September 2012

The precise atomic structure and relative atomic conformation of the individual carbon nanotubes comprising a double wall carbon nanotube (DWCNT) is determined. The DWCNTs are imaged using an aberration corrected high resolution transmission electron microscope (HRTEM) operating at 80 kV. Using processing in Fourier space images of the inner and outer tube of a double‐wall carbon nanotube (DWCNT) are analysed. Comparisons of these results with simulated HRTEM images enable the chiral indices and relative atomic correlation of the component tubes of non‐commensurate DWCNTs to be determined. This technique is used to reveal the presence of a defect in the inner tube of a (6, 6)@(18, 2) DWCNT.
Controlling Nozzle Clogging by Secondary Steelmaking Without Reheating
Authors: Harcsik Bela , Karoly Gyula
Published: September 2012

Ever since continuous casting was introduced, nozzle clogging has been a recurring subject of metallurgical research and publications. Nozzle clogging is caused by the deposition of non‐metallic inclusions – on the casting equipment – which are solid at the temperature of casting. Calcium treatment already represents a possible solution to eliminate this phenomenon, but there are special steel grades which do not allow its application either because they are price sensitive or for certain other reasons.3 Cleaning the steel melt by agitation is an alternative solution, but it has time constraints due to the cooling of the melt. Over extensive cooling can be prevented by heating the melt (in ladle), but its introduction and operational costs per heat are often too high for an individual steelmaking plant to afford. The goal of our research is to find metallurgical solution to reduce the rate of nozzle clogging in plants which do not possess a ladle furnace and the time devoted to treatment or the price of the product do not allow Ca‐treatment to be applied.
Effect of Dynamic Transformation on the Mean Flow Stress
Authors: Jonas John J. , Ghosh Chiradeep , Basabe Vladimir V.
Published: September 2012

Flow curves were determined in torsion at a series of temperatures on four plain C steels and a Nb microalloyed steel of increasing C concentration. The mean flow stresses (MFSs) pertaining to each experimental condition were calculated from the flow curves by integration. These are plotted against inverse absolute temperature in the form of Boratto diagrams. The stress drop temperatures, normally defined as the upper critical temperature $A_{{\rm r3}}^{{\rm *}} $, were determined from these diagrams. These are shown to be about 40°C above the paraequilibrium and about 20°C above the orthoequilibrium temperatures. This type of behavior is ascribed to the occurrence of dynamic transformation (DT) during deformation. The general characteristics of the DT of austenite to ferrite are reviewed. It is suggested that some of the unexpected load drops that have been reported to take place above the Ae3 temperature in strip mills may be attributable to this phenomenon.
Yarrowia lipolytica
Authors: Nicaud Jean‐Marc
Published: September 2012

The yeast Yarrowia lipolytica presents specific physiological, metabolic and genomic characteristics, which differentiate it from the model yeast Saccharomyces cerevisiae. These properties have led several research groups to use this yeast as a model for basic knowledge. Thanks to the development of advanced genetic tools and ‐omic approaches, significant progress has been achieved in the understanding of specific biological processes. This review, after a short presentation of this model yeast, will briefly highlight the different use of Y. lipolytica for basic knowledge and the advantages gained by exploiting this non‐conventional yeast. Future perspectives in employing this yeast for basic knowledge in the field of RNA splicing and genome evolution, and for the study of lipid metabolism, are also discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Crystal Structure of FePb4Sb6Se14 and its Structural Relationship with FePb3Sb4Se10
Authors: Poudeu Pierre F. P. , Djieutedjeu Honore , Sahoo Pranati
Published: September 2012

Single crystals of FePb4Sb6Se14, were obtained from solid‐state combination of high purity elemental powders at 873K for three days. Single crystal X‐ray structure determination revealed that the compound crystallizes in the monoclinic space group P21/c (no. 14) and adopts the structure of Jamesonite (FePb4Sb6S14). The structure contains two crystallographically independent lead atoms with monocapped and bicapped trigonal prismatic coordinations, three antimony atoms located in a distorted octahedral environment and one iron atom occupying a flattened octahedral coordination. Neighboring monocapped and bicapped trigonal prims around lead atoms share faces and edges to build a corrugated layer parallel to the ac plane. Octahedrally coordinated antimony atoms share edges to form one‐dimensional (1D) {SbSe}∞ ribbons connecting adjacent corrugated layers. The distortion of the octahedral coordination around antimony atoms within the {SbSe}∞ ribbons with the longest bond pointing towards the center of the ribbon, suggests the stereochemical activity of antimony lone‐pairs with their electron clouds pointing towards the center of the {SbSe}∞ ribbon. The three dimensional framework resulting from the connectivity between the corrugated layers and the {SbSe}∞ ribbons, contains isolated cylindrical voids parallel to [100] which are filled by a 1D FenSe4n+2 straight chain of edge‐sharing FeSe6 octahedra. The crystal structure of FePb4Sb6Se14 is closely related to that of FePb3Sb4Se10 as they are formed by similar building units with different sizes.
Investigations on the Structure Diversity and Thermal Degradation Behavior of CdII and ZnII Thiocyanato Coordination Compounds based on 3‐Acetylpyridine as Neutral Co‐Ligand
Authors: Werner Julia , Boeckmann Jan , Näther Christian
Published: September 2012

Reaction of CdII and ZnII thiocyanate with 3‐acetylpyridine leads to the formation of the new CdII and ZnII coordination compounds [Cd(NCS)2(3‐acetylpyridine)4] (1A), [Cd(NCS)2(3‐acetylpyridine)2]n (1B), [Cd(NCS)2(3‐acetylpyridine)]n (1C) and [Zn(NCS)2(3‐acetylpyridine)2] (2A). Compound 1A consists of discrete complexes, in which the metal centers are octahedrally coordinated by four terminal bonded N‐donor co‐ligands and two terminal N‐bonded thiocyanato anions. In compound 2A the metal centers are only tetrahedrally coordinated by two terminal bonded N‐donor co‐ligands and two terminal N‐bonded thiocyanato anions. In compound 1B the CdII cations are octahedrally coordinated by two terminal bonded N‐donor co‐ligands and four thiocyanato anions. The metal centers are linked by μ‐1, 3 bridging thiocyanato anions into chains. In compound 1C the metal cations are octahedrally coordinated by two μ‐1, 5 bridging 3‐acetyl‐pyridine ligands and four μ‐1, 3 bridging thiocyanato anions building up a three‐dimensional coordination network. Investigations on the thermal degradation behavior of all compounds using simultaneous differential thermoanalysis and thermogravimetry as well as X‐ray powder diffraction and IR spectroscopy prove that on heating compound 2A decompose without the formation of 3‐acetylpyridine‐deficient intermediates. In contrast, for compound 1A a stepwise decomposition is observed, leading to the formation of the 3‐acetylpyridine‐deficient compound [Cd(NCS)2(3‐acetylpyridine)2]n (1B) which decomposes on further heating
Non‐Corner‐Capped Discrete T4 Cluster Stabilized by a Metal‐Bipyridine Complex
Authors: Pu Ya‐Yang , Zhang Xiang , You Li‐Shen , Bian Guo‐Qing , Zhu Qin‐Yu , Dai Jie
Published: September 2012

Our efforts have focused on the synthesis of novel chalcogenidometalates, in which M‐phen/bpy complexes are embedded (M = transition metals, phen = 1, 10‐phenanthroline, bpy = 2, 2′‐bipyridine), because the MII‐phen/bpy cations have offered extensive applications in light harvesting and energy conversion. We report herein discrete supertetrahedral Fe4In16S35 clusters (T4) co‐crystallized with [Fe(bpy)3]2+ cations, namely [Fe(bpy)3]3[Fe4H2In16S35]·4Htean·2Hbpy·5H2O. The spectroscopic properties and thermal stability of the compound are discussed. It is the first example of a non‐corner‐capped discrete M4In16S35 T4 cluster. A notable feature of the compound is the soluble discrete nanoscaled thioindiate cluster. The related 1D InS T3 chain [Fe(bpy)3]2[H2In10S19]·2Htean·8H2O is also presented herein in order to understand the effect of the reaction conditions on the formation of the Tn structures.
1, 9‐Dihydro‐purine‐6‐thione Derivatives of the d8–d10 Metal Ions (PdII, PtII, and CuI): Synthesis, Spectroscopy, and Structures
Authors: Lobana Tarlok S. , Kaur Parminderjit , Hundal Geeta , Butcher Ray J. , Liu Chen W.
Published: September 2012

Reaction of 1, 9‐dihydro‐purine‐6‐thione (puSH2) in presence of aqueous sodium hydroxide with PdCl2(PPh3)2 suspended in ethanol formed [Pd(κ2‐N7,S‐puS)(PPh3)2] (1). Similarly, complexes [Pd(κ2‐N7,S‐puS)(κ2‐P, P‐L‐L)] (2–4) {L‐L = dppm (m = 1) (2), dppp (m = 3) (3), dppb (m = 4) (4)} were prepared using precursors the [PdCl2(L‐L)] {L‐L = Ph2P–(CH2)m–PPh2}. Reaction of puSH2 suspended in benzene with platinic acid, H2PtCl6, in ethanol in the presence of triethylamine followed by the addition of PPh3 yielded the complex [Pt(κ2‐N7,S‐puS)(PPh3)2] (5). Complexes [Pt(κ2‐N7,S‐puS)(κ2‐P, P‐L‐L)] (6–8) {L‐L = dppm (6), dppp (7), dppb (8)} were prepared similarly. The 1, 9‐dihydro‐purine‐6‐thione acts as N7,S‐chelating dianion in compounds 1–8. The reaction of copper(I) chloride [or copper(I) bromide] in acetonitrile with puSH2 and the addition of PPh3 in methanol yielded the same product, [Cu(κ2‐N7,S‐puSH)(PPh3)2] (9), in which the halogen atoms are removed by uninegative N, S‐chelating puSH– anion. However, copper(I) iodide did not lose iodide and formed the tetrahedral complex, [CuI(κ1‐S‐puSH2)(PPh3)2] (10), in which the thio ligand is neutral. These complexes were characterized with the help of elemental analysis, NMR spectroscopy (1H, 31P), and single‐crystal X‐ray crystallography (3, 7, 8, 9, and 10).
On the Existence of the Trimer of Gallium Trichloride in the Gaseous Phase
Authors: Tsirelnikov Viacheslav I. , Lokshin Boris V. , Melnikov Petr , Nascimento Valter A.
Published: September 2012

The dependence of the gallium trichloride saturated and unsaturated vapor pressures on temperature was studied by the static method using a quartz membrane zero‐manometer and taking into account the volume of its working chamber and substance mass. Conclusions about the presence of a distinguishable amount of trimeric molecules along with dimeric and momomeric molecules in the vapor were drawn on the basis of the obtained data. The following rough thermodynamic characteristics of a gaseous trimer of gallium trichloride were calculated: ΔfH° (Ga3Cl9, gas, 298 K) = –1466 kJ·mol–1. S°(Ga3Cl9, gas, 298 K) = 654 J·mol–1·K–1. These data were used to elucidate the composition of the gaseous phase at a total pressure of 1 atm in the temperature range of 400–750 K. The suggested existence of trimeric molecules was not contradicted by vibrational spectroscopic analysis of gallium trichloride saturated vapor.
Synthesis and Structure Determination of Two Neutral Cadmium Thiophenolate Clusters
Authors: Gruber Franziska
Published: September 2012

The polynuclear complexes [Cd8S(SPh)14(DMF)3] (1) and [Cd17S4(SH)2(SPh)24(PPh3)2] (2) were prepared by an organometallic synthesis route. X‐ray diffraction on single‐crystals revealed a hexagonal closed packing of the cluster unit in 1 in the triclinic space group P$\bar{1}$. Compound 2 crystallized in the monoclinic space group C2/c. In contrast to related cluster compounds, the ligand sphere of 1 is expanded resulting in an unusual trigonal‐bipyramidal coordination of one of the cadmium ions. The heterogeneous composition of the ligand sphere of 2 results in the formation of individual cluster molecules.
Synthesis and Crystal Structure of Two Succinato‐Bridged Macrocyclic Nickel(II) Complexes
Authors: Ou Guang‐Chuan , Yuan Xian‐You , Li Zhi‐Zhang
Published: September 2012

Two dinuclear succinato‐bridged nickel(II) complexes [Ni(RR‐L)]2(μ‐SA)(ClO4)2 (1) and [Ni(SS‐L)]2(μ‐SA)(ClO4)2 (2) (L = 5, 5, 7, 12, 12, 14‐hexamethyl‐1, 4, 8, 11‐tetraazacyclotetradecane, SA = succinic acid) were synthesized and characterized by EA, Circular dichroism (CD), as well as IR and UV/Vis spectroscopy. Single crystal X‐ray diffraction analyses revealed that the NiII atoms display a distorted octahedral coordination arrangement, and the succinato ligand bridges two central NiII atoms in a bis bidentate fashion to form dimers in 1 and 2. The monomers of {[Ni(RR‐L)]2(μ‐SA)}2+ and {[Ni(SS‐L)]2(μ‐SA)}2+ are connected by O–H···O and N–H···O hydrogen bonds into a 1D right‐handed and left‐handed helical chain along the b axis, respectively. The homochiral natures of 1 and 2 are confirmed by the results of CD spectroscopy.