bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cu2Zn1–xCdx Sn(Se1–ySy)4 solid solutions as absorber materials for solar cells
Authors: Altosaar M. , Raudoja J. , Timmo K. , Danilson M. , Grossberg M. , Krustok J. , Mellikov E. 
Published: January 2008

AbstractCu2Zn1–x Cdx Sn(Se1–y Sy)4 monograin powders with different x ‐ and y ‐values were prepared from binary compounds in the liquid phase of flux material (KI) in evacuated quartz ampoules. All the materials had uniform composition and p‐type conductivity. PL spectra (10 K) of the as grown Cu2Zn1–x Cdx Sn(Se)4 monograin powders showed one PL band with peak position around 0.85 eV which shifted linearly to the lower energy side with increasing Cd content. Cu2ZnSnS4 material showed asymmetrical PL band at 1.31 eV attributed to band‐to‐tail recombination. RT Raman spectra of Cu2ZnSnSe4 revealed two main peaks at 196 cm–1 and 173 cm–1 and a third less intensive peak with varying peak position in the region 231–253 cm–1. Raman spectra of Cu2ZnSnS4 showed an intensive peak at 338 cm–1 and additional peaks at 287 cm–1 and 368 cm–1. Narrow sieved fractions of grown powders were used as absorber materials in monograin layer (MGL) solar cell structures: graphite/ Cu2Zn1–x Cdx Sn(Se1–y Sy)4/CdS/ZnO. The best so far solar cell that was based on the Cu2Zn0.8Cd0.2SnSe4 had open circuit voltage 422 mV, short circuit current 12 mA/cm2 and fill factor 44%. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Annealing experiments of the GaP based dilute nitride Ga(NAsP)
Authors: Kunert B. , Trusheim D. , Voßebürger V. , Volz K. , Stolz W. 
Published: January 2008

AbstractThe post‐growth annealing behaviour of Ga(NAsP) multi quantum well heterostructures (MQWHs) grown pseudomorphically strained to GaP substrate has been investigated. The optical properties as well as the structural crystal quality of the novel dilute nitride show an obvious dependence on the applied annealing temperature. Photoluminescence (PL) measurements reveal a step‐like blue shift of the PL peak position in line with an increase of PL intensity with rising annealing temperature. The PL line width decreases to a mini‐ mal value for an optimized heating temperature around 800 °C. This annealing behaviour of the Ga(NAsP)/GaP‐MQWHs up to 850 °C is quite typical for a dilute nitride, however, the functional dependence of the integrated intensity above 850 °C is unusual. The increase of the PL line width above 850 °C suggests a deterioration of the crystalline MQW quality, but transmission electron microscopy (TEM) and high resolution X‐ray diffraction (XRD) prove the opposite. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of the electric field on the current instability in the hopping conductivity region
Authors: Aladashvili D. I. , Adamia Z. A. , Adamia A. Z. 
Published: January 2008

AbstractThe dependence of the shape of current oscillations observed in the hopping conductivity region in a weakly compensated p‐Si on the supply voltage applied to the sample is established. With increasing bias voltage the current pulse shape to form a hopping domain changes significantly. The change in the shape is ascribed to voltage redistribution in corresponding regions in the bulk of the crystal. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ion channels allow atomic control of macroscopic transport
Authors: Eisenberg Bob 
Published: January 2008

AbstractIon channels are proteins with a hole down their middle that control an enormous range of biological function. Thousands of biologists and clinicians study ion channels every day because of their crucial involvement in disease. Ion channels have a definite structure once open and ions move through them by electrodiffusion. Theories that describe the movement of charged spheres through definite structure are able to account for the experimental behavior of channels in a wide range of conditions with just a few parameters with fixed values. Selectivity is produced by the balance of electrostatic attraction and hard sphere repulsion in at least three types of channels. More ‘chemical’ forces are not involved. The free energy landscapes of these systems are variables. Preformed binding sites are not involved. Indeed, in some cases selectivity is produced by depletion zones, not binding sites. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theory of hopping charge‐carrier transport at large carrier concentrations in disordered organic solids: Polarons versus bare charge carriers
Authors: Fishchuk I. I. , Kadashchuk A. , Bässler H. 
Published: January 2008

AbstractAn analytical theory based on the effective medium approach with employing the concept of the effective transport energy is formulated to describe the charge carrier mobility as a function of the charge carrier concentration in a disordered organic material with a Gaussian density‐of‐state distribution. Jump rate expressions based either on the Miller‐Abrahams (MA) or polaron models are used. A key result of the present study is that a considerably weaker dependence of the mobility on the carrier concentration is found for the polaron jump rate model than for the MA model where we have considerable increase of the drift charge‐carrier mobility with increasing carrier concentration. Our results for the MA model are in good agreement with previous theoretical studies, numerical simulation and experiment data. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Metallic conductivity in a polyamidine film
Authors: Ionov A. N. , Rentzsch R. , Nikolaeva M. N. 
Published: January 2008

AbstractExperimental results are discussed which deal with metallic conductivity in partially conjugated and undoped polyamidine thin films placed between metallic electrodes. In the framework of a model, the electrification effect due to metallic electrodes plays the significant role in obtaining metallic conductivity. The main reason for metallic conductivity in dielectric polyamidine films is the collapse of the HOMO/ LUMO gap of macromolecules (here HOMO – is the highest occupied molecular orbital and LUMO – is the lowest unoccupied molecular orbital) in a strong internal electrical field inside the polymer. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
One‐dimensional lucky‐drift model with scattering and movement asymmetries for impact ionization in amorphous semiconductors
Authors: Jandieri K. , Rubel O. , Baranovskii S. D. , Reznik A. , Rowlands J. A. , Kasap S. O. 
Published: January 2008

AbstractA lucky‐drift (LD) model for impact ionization has been recently successfully used to account for avalanche phenomenon in amorphous semiconductors. This model however leads to the dependence of the impact ionization coefficient on the sample thickness. However such dependence has not been confirmed experimentally. Recently LD model has been improved taking into account the scattering and movement asymmetry of charge carriers in the applied electric field. As a result, the impact ionization coefficient was obtained independent on the sample thickness. We apply the improved LD model to study the field dependence of the impact ionization coefficient in a‐Se, a‐Si:H and Ge2Sb2Te5. We show that even in one‐dimensional formulation of the improved LD model the agreement between theoretical results and experimental data evidenced in a‐Se is better than that in the formulation with scattering and movement symmetry. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Particle on a ring coupled with a dirty metal
Authors: Kagalovsky Victor , Horovitz Baruch 
Published: January 2008

AbstractA charged particle of mass M on a ring of radius R is coupled to a dirty metal environment. With Monte‐Carlo methods we evaluate the curvature of the Aharonov‐Bohm oscillations and find a quantum phase transition at a critical Rc. At low temperatures T the curvature has the form 1/M*R2 with an R independent M* > M in the R > Rc phase, while M* rapidly approaches M in the R < Rc phase. The approach to T = 0 defines diverging length scales ∼T–η with η ≈ 1 and η ≈ 1/4 in the large and small R phases, respectively. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phase diagram and excitations of a Coulomb glass
Authors: Malik Vikas , Kumar Deepak 
Published: January 2008

AbstractThis paper studies the phase diagram and the singleparticle density of states of a lattice model of the Coulomb glass in three dimensions. For this purpose we calculate the free energy in the random phase approximation using the replica method to average over disorder. We find that the system has a transition to an antiferromagnetic phase below a critical disorder. Above the critical disorder the system has a glassy ‘independent spin phase’ at zero temperature which crosses over to paramagnetic phase as the temperature is increased. In the antiferromagnetic phase the single‐particle excitation density has a feature, including the gap at the Fermi level due to long‐range order. In the glassy phase we find the density of states (DOS) at nonzero temperatures and find that with temperature the DOS at the Fermi level increases faster than quadratically and the Coulomb gap decreases linearly. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The clinical investigator site audit – process‐driven good clinical practice
Authors: Winchell Terry 
Published: January 2008

AbstractThis article describes a process‐driven approach to the conduct of a Good Clinical Practice (GCP) audit at a clinical investigator site and to the assessment of systemic GCP compliance in just a few days with little or no background information. The technique involves looking at the site and resulting observations from a system‐related point of view, with the primary goal of finding flaws in methods of operation as opposed to looking for isolated errors. Then, expanding the impact of corrective actions to the maximum extent (i.e. to all systemic flaws). To put it simply, it is a process‐driven approach with the ultimate goal of getting the GCP system under satisfactory control. Copyright © 2008 John Wiley & Sons, Ltd.
Quality assurance in cardiac surgery: setting up the Austrian heart register. Are standard hospital information systems suitable?
Authors: Staudinger O. , Staudinger B. , Ostermann H. , Staudinger R. , Tilg B. 
Published: January 2008

AbstractObjectives: The Austrian Health 2006 Structural Plan of 28 June 2006 requires that reference centres for cardiac surgery ‘participate in result‐quality registers (e.g. heart registers)’. The aim of the project was to determine the conditions under which existing hospital information systems (HIS) would be suitable for the intended heart register system.Methods: Between November 2004 and December 2005, a survey was performed in the Austrian heart centers in order to ascertain the medical requirements, the existing technical and organizational situation, and the demands potential users would make on a comprehensive, national heart register. The possibilities of using existing hospital information systems for this purpose were evaluated on the basis of a criteria catalogue.Results: From the medical point of view, the requirements of a heart register covering the whole of Austria, though complex, are readily definable. The reality of heterogeneous information technology (IT) landscapes, coupled with demands for interactivity (on‐line queries to a central cardiac database) and benchmarking the users within a single system, combined with what must objectively be regarded as a small group of users, are the reasons why this function is not provided as standard in any HIS.Conclusion: The level of standardization of predictive models and data records is too low in the light of the local and national demands and expectations of a heart register, so that an adequate Quality Assurance (QA) function for cardiac surgeries, which is based on statistical data, is not offered as a standard module in today's HIS. Copyright © 2008 John Wiley & Sons, Ltd.
Enhanced resolution triple‐quadrupole mass spectrometry for ultra‐sensitive and quantitative analysis of the investigational anticancer agent EO9 (apaziquone) and its metabolite EO5a in human and dog plasma to support (pre)‐clinical studies of EOquin® given intravesically
Authors: Vainchtein Liia D. , Rosing Hilde , Mirejovsky Dorla , Huynh Van , Lenaz Luigi , Schellens Jan H. M. , Beijnen Jos H. 
Published: January 2008

AbstractA highly sensitive and selective liquid chromatography/tandem mass spectrometric (LC/MS/MS) method was developed to quantify the experimental anticancer agent EO9 and its metabolite EO5a in biological matrices. A 200‐µL aliquot of human/dog plasma was spiked with a mixture of deuterated internal standards EO9‐d3 and EO5a‐d4 and extracted with 1.25 mL of ethyl acetate. Dried extracts were reconstituted in 0.1 M ammonium acetate/methanol (7:3, v/v) and 20‐µL volumes were injected onto the LC system. Separation was achieved on a 150 × 2.1 mm C18 column using an alkaline eluent (1 mM ammonium hydroxide/methanol (gradient system)). The detection was performed by a Finnigan TSQ Quantum Ultra equipped with an electrospray ionization source operated in positive mode and enhanced mass resolution capability. It demonstrated improved sensitivity with a factor 10–20 for EO9 and EO5a over a 3‐decades dynamic range, with acceptable accuracy and precision, when compared with the previously described assay for EO9 and EO5a, developed by our group, using an API 2000. The assay quantifies a range from 0.5 to 500 ng/mL for EO9 and EO5a using 200‐µL human plasma and dog samples. The described mass resolution method was successfully applied for the evaluation of the pharmacokinetic profile of EO9 and its metabolite EO5a in human and dog plasma. Copyright © 2008 John Wiley & Sons, Ltd.
Feasibility of locating tumours in lung via kinaesthetic feedback
Authors: McCreery G. L. , Trejos A. L. , Naish M. D. , Patel R. V. , Malthaner R. A. 
Published: January 2008

AbstractBackgroundLocalizing lung tumours during minimally invasive surgery is difficult, since restricted access precludes manual palpation and pre‐operative imaging cannot map directly to the intra‐operative lung. This study analyses the force‐sensing performance that would allow an instrumented kinaesthetic probe to localize tumours based on stiffness variations of the lung parenchyma.MethodsAgar injected intoex vivoporcine lungs produced a model approximating commonly encountered tumours. Force‐deformation data were collected from multiple sites at various palpation depths and velocities, before and after the tumours were injected.ResultsAnalysis showed an increase in force after the tumours were injected, in the range 0.07–0.16 N at 7 mm (p< 10−4). A 2 mm/s palpation velocity minimized exponential stress decay at constant depths, facilitating easier comparisons between measurements.ConclusionA sensing range of 0–2 N, with 0.01 N resolution, should allow a kinaesthetic palpation probe to resolve local tissue stiffness changes that suggest an underlying tumour. Copyright © 2008 John Wiley & Sons, Ltd.
Surface characterization of photodegraded dyed styrene butadiene and natural rubbers
Authors: Ruch David , Exposito Junien , Becker Claude , Aubriet Frédéric 
Published: January 2008

AbstractThe combination of laser ablation coupled to mass spectrometry, Ultraviolet‐visible spectroscopy and environmental scanning electron microscopy (coupled with energy dispersive X‐ray spectrometry EDX) as independent techniques to investigate the surface photooxidation of dyed filled natural rubber (NR) and styrene butadiene rubber (SBR), designed for outdoor applications, have been investigated. The aging results in the deterioration of the exposed surface material properties. Results indicate that dyed filled NR and SBR samples behave differently during the photooxidation. The fading of the dyed polymers was found to be promoted in the NR sample. This is proved by the disappearance of [M − H]− pseudomolecular ion of orange pigment and also its fragment ions after aging, which was detected by LDI–FTICRMS. This is confirmed by both EDX and UV/vis spectroscopy. EDX analysis indicates a concentration of chlorine atoms, which is a marker of orange pigment or of its degradation products, at the surface of SBR flooring after aging, which is not observed with NR. Reactivity of the radicals formed during flooring aging is thought to greatly affect the behavior of the organic pigment and is discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Adaptive management: making it happen through participatory systems analysis
Authors: Smith Carl , Felderhof L. , Bosch O. J. H. 
Published: January 2008

AbstractParticipatory systems analysis was used to construct system models of the operating environment for fire management in conservation reserves in north Queensland, Australia. The aim of the study was to identify stumbling blocks to the adaptive management of fire and to test whether this could be done using participatory methods and a systems modelling tool called Bayesian Belief Networks (BBN). Results from the case study indicate that the participatory system analysis approach provides a co‐learning environment that captures the collective (corporate) knowledge of the factors influencing planning, implementing, monitoring and reviewing outcomes, thus allowing critical success factors (CSFs) influencing the success of adaptive management to be identified. BBN provided the scaffolding for piecing together this knowledge, allowing managers to structure complex problems and conduct dynamic sensitivity and scenario analysis to identify where intervention or investment can significantly improve the practice of adaptive management within a natural resource management (NRM) agency. Copyright © 2007 John Wiley & Sons, Ltd.
Adjuvant Intraportal Venous Chemotherapy for Patients with Hepatocellular Carcinoma and Portal Vein Tumor Thrombi Following Hepatectomy Plus Portal Thrombectomy
Authors: Liang Li‐Jian , Hu Wen‐Jie , Yin Xiao‐Yu , Zhou Qi , Peng Bao‐Gang , Li Dong‐Ming , Lu Ming‐De 
Published: January 2008

AbstractBackgroundThe aim of this study was to evaluate the clinical value of adjuvant chemobiotherapy via portal vein for patients with hepatocellular carcinoma (HCC) with portal vein tumor thrombi (PVTT) following hepatectomy plus thrombectomy.MethodsEighty‐six HCC patients with tumor thrombi in the portal trunk and/or the first‐order branch were divided into groups A (n = 33) and B (n = 53). Patients in group A were treated with hepatectomy plus portal thrombectomy in combination with postoperative adjuvant chemobiotherapy administered via portal vein. The chemobiotherapy regimen consisted of 5‐FU, adriamycin, cisplatin, and IFNα. Patients in Group B were subjected to hepatectomy plus thrombectomy alone. Survival rates of the two groups were compared and prognostic factors were identified using Cox proportional hazards model.ResultsGroup A had a significantly longer median tumor‐free survival time and median survival time compared with group B, i.e., 5.1 vs. 2.5 months (p = 0.017) and 11.5 vs. 6.2 months (p = 0.007), respectively. One‐, two‐, and three‐year tumor‐free survival rates were remarkably higher in group A than in group B, i.e., 18.4% vs. 8.4%, 13.8% vs. 4.2%, and 9.2% vs. 4.2%, respectively. One‐, two‐, and three‐year survival rates were markedly greater in group A than in group B, i.e., 46.8% vs. 23.4%, 14.4% vs. 5.8%, and 9.6% vs. 5.8%, respectively. Multivariate analysis using the Cox proportional hazards model revealed that adjuvant chemobiotherapy, pathologic grading, and tumor size were independent prognostic factors for survival time (p = 0.000, 0.001, and 0.013, respectively), and chemobiotherapy and pathologic grading were independent prognostic factors for tumor‐free survival time (p = 0.002 and 0.003, respectively).ConclusionsSurgical resection combined with adjuvant chemobiotherapy via portal vein is an effective and safe treatment modality for hepatocellular carcinoma with major portal vein thrombus.
Viability of Cryopreserved Parathyroid Tissue: When Is Continued Storage versus Disposal Indicated?
Authors: Guerrero Marlon A. , Evans Douglas B. , Lee Jeffrey E. , Bao Ruijun , Bereket Abby , Gantela Swaroop , Griffin Gary D. , Perrier Nancy D. 
Published: January 2008

AbstractBackgroundParathyroid cryopreservation is used for potential autografting in patients who are rendered hypocalcemic following surgery. Cryopreservation employs multiple resources and carries a significant cost for processing and storage of tissue. Importantly, the length of time that parathyroid tissue remains functional after cryopreservation is not known. The goal of our study was to assess ex‐vivo viability of parathyroid tissue in relation to the length of time in storage. We sought to define the appropriate time frame for tissue utilization and disposal to assist with long‐term surgical planning.MethodsFrom 1991 to 2006, 501 parathyroid specimens from 149 patients were cryopreserved at −80°C according to standardized techniques. A single trained technician assessed viability, using a hemacytometer to count viable (clear cell) and nonviable (blue cell) tissue. Univariate analysis was performed to correlate length of preservation, diagnosis with viability. Results: We evaluated 106 random parathyroid specimens. Samples were divided into two groups: those stored > 24 months and those stored ≤ 24 months. Eleven (10%) of 106 specimens were deemed viable. Length of storage time was associated with ex‐vivo tissue viability. Viability of samples cryopreserved ≤ 24 months was 71% (10/14) versus 1% (1/92) of those specimens stored > 24 months (p < 0.001).ConclusionsViability of cryopreserved parathyroid cells is associated with duration of storage. Parathyroids preserved for greater than 24 months are unlikely to be viable. It seems reasonable to limit parathyroid cryopreservation to 24 months when frozen at −80°C. Further studies are needed to optimize the process of cryopreservation to enhance cell viability.
Misattribution bias of threat-related facial expressions is related to a longer duration of illness and poor executive function in schizophrenia and schizoaffective disorder
Authors: Premkumar Preethi , Cooke Michael A. , Fannon Dominic , Peters Emmanuelle , Michel Tanja M. , Aasen Ingrid , Murray Robin M. , Kuipers Elizabeth , Kumari Veena 
Published: January 2008

AbstractBackgroundWhile it is known that patients with schizophrenia recognize facial emotions, specifically negative emotions, less accurately, little is known about how they misattribute these emotions to other emotions and whether such misattribution biases are associated with symptoms, course of the disorder, or certain cognitive functions.MethodOutpatients with schizophrenia or schizoaffective disorder (n = 73) and healthy controls (n = 30) performed a computerised Facial Emotion Attribution Test and Wisconsin Card Sorting Test (WCST). Patients were also rated on the Positive and Negative Syndrome Scale (PANSS).ResultsPatients were poor at recognizing fearful and angry emotions and attributed fear to angry and angry to neutral expressions. Fear-as-anger misattributions were predicted independently by a longer duration of illness and WCST perseverative errors.ConclusionThe findings show a bias towards misattributing fearful and angry facial emotions. The propensity for fear-as-anger misattribution biases increases as the length of time that the disorder is experienced increases and a more rigid style of information processing is used. This, at least in part, may be perpetuated by subtle fearfulness expressed by others while interacting with people with schizophrenia.