bluuebunny/crossref_metadata_2025 huggingface dataset:
Controlled Study of Fatigue, Quality of Life, and Somatic and Mental Morbidity in Epithelial Ovarian Cancer Survivors: How Lucky Are the Lucky Ones?
Authors: Liavaag Astrid H. , Dørum Anne , Fosså Sophie D. , Tropé Claes , Dahl Alv A.
Published: May 2007

Purpose

There are few studies of somatic and mental morbidity in epithelial ovarian cancer survivors (EOCSs). The aim of this controlled, cross-sectional study was to explore fatigue, quality of life (QOL), and somatic and mental morbidity in EOCSs.

Patients and Methods

Among 287 EOCSs treated according to protocols at The Norwegian Radium Hospital between 1977 and 2003, 189 patients (66%) participated. Information was collected by a questionnaire containing demographic and morbidity items and self-rating scales. Internal comparisons of various subgroups of EOCSs were performed, and EOCSs were compared with age-adjusted controls from the general population.

Results

Minimal differences were observed relating to somatic and mental morbidity, fatigue, and QOL between EOCSs with and without relapse, long or short follow-up time, and prognostic index status. Chronic fatigue was found in 22% (95% CI, 16% to 28%), and only body image was significantly associated with chronic fatigue in multivariable analyses. EOCSs showed significantly more somatic and mental morbidity, somatic complaints, use of medications, and use of health care services than controls. The levels of anxiety and fatigue were also significantly higher in EOCSs than in controls, whereas the levels of depression and of several QOL dimensions were lower. The prevalence of chronic fatigue was 12% among controls.

Conclusion

EOCSs had more somatic and mental morbidity, more fatigue, poorer QOL, and used more medication and health services than controls. Minimal differences were observed between various EOCS subgroups. Health care professionals should try to improve and be attentive to the health of EOCSs.
Pathologic Complete Response With Six Compared With Three Cycles of Neoadjuvant Epirubicin Plus Docetaxel and Granulocyte Colony-Stimulating Factor in Operable Breast Cancer: Results of ABCSG-14
Authors: Steger Günther G. , Galid Arik , Gnant Michael , Mlineritsch Brigitte , Lang Alois , Tausch Christoph , Rudas Margaretha , Greil Richard , Wenzel Catharina , Singer Christian F. , Haid Anton , Pöstlberger Sabine , Samonigg Hellmut , Luschin-Ebengreuth Gero , Kwasny Werner , Klug Eduard , Kubista Ernst , Menzel Christian , Jakesz Raimund
Published: May 2007

Purpose

Preoperative (neoadjuvant) chemotherapy for operable breast cancer downstages tumors initially not suitable for breast-conserving surgery. A pathologic complete response (pCR) to neoadjuvant chemotherapy may be a surrogate for longer overall survival, but this beneficial effect remains to be established. This phase III trial evaluated whether doubling the number of cycles of neoadjuvant treatment increased the pCR rate.

Patients and Methods

Patients with biopsy-proven breast cancer (T1-4a-c, N±, M0; stage I to III) were eligible and randomly assigned to either three or six cycles of epirubicin 75 mg/m2 and docetaxel 75 mg/m2 on day 1 and granulocyte colony-stimulating factor on days 3 through 10 (ED+G), every 21 days. The primary end point was the pCR rate of the breast tumor. Secondary end points were pathologic nodal status after surgery and the rate of breast-conserving surgery.

Results

A total of 292 patients were accrued, and 288 patients were assessable for efficacy and safety. Groups were well balanced for known prognostic factors. Six cycles of ED+G, compared with three cycles, resulted in a significantly higher pCR rate (18.6% v 7.7%, respectively; P = .0045), a higher percentage of patients with negative axillary status (56.6% v 42.8%, respectively; P = .02), and a trend towards more breast-conserving surgery (75.9% v 66.9%, respectively; P = .10). Rates of adverse events were similar, and no patients died on treatment.

Conclusion

Doubling the number of neoadjuvant ED+G cycles from three to six results in higher rates of pCR and negative axillary nodal status with no excess of adverse effects. Thus, six cycles of ED+G should be the standard neoadjuvant treatment for operable breast cancer if this combination is chosen.
Imaging in Local Staging of Gastric Cancer: A Systematic Review
Authors: Kwee Robert Michael , Kwee Thomas Christian
Published: May 2007

Purpose

Endoscopic ultrasound (EUS) has been established as the diagnostic modality of choice in local (T) staging of gastric cancer. Multidetector row computed tomography (MDCT) and magnetic resonance imaging (MRI) are promising alternatives. The aim of this study was to systematically review the literature regarding the performance of each of these imaging modalities.

Methods

A systematic search for relevant studies was performed in the PubMed/MEDLINE and EMBASE databases. Two reviewers independently assessed the methodological quality of each study. Local staging performance of included studies was calculated.

Results

Twenty-two EUS studies, five MDCT studies, one combined EUS and MDCT study, and three MRI studies met the inclusion criteria. The studies were of moderate methodological quality. Diagnostic accuracy of overall T staging for EUS, MDCT, and MRI varied between 65% to 92.1%, 77.1% to 88.9%, and 71.4% to 82.6%, respectively. Sensitivity for assessing serosal involvement for EUS, MDCT, and MRI varied between 77.8% to 100%, 82.8% to 100%, and 89.5% to 93.1%, respectively. Specificity for assessing serosal involvement for EUS, MDCT, and MRI varied between 67.9% to 100%, 80% to 96.8%, and 91.4% to 100%, respectively.

Conclusion

EUS, MDCT, and MRI achieve similar results in terms of diagnostic accuracy in T staging and in assessing serosal involvement. Most experience has been gained with EUS. Few MDCT studies and even fewer MRI studies are available. Thus, EUS remains the first-choice imaging modality in preoperative T staging of gastric cancer.
Chromogranin A: Is It a Useful Marker of Neuroendocrine Tumors?
Authors: Campana Davide , Nori Francesca , Piscitelli Lidya , Morselli-Labate Antonio Maria , Pezzilli Raffaele , Corinaldesi Roberto , Tomassetti Paola
Published: May 2007

Purpose

We evaluated the pattern of chromogranin A (CgA) plasma levels in a large number of patients with neuroendocrine tumors (NETs), in a series of patients with chronic atrophic gastritis (CAG) with and without enterochromaffin-like (ECL) cell hyperplasia, and in healthy participants (HPs).

Patients and Methods

Two hundred thirty-eight patients with NETs, 42 patients with CAG with or without ECL cell hyperplasia, and 48 HPs were studied. All patients underwent a baseline visit, biochemical routine check-up, imaging techniques, endoscopy, and histologic determination.

Results

CgA plasma levels were higher in patients with NETs compared with CAG patients or HPs (P < .001). In the NET group, we observed higher CgA levels in patients with diffuse disease compared with patients with local or hepatic disease (P < .001). CgA plasma levels were significantly higher in patients with Zollinger-Ellison syndrome compared with other types of endocrine tumors (P < .001). We found the best cutoff range between HPs and NET patients to be 18 to 19 U/L (sensitivity, 85.3%; specificity, 95.8%). Comparing all participants without neoplasia (HPs, CAG patients, and disease-free patients) and patients with endocrine tumors, the best cutoff range was 31 to 32 U/L (sensitivity, 75.3%; specificity, 84.2%). Setting the specificity at 95%, the cutoff range was 84 to 87 U/L (sensitivity, 55%).

Conclusion

Our study confirms the high specificity and sensitivity of CgA in diagnosing an endocrine tumor. It is necessary to use a cutoff range of 84 to 87 U/L to obtain a high specificity in diagnosing NETs, with the aim of excluding patients in whom the CgA was elevated as a result of other non-neoplastic diseases.
The decapping activator Lsm1p-7p–Pat1p complex has the intrinsic ability to distinguish between oligoadenylated and polyadenylated RNAs
Authors: Chowdhury Ashis , Mukhopadhyay Jaba , Tharun Sundaresan
Published: May 2007

Decapping is a critical step in mRNA decay. In the 5′-to-3′ mRNA decay pathway conserved in all eukaryotes, decay is initiated by poly(A) shortening, and oligoadenylated mRNAs (but not polyadenylated mRNAs) are selectively decapped allowing their subsequent degradation by 5′ to 3′ exonucleolysis. The highly conserved heptameric Lsm1p-7p complex (made up of the seven Sm-like proteins, Lsm1p–Lsm7p) and its interacting partner Pat1p activate decapping by an unknown mechanism and localize with other decapping factors to the P-bodies in the cytoplasm. The Lsm1p-7p–Pat1p complex also protects the 3′-ends of mRNAs in vivo from trimming, presumably by binding to the 3′-ends. In order to determine the intrinsic RNA-binding properties of this complex, we have purified it from yeast and carried out in vitro analyses. Our studies revealed that it directly binds RNA at/near the 3′-end. Importantly, it possesses the intrinsic ability to distinguish between oligoadenylated and polyadenylated RNAs such that the former are bound with much higher affinity than the latter. These results indicate that the intrinsic RNA-binding characteristics of this complex form a critical determinant of its in vivo interactions and functions.
High-pressure investigations of solubility
Authors: Sawamura Seiji
Published: May 2007

We have measured the solubilities of several inorganic and organic compounds at high pressures up to 400 MPa. For this purpose, care should be exercised in instrumentation. The results include solubility values for aqueous solutions of NaCl, NaCl.2H2O, toluene, anthracene, phenanthrene, and amino acids (Gly, Ala, Val, Leu, and Ile). In addition, we determined the solubility of C60inn-hexane and toluene. The data for individual systems served to elucidate the mechanisms of dissolution. For example, the data for toluene, anthracene, and phenanthrene in water provided insight into hydrophobic hydration.
Solubility data in radioactive waste disposal
Authors: Wanner Hans
Published: May 2007

Radioactive waste arises mainly from the generation of nuclear power but also from the use of radioactive materials in medicine, industry, and research. It occurs in a variety of forms and may range from slightly to highly radioactive. It is a worldwide consensus that radioactive waste should be disposed of in a permanent way which ensures protection of humans and the environment. This objective may be achieved by isolating radioactive waste in a disposal system which is located, designed, constructed, operated, and closed such that any potential hazard to human health is kept acceptably low, now and in the future.

For highly radioactive waste and spent nuclear fuel, which are the waste types representing the highest potential danger to human health, an effective isolation from the biosphere is considered to be achievable by deep geological disposal. Disposal concepts rely on the passive safety functions of a series of engineered and natural barriers. Since total isolation over extended timescales is not possible, radionuclides will eventually be released from the waste matrix and migrate through the engineered and natural barriers. The assessment of their mobility in these environments is essential for the safety demonstration of such a repository. The solubility of many radionuclides is limited and may contribute significantly to retention. Reliable predictions of solubility limitations are therefore important.

Predictions of maximum solubilities are always subject to uncertainties. Complete sets of thermodynamic and equilibrium data are required for a reliable assessment of the chemical behavior of the radionuclides. Gaps in the thermodynamic databases may lead to erroneous predictions. Missing data and insufficient knowledge of the solubility-limiting processes increase the uncertainties and require pessimistic assumptions in the safety analysis; however, these are usually not detrimental to safety owing to the robustness of the multi-barrier approach.
Chemical speciation of environmentally significant metals with inorganic ligands Part 2: The Cu2+-OH-, Cl-, CO32-, SO42-, and PO43- systems (IUPAC Technical Report)
Authors: Powell Kipton J. , Brown Paul L. , Byrne Robert H. , Gajda Tamás , Hefter Glenn , Sjöberg Staffan , Wanner Hans
Published: May 2007

Complex formation between CuIIand the common environmental ligands Cl-, OH-, CO32-, SO42-, and PO43-can have a significant effect on CuIIspeciation in natural waters with low concentrations of organic matter. Copper(II) complexes are labile, so the CuIIdistribution amongst these inorganic ligands can be estimated by numerical modeling if reliable values for the relevant stability (formation) constants are available. This paper provides a critical review of such constants and related thermodynamic data. It recommends values of log10βp,q,r° valid atIm= 0 mol kg-1and 25 °C (298.15 K), along with the equations and specific ion interaction coefficients required to calculate log10βp,q,rvalues at higher ionic strengths. Some values for reaction enthalpies, ΔrHm, are also reported where available. In weakly acidic fresh water systems, in the absence of organic ligands, CuIIspeciation is dominated by the species Cu2+(aq), with CuSO4(aq) as a minor species. In seawater, it is dominated by CuCO3(aq), with Cu(OH)+, Cu2+(aq), CuCl+, Cu(CO3)OH-, Cu(OH)2(aq), and Cu(CO3)22-as minor species. In weakly acidic saline systems, it is dominated by Cu2+(aq) and CuCl+, with CuSO4(aq) and CuCl2(aq) as minor species.
The microbiological quality of seven large commercial private water supplies in the United Kingdom
Authors: Kay D. , Wyn-Jones A. P. , Stapleton C. M. , Fewtrell L. , Wyer M. D. , Watkins J. , Francis C. A. , Drury D.
Published: May 2007

Some 1% of the UK population derives their potable water from 140,000 private water supplies (PWSs) regulated by Local Authorities. The overwhelming majority of these are very small domestic supplies serving a single property or a small number of properties. Treatment for such supplies is rudimentary or non-existent and their microbiological quality has been shown to be poor in every published study to date. Private water supplies serving commercial enterprises such as hotels, restaurants, food production premises and factories are more frequently treated and subject to closer regulation in the United Kingdom. As a result, it has been assumed that these larger commercial supplies are less likely to experience elevated faecal indicator and pathogen concentrations at the consumer tap which have been observed at small domestic supplies.

This paper reports on intensive monitoring at seven commercial private water supplies (six of which were treated) spread throughout the UK serving hotels, holiday parks and food production enterprises. Daily sampling of ‘potable’ water, both at the consumer tap and using large volume filtration for Giardia and Cryptosporidium spp. was conducted over two six week periods in the spring and autumn of 2000. This allowed the effects of short term episodic peaks in faecal indicator and pathogen concentration to be quantified. All the supplies experienced intermittent pathogen presence and only one, a chlorinated deep borehole supply, fully complied with UK water quality regulations during both periods of sampling.

Poor microbiological water quality typically followed periods of heavy rainfall. This suggests that the design and installation of such systems should be undertaken only after the likely range of raw water quality has been characterised, which requires a thorough understanding of the effects of flow and seasonality on raw water quality. There is no reason to suspect that the monitored sites are uncharacteristic of other commercial supplies and the results reinforce public health concerns related to domestic supplies. Furthermore, the pattern of contamination is highly episodic, commonly lasting only a few days. Thus, the relatively infrequent regulatory monitoring of such supplies would be unlikely to identify the poor water quality episodes and does not provide the data necessary for public health protection.

Although some statistical relationship was found between faecal indicator organisms and the presence of pathogens, the use of FIOs in assessments of regulatory compliance may not always provide a reliable measure of public health risk, i.e. indicator absence does not preclude pathogen presence. The results of this study suggest that a risk assessment system similar to the WHO ‘Water Safety Planning’ approach might offer a more appropriate regulatory paradigm for private water supplies.
Water quality assessment of Lebanese coastal rivers during dry season and pollution load into the Mediterranean Sea
Authors: Houri Ahmad , El Jeblawi Saadieh W.
Published: May 2007

The chemical and microbiological properties of Lebanese perennial coastal rivers were studied during the dry season extending from July to September 2004. The results indicate significant levels of pollution in all eight rivers. Although many physical and chemical variables were within WHO guidelines for drinking water, coliform levels were unacceptably high indicating pollution from untreated sewage. The most polluted rivers in most categories were the Abu Ali and Antelias. With the exception of bacterial and phosphate loadings, Awali River provides the highest amount of pollution to the Mediterranean mainly due to its high water flow, although it is one of the least polluted rivers. The urgent need for controlling wastewater dumping into river streams is emphasized. The data obtained should serve as a reference point to assess the efficiency of planned wastewater treatment plants.
Effect of water suspended particles on the recovery of Cryptosporidium parvum from tomato surfaces
Authors: Chaidez Cristobal , Soto Marcela , Campo Nohelia Castro-del
Published: May 2007

An increase in the number of outbreaks of foodborne disease associated with fresh produce consumption has been described. The objective of the present study was to evaluate the effect of water suspended particles during immersing/spraying disinfection processes and the recovery of Cryptosporidium parvum oocysts from tomato surfaces. Tomatoes (Lycopersicum esculetum Mill.) were immersed/sprayed with chlorinated water with low and high suspended particle content (10 and 1,000 mg/l) containing 100, 1,000 or 10,000 oocysts/l. Tomatoes were evaluated after a contact time of 120 seconds and 30 seconds for immersing and spraying procedures, respectively. The immersing procedure showed a high recovery of C. parvum oocysts from the tomato surface when the concentration was 10,000 oocysts/l and 10 mg/l suspended particles (295±94 [mean±standard deviation]). High particle content affected oocyst recovery and dissolved particles exerted a chlorine demand reducing the disinfectant residual. In the spraying procedure, the highest recovery was observed with 10,000 oocysts/l (225±72). Our understanding is that the association of C. parvum oocysts with suspended particles might promote the oocyst deposition in the wash water tanks and that this interaction should be considered when evaluating the quality of the water.
Cost determination and sustainable financing for rural water services in sub-Saharan Africa
Authors: Harvey Peter A.
Published: May 2007

Access to safe, sufficient and affordable water in rural Africa will not increase unless sustainable financing strategies are developed which ensure the sustainability of existing water services. There is a strong need for international donors and national governments to confront the true costs associated with sustained service provision in order to develop practicable long-term financing mechanisms. This paper presents a systematic approach that can be applied to determine the overall cost of service delivery based on respective cost estimates for operation and maintenance, institutional support, and rehabilitation and expansion. This can then be used to develop a tariff hierarchy which clearly indicates the cost to water users of different levels of cost recovery, and which can be used as a planning tool for implementing agencies. Community financing mechanisms to ensure sustained payment of tariffs must be matched to specific communities and their economic characteristics; a blanket approach is unlikely to function effectively. Innovative strategies are also needed to ensure that the rural poor are adequately served, for which a realistic, targeted and transparent approach to subsidy is required.
Can economists value water's multiple benefits?
Authors: Batten David F.
Published: May 2007

If we recognize that water is not an ordinary economic good, we begin to understand why it is so difficult to assess and compare its many and varied benefits. Market instruments devised for conventional goods may not ensure that water is allocated efficiently and equitably. Classical economic tools, such as cost–benefit analysis, input–output analysis or equilibrium models, may not be able to embrace water's multiplicity of short, medium and long-term benefits. Only those parts of the water cycle close to intermediate and final users are usually treated as economic goods. If its vision is limited to linear, short run quantities and relationships, a computable model abstracts from a real world that we know is dynamic, nonlinear and co-evolutionary. Short run economic priorities for water policy tend to dominate over sustainable allocation and quality conservation in the longer run. There is a need to consider longer time horizons and the complex, dynamic character of water, if we are to meet the challenge of repairing Australia's seriously impaired natural waterways.
Molecular dynamics simulations of potassium channels
Authors: Domene Carmen
Published: May 2007

Despite the complexity of ion-channels, MD simulations based on realistic all-atom models have become a powerful technique for providing accurate descriptions of the structure and dynamics of these systems, complementing and reinforcing experimental work. Successful multidisciplinary collaborations, progress in the experimental determination of three-dimensional structures of membrane proteins together with new algorithms for molecular simulations and the increasing speed and availability of supercomputers, have made possible a considerable progress in this area of biophysics. This review aims at highlighting some of the work in the area of potassium channels and molecular dynamics simulations where numerous fundamental questions about the structure, function, folding and dynamics of these systems remain as yet unresolved challenges.
Exact solutions of the radial Schrödinger equation for some physical potentials
Authors: Ikhdair Sameer , Sever Ramazan
Published: May 2007

By using an ansatz for the eigenfunction, we have obtained the exact analytical solutions of the radial Schrödinger equation for the pseudoharmonic and the Kratzer potentials in two dimensions. The bound-state solutions are easily calculated from this eigenfunction ansatz. The corresponding normalized wavefunctions are also obtained.
Exploring the Willingness of Scholars to Accept Open Access: A Grounded Theory Approach
Authors: Park Ji-Hong , Qin Jian
Published: May 2007

This article aims to explore what factors increase or decrease scholars' willingness to publish and use articles in open-access journals and discusses how these factors are related to one another. Research-oriented publications on the topic of open-access journals have been few, and there is widespread concern about whether scholars will adopt this new form of scholarly communication. The growing number of open-access journals leads scholars to encounter decision-making situations in which they must choose one journal among multiple alternatives, including open access and non–open access. We conducted open-ended and semi-structured in-depth interviews with eight faculty members and six doctoral students at Syracuse University. Based on the interview transcripts, willingness factors and their relationships were identified and refined using the iterative steps of grounded theory approach proposed by Strauss and Corbin in the 1998 edition of their Basics of Qualitative Research: Techniques and Procedures for Developing Grounded Theory. The findings show seven factors (perceived journal reputation, perceived topical relevance, perceived availability, perceived career benefit, perceived cost, perceived content quality, and perceived ease of use) and eight relationships. There were six positive and two negative relationships. The factors and relationships were then compared to the relevant literature to increase internal validity and generalizability of the study. Both theoretical and practical implications of the research are discussed. Theoretically, this study broadens the scope of relevance criteria studies, first identifies the relationship between two important scholarly communication activities, conceptually contributes to the concept of open access, and applies literature comparison methodology in a pure qualitative study to increase internal validity and generalizability. Practically, the findings of this study may be helpful for promoting open-access publishing by encouraging facilitators and discouraging hinderers. The research may also provide an ongoing working framework for evaluating open-access journal systems.
Training Non-native Second Language Teachers: The Case of Anglophone FSL Teacher Candidates
Authors: Bayliss Doreen , Vignola Marie-Josée
Published: May 2007

Abstract:

This study documents the experiences of anglophone French as a second language (FSL) teacher candidates during their pre-service program. The authors describe how this group of non-native FSL teacher candidates felt about the adequacy of their FSL skills, their need for some level of second language (L2) support, and the maintenance of their L2 skills during their teaching careers. Participants represented three teaching divisions (elementary through secondary school), interviewed separately in focus groups. Most students felt that their L2 skills were adequate. In all cases, students expressed a need for some form of FSL support; although they felt responsible for maintaining their L2 themselves, they recognized the need for some level of organizational support. Results are similar to those of studies of non-native ESL teachers and raise many issues that should be addressed in a wider forum to ensure the continuation and improvement of quality FSL education.
The Council of Editors of Learned Journals (CELJ) Keynote Address MLA Convention 2005
Authors: Vandenberg Peter , Hanson David C.
Published: May 2007

Drawing on his experience assuming and relinquishing the editorship of the award-winning journal Composition Studies, Peter Vandenberg suggests that a successful editorial transition is the final obligation of a retiring editor, particularly one without imposed term limits. The author illustrates why a successful transition begins with early planning, is made possible by ongoing documentation of practice throughout an editor's term, and culminates in effective mentoring as the new editor becomes acclimated. The author encourages editors to ensure that their commitment is sustained throughout the transition period by planning an exit strategy.
Eggs
Authors: Bergquist Dwight H. ,   Updated by Staff
Published: May 2007

Eggs are used in homes, restaurants, and institutions as shell eggs; they are used in the food industry primarily as egg products. Eggs, which have various functional properties including coagulation by heat, whipping ability, and emulsifying power, are also highly nutritious. Egg products are produced under USDA inspection, which requires that all egg products be pasteurized so they are
Salmonella
‐negative.

There are liquid, frozen, and dried egg products. Automation has come into play for the production of shell eggs and egg products including handling, breaking and separating, processing, and drying of eggs. Eggs are separated into three components in an egg products plant, ie, whites, yolk, and whole egg, at a rate of 32,000 eggs per h per single row, single‐tier egg breaking machine. Eggs are spray‐dried under very mild conditions to preserve quality.

Economic data are given and information on organic eggs is included. Labeling requirements are listed. The safety section gives information on
Salmonella
prevention, allergies, and safe cooking and storage details.
Heat Transfer and Heat Exchangers
Authors: Sunden Bengt
Published: May 2007

This article provides an introduction to heat transfer theory. Then the important application area of heat exchangers is extensively treated. The modes of heat transfer are introduced and major definitions are presented. Correlations for convective heat transfer are provided and heat transfer of extended surfaces, as well as composite walls, is briefly introduced. Functioning and classification of heat exchangers are discussed. Common methods for analysis, design, rating and sizing are given. Plate heat exchangers, shell‐and‐tube heat exchangers, compact and regenerative heat exchangers are considered. Special applications are also discussed.
Flow cytometric evaluation of circulating endothelial cells: A new protocol for identifying endothelial cells at several stages of differentiation
Authors: Ozdogu Hakan , Sozer Oktay , Boga Can , Kozanoglu llknur , Maytalman Erkan , Guzey Meral
Published: May 2007

Several factors may influence the analysis of endothelial cells (ECs) by flow cytometry: separation of mononuclear cell, washing and centrifugation steps, panel of monoclonal antibodies, and the lack of standardization of gating technique. Therefore, the reliable quantification of ECs remains a technical challenge. The purpose of this study is to define a new flow cytometric protocol to characterize and quantitate ECs. In previous investigations, increased numbers of circulating ECs have been found in sickle cell disease. The patients with sickle cell disease might provide useful material for the study. We performed flow cytometry on whole blood from 20 normal controls and 31 patients with sickle cell disease (20 patients with steady‐state disease and 11 patients with vaso‐occlusive crises) using a lyse/no‐wash procedure, specific and nonspecific antibody combinations (CD146, CD144, CD34, and CD117), and broad gating. This protocol produced much higher values for the number of circulating ECs (a mean of 2,396.55 ± 658.37 ECs/mL in controls vs 6,709.60 ± 1,772.32 ECs/mL in the steady‐state group, or 18,213.50 ± 8,451 in the vaso‐occlusive crises group, P < 0.001 for both), and also showed variable EC size and granularity, which may reflect activated, or early release ECs. This novel protocol performed comparably in terms of reproducibility, reliability, and dilution linearity with a previously described protocol. This approach has significant advantages for the characterization and quantitation ECs compatible with the pathophysiology. Using the specific antibodies, CD146 and CD144, together may give more informative EC data than the general approach used. Am. J. Hematol., 2007. © 2007 Wiley‐Liss, Inc.
Benzene‐induced acute myeloid leukemia: A clinician's perspective
Authors: Natelson Ethan A.
Published: May 2007

Benzene‐induced acute myeloid leukemia (AML) is considered a secondary form of AML, based both in theory and on limited cohort observations. Its latency, cytogenetic aberrations, and clinical features are thought similar to, or identical with, AML resulting from the use of modern day cytotoxic agents for chemotherapy and immunotherapy. Although distinction between secondary AML and the far more common de novo AML is difficult to establish with certainty in any given case, latency from toxic therapeutic and environmental exposure and certain clinical and pathological features generally separate these two entities. AML is the only human neoplasm proven to be potentially caused by benzene, which actually is an obsolete form of chemotherapy. Despite many years of environmental regulation, alleged toxic exposure to this ubiquitous chemical has become an expanding area of litigation. A review of benzene‐induced AML suggests that, in developed countries, this entity should no longer merit serious consideration among workers in the modern petrochemical industry and related fields. Am. J. Hematol., 2007. © 2007 Wiley‐Liss, Inc.
Supplementary breaks and stretching exercises for data entry operators: A follow‐up field study
Authors: Galinsky Traci , Swanson Naomi , Sauter Steven , Dunkin Robin , Hurrell Joseph , Schleifer Lawrence
Published: May 2007

Background

This study expanded previous NIOSH‐IRS research examining the effects of rest breaks and stretching exercises on symptoms and performance in data‐entry workers.

Methods

All workers spent 4 weeks with conventional breaks (two 15 min breaks per day) and 4 weeks with supplementary breaks (two 15 min breaks plus four 5 min breaks per day). One‐half were assigned at random to a group instructed to perform brief stretching exercises during breaks. The remainder comprised the “no stretching” (control) group.

Results

51 workers (stretch group n = 21; no stretch group n = 30) completed the study symptom questionnaires. Discomfort and eyestrain were significantly lower with supplementary breaks, and supplementary breaks attenuated accumulation of discomfort and eyestrain during work sessions. Data‐entry speed was significantly faster with supplementary breaks so that work output was maintained, despite replacing 20 min of work time with break time. In the stretch group, workers reported stretching during only 25% of conventional breaks and 39% of supplementary breaks, and no significant effects of stretching on discomfort or performance were observed.

Conclusions

These results provide further converging evidence that supplementary breaks reliably minimize discomfort and eyestrain without impairing productivity. Low compliance in performing stretches prevented valid assessment of stretching effects. Further research on stretching exercises and exercise compliance is warranted. Am. J. Ind. Med. 50:519–527, 2007. Published 2007 Wiley‐Liss, Inc.
Electrometrische Untersuchungen
Authors: Hallwachs W.
Published: May 2007

Methode zur Bestimmung von Contactpotentialdifferenzen ohne Anwendung des Condensators. Quadrantelectrometer von constanter Empfindlichkeit.
On the Problem of Transformation Properties of the Spin Pseudo‐Vector
Authors: Sokolov A. A. , Ternov I. M. , Loskutov Ju. M.
Published: May 2007

Polarization 4‐ vector of Dirac's particles is introduced by the covariant method, and its transformation properties are investigated. The results obtained are used to discuss the phenomena related to parity non‐conservation.
Die Richtungsabhängigkeit der Magnetostriktion
Authors: Döring W. , Simon G.
Published: May 2007

In Einkristallen läßt sich die Magnetostriktion durch einen symmetrischen zweistufigen Tensor beschreiben, dessen Komponenten von der Magnetisierungsrichtung abhängen. Diese Abhängigkeit wird mit Hilfe eines gruppentheoretischen Verfahrens für alle Kristallklassen in eine solche Form gebracht, daß sie der Kristallsymmetrie genügt. Die Resultate sind nicht nur auf die Magnetostriktion, sondern auch z. B. auf den Widerstand in magnetischen Einkristallen und in der Theorie der Gitterschwingungen anwendbar.
Über die Struktur von Caesium‐Wismut‐Fotokathoden
Authors: Oertel G.
Published: May 2007

Die Struktur der Verbindungen des Systems CsBi wird an dünnen Schichten durch Elektronenbeugung untersucht. Auswertbare Aufnahmen werden nur für die Verbindung Cs3Bi nach längerem Tempern der Schichten erhalten. Als Ergebnis wird in Übereinstimmung mit aus Röntgenstrukturuntersuchungen bekannten Angaben gefunden, daß Cs3Bi auch in dünnen Schichten nach dem Cu3Al(DO3)‐Typ kristallisiert, mit a = 9,292 ± 0,013 Å.
Diskussion einer normierten WKB‐ähnlichen Wellenfunktion
Authors: Macke W. , Rennert P.
Published: May 2007

Es wird ein Näherungsverfahren zur Berechnung der Wellenfunktion eines Teilchens im gegebenen Potential besprochen, das zu einer WKB‐ähnlichen Lösung führt. In erster Näherung ergibt sich dabei ein der von Langer ver‐besserten WKB‐Lösung entsprechender Ausdruck. Das Verfahren läßt die physikalischen Annahmen, die zur WKB‐Lösung führen, genau erkennen. Sie blieben bei der nach der WKB‐Methode durchgeführten Entwicklung nach Potenzen von ℏ unklar.
Das Prinzip der minimalen Entropieproduktion bei dynamischer Kernpolarisation
Authors: Vojta Günter
Published: May 2007

Unter Verwendung des Begriffs der Spintemperatur wird eine einfache Herleitung der Formeln für die stationäre dynamische Polarisation von Kernspins beim Overhauser‐, „Underhauser”︁‐, Abragam‐Jeffries‐ und „Solid”︁‐Effekt gegeben. Danach wird für diese Effekte das Prinzip der minimalen Entropieproduktion in allgemeiner Weise innerhalb des Spintemperaturformalismus bewiesen.
Das allgemein‐relativistische Analogon des Coulombfeldes im Dielektrikum
Authors: Kasper Uwe
Published: May 2007

In einer Arbeit von H.‐G. Schöpf2) wird das Dielektrikum und das elektromagnetische Feld als abgeschlossenes System behandelt. Es wird darauf hingewiesen, daß man die Einsteinschen Feldgleichungen, die Maxwellschen Gleichungen und die Eulerschen Bewegungsgleichungen für das Dielektrikum simultan zu lösen hat. Bei konstantem ϵ und μ läßt sich dieses Vorgehen sofort auf den Fall des geladenen Dielektrikums ausdehnen. Man hat dazu nur in der Lagrange ‐ Dichte den Term ϱUαθα hinzuzufügen. Bekanntlich liefert dieser Ausdruck keinen Beitrag zum Energie‐Impuls‐Tensor. Nur im Kraftdichteterm tritt das Glied FμνUν neu hinzu. Wir spezialisieren das so erweiterte Gleichungssystem auf kugelsymmetrische, elektrostatische Verhältnisse, d. h. wir betrachten das allgemein‐relativistische Analogon des Coulombfeldes, und geben eine spezielle Lösung an mit einer idealen Flüssigkeit als Dielektrikum. Durch den Ansatz = 0 kommen wir dann zum ungeladenen Dielektrikum zurück. Die durchgeführten Rechnungen zeigen, daß unter dem Einfluß des Gravitationsfeldes, das vom Dielektrikum und elektrostatischen Feld erzeugt wird, homogene scheinbare Flächenbelegungen von Ladungen auf Grenzflächen benachbarter Medien nur durch zusätzliche Spannungen aufrechterhalten werden können.
Zur Magnetostriktion ferromagnetischer Kristalle
Authors: Hubert Alex
Published: May 2007

Es wird gezeigt, daß man die pauschale Magnetostriktion eines ferromagnetischen Einkristalls stets durch die Bildung des Volummittelwertes über die „freien”︁ Magnetostriktionen der einzelnen Weißschen Bezirke gewinnen kann; frei soll hier diejenige Verzerrung heißen, der ein Bereich in freiem Zustand, also ohne äußere Kräfte, unterliegen würde.

Dies gilt dagegen nicht für einen Vielkristall aus elastisch anisotropem Material. Die Voraussetzungen der Formel von Becker und Döring1) für die Magnetostriktion eines pauschal isotropen Vielkristalls erweisen sich als nicht gegeben. Eine bessere Abschätzung wird vorgeschlagen.
Zur Theorie der Magnetisierungsschwankungen und der Blockierung in dünnen Permalloyschichten
Authors: Schnupp Peter
Published: May 2007

Für ein idealisiertes Schichtmodell wird eine Differenzengleichung für die Magnetisierungseinstellung in der Schicht in Abhängigkeit von den Schwankungen der uniaxialen und der Kristallanisotropie aufgestellt. Die linearisierte Gleichung wird mit Hilfe einer Fouriertransformation gelöst. Die sich ergebenden Richtungsschwankungen der Magnetisierung („Ripple”︁) können als das „gefilterte zweidimensionale Rauschen”︁ der Anisotropie‐Richtungsschwankungen aufgefaßt werden. Nach üblichen Methoden der Behandlung von Rauschvorgängen werden bei Annahme eines bandbegrenzten weißen Rauschens für die Anisotropieschwankungen die mittlere Amplitude und die mittleren Nullstellenabstände der Magnetisierungsabweichung von der mittleren leichten Richtung berechnet und mit Literaturangaben verglichen. Die Auswertung defokussierter elektronenmikroskopischer Schichtaufnahmen wird in diesem Zusammenhang eingehender besprochen. Es zeigt sich, daß die zu erwartende Feinstruktur unter der bis jetzt erreichten Auflösungsgrenze für derartige Aufnahmen liegt. Aus der Grobstruktur der Aufnahmen können lediglich qualitative Angaben über die „mittlere Wellenlänge”︁ des Ripples erhalten werden, welche mit den theoretischen Ergebnisse befriedigend übereinstimmen.
Über den mutmaßlichen radioaktiven Zerfall von Ce‐136
Authors: Hohmuth Karl , Schintlmeister Josef
Published: May 2007

Auf Grund der Massenwerte für Isobare mit A = 136 kann man vermuten, daß Ce‐136, das als stabil angesehen wird, möglicherweise instabil gegen E‐Einfang ist. Um diese Vermutung zu prüfen, wurden 2 g Ce2O3 in einem Proportionalzählrohr auf die Emission der L‐Röntgenlinie von Ba136 untersucht. Diese Linie müßte auf Grund des Zerfalles des Folgekernes La136 (9,25 Minuten) von dem Ce‐Präparat emittiert werden. Das Ergebnis der Untersuchung zeigte keine solche Linie. Daraus folgt eine untere Grenze für die Halbwertszeit des Ce‐136 von 2,9 · 1011 Jahren.
Entwicklung der Slatersumme in der Nähe der klassischen Grenze
Authors: Hoffmann H. J. , Kelbg G.
Published: May 2007

Die Struktur früher erhaltener Entwicklungen der SLATER‐Summe einer quantenstatistischen kanonischen Gesamtheit nach Potenzen von ħ2 bzw. des Kopplungsparameters q der Teilchenwechselwirkung wird weiter aufgeklärt. Dabei wird eine zweckmäßige Diagramm‐Schreibweise eingeführt. Es ergibt sich, daß alle in der Quantenkorrektur zum klassischen BOLTZMANNschen e‐Faktor auftretenden nichtzerfallenden Diagramme in den Exponenten gesetzt werden können und so die ganze Störungsreihe liefern. Man erhält eine Entwicklung im Exponenten der e‐Funktion, die zur Berechnung eines effektiven Potentials Verwendung finden kann. Unter Vernachlässigung von Symmetrie‐Effekten werden für die Doppelentwicklung im Exponenten zwei Ausdrücke angegeben: 1. alle Glieder bis zur Ordnung ħ6, 2. alle Terme bis q2 unter Einschluß sämtlicher ħ2‐Potenzen.
Über die Anwendung von Dispersionsrelationen zur Bestimmung optischer Konstanten
Authors: Wilhelmi B.
Published: May 2007

Für ein allgemeines Spektrum, das nur durch die Existenz einer oberen FOURIER‐Grenzfrequenz charakterisiert wird, werden von den KRAMERS‐KRONIG‐Relationen ausgehend einfache Gleichungen zwischen Brechungsindex und Absorptionskoeffizient bzw. zwischen Betrag und Phase des Reflexionskoeffizienten an diskreten Punkten, den Musterpunkten, abgeleitet. Bei beliebigem vorgegebenen spektralen Verlauf des Absorptionskoeffizienten ist es möglich, den Brechungsindex zu bestimmen.

Der Rechenaufwand bleibt durch die Anwendung der Musterpunktkonzeption und durch eine geeignete Aufteilung in voneinander getrennte Absorptionsbereiche relativ niedrig. Als Beispiel wurde der Brechungsindex von CS2 im Infrarotgebiet berechnet und mit Meßwerten zwischen 2 μm und 30 μm verglichen. Aus Werten des Reflexionsvermögens von Caesiumbromid wurden die zugehörigen Phasenwinkel und optischen Konstanten ermittelt und entsprechenden Meßwerten von GEICK gegenübergestellt.
Activation Energies of Brownian Motion in Liquid Determinated by Luminescence Methods
Authors: Głowacki J.
Published: May 2007

The activation energies for rotation and translation of fluorescein molecules in glycerin determined in this paper are different. These activation energies decreases with increasing concentration of fluorescence quenching molecules (KI).
Durch Wechselwirkung mit Atomen bedingte Frequenzaufspaltung in einem Resonator. I
Authors: Paul H. , Frahm J. , Rauh D.
Published: May 2007

Making use of the eigenfunctions of the total Hamiltonian, the correlation function 〈𝔈̂(−) (t1) 𝔈̂(+) (t2)〉 is calculated explicitly for a one‐mode radiation field interacting incessantly with an atom. In the frequency spectrum following from this correlation function there appear frequency shifts corresponding, just as in [7], in one case, to a change of the effective dielectric constant within the cavity due to the atom, and, in the other case, to an amplitude modulation due to the alternating absorption and emission of a photon by the atom.
Lichtgeschwindigkeitsmessungen mit einem HeNe‐Gaslaser als Lichtquelle
Authors: Karolus A. , Helmberger J.
Published: May 2007

Auf der Basis des Deutschen Geodätischen Forschungsinstituts in München wurden im Herbst 1965 Messungen der Vakuum‐Lichtgeschwindigkeit unter Verwendung eines HeNe‐Lasers als Lichtquelle durchgeführt. Das Licht dieses Lasers (λo = 632,8 nm), durch Ultraschall mit einer Frequenz von 18,72 MHz sinusförmig moduliert. wird in zwei gleiche Teile — Meß‐ und Vergleichslicht — aufgeteilt. Das Meßlicht durchläuft bei zwei aufeinanderfolgenden Messungen zwei um die Länge der Basis (48 m) verschieden lange Wege und trifft in beiden Fällen gegenphasig zum Vergleichslicht auf die Kathode eines Photomultipliers. Bei Gleichheit der Amplituden von Meß‐ und Vergleichslicht geht die Modulation des Photostromes durch Null. Die Basis wurde mit einem Interferenzkomparator nach VÄISÄLÄ mit einer Unsicherheit von 1: 107 bestimmt. Die Modulationsfrequenz wurde mit einem elektronischen Zähler mit einem Fehler < 1: 108 gemessen. Mit den bei jeder Meßreihe bestimmten meteorologischen Daten (Temperatur, Luftdruck Luftfeuchtigkeit) wurde über die Dispersionsgleichung von EDLEN aus der Gruppengeschwindigkeit in Luft die Vakuum‐Lichtgeschwindigkeit berechnet. Durch Änderungen im Meßaufbau wurde versucht, systematische Fehler aufzudecken.

Aus 6 Gruppen mit zusammen 60 Meßreihen ergab sich die Ausbreitungsgeschwindigkeit des Lichtes in Vakuum zu c0 = 299 792,5km/s ± 0,15 km/s.
Das Verhalten geladener Teilchen in elektrischen Vierpolfeldern
Authors: Gradewald R.
Published: May 2007

Befinden sich geladene Partikel in einem hyperbolischen Vierpol‐Wechselfeld, dann können die Teilchen unter bestimmten Bedingungen stabile Bewegungen ausführen. Derartige Bewegungsvorgänge sind schon mehrfach beschrieben worden [1…16]. Als Partikel werden Ionen oder makroskopische Teilchen (Metallstaub, Salzstaub) verwendet. Liegt an den Platten des Vierpolkondensators eine elektrische Spannung, dann bildet sich zwischen den Platten ein nichtlineares Feld aus. In [1…11] wird der Feldverlauf linearisiert. Für die Bewegung erhält man die MATHIEUsche Differentialgleichung. Die Experimente sind so gestaltet, daß die Koeffizienten im stabilen Bereich liegen. Im Einklang mit der Theorie stellen sich stabile Bewegungen ein. Ist die Dämpfung vernachlässigbar, dann hängt in diesen Bereich die Amplitude von den Parametern ab, mit denen die Teilchen in das Feld gebracht werden. Muß die Dämpfung berücksichtigt werden, klingt die Amplitude ab, wobei sich gleichzeitig der stabile Bereich erweitert. Wird die Nichtlinearität das Feldes berücksichtigt, dann treten nichtlineare Resonanzen auf [12].

Die eigenen Experimente werden mit Salzstaub bei normalem Luftdruck durchgeführt. Es muß die Dämpfung berücksichtigt werden. Der Theorie der MATHIEUschen Differentialgleichung nach ist zu erwarten, daß im stabilen Bereich die Schwingungen abklingen, die Amplitude also Null wird. Das gilt auch für den durch die Dämpfung verbreiterten Bereich. Überschreitet man jedoch durch Veränderung der Koeffizienten die Stabilitätsgrenze und erweitert somit den bisherigen Untersuchungsbereich, dann wird der Theorie der MATHIEUschen Differentialgleichung nach die Schwingung instabil. Die Amplitude müßte also trotz der Dämpfung unbegrenzt wachsen. Dem widerspricht jedoch das Experiment [13…16]. Im stabilen Bereich wird die Amplitude erwartungsgemäß Null. Nach Überschreiten der alten Stabilitätsgrenze jedoch wird sie nicht instabil, sondern erreicht einen endlichen Wert. Es bildet sich ein neuer Schwingungstyp: Die Teilchen durchlaufen Bewegungskurven in Form von vierstrahligen Sternen. Die in [1…11] benutzte rheo‐lineare Differentialgleichung reicht nicht mehr aus, um in diesem Bereich die Schwingungen zu erfassen. Wir haben ein rheo‐nichtlineares Problem vor aus. Zieht man zur Lösung die rheo‐nichtlineare Differentialgleichung heran, dann ist das Problem lösbar. Das sich ergebende rheo‐nichtlineare Differentialgleichungssystem wird für das vorliegende ebene Problem näherungsweise gelöst und mit dem Experiment verglichen.