bluuebunny/crossref_metadata_2025 huggingface dataset:
Mortality Associated with Caregiving, General Stress, and Caregiving‐Related Stress in Elderly Women: Results of Caregiver‐Study of Osteoporotic Fractures
Authors: Fredman Lisa , Cauley Jane A. , Hochberg Marc , Ensrud Kristine E. , Doros Gheorghe ,   for the Study of Osteoporotic Fractures
Published: March 2010

OBJECTIVES: To investigate the separate and combined effects of caregiver status and high stress on mortality risk over 8 years in elderly women.

DESIGN: Prospective cohort study conducted in four U.S. communities followed from 1999/01 (baseline) to December 31, 2007.

SETTING: Home‐based interviews.

PARTICIPANTS: Three hundred seventy‐five caregiver and 694 noncaregiver participants from the Caregiver‐Study of Osteoporotic Fractures (Caregiver‐SOF) who participated in the baseline Caregiver‐SOF interview.

MEASUREMENTS: Caregiver status was based on SOF respondents' self‐report of performing one or more instrumental or basic activities of daily living for a relative or friend with impairments. Two measures of stress were used: Perceived Stress Scale and stress related to caregiving tasks. All‐cause mortality was the outcome.

RESULTS: Caregivers were more stressed than noncaregivers; 19.7% of caregivers and 27.4% of noncaregivers died. Mortality was lower in caregivers than noncaregivers (adjusted hazard ratio, (AHR)=0.74, 95% confidence interval (CI)=0.56–0.89). High‐stress respondents had greater mortality risk than low‐stress respondents over the first 3 years of follow‐up (AHR=1.81, 95% CI=1.16–2.82) but not in later years. Likewise, high‐stress caregivers and noncaregivers had higher mortality risk than low‐stress noncaregivers, although low‐stress caregivers had significantly lower mortality than did noncaregivers, whether perceived stress or caregiving‐related stress was measured (AHR=0.67 and 0.57). Similar results were observed in analyses comparing spouse caregivers with married noncaregivers.

CONCLUSION: Short‐term effects of stress, not caregiving per se, may increase the risk of health decline in older caregivers.
Diffuse Leukoencephalopathy and Brain Edema: Unusual Presentations of CNS Relapse of Acute Myeloid Leukemia
Authors: Schumann Michael , Kiewe Philipp , Hartlieb Sissel , Neumann Martin , Schilling Andreas , Koch Hans‐Christian , Thiel Eckhard , Korfel Agnieszka
Published: March 2010

An isolated CNS relapse is rarely seen in acute myeloid leukemia. However, it has a potentially fatal clinical outcome. We herein present the case of a 39‐year‐old man, who presented to our emergency room with horizontal diplopic images, vertigo, bilateral deafness, and progressing somnolence. Cerebral imaging revealed cerebral and cerebellar edema and a diffuse leukoencephalopathy. With the one‐year‐old history of an initially successfully treated FAB‐M0 acute myeloid leukemia (AML) in mind, a lumbar puncture was carried out that showed a vast number of myeloid blasts in the morphologic analysis of the cerebrospinal fluid. In conjunction with normal findings in the peripheral blood‐count with differential and the bone marrow examination a diagnosis of an isolated CNS relapse of the AML was made. Cytarabine chemotherapy was initiated and the symptoms resolved rapidly. To our surprise, cerebral imaging in the course of the treatment not only showed a resolution of the brain edema but also of the leukoencephalopathy, pointing to a direct infiltration of brain parenchyma by leukemic blasts. The case highlights the relevance of the CNS as a pharmacologic “sanctuary” for tumor cells in patients that on prior treatments have not received intrathecal chemotherapy or chemotherapeutics that cross the blood‐brain barrier.
Multiple Cranial Nerve Enhancement: Uncommon Imaging Finding in Early Infantile Krabbe's Disease
Authors: Ganesan Karthik , Desai Shrinivas , Hegde Anaita
Published: March 2010

Multiple cranial nerve enhancement in early infantile Krabbe's disease is an uncommon imaging finding. We present an 8‐month‐old infant with early infantile Krabbe's disease with enhancement of multiple cranial nerves and optic nerve hypertrophy.
Neuroradiologic Evidence of Pre‐Synaptic and Post‐Synaptic Nigrostriatal Dopaminergic Dysfunction in Idiopathic Basal Ganglia Calcification: A Case Report
Authors: Saito Takahiro , Nakamura Mitsuru , Shimizu Teruhiko , Oda Keiichi , Ishiwata Kiichi , Ishii Kenji , Isse Kunihiro
Published: March 2010

Idiopathic basal ganglia calcification (IBGC) is a neuropathological condition known to manifest as motor disturbance, cognitive impairment, and psychiatric symptoms. The pathophysiology of the psychiatric symptoms of IBGC, however, remains controversial. A previous biochemical study suggested that dopaminergic impairment is involved in IBGC. We thus hypothesized that dopaminergic dysfunction might be related with the psychiatric manifestations of IBGC. We used positron emission tomography to measure glucose metabolism and dopaminergic function in the basal ganglia of an IBGC patient with psychiatric symptoms. The results showed that widespread hypometabolism was evident in the frontal, temporal, and parietal cortices while the decline in dopaminergic function was severe in the bilateral striatum. The functional decline of the dopamine system in the calcified area of the bilateral striatum and the disruption of cortico‐subcortical circuits may contribute to clinical manifestations of IBGC in our patient.
Thromboembolic Events Associated with Neuroform Stent™ in Endovascular Treatment of Intracranial Aneurysms
Authors: Yahia Abutaher M. , Latorre Julius , Gordon Vickie , Whapham John , Malek Ali , Fessler Richard D.
Published: March 2010

BACKGROUND

The incidence of thromboembolic events associated with Neuroform stent™ (Boston Scientific Target, Fremont, CA) is known from previous studies but there are uncertainties of scale.

PURPOSE

To report our rate of ischemic events associated with Neuroform stent™.

METHODS

Consecutive patients treated with Neuroform stent™ for intracranial aneurysms were prospectively enrolled from January 2003 to August 2006. Thromboembolic events as well as clinical outcomes were measured. Mean follow‐up was 12 months.

RESULTS

Successful stent deployment was achieved in (65/67) 97% of patients without any ischemic event. However, postoperative thromboembolic events were observed in 3 patients despite being on clopidogrel and aspirin. These 3 patients demonstrated poor platelet inhibitions in platelet aggregation (aggregometry) studies, and were successfully treated with intravenous eptifibatide with good outcome. The majority of the patients had good outcomes [Glasgow Outcome Score (GOS) 5 or National Institute of Health Stroke Scale (NIHSS) 0 in (63/67) 94%, GOS 4 or NIHSS 2 in 1 patient, and GOS 3 or NIHSS 4 was observed in 3 cases].

CONCLUSION

Our study reveals that the thromboembolic events associated with Neuroform stent™ may present in a delayed fashion. These events can be successfully treated with good outcome. Therefore, postoperative close follow‐up is strongly recommended for all Neuroform stent™‐treated patients.
Distribution of Foxp3‐, CD4‐ and CD8‐positive lymphocytic cells in benign and malignant prostate tissue
Authors: VALDMAN ALEXANDER , JARAJ SARA JONMARKER , COMPÉRAT EVA , CHARLOTTE FRÉDERIC , ROUPRET MORGAN , PISA PAVEL , EGEVAD LARS
Published: March 2010

Valdman A, Jaraj SJ, Compérat E, Charlotte F, Roupret M, Pisa P, Egevad L. Distribution of Foxp3‐, CD4‐ and CD8‐positive lymphocytic cells in benign and malignant prostate tissue. APMIS 2010; 118: 360–5.

Foxp3 is a transcription factor that inhibits antitumor immune response and is expressed in regulatory T cells (Tregs). High levels of Tregs have been reported in several human cancers. This study investigates the distribution of cells positive for Foxp3, CD4 and CD8 in benign prostatic tissues and prostatic carcinoma. Tissue microarrays were constructed from radical prostatectomy specimens of 36 patients. From each patient, six cores were taken: two cores from cancer, one from benign tissue of each of the peripheral (PZ), transition (TZ) and central zones (CZ) and one from atrophy. Foxp3‐, CD4‐ and CD8‐positive cells were more common in cancer than in non‐atrophic benign tissue (p < 0.01) and more common in atrophy than in non‐atrophic PZ, but did not differ significantly between cancer and atrophy. Cells positive for Foxp3 and CD4 were less prevalent in CZ than in PZ and TZ. Tregs infiltrate more in prostate cancer (PC) than in benign tissue. Their presence in atrophy may have relevance for the hypothesis on atrophy as a potential precursor lesion of PC. CZ has the lowest Treg levels, and a possible role for the low rate of cancer in this zone remains to be investigated.
Pulmonary myoepithelial carcinoma resembling matrix‐producing carcinoma of the breast: case report and review of the literature
Authors: TANAHASHI JIN , KASHIMA KENJI , DAA TSUTOMU , YADA NAOMI , TANAKA KO‐ICHI , KAWANO YOZOH , YOKOYAMA SHIGEO
Published: March 2010

Tanahashi J, Kashima K, Daa T, Yada N, Tanaka K‐I, Kawano Y, Yokoyama S. Pulmonary myoepithelial carcinoma resembling matrix‐producing carcinoma of the breast: case report and review of the literature. APMIS 2010; 118: 401–6.

We report a case of pulmonary myoepithelial carcinoma with extensive myxohyaline stroma, resembling matrix‐producing carcinoma of the breast. A 76‐year‐old Japanese man presented with a nodular lesion in the left lung (S8), and underwent partial resection of the left lower lobe. Microscopically, the resected tumor was relatively well circumscribed with central hypocellular myxohyaline and peripheral hypercellular area. In the central area, eosinophilic and clear polygonal cells proliferated in a cord‐like or reticulated pattern with extensive myxohyaline stroma, while the peripheral area was composed of solid lobules of different shapes and sizes with occasional comedonecrosis. The tumor cells were markedly atypical with frequent mitotic figures. Vascular and lymphatic invasion was evident with regional lymph node metastasis. No squamous or glandular differentiation was evident in the tumor. Immunohistochemical staining implied myoepithelial differentiation. The patient developed multiple brain metastases, and died of the disease 11 months after the surgery. In this report, we discuss the histopathologic uniqueness of the present case together with a review of the literature.
Undifferentiated carcinoma of the renal pelvis with osteoclast‐like giant cells: a report of two cases
Authors: MCCASH SAMUEL I. , UNGER PAMELA , DILLON ROBERT , XIAO GUANG‐QIAN
Published: March 2010

McCash SI, Unger P, Dillon R, Xiao G‐Q. Undifferentiated carcinoma of the renal pelvis with osteoclast‐like giant cells: a report of two cases. APMIS 2010; 118: 407–12.

Undifferentiated carcinoma with osteoclast‐like giant cells arising in the urothelium of the bladder or upper urinary tract is an extremely rare entity. The majority of cases found in the renal pelvis and bladder are associated with either an in situ urothelial malignancy or a conventional high‐grade urothelial carcinoma. These malignancies tend to behave poorly with a grim prognosis and course. We report two additional cases of undifferentiated carcinoma with osteoclast‐like giant cells of the renal pelvis in two patients disease free 42 and 18 months after surgical treatment, respectively.
Accuracy of three‐dimensional imaging in assessing maxillary molar furcation involvement
Authors: Walter Clemens , Weiger Roland , Zitzmann Nicola U.
Published: March 2010

Walter C, Weiger R, Zitzmann NU. Accuracy of three‐dimensional imaging in assessing maxillary molar furcation involvement. J Clin Periodontol 2010; 37: 436–441. doi: 10.1111/j.1600‐051X.2010.01556.x.

Aim: To assess the accuracy of cone beam computed tomography (CBCT) in detecting furcation involvement (FI) in maxillary molars.

Material and Methods: Fourteen patients with generalized advanced chronic periodontitis were consecutively recruited and treated non‐surgically. In maxillary molars considered for furcation surgery due to increased FI and/or increased probing pocket depths during re‐evaluation, CBCT was performed and the degree of FI was evaluated from the CBCT images. Furcation surgery was performed in 25 maxillary molars. Intra‐surgical FI assessments were compared with data derived from CBCT images.

Results: Overall, 84% of the CBCT data were confirmed by the intra‐surgical findings (weighted κ=0.926, 95% confidence interval: 0.681–1.0). While 14.7% (11 sites) were underestimated (CBCT less than intra‐surgical value), in only 1.3% (one site) did the CBCT data lead to an overestimation compared with the intra‐surgical analysis. The agreement between both assessments was the highest in distopalatal furcation entrances, followed by buccal and mesiopalatal.

Conclusions: CBCT images demonstrate a high accuracy in assessing the loss of periodontal tissue and classifying the degree of FI in maxillary molars.
Granulomas in acquired immunodeficiency syndrome‐associated cutaneous Kaposi sarcoma: evidence for a role for Mycobacterium tuberculosis
Authors: Ramdial Pratistadevi K. , Sing Yetish , Subrayan Sumeshini , Calonje Eduardo , Aboobaker Jamila , Sydney Clive , Sookdeo Dinesh , Ramburan Amsha , Madiba Thandinkosi E.
Published: March 2010

Background: Co‐lesional acquired immunodeficiency syndrome‐associated cutaneous Kaposi sarcoma (AIDS‐KS) and Mycobacterium tuberculosis‐associated granulomatous inflammation are undocumented.

Method: Retrospective appraisal of skin biopsies with co‐lesional AIDS‐KS and microscopic tuberculosis (TB).

Results: Sixteen biopsies from nine males and seven females form the study cohort. Histological assessment confirmed nodular and plaque KS in 12 and 4 cases each, respectively. Necrotizing, non‐necrotizing and a combination of necrotizing and non‐necrotizing granulomatous inflammation were present in nine, two and five biopsies each, respectively. The identification of acid fast bacilli on Ziehl‐Neelsen staining and M. tuberculosis on polymerase chain reaction confirmed co‐lesional TB in 15/16 biopsies. Co‐lesional AIDS‐KS and lichen scrofulosorum, hitherto undocumented, were confirmed in one biopsy. The histopathological findings served as a marker of human immunodeficiency virus (HIV) infection, visceral TB, therapeutic noncompliance and multidrug resistant pulmonary TB in nine, eight, five and one patient, respectively. M. tuberculosis was cultured from sputum or nodal tissue of all patients.

Conclusion: Granulomatous inflammation in KS requires optimal histopathological and molecular investigation to confirm an M. tuberculosis origin. The cutaneous co‐lesional occurrence of AIDS‐KS and microscopic TB may serve as the sentinel clue to HIV infection, systemic TB, therapeutic noncompliance or multidrug resistant TB.

Ramdial PK, Sing Y, Subrayan S, Calonje E, Aboobaker J, Sydney C, Sookdeo D, Ramburan A, Madiba TE. Granulomas in acquired immunodeficiency syndrome‐associated cutaneous Kaposi sarcoma: evidence for a role for Mycobacterium tuberculosis.
Frequency of congenital dyserythropoietic anemias in Europe
Authors: Heimpel Hermann , Matuschek Andreas , Ahmed Momin , Bader‐Meunier Brigitte , Colita Adriana , Delaunay Jean , Garcon Loic , Gilsanz Florinda , Goede Jeroen , Högel Josef , Kohne Elisabeth , Leichtle Rosi , Munoz Juan , Perrotta Silverio , Piscopo Carlo , Renella Raffaele , Schwarz Klaus , Smolenska‐Sym Gabriela , Wickramasinghe Sunitha , Zanella Alberto , Iolascon Achille
Published: March 2010

Congenital dyserythropoietic anemias (CDAs) are rare hereditary disorders characterized by ineffective erythropoiesis and striking abnormalities of erythroblast morphology. The mutated genes are known for the most frequent types, CDA I and II, but data about their frequency do not exist. The objective of this retrospective study was to estimate the frequency of CDA I and II, based on all cases reported in the last 42 yr in publications and identified registries or surveys. Reports were collected of 124 and 377 confirmed cases of CDA I and CDA II cases, respectively. The cumulated incidence of both types combined varied widely between European regions, with minimal values of 0.08 cases/million in Scandinavia and 2.60 cases/million in Italy. CDA II is more frequent than CDA I, with an overall ratio of approximately 3.2, but the ratio also varied between different regions. The most likely explanations for the differences are both differences in the availability of advanced diagnostic procedures and different levels of the awareness for the diagnosis of the CDAs. The estimations reported here are most probably below the true incidence rates, because of failure to make the correct diagnosis and to underreporting. Limited data do not suggest differing levels of risk in identified ethnic groups.
Human melanocytes can be isolated, propagated and expanded from plucked anagen hair follicles
Authors: Dieckmann Christina , Milkova Linda , Hunziker Thomas , Emmendörffer Andreas , Simon Jan C.
Published: March 2010

Please cite this paper as: Human melanocytes can be isolated, propagated and expanded from plucked anagen hair follicles. Experimental Dermatology 2010; 19: 543–545.

Abstract:  Herein, we report a technically simple method for isolation and culture of human follicular melanocytes based on explant cultures of epilated hair follicles. This technique does not require any surgical intervention and allows the isolation and cultivation of follicular melanocytes from a comparatively small amount of raw material. Generally, 30–60 human anagen hair follicles have been plucked from the scalp of healthy donors and cultivated under low oxygen pressure (5%). After a short period of time cells of various types were growing out from the outer root sheath (ORS) of the hair follicles. Under the selected culture conditions, most of the cells other than melanocytes have been eliminated and a nearly 100% pure population of melanocytes has been achieved, as confirmed by immunohistochemical analyses for melanocyte‐specific markers, for example, Tyrosinase‐1, S‐100 and premelanosomal antigens. These melanocytes derived from the ORS were proliferating for up to 2 months.
GuanxiDynamics and Entrepreneurial Firm Creation and Development in China
Authors: Guo Chun , Miller Jane K.
Published: March 2010

Guanxinetworks are critical for achieving entrepreneurial success in China. Informed by the literatures on network-based entrepreneurship andguanxi, this study used a multiple-case method to examine the development of Chinese entrepreneurs'guanxinetworks in the entrepreneurial process. Data induction based on within- and cross-case analyses of six entrepreneurial firms revealed three major findings. First,guanxinetwork dynamics in terms of network structure, governance mechanisms, and network content change systematically across the stages of the entrepreneurship process. Second, the usefulness ofguanxities (such as family, business associates, or government officials) is contingent on the stage of the entrepreneurial process as well as on industrial-level factors. Third, in knowledge-intensive industries, cultivating and maintainingguanxican be achieved through knowledge and information exchange rather than traditional gift-giving or favours. The overall conclusion is thatguanxiis still of paramount importance for Chinese entrepreneurs in the midst of China's transformation from a centrally planned to a socialist market economy. We propose a stage model ofguanxinetwork development in the entrepreneurial process and discuss implications for future research.
Assessing Women’s Sexual Arousal in the Context of Sexual Assault History and Acute Alcohol Intoxication
Authors: Gilmore Amanda K. , Schacht Rebecca L. , George William H. , Otto Jacqueline M. , Davis Kelly Cue , Heiman Julia R. , Norris Jeanette , Kajumulo Kelly F.
Published: March 2010

Introduction

Few studies have examined differences in women’s sexual arousal based on sexual assault history (SAH) or in-the-moment alcohol intoxication. Only one has examined combined effects. Findings regarding the relationship between SAH and arousal are contradictory.

Aim

We aimed to determine the relationship between SAH, alcohol intoxication, and sexual arousal.

Methods

Women were randomly assigned to an alcohol (target blood alcohol level=0.10%) or control condition and categorized as having an SAH or not. After beverage administration, all women watched erotic films while genital arousal (vaginal pulse amplitude; VPA) was measured. Afterward, self-reported sexual arousal was measured.

Main Outcome Measures

Genital response was measured by VPA using vaginal photoplethysmography while watching erotic films. Self-reported sexual arousal was assessed after watching erotic films.

Results

Women with an SAH had smaller increases in genital arousal in response to the films than women without an SAH. Intoxicated women had smaller increases in genital arousal than sober women. However, no differences for SAH or intoxication were found in self-reported arousal.

Conclusion

SAH and alcohol intoxication are associated with smaller increases in genital arousal compared to women without an SAH and sober women, suggesting that these co-occurring factors impact sexual arousal.
Repressive Coping Style and Its Relation to Psychosocial Distress in Males With Erectile Dysfunction
Authors: Wiltink Jörg , Subic-Wrana Claudia , Tuin Inka , Weidner Wolfgang , Beutel Manfred E.
Published: March 2010

Introduction

There is evidence that repressive coping adversely affects medical conditions such as coronary heart disease, hypertension, and bronchial asthma. Erectile dysfunction (ED) is known to have a severe and lasting negative impact on health, quality of life, and partnership. Although ED may be eminently threatening for the self-image of affected men, a repressive coping style and its consequences for their mental health and partnership has not yet been investigated.

Aim

Based on the presumption that the male self-image is threatened by ED, we expected men with repressive coping strategies—although reporting the same degree of impairments regarding their sexual function—to describe themselves as more satisfied with: (i) their sexual relationship, to report (ii) a better quality of their partnership; and (iii) less distress (depression and physical complaints) as compared with those who do not use such strategies.

Methods

Fifty-nine patients with ED from the outpatient unit of the Clinic of Urology, Pediatric Urology and Andrology of the University of Giessen were examined using standardized German versions of international questionnaires. Coping style was determined using a combination of the State Trait Anxiety Inventory (STAI) and the Marlowe Crown Social Desirability Scale (SDS-CM) measuring defensiveness.

Main Outcome Measures

Questionnaires measuring anxiety (STAI), depression (Center for Epidemiological Studies Depression Scale), social desirability (SDS-CM), quality of partnership (Partnership Questionnaire), and physical complaints (Complaint List) were administered.

Results

Repressors did not differ from nonrepressors with regard to their self-reported sexual function (International Index of Erectile Function). However, they described themselves as less distressed (depression, physical complaints) and rated the quality of their partnership as higher.

Conclusion

Repressors tend to report their complaints in a manner that protects their self-worth. Clinicians therefore might have difficulties deciding whether and which treatment is necessary. Additional clinical information (e.g., interview together with the female partner) or questionnaires might prove useful sources of information on patients’ coping style.
Successful Removal of a 3.6-cm Long Metal Band Used as a Penile Constriction Ring
Authors: Horstmann Marcus , Mattsson Björn , Padevit Christian , Gloyer Marcel , Hotz Thomas , John Hubert
Published: March 2010

Introduction

Penile constriction rings are either used for autoerotic stimulus or to increase sexual performance. Potentially, they can become irremovable and cause urologic emergencies.

Aim

We describe the successful removal of a 3.6-cm long piece of heavy metal tubing used as a penile constriction ring.

Methods

An angel grinder was used to open the metal tubing on both lateral sides. During the cutting procedure, the soft tissue parts were protected by two metal spatulas. Wet towels and cool running water prevented thermal injury.

Results

After removal of the band, no iatrogenic injury was visible and the further recovery of the patient remained uneventful. Postoperatively, one of the surgeons suffered from conjunctivitis of the left eye possibly due to metal sparks.

Conclusion

Depending on the constricting object, heavy-duty technical equipment might become necessary for their removal. In such cases, special care should be taken to avoid injury to the patient and the medical crew.
Vaginismus and Dyspareunia: Automatic vs. Deliberate Disgust Responsivity
Authors: Borg Charmaine , de Jong Peter J. , Schultz Willibrord Weijmar
Published: March 2010

Introduction

The difficulty of penetration experienced in vaginismus and dyspareunia may at least partly be due to a disgust-induced defensive response.

Aims

To examine if sex stimuli specifically elicit: (i) automatic disgust-related memory associations; (ii) physiological disgust responsivity; and/or (iii) deliberate expression of disgust/threat.

Methods

Two single target Implicit Association Task (st-IAT) and electromyography (EMG) were conducted on three groups: vaginismus (N=24), dyspareunia (N=24), and control (N=31) group.

Main Outcome Measures

st-IAT, to index their initial disgust-related associations and facial EMG for the m. levator labii and m. corrugator supercilii regions.

Results

Both clinical groups showed enhanced automatic sex-disgust associations. As a unique physiological expression of disgust, the levator activity was specifically enhanced for the vaginismus group, when exposed to a women-friendly SEX video clip. Also at the deliberate level, specifically the vaginismus group showed enhanced subjective disgust toward SEX pictures and the SEX clip, along with higher threat responses.

Conclusions

Supporting the view that disgust is involved in vaginismus and dyspareunia, for both, clinical groups’ sex stimuli automatically elicited associations with disgust. Particularly for the vaginismus group, these initial disgust associations persisted during subsequent validation processes and were also evident at the level of facial expression and self-report data. Findings are consistent with the notion that uncontrollable activated associations are involved in eliciting defensive reactions at the prospect of penetration seen in both conditions. Whereas deliberate attitudes, usually linked with the desire for having intercourse, possibly generate the distinction (e.g., severity) between these two conditions.
The discovery of two new rapidly oscillating Ap stars, HD92499 and HD143487
Authors: Elkin V. G. , Kurtz D. W. , Mathys G. , Freyhammer L. M.
Published: March 2010

We report the discovery of short periodic radial velocity variations in the stars HD92499 and HD143487. Both stars show strong magnetic fields and large overabundances of rare earth elements and belong to the class of cool chemically peculiar stars of the main sequence. They are therefore new rapidly oscillating Ap stars. Pulsations were detected from analysis of high time resolution spectra obtained with the European Southern Observatory Very Large Telescope by using a cross-correlation method for large spectral bands and from combinations of lines belonging to rare earth elements. The amplitudes of the pulsations are small and do not exceed several dozens of ms−1 with periods of around 10min. The detection of such low amplitudes is important for the determination of which magnetic Ap stars pulsate, and which are constant, a distinction important for the understanding of the pulsation driving mechanism in these stars.
Assessment of apparent losses in urban water systems
Authors: Mutikanga H. E. , Sharma S. K. , Vairavamoorthy K.
Published: March 2010

Apparent losses relate to water that is consumed but not paid for. Most research carried out in the last decade particularly in the United Kingdom focused mainly on leakage. Until now, there are no set procedures and guidelines for assessment of apparent losses. Much work remains to bring it to par with the available tools and methodologies for leakage management. In the absence of adequate data and proper methodology, most developed countries use default values, which tend to be lowest values for well‐managed water systems, for computation of apparent losses. These may not be appropriate for developing countries. This paper presents a methodology for the assessment of different components of apparent losses based on field audit and operational data for Kampala city's water distribution system in Uganda. Metering inaccuracies and illegal use have been found to be significant components of apparent losses. Appropriate intervention strategies have been developed based on the assessment.
Oxidation of gasoline oxygenates by closely related non‐haem‐iron alkane hydroxylases in Pseudomonas mendocina KR1 and other n‐octane‐utilizing Pseudomonas strains
Authors: Smith Christy A. , Hyman Michael R.
Published: March 2010

Pseudomonas mendocina KR1 oxidizes the gasoline oxygenate methyl tertiary butyl ether (MTBE) to tertiary butyl alcohol (TBA) during growth on C5–C8n‐alkanes. We have further explored oxidation of ether oxygenates by this strain to help identify the enzyme that catalyses these reactions. High levels of MTBE‐oxidizing activity occurred in resting cells grown on C5–C8n‐alkanes. Lower activities occurred in cells grown on longer‐chain n‐alkanes (C9–C11) and 1°‐alcohols (C5–C10). N‐octane‐grown cells also oxidized tertiary amyl methyl ether (TAME) to tertiary amyl alcohol (TAA), but did not oxidize ethyl tertiary butyl ether (ETBE), TBA or TAA. A 39 kDa polypeptide in whole cell extracts of n‐octane‐grown cells strongly cross‐reacted with an anti‐AlkB polyclonal antiserum in an SDS‐PAGE/immunoblot. This polypeptide was absent or less abundant in cells grown on dextrose, dextrose plus dicyclopropylketone or 1‐octanol. N‐octane‐grown cells of Pseudomonas aeruginosa strains KSLA‐473 and ATCC 17423 oxidized MTBE and TAME but not ETBE. N‐hexadecane‐grown cells of these strains and strain PAO1 did not oxidize any of the oxygenates tested. Our results indicate ether oxygenate‐degrading activity in alkane‐utilizing pseudomonads is consistently observed with close homologues of the GPo1 non‐haem‐iron alkane hydroxylases but is otherwise not a consistent catalytic feature of these diverse enzymes.
A Method for Forced Response Analysis of Mistuned Bladed Disks With Aerodynamic Effects Included
Authors: Petrov E. P.
Published: March 2010

A method has been developed for high-accuracy analysis of forced response levels for mistuned bladed disks vibrating in gas flow. Aerodynamic damping, the interaction of vibrating blades through gas flow, and the effects of structural and aerodynamic mistuning are included in the bladed disk model. The method is applicable to cases of high mechanical coupling of blade vibration through a flexible disk and, possibly shrouds, to cases with stiff disks and low mechanical coupling. The interaction of different families of bladed disk modes is included in the analysis providing the capability of analyzing bladed disks with pronounced frequency veering effects. The method allows the use of industrial-size sector models of bladed disks for analysis of forced response of a mistuned structure. The frequency response function matrix of a structurally mistuned bladed disk is derived with aerodynamic forces included. A new phenomenon of reducing bladed disk forced response by mistuning to levels that are several times lower than those of their tuned counterparts is revealed and explained.
Gas Turbine Engine Emissions—Part I: Volatile Organic Compounds and Nitrogen Oxides
Authors: Timko Michael T. , Herndon Scott C. , Wood Ezra C. , Onasch Timothy B. , Northway Megan J. , Jayne John T. , Canagaratna Manjula R. , Miake-Lye Richard C. , Knighton W. Berk
Published: March 2010

The potential human health and environmental impacts of aircraft gas turbine engine emissions during normal airport operation are issues of growing concern. During the JETS/Aircraft Particle Emissions eXperiment(APEX)-2 and APEX-3 field campaigns, we performed an extensive series of gas phase and particulate emissions measurements of on-wing gas turbine engines. In all, nine different CFM56 style engines (including both CFM56-3B1 and -7B22 models) and seven additional engines (two RB211-535E4-B engines, three AE3007 engines, one PW4158, and one CJ6108A) were studied to evaluate engine-to-engine variability. Specific gas-phase measurements include NO2, NO, and total NOx, HCHO, C2H4, CO, and a range of volatile organic compounds (e.g., benzene, styrene, toluene, naphthalene). A number of broad conclusions can be made based on the gas-phase data set: (1) field measurements of gas-phase emission indices (EIs) are generally consistent with ICAO certification values; (2) speciation of gas phase NOx between NO and NO2 is reproducible for different engine types and favors NO2 at low power (and low fuel flow rate) and NO at high power (high fuel flow rate); (3) emission indices of gas-phase organic compounds and CO decrease rapidly with increasing fuel flow rate; (4) plotting EI-CO or volatile organic compound EIs against fuel flow rate collapses much of the variability between the different engines, with one exception (AE3007); (5) HCHO, ethylene, acetaldehyde, and propene are the most abundant volatile organic compounds present in the exhaust gases that we can detect, independent of engine technology differences. Empirical correlations accurate to within 30% and based on the publicly available engine parameters are presented for estimating EI-NOx and EI-NO2. Engine-to-engine variability, unavailability of combustor input conditions, changing ambient temperatures, and complex reaction dynamics limit the accuracy of global correlations for CO or volatile organic compound EIs.
Gas Turbine Engine Emissions—Part II: Chemical Properties of Particulate Matter
Authors: Timko Michael T. , Onasch Timothy B. , Northway Megan J. , Jayne John T. , Canagaratna Manjula R. , Herndon Scott C. , Wood Ezra C. , Miake-Lye Richard C. , Knighton W. Berk
Published: March 2010

The characterization of volatile and nonvolatile particle materials present in gas turbine exhaust is critical for accurate estimation of the potential impacts of airport activities on local air quality, atmospheric processes, and climate change. Two field campaigns were performed to collect an extensive set of particle and gaseous emission data for on-wing gas turbine engines. The tests included CFM56, RB211-535E4-B, AE3007, PW4158, and CJ610 engines, providing the opportunity to compare emissions from a wide range of engine technologies. Here we report mass, number, composition, and size data for the nonvolatile (soot) and volatile particles present in engine exhaust. For all engines, soot emissions (EIm-soot) are greater at climbout (85% power) and takeoff (100%) power than idle (4% or 7%) and approach (30%). At the engine exit plane, soot is the only type of particle detected. For exhaust sampled downwind (15–50 m) and diluted by ambient air, total particle number emissions (EIn-total) increases by about one or two orders of magnitude relative to the engine exit plane, and the increase is driven by volatile particles that have freshly nucleated in the cooling exhaust gas both in the free atmosphere and in the extractive sample lines. Fuel sulfur content is the determining factor for nucleation of new particles in the cooling exhaust gases. Compositional analysis indicates that the volatile particles consist of sulfate and organic materials (EIm-sulfate and EIm-organic). We estimate a lower bound S[IV] to S[VI] conversion efficiency of (0.08±0.01)%, independent of engine technology. Measurements of EIm-organic ranged from about 0.1 mg kg−1 to 40 mg kg−1. Lubrication oil was present in particles emitted by all engines and accounted for over 90% of the particulate organic mass under some conditions. The products of incomplete combustion are a likely source of the remaining volatile organic particle material.
Analysis of Compressor On-Line Washing to Optimize Gas Turbine Power Plant Performance
Authors: Schneider Ernst , Demircioglu Bussjaeger Saba , Franco Susana , Therkorn Dirk
Published: March 2010

Due to compressor fouling, gas turbine efficiency decreases over time, resulting in decreased power output of the plant. To counteract the effects of compressor fouling, compressor on-line and off-line washing procedures are used. The effectiveness of compressor off-line washing is enhanced if combined with the cleaning of the VIGVs and the first compressor blade row by hand. This paper presents a thorough analysis of the effects of compressor on-line washing on the gas turbine performance. The analysis is based on the measured data of six gas turbines operated at two different plants. Different washing schedules and washing fluids are analyzed and compared. Furthermore, the effects of compressor on-line washing on the load distribution within the compressor are analyzed. The performance benefit of daily compressor on-line washing compared with weekly compressor on-line washing is quantified. As expected, daily compressor on-line washing yields the lowest power degradation caused by compressor fouling. Also, the effect of washing additives is analyzed. It is shown with long term data that compressor on-line washing cleans up to the first 11 compressor stages, as can be detected well in the compressor. With a view to gas turbine performance optimization, the recommendation is to perform compressor off-line washing at regular intervals and to take advantage of occasions such as inspections, when the gas turbine is cooled down anyhow. Especially for gas turbines with a high fouling rate, a daily compressor on-line washing schedule should be considered to reduce the power loss. For gas turbines operating with high fogging, compressor on-line washing has no added benefit. To determine the optimal compressor washing schedule, compressor blade erosion also has to be considered. A reasonable balance between compressor on-line washing and off-line washing improves the gas turbine performance and optimizes the gas turbine availability.
Application of the Geared Turbofan With Constant Volume Combustor on Short-Range Aircraft: A Feasibility Study
Authors: Colmenares Quintero Ramón F. , Brink Rob , Ogaji Stephen , Pilidis Pericle , Colmenares Quintero Juan C. , Quintero Alexander García
Published: March 2010

Recently a considerable effort was made to understand the gas- and thermodynamics of wave rotor combustion technology. Pressure-gain combustors potentially have superior performance over conventional combustors due to their unsteady flow behavior. Wave rotor combustion provides semiconstant volume combustion and could be integrated in the steady-flow gas turbine. However, a feasibility study to assess the economical and environmental aspects of this concept has not been conducted for short-range missions. Preliminary multidisciplinary design framework was developed to assess novel and radical engine cycles. The tool comprises modules to evaluate noise, emissions, and environmental impact. Uncertainty can be accounted for with Monte Carlo simulation. The geared turbofan with constant volume combustor is simulated and benchmarked against a baseline geared turbofan engine. Results indicate that the former complies with CAEP/6 and FAR Part 36 regulations for noise and emissions. Furthermore, the acquisition cost of the engine is higher, but the engine direct operating cost decreases by 25.2%. The technology requires further development to meet future noise and emission requirements.
Effect of Tungsten Addition on the Nucleation of Borides in Wide Gap Brazed Joint
Authors: McGuire Daniel , Huang Xiao , Nagy Doug , Chen Weijie
Published: March 2010

Wide gap brazing (WGB) is a cost effective and reliable means to repair gas turbine hot section components with defect sizes exceeding 0.3 mm. However, it has been shown that WGB joints of nickel-based superalloys suffer from reduced ductility and thermal fatigue life due to the presence of brittle intermetallics and porosities in the brazed joint. In order to disperse the brittle intermetallic compounds, potentially increase the ductility of the repaired region, and reduce the risk of the thermomechanical fatigue failure, elemental tungsten (W) was added to the braze additive filler alloy IN738 by mechanical alloying. The alloyed IN738 was then brazed with the addition of 30 wt %, 50 wt %, and 80 wt % of braze alloy (BNi-9). After brazing at 1200°C for 20 min, microstructural analysis of WGB joints showed a decreasing trend of discrete boride size and the amount of eutectic and script-shaped borides with the increases of W. The increase in the braze alloy to additive filler alloy ratio diminished the effect of W addition due the dissolution of W particulates.
Comparison of Preanode and Postanode Carbon Dioxide Separation for IGFC Systems
Authors: Liese Eric
Published: March 2010

This paper examines the arrangement of a solid oxide fuel cell (SOFC) within a coal gasification cycle, this combination generally being called an integrated gasification fuel cell cycle. This work relies on a previous study performed by the National Energy Technology Laboratory (NETL) that details thermodynamic simulations of integrated gasification combined cycle (IGCC) systems and considers various gasifier types and includes cases for 90% CO2 capture (2007, “Cost and Performance Baseline for Fossil Energy Plants, Vol. 1: Bituminous Coal and Natural Gas to Electricity,” National Energy Technology Laboratory Report No. DOE/NETL-2007/1281). All systems in this study assume a Conoco Philips gasifier and cold-gas clean up conditions for the coal gasification system (Cases 3 and 4 in the NETL IGCC report). Four system arrangements, cases, are examined. Cases 1 and 2 remove the CO2 after the SOFC anode. Case 3 assumes steam addition, a water-gas-shift (WGS) catalyst, and a Selexol process to remove the CO2 in the gas cleanup section, sending a hydrogen-rich gas to the fuel cell anode. Case 4 assumes Selexol in the cold-gas cleanup section as in Case 3; however, there is no steam addition, and the WGS takes places in the SOFC and after the anode. Results demonstrate significant efficiency advantages compared with IGCC with CO2 capture. The hydrogen-rich case (Case 3) has better net electric efficiency compared with typical postanode CO2 capture cases (Cases 1 and 2), with a simpler arrangement but at a lower SOFC power density, or a lower efficiency at the same power density. Case 4 gives an efficiency similar to Case 3 but also at a lower SOFC power density. Carbon deposition concerns are also discussed.
Comparative Performance, Emission, and Combustion Characteristics of Rice-Bran Oil and Its Biodiesel in a Transportation Diesel Engine
Authors: Agarwal Avinash Kumar , Dhar Atul
Published: March 2010

The methyl esters of vegetable oils known as biodiesel are becoming increasingly popular because of their low environmental impact and potential as a green alternative fuel for diesel engines. Methyl ester of rice-bran oil (RBOME) is prepared through the process of transesterification. In the present investigation, experiments have been carried out to examine the performance, emission, and combustion characteristics of a direct-injection transportation diesel engine running with diesel, 20% blend of rice-bran oil (RBO), and 20% blend of RBOME with mineral diesel. A four-stroke, four-cylinder, direct-injection transportation diesel engine (MDI 3000) was instrumented for the measurement of the engine performance, emissions, in-cylinder pressure-crank angle history, rate of pressure rise, and other important combustion parameters such as instantaneous heat release rate, cumulative heat release rate, mass fraction burned, etc. A careful analysis of the performance, emissions, combustion, and heat release parameters has been carried out. HC, CO, and smoke emissions for RBO and RBOME blends were lower than mineral diesel while NOx emissions were almost similar and brake specific fuel consumption (BSFC) was slightly higher than mineral diesel. Combustion characteristics were quite similar for the three fuels.
Detailed Numerical Simulations of the Primary Atomization of a Turbulent Liquid Jet in Crossflow
Authors: Herrmann Marcus
Published: March 2010

This paper presents numerical simulation results of the primary atomization of a turbulent liquid jet injected into a gaseous crossflow. Simulations are performed using the balanced force refined level set grid method. The phase interface during the initial breakup phase is tracked by a level set method on a separate refined grid. A balanced force finite volume algorithm together with an interface projected curvature evaluation is used to ensure the stable and accurate treatment of surface tension forces even on small scales. Broken off, small scale nearly spherical drops are transferred into a Lagrangian point particle description allowing for full two-way coupling and continued secondary atomization. The numerical method is applied to the simulation of the primary atomization region of a turbulent liquid jet (q=6.6, We=330, Re=14,000) injected into a gaseous crossflow (Re=570,000), analyzed experimentally by Brown and McDonell (2006, “Near Field Behavior of a Liquid Jet in a Crossflow,” ILASS Americas, 19th Annual Conference on Liquid Atomization and Spray Systems). The simulations take the actual geometry of the injector into account. Grid converged simulation results of the jet penetration agree well with experimentally obtained correlations. Both column/bag breakup and shear/ligament breakup modes can be observed on the liquid jet. A grid refinement study shows that on the finest employed grids (flow solver 64 points per injector diameter, level set solver 128 points per injector diameter), grid converged drop sizes are achieved for drops as small as one-hundredth the size of the injector diameter.
Characterization of zinc magnesium stannate phosphor fine particles synthesized by electromagnetic wave heating
Authors: Kitaura Mamoru , Tani Shinji , Mitsudo Seitaro , Fukui Kazutoshi
Published: March 2010

The authors have studied photoluminescence (PL) of Mg2SnO4:Mn, Zn2SnO4:Mn, and their solid solutions Zn2xMg2(1−x)SnO4:Mn synthesized under irradiation with the millimeter wave of 28 GHz, in order to find its advantage in the synthesis of stannate phosphors. The PL spectra of Mg2SnO4:Mn exhibit a single band peaking at 500 nm. Comparison on the intensity of the 500 nm band was done between the samples synthesized by the millimeter wave heating and electric furnace heating. The origin of the difference in intensity between them will be discussed on the basis of experimental results. The influence of Zn2+ addition on PL spectra has also been investigated in Zn2xMg2(1−x)SnO4:Mn, in order to develop a new phosphor for electron beam excitation. It will be cleared whether Zn2+ addition is effective for the PL enhancement of the 500 nm band.