bluuebunny/crossref_metadata_2025 huggingface dataset:
Psychiatric Tutor—Rumour or Reality?
Authors: McKeith Ian
Published: May 2008

Reviving the title of Dr Derek Chiswick's article in an APIT Newsletter some five years ago, the second Trainee's Forum to be organized by the Collegiate Trainees Committee met to re-examine the question during the College's Winter Quarterly Meeting at Charing Cross Hospital Medical School in February 1984. The 40 tutors and trainees attending heard presentations by Dr Peter Kennedy (Psychiatric Tutor from York), Dr Jane Price (formerly Senior Registrar in Psychotherapy in Nottingham), and Dr Desmond Dunleavy (Course Organizer and College Convener from Newcastle).
The Edinburgh Three-Year Course and M.Phil Degree
Authors: Kendell R. E.
Published: May 2008

The introduction of the College's Membership Examination in 1971 created a dilemma for the university departments which had previously provided postgraduate teaching for a Diploma in Psychological Medicine. For it was clear that the MRCPsych would soon become a mandatory qualification for anyone wishing to pursue a psychiatric career, at least in this country, and that consequently there would no longer be a useful role for these diplomas. The universities concerned therefore had to choose between letting their diplomas die, or converting them into something other than a basic clinical qualification. The University of Edinburgh, like the Institute of Psychiatry and one or two other departments, decided to replace its DPM with a master's degree (M.Phil) in psychiatry which would be primarily an academic and research qualification, complementing rather than rivalling the College Membership.
Misunderstandings on Consent to Treatment in the Mental Health Act 1983
Authors: Jefferys P. M.
Published: May 2008

Part IV of the 1983 Mental Health Act (Sections 56–64) introduces new safeguards and procedures relating to Consent to Treatment for detained patients and in limited situations to informal patients. Many psychiatrists have expressed misgivings about these provisions and many are unfamiliar with the new requirements. One medical member of the Mental Health Act Commission visited twenty different hospitals for the purposes of issuing a Certificate of Second Opinion during a four-month period between October 1983 and February 1984. This paper discusses some of the practices and misunderstandings encountered.
Mental Illness in Primary Care Settings
Authors: Wilkinson Greg
Published: May 2008

A Conference on the above topic took place at the Institute of Psychiatry, London, on 17 and 18 July 1984. The Conference was sponsored by the Department of Health and Social Security and was organized by the General Practice Research Unit. Over 100 invited clinicians, research workers and policy-makers took part. The majority of the participants were either psychiatrists or general practitioners, but representatives of all relevant disciplines attended.
Consistency of Phase III Clinical Trial Abstracts Presented at an Annual Meeting of the American Society of Clinical Oncology Compared With Their Subsequent Full-Text Publications
Authors: Tam Vincent C. , Hotte Sebastien J.
Published: April 2008

Purpose

This study aimed to determine the consistency of phase III clinical trial abstracts presented at American Society of Clinical Oncology (ASCO) Annual Meetings compared with their subsequent full-text publications.

Methods

We identified abstracts describing phase III clinical trials of chemotherapy, chemoradiotherapy, immunotherapy, and hormone therapy presented at the 36th ASCO Annual Meeting in May 2000. We searched MEDLINE and PubMed for all corresponding publications. Data were extracted from the abstracts and publications that met our inclusion criteria.

Results

A total of 192 abstracts were identified. Seventy-four abstracts met our inclusion criteria. Six years after the 2000 ASCO Meeting, 74% of abstracts had corresponding publications. The primary end point was stated in 34% of abstracts and 100% of published papers. The primary end point result differed by more than 5% between the abstract and publication in 42% of comparisons. The statistical significance of the primary end point and study conclusions were consistent between abstracts and subsequent publications in 89% and 91% of the comparisons, respectively. Abstracts selected as plenary or oral presentations were significantly more likely to be published. No factors predicted consistency for primary end point significance and overall conclusion between ASCO abstracts and their journal publications.

Conclusion

When carefully selected, ASCO Annual Meeting abstracts of phase III trials consistently reflect final published results, but some differences were observed that warrant caution in using abstract results to shape treatment decisions before full publication.
Ab initio RNA folding by discrete molecular dynamics: From structure prediction to folding mechanisms
Authors: Ding Feng , Sharma Shantanu , Chalasani Poornima , Demidov Vadim V. , Broude Natalia E. , Dokholyan Nikolay V.
Published: May 2008

RNA molecules with novel functions have revived interest in the accurate prediction of RNA three-dimensional (3D) structure and folding dynamics. However, existing methods are inefficient in automated 3D structure prediction. Here, we report a robust computational approach for rapid folding of RNA molecules. We develop a simplified RNA model for discrete molecular dynamics (DMD) simulations, incorporating base-pairing and base-stacking interactions. We demonstrate correct folding of 150 structurally diverse RNA sequences. The majority of DMD-predicted 3D structures have <4 Å deviations from experimental structures. The secondary structures corresponding to the predicted 3D structures consist of 94% native base-pair interactions. Folding thermodynamics and kinetics of tRNAPhe, pseudoknots, and mRNA fragments in DMD simulations are in agreement with previous experimental findings. Folding of RNA molecules features transient, non-native conformations, suggesting non-hierarchical RNA folding. Our method allows rapid conformational sampling of RNA folding, with computational time increasing linearly with RNA length. We envision this approach as a promising tool for RNA structural and functional analyses.
The Ombudsman: Verification of Citations: Fawlty Towers of Knowledge?
Authors: Wright Malcolm , Armstrong J. Scott
Published: April 2008

The prevalence of faulty citations impedes the growth of scientific knowledge. Faulty citations include omissions of relevant papers, incorrect references, and quotation errors that misreport findings. We discuss key studies in these areas. We then examine citations to “Estimating nonresponse bias in mail surveys,” one of the most frequently cited papers from the Journal of Marketing Research, to illustrate these issues. This paper is especially useful in testing for quotation errors because it provides specific operational recommendations on adjusting for nonresponse bias; therefore, it allows us to determine whether the citing papers properly used the findings. By any number of measures, those doing survey research fail to cite this paper and, presumably, make inadequate adjustments for nonresponse bias. Furthermore, even when the paper was cited, 49 of the 50 studies that we examined reported its findings improperly. The inappropriate use of statistical-significance testing led researchers to conclude that nonresponse bias was not present in 76 percent of the studies in our sample. Only one of the studies in the sample made any adjustment for it. Judging from the original paper, we estimate that the study researchers should have predicted nonresponse bias and adjusted for 148 variables. In this case, the faulty citations seem to have arisen either because the authors did not read the original paper or because they did not fully understand its implications. To address the problem of omissions, we recommend that journals include a section on their websites to list all relevant papers that have been overlooked and show how the omitted paper relates to the published paper. In general, authors should routinely verify the accuracy of their sources by reading the cited papers. For substantive findings, they should attempt to contact the authors for confirmation or clarification of the results and methods. This would also provide them with the opportunity to enquire about other relevant references. Journal editors should require that authors sign statements that they have read the cited papers and, when appropriate, have attempted to verify the citations.
Book Reviews
Authors: Lev Benjamin
Published: April 2008

In “Book Reviews,” we review an extensive and diverse range of books. They cover theory and applications in operations research, statistics, management science, econometrics, mathematics, computers, and information systems. In addition, we include books in other fields that emphasize technical applications. However, we do not review software. To submit a book for review, please send it to me at the above address. Although we cannot review all books because of space limitations, we do list all books that we receive. We commission all book reviews and do not accept unsolicited reviews. To become a reviewer, please send me your name, address, and specific areas of expertise. We encourage readers to suggest books for review or to ask publishers to send copies of such books.

The authors or editors of books we review in this issue are Gautam Appa, Leonidas Pitsoulisi, H. Paul Williams, Joseph Sarkis, Aimo Törn, and Julius Žilinskas.
Practice Abstracts
Authors: Denton Brian T.
Published: April 2008

The goal of “Practice Abstracts” is to present interesting, topical, and novel applications of operations research methodology to a wide range of industrial applications. “Practice Abstracts” are intended to provide Interfaces readers with short (2–4 pages) descriptions of the most relevant aspects of operations research-based projects, in a form that is accessible to academics and practitioners in other organizations. Contributions should be sent for evaluation to the editor of “Practice Abstracts,” Brian T. Denton, Edward P. Fitts Department of Industrial and Systems Engineering, North Carolina State University, 370 Daniels Hall, 111 Lampe Drive, Raleigh, North Carolina 27695-7906, bdenton@ncsu.edu.
An Optimization Model for Empty Freight Car Assignment at Union Pacific Railroad
Authors: Narisetty Amar Kumar , Richard Jean-Philippe P. , Ramcharan David , Murphy Deby , Minks Gayle , Fuller Jim
Published: April 2008

Railroad companies face a difficult problem in assigning empty freight cars based on customer demand because these assignments depend on a variety of factors; these include the location of available empty cars, the urgency of the demand, and the possibilities of car substitution. In this paper, we present an optimization model implemented at Union Pacific Railroad (UP) to assign empty freight cars based on demand. The model seeks to reduce transportation costs, and improve delivery time and customer satisfaction. UP currently uses the model to make real-time assignments in a total car-management system. The model has helped UP to achieve significant reductions in its transportation costs, similar to the savings that our simulation study predicted. In addition, UP reduced the staff required for its demand fulfillment process, resulting in an ROI of 35 percent.
Setting Safety-Stock Targets at Intel in the Presence of Forecast Bias
Authors: Manary Matthew P. , Willems Sean P.
Published: April 2008

Inventory target setting within Intel's embedded devices group historically consisted of management-determined inventory targets that were uniformly applied across product families. Achieving and maintaining these inventory targets at the individual product level proved to be a difficult task. To better align inventory resources and improve customer-service levels, Intel employed a multiechelon inventory optimization (MEIO) model to set inventory targets. However, the company could not implement the model's initial recommendations because of the presence of bias in the sales forecast data. Managing the forecast bias by directly modifying the raw sales forecast data was not an option because Sales and Marketing controlled and loaded the data into the manufacturing resource planning (MRP) system before the planning organization received it. Therefore, the average forecast demand, with its bias present, was already in the system; the only adjustment that the planning organization could make was to change the inventory target. This paper describes the inventory optimization problem in Intel's embedded devices group and the adjustment procedure that we developed to produce appropriate inventory targets in the presence of forecast bias.
ASP, The Art and Science of Practice: Skills Employers Want from Operations Research Graduates
Authors: Sodhi ManMohan S. , Son Byung-Gak
Published: April 2008

We analyzed the text of more than 1,000 ads for operations research (OR) jobs. Our objective was to help industry employers benchmark the skills they are seeking in OR graduates with those that other employers are seeking. Educators can also compare their offerings against the skills industry employers seek. We found that employers of OR graduates consistently require modeling, statistics, programming, and general analytical skills in an operations management context as their primary requirements regardless of sector, function within company, and even degree type. These employers also require communication, leadership, project management, spreadsheet and database, and team skills in that order.
NBC-Universal Uses a Novel Qualitative Forecasting Technique to Predict Advertising Demand
Authors: Bollapragada Srinivas , Gupta Salil , Hurwitz Brett , Miles Paul , Tyagi Rajesh
Published: April 2008

NBC-Universal (NBCU), a subsidiary of the General Electric Company (GE), implemented a novel demand prediction and analysis system to support its annual upfront market. The upfront market is a brief period in late May when the television networks sell a majority of their on-air advertising inventory. The system uses an innovative combination of the Delphi method and the Grass Roots forecasting methodology to estimate demand for television commercial time. We embedded this forecasting methodology within a workflow system that automates the demand estimates gathering process and seamlessly integrates into NBCU's existing sales systems. Since 2004, over 200 sales and finance personnel at NBCU have been using the system to support sales decisions during the upfront market when NBCU signs advertising deals worth over $4.5 billion. The system enables NBCU to sell and analyze pricing scenarios across all of NBCU's television properties with ease and sophistication, while predicting demand with a high accuracy. NBCU's sales leaders credit the system with having given them a unique competitive advantage.
Knowing who knows what and who knows whom: Expertise recognition, network recognition, and individual work performance
Authors: Ho Violet T. , Wong Sze‐Sze
Published: April 2008

We tested the relationship between individuals' expertise recognition and work performance, the role of job resourcefulness (i.e. individuals' ability to garner resources to overcome obstacles) as a mediator, and network recognition as a moderator in the link between expertise recognition and job resourcefulness. We found that the positive impact of expertise recognition on work performance was mediated by job resourcefulness, but network recognition did not play a moderating role.
Book Reviews
Authors: Siu Carmen , Sterritt David
Published: May 2008

Cinema Before Cinema: The Origins of Scientific Cinematography, Virgilio Tosi, (2005) London: British Universities Film and Video Council, 234 pp., ISBN 0901299758 (pbk), $45.99

Filmosophy, Daniel Frampton, (2006) London: Wallflower Press, 254 pp.,
ISBN 1904764843 (pbk), $24.00, ISBN 1904764851 (hbk), $80.00
Festivals
Authors: Arancio Nadia , Moffat Luke , Joll Harry , Kessenides Dimitra , Kreul James , Kreul James , Lumholdt Jan , Portis Larry
Published: May 2008

Compass International Festival of Resistance, 21 October9 November 2007 A report by Nadia Arancio and Luke Moffat

The fifty-first London Film Festival, 17 October1 November 2007 A report by Harry Joll

Hed: supersized Dek: on the scene at the forty-eighth Thessaloniki
International Film Festival A report by Dimitra Kessenides

Cucalorus Film Festival, 710 November 2007 A report by James Kreul

Turin 2007: legendary encounters
Jan Lumholdt visits an Eldorado for cinephiles and Italophiles alike.

The twenty-ninth annual
Mediterranean Film Festival in Montpellier, France: Under Bombardment in Montpellier (among other films from Greece, Lebanon, Palestine, Israel, Algeria, Spain and elsewhere) A report by Larry Portis
Have Broad‐Based Community and Professional Education Programs Influenced Mental Health Literacy and Treatment Seeking of those with Major Depression and Suicidal Ideation?
Authors: Goldney Robert D. , Fisher Laura J.
Published: April 2008

Mental health literacy is the knowledge and beliefs about mental disorders that aid in their recognition, management, or prevention; it is also a determinant of help seeking. As such, it is presumed to be important in community suicide prevention programs. In Australia there have been a number of government, professional, and charitable organizations as well as pharmaceutical company suicide prevention initiatives which have been designed to enhance public and professional knowledge about mental disorders, particularly depression. This naturalistic study conducted between 1998 and 2004 in a random and representative population sample examined the changes in mental health literacy and treatment seeking of those with major depression, both with and without suicidal ideation, and those who were neither depressed nor suicidal. Results indicated that there was marked improvement in mental health literacy for all three groups, although there was less change for those most in need of intervention (i.e., those with major depression and suicidal ideation). Furthermore, there were fewer changes in appropriate treatment seeking in those with major depression and suicidal ideation. These findings are consistent with literature reporting limited problem solving and decision making in those who are suicidal, and indicate that there are limits to broad‐based community education programs. More focused suicide prevention initiatives are required, specifically for those who are depressed and suicidal.
Assessing the Effects of Peer Suicide on Youth Suicide
Authors: Feigelman William , Gorman Bernard S.
Published: April 2008

Using data from all waves of the National Longitudinal Survey of Adolescent Health, we investigated the short‐term and long‐term impact of an adolescent friend's suicide on an adolescent's depression and suicidality. Results suggest that a friend's suicide is associated with heightened suicide thoughts and attempts and greater depression during the first year after loss. Six years later, analyses show concurrent behaviors most relevant to explain suicidality fluctuations. Findings suggest the importance of therapeutic availability, especially during the first year, for those losing a friend to suicide.
Completed Suicide among Sinhalese in Sri Lanka: A Psychological Autopsy Study
Authors: Samaraweera Sudath , Sumathipala Athula , Siribaddana Sisira , Sivayogan S. , Bhugra Dinesh
Published: April 2008

Sri Lanka has the one of highest rates of suicide. Important factors associated with suicide were determined via the psychological autopsy approach (which had not been carried out previously in Sri Lanka). Over a 3‐month period, in a catchment area, 31 suicides among Sinhalese were identified and 27 were investigated. Males were more likely to commit suicide and alcohol abuse and domestic violence were reported as contributory factors. We found it possible to use psychological autopsy methods to obtain information which can inform planned prevention measures.
The “Sky-Blue” Variety: William James, Walt Whitman, and the Limits of Healthy-Mindedness
Authors: Tessitore John
Published: May 2008

Although Neo-Pragmatist scholars have long considered Walt Whitman an intellectual and literary forebear to William James and the American Pragmatic tradition, James believed Whitman to be a far more problematic thinker than has been acknowledged. Haunting much of James's writings, and The Varieties of Religious Experience (1902) in particular, is a Whitman who is less a figure for emulation than an embodiment of a particular kind of metaphysical excess, at once unworldly and effeminate. In characterizing Whitman as a paragon of an untrustworthy “healthy-mindedness” and a “queer” idealism that he wished to excise from his own Transcendental inheritance, James developed a gendered critique of the “sky-blue” optimism he recognized as the peculiar legacy of the poet, a critique that took into account Whitman's roots in Hegelian and Emersonian thought as well as the well-publicized homoeroticism of his life and work. Ambivalent about the sexual and moral “indifferentism” that he believed accompanied Whitman's “sky-blue” acceptance of evil and death, James then traced Whitman's influence—both implicitly and explicitly—through the writings of the leading gay Whitmanites of his era, including the “mystics” John Addington Symonds and Edward Carpenter. Thus, in the war for the American soul—a war that James waged on the battlefields of metaphysics, religion, and gender identity as well as within his own person—the father of Pragmatism turned a “feminine” and “unnatural” Whitman into his chief foil and his main adversary; Whitman became the standard against which his own “manly” beliefs and methodologies, particularly with respect to religious experience, were defined.
Cabergoline and the risk of valvular lesions in endocrine disease.
Authors: Lancellotti Patrizio , Livadariu Elena , Markov Muriel , Daly Adrian F , Burlacu Maria-Cristina , Betea Daniela , Pierard Luc , Beckers Albert
Published: May 2008

Aims

The cardiac valvular risk associated with lower exposure to cabergoline in common endocrine conditions such as hyperprolactinemia is unknown.

Methods and results

We performed a cross-sectional, case–control echocardiographic study to assess the valvular status in 102 subjects receiving cabergoline for endocrine disorders and 51 matched control subjects. Cabergoline treatment ranged from 12 to 228 months, with a cumulative dose of 18–1718 mg. Valvular regurgitation was equally prevalent in both groups and was almost exclusively mild. Two cabergoline-treated subjects had moderate mitral regurgitation; there was no relationship between cabergoline dose and the presence or severity of mitral valve regurgitation (P=NS). Mitral valve tenting area was significantly greater in the cabergoline group when compared with the control subjects (P=0.03). Mitral valve leaflet thickening was observed in 5.9% of cabergoline-treated subjects; no relationship with the cumulative cabergoline dose was found. No patient had aortic or tricuspid valvular restriction.

Conclusion

No significantly increased risk of clinically relevant cardiac valve disorders was found in subjects treated with long-term cabergoline therapy at the doses used in endocrine practice. While exposure to cabergoline appears to be safe during low-dose long-term therapy, an association with subclinical changes in mitral valve geometry cannot be completely excluded.
Administrative and reporting tasks of family physicians in Europe. Comparison with the Hungarian system
Authors: Rurik Imre , Kalabay László
Published: May 2008

A háziorvosok díjazása többnyire a fejkvótán vagy teljesítményükön, néhány országban ezek kombinációján alapszik. Munkájukról beszámolókat, jelentéseket készítenek, amelyek a beteg azonosító adatait, a felállított diagnózist és az alkalmazott kezelést tartalmazzák, a közleményben országonként részletezve. Mindezeken kívül a vényírás sajátosságait, a felírt gyógyszerek térítését, valamint a szakorvosi konzíliumokra vagy a kórházba való utalás adminisztratív kötelezettségeit is elemezték. Az európai és hazai előírásokat összehasonlítva megállapítható, hogy a magyar jelentési kötelezettségek esetenként gyakoribbak, általában sokkal részletesebbek, gyakran egymást átfedők, és a kért adatok célja és szükségessége nem mindig érthető. Az adminisztratív feladatok a kuratív tevékenységre fordított időt jelentősen csökkentik, nagyfokban gátolják a háziorvos kapuőrfunkcióját, prevencióra pedig szinte egyáltalán nincs idő. Hivatalos verzió hiányában az alkalmazott háziorvosi software-ek száma túl sok, minőségük eltérő, egymással nem kompatibilisak. Az adminisztratív feladatok és a jelentési kötelezettségek felülvizsgálata indokolt lenne, célszerűen csak azon adatokra szűkítendően, amelyeknek epidemiológiai és/vagy lényeges gazdasági konzekvenciája van, jobban figyelembe véve az adatvédelmi szempontokat is.
Conjoined Twins with Mirror-Image Cleft Lip and Palate: Case Report in Brazil
Authors: da Silva Dalben Gisele , dos Santos Souza Mireile São Geraldo , de Castro Carlos Henrique Bettoni Cruz , Gonçalves Márcio , dos Santos Cássio Roberto Rocha , Consolaro Alberto
Published: May 2008

The observation of mirror-image clefts in conjoined twins may suggest an influence from environmental factors (e.g., poor blood supply) on the appearance of clefts. The present paper reports on a pair of male thoracopagus twins born to a 20-year-old woman. The twins were stillborn. Both twins exhibited complete unilateral cleft lip and palate with mirror-image configuration, affecting the left side for twin A and the right side for twin B. The twins also shared some organs. The case is discussed with similar information in the literature, with reference to possible related etiologic factors. Reporting on such occurrences throughout the world is important to shed light on important aspects underlying the formation of clefts.
Dental Development of Chinese Children with Cleft Lip and Palate
Authors: Lai Moon Cheung , King Nigel M. , Wong Hai Ming
Published: May 2008

Objective:

To compare the dental development and rate of tooth development between children with and without cleft lip and palate.

Patients:

Age- and gender-matched pairs (231 in all) of southern Chinese children ages 3 to 12 years, with and without cleft lip and palate.

Methods:

Dental histories and radiographs were studied. From these, dental development was determined.

Results:

Of 2946 tooth pairs in the children with cleft lip and palate, 252 (8.6%) were found to be asymmetric, significantly (p < .001) more than the 63 of 3179 (2.0%) tooth pairs observed in the children without cleft lip and palate. The teeth with the highest frequency of asymmetry were the maxillary lateral incisors (38.1%). Differences in dental development on the cleft versus noncleft sides of children with unilateral cleft lip and palate were significant for both maxillary and mandibular teeth (p < .001 and p  =  .039, respectively). The mean delay in tooth formation of the children with cleft lip and palate was 4.4 months relative to the children without cleft lip and palate. The majority of the teeth in the cleft lip and palate group were delayed by one developmental stage. This happened in 40.0% of the maxillary teeth and 30.1% of the mandibular teeth. The delay in tooth formation increased as the number of missing teeth increased in the children with cleft lip and palate, although not significantly.

Conclusions:

This group of southern Chinese children with cleft lip and palate demonstrated a higher prevalence of asymmetric and delayed dental development than did their counterparts who did not have cleft lip and palate.
12q Interstitial Deletion with Bilateral Cleft Lip and Palate: Case Report and Literature Review
Authors: Yamanishi Tadashi , Nishio Juntaro , Miya Shigenori , Okamoto Nobuhiko , Takahashi Akihito , Toribe Yasuhisa , Mukai Takao , Kobayashi Chie
Published: May 2008

The authors report the case of a Japanese girl with interstitial deletion of chromosome 12q15–q21.2 who had multiple congenital anomalies including bilateral cleft lip and palate (BCLP) with intrauterine onset of growth retardation and severe psychomotor developmental delay. Only two other patients with a similar deletion have been reported previously. However, these two patients showed such different clinical features that defining the karyotype-phenotype correlation has remained unfeasible. The additional case presented here reveals that two of the three cases with an overlapping deletion in 12q show the phenotype of BCLP, suggesting the correlation between this area of gene deletion and cleft lip and palate.
Biodegradation of Three Different Collagen Membranes in the Rat Calvarium: A Comparative Study
Authors: Moses Ofer , Vitrial Doron , Aboodi Guy , Sculean Anton , Tal Haim , Kozlovsky Avital , Artzi Zvi , Weinreb Miron , Nemcovsky Carlos E.
Published: May 2008

Background: Collagen barrier membranes are commonly applied in periodontal and bone‐regenerative procedures. Membranes differ in their resorption pattern following implantation, thus influencing clinical outcome. The purpose of this study was to quantitatively evaluate the biodegradation of three different commercially available collagen membranes.

Methods: Collagen membranes were cut into 5‐mm‐diameter disks and labeled with aminohexanoyl‐biotin‐N‐hydroxy‐succinimide ester. One membrane disk of each type (non‐cross‐linked [NCL], glutaraldehyde cross‐linked [GCL], and ribose cross‐linked [RCL]) was implanted on the calvaria of 20 Wistar rats. Block sections were retrieved after 2 days (baseline, two animals), 14 days (10 animals), or 28 days (eight animals). Decalcified histologic sections were stained with streptavidin horseradish peroxidase. Residual membrane thickness and area were measured. Statistical analysis consisted of analysis of variance (ANOVA) with repeated measures.

Results: Statistically significant differences in the amount of residual membrane material were recorded within each membrane (among different time points) and among different membranes at the same time points (P <0.001). At 28 days, the least amount of residual collagen area, expressed as the percentage of baseline, was observed in the NCL group (13.9% ± 10.25%), followed by the GCL (24.7% ± 35.11%) and RCL (91.3% ± 10.35%) groups. Residual membrane thickness, expressed as the percentage of baseline thickness, presented a similar pattern (31% ± 16.55%, 37% ± 41.90%, and 94.1% ± 12.22%, respectively). ANOVA with repeated measures showed a significant interaction between membranes and time (P <0.001).

Conclusions: The tested membranes differed in their degradation patterns and collagen contents. Membranes should be chosen for each clinical case according to the desired biodegradation characteristics.
Stromal‐Derived Factor‐1α (CXCL12) Levels Increase in Periodontal Disease
Authors: Havens Aaron M. , Chiu Evonne , Taba Mario , Wang Jincheng , Shiozawa Yusuke , Jung Younghun , Taichman L. Susan , D'Silva Nisha J. , Gopalakrishnan R. , Wang CunYu , Giannobile William V. , Taichman Russell S.
Published: May 2008

Background: The CXC chemokine receptor 4 (CXCR4) and its ligand, stromal cell–derived factor‐1 (SDF‐1α or CXC chemokine ligand 12) are involved in the trafficking of leukocytes into and out of extravascular tissues. The purpose of this study was to determine whether SDF‐1α secreted by host cells plays a role in recruiting inflammatory cells into the periodontia during local inflammation.

Methods: SDF‐1α levels were determined by enzyme‐linked immunosorbent assay in gingival crevicular fluid (GCF) of 24 individuals with periodontitis versus healthy individuals in tissue biopsies and in a preclinical rat model of Porphyromonas gingivalis lipopolysaccharide–induced experimental bone loss. Neutrophil chemotaxis assays were also used to evaluate whether SDF‐1α plays a role in the recruitment of host cells at periodontal lesions.

Results: Subjects with periodontal disease had higher levels of SDF‐1α in their GCF compared to healthy subjects. Subjects with periodontal disease who underwent mechanical therapy demonstrated decreased levels of SDF‐1α. Immunohistologic staining showed that SDF‐1α and CXCR4 levels were elevated in samples obtained from periodontally compromised individuals. Similar results were observed in the rodent model. Neutrophil migration was enhanced in the presence of SDF‐1α, mimicking immune cell migration in periodontal lesions.

Conclusions: SDF‐1α may be involved in the immune defense pathway activated during periodontal disease. Upon the development of diseased tissues, SDF‐1α levels increase and may recruit host defensive cells into sites of inflammation. These studies suggest that SDF‐1α may be a useful biomarker for the identification of periodontal disease progression.
Tissue‐Engineered Cultured Periosteum Used With Platelet‐Rich Plasma and Hydroxyapatite in Treating Human Osseous Defects
Authors: Yamamiya Kanoko , Okuda Kazuhiro , Kawase Tomoyuki , Hata Ken‐ichiro , Wolff Larry F. , Yoshie Hiromasa
Published: May 2008

Background: The aim of the present controlled clinical study was to compare the clinical response of human cultured periosteum (HCP) sheets in combination with platelet‐rich plasma (PRP) and porous hydroxyapatite (HA) granules to a mixture of PRP and HA in the treatment of human infrabony periodontal defects.

Methods: Thirty interproximal infrabony osseous defects in 30 healthy, non‐smoking subjects diagnosed with chronic periodontitis were included in this study. The subjects were randomly assigned to the test group (HCP sheets combined with PRP and HA) or the control group (PRP with HA). Clinical and radiographic measurements were made at baseline and the 12‐month post‐surgical evaluation.

Results: Compared to baseline, the 12‐month results indicated that both treatment modalities resulted in statistically significant changes (P <0.01) in the gingival index, bleeding on probing, probing depth, clinical attachment level, and radiographic infrabony defect depth. Compared to the control group, the test group exhibited a statistically significantly more favorable change in clinical attachment gain (3.9 ± 1.6 mm versus 2.7 ± 1.3 mm; P <0.05), vertical relative attachment gain (83.5% ± 31.7% versus 55.0% ± 21.9%; P <0.05), and radiographic infrabony defect fill (4.9 ± 1.2 mm versus 3.2 ± 1.1 mm; P <0.01).

Conclusions: Compared to PRP with HA, treatment with a combination of HCP sheets, PRP, and HA led to a significantly more favorable clinical improvement in infrabony periodontal defects. A factor likely contributing to these favorable clinical results is the presence of osteogenic cells in the HCP sheets, which provided greater regeneration potential.
Simultaneous Flapless Implant Placement and Peri‐Implant Defect Correction: An Experimental Pilot Study in Dogs
Authors: Jeong Seung‐Mi , Choi Byung‐Ho , Li Jingxu , Xuan Feng
Published: May 2008

Background: Minimally invasive implant surgery allows clinicians to place implants in less time, without extensive flaps, and with less bleeding and postoperative discomfort. The purpose of this study was to evaluate a new surgical technique by which implants are inserted in a deficient alveolar ridge using a flapless technique simultaneously with a peri‐implant defect correction that is performed using a subperiosteal tunneling procedure.

Methods: Bilateral, horizontal defects of the alveolar ridge were created in the mandibles of five mongrel dogs. After 3 months of healing, one implant was placed on each side of the mandible by a flapless procedure. The exposed threads of the implant on one side of the mandible were covered with a 1:1 autogenous bone/xenograft mixture using a subperiosteal tunneling technique. Four months later, biopsies of the implant sites were taken and prepared for ground sectioning and analysis.

Results: All implants were well osseointegrated with the host bone. All of the peri‐implant defects at the test sites were covered with tissue that resembled bone. In all specimens, a mixture of bone, connective tissue, and residual bone particles was observed in the graft area. In the control sites, where no graft was used, none of the exposed threads on any implants were covered with new bone.

Conclusion: This preliminary report indicates the potential use of a minimally invasive flapless technique as a substitute for a more invasive implant placement and ridge augmentation procedure.
Slip Calculation of Rotational Speed of Electrical Submersible Progressive Cavity Pumps
Authors: Zhou Desheng , Yuan Hong
Published: April 2008

Progressive cavity pumps (PCPs) are usually driven at surface through sucker rods. Due to the shear strength of sucker rods and the wear of the rod and tubing, the surface drive system limits its application in production rate and well depth, and in deviated and horizontal wells. Instead of using sucker rods to transmit driving torque from surface to pump, bottom driving PCP assembly sets electric submersible motors below PCP to drive the pump directly.

Electric submersible motors for PCP are three phase, squirrel cage, induction motors. Motor speed is controlled by its winding poles. Nominal motor speeds widely used are 3500 RPM for two-pole motors and 1700 RPM for four-pole motors. This paper presents simplified correlations by using the nominal motor speeds in the design and analysis of bottom driving PCP wells.

The simplified correlations do not account for the effect of motor speed slip. Actually, motor output speeds depend on loading power on the motor. Loading power is the power required by a PCP and its associated equipments to lift well fluid to surface. This paper presents the power consumption of each part in the bottom drive assembly, and the method of calculating motor slip from motor speed performance and calculated total required power. Also presented is the effect of frequency on motor speed. Finally presented are a model to design motor frequency with motor slip and an iteration algorithm to determine production rate at given frequency.

This paper clarifies the concepts of volumetric, brake, mechanical, hydraulic, and slip powers associated with PCP pumping. It also differentiated motor output nominal, no-load, and full-load speeds, and the output speeds at load factors, at standard frequency, and at design frequencies.
The Development of PCP Wells Troubleshooting Technique in Daqing Oilfield
Authors: He Liu , Yong Bi , Guochen Shi , Zhongguo Wang , Chaoyong Liu , Zhaoping Jiang
Published: April 2008

Trouble-shooting technique is an important part in artificial lift technology. Based on wave equation created by Gibbs from 1970s, dynamometer card method has been applied successfully in beam pumping well's trouble-shooting technique. As for PCP wells, there's no such the same parameter as beam pumping unit's dynamometer card which could indicate systems performance directly. In Daqing Oilfield, PCP trouble-shooting technique has been studied for more than ten years. Many methods were tried, such as operating current, effective power, rod string's operating torque and axial load, oscillation frequency, etc. Application indicated that, among all the above parameters, rod string's operating torque and axial load were the most effective ones to reflect PCP system's operating status to date. However, it was still difficult to give a clear description of a PCP system without the assistance of other parameters.

This paper overviewed the development history of PCP well's trouble-shooting technique in Daqing Oilfield. A comprehensive testing and trouble-shooting system was presented consisting of a loads sensor, a wireless signal processing system and the trouble-shooting software. The diagnose model was created on the basis of PCP wells' operating loads and the related production data base, which could distinguish ten types of operating status of PCP system. In the past few years, this system has been applied in more than 300 PCP wells in Daqing Oilfield. Although the compatibility of the model for different driving methods needs to be improved for a wider application（such as ASP flooding）, the system has been approved to be convenient and effective in water flooding and polymer flooding area which could apply a good reference for other issues.
The Mechanism of PCP Wells' Tubing and Rod Wear Issue in Polymer Flooding in Daqing Oil Field
Authors: He Liu , Xiaohan Pei , Baiqi Peng , Yu Hou , Yumei Wang , Guoqing Wang
Published: April 2008

Although PCP technology has been used in Daqing Oilfield from 1980s, and the number of PCP wells in the whole oilfield has reached 2429 till September in 2006, it wasn’t applied in polymer flooding producers with displacement of over 150m3/d until 2004. However, the application of the high volume PCP systems has witnessed severe wear issue both in tubing and rods. Study indicated that, due to the great increment in displacement, the original design for smaller volume PCPs showed serious incompatibility with high volume PCP systems. For instance, bigger structure parameter resulted in higher rod oscillation in operation, and pipe string bending issue in high volume PCP was more popular than in lower ones using the traditional anchor. In addition, improper rod guiding also played an important role in wear of tubing and rod string.

This paper analyzes the mechanism of tubing & rod wear for high volume PCPs in detail, and presents a series of harness treatments including: 1) optimizing pump selection method and operation parameter; 2) improving tubing anchoring method; and 3) optimizing rod string guiding method. Based on the above treatments, a set of optimum design model for high volume PCPs was created. Experiments and application showed that, using this optimum design model, tubing & rod wear failure rate was decreased sharply, and the operation performance was improved effectively for high volume PCPs in polymer flooding area.

This study contributed a lot in not only improving the design method of traditional PCP technology, expanding the application scale of PCP system, but also presenting a good reference on how to squeeze the benefit of artificial lift technology in EOR stage.
The Successful Application of PCPs' Personalized Design in Hailar Oilfield
Authors: Gang Cao , Linghui He , Zhaomei Chen , Xuecheng Zheng , Qingbo Wang , Mingzhan Chen
Published: April 2008

Hailar Oilfield is a new block of Daqing Oilfield developed from the end of last century. In the beginning of the development, beam pumping unit was the only lifting method of the Oilfield. Due to the low pump efficiency and higher rod failure rate as well as the 2000m lift, beam pumping system was not as economic as other in blocks of Daqing Oilfield. As the result, PCP was put into production from 2005. Though all the four wells had a good performance with high pumping efficiency in the beginning, after several months' operation, rod strings suffered from severe oscillation and resulted in fatigue failures in a short period. Theoretical and experimental study indicated that, high working temperature (85 centigrade) and special oil characteristics caused much higher swelling degree of elastomer than in other blocks, which led to the increment of interference fit and friction force between rotor and stator.

In the initial application, although pump parameter and elastomer formula were adjusted before treatment to reduce the swelling effect, these adjustments didn’t take into effect as predicted. In that case, a personalized PCP design was brought forward which gave an integrated methodology for PCP application in Hailar Oilfield. In this design, all the lifting parts from surface to downhole equipments were considered as a whole system. FEM analysis was applied to make a detailed description of the pump for different operating temperature. Based on deeper adjustment of elastomer and pump's structure parameters, the optimum design of rod and other equipments were take into consideration as well. In the end of 2006, 4 new personalized design pumps were put into production. In the following year, despite of small oscillation in the first few days due to the influence of treatment water, all PCP systems performed stably with high efficiency.
Design of Progressive Cavity Pump Wells
Authors: Zhou Desheng , Yuan Hong
Published: April 2008

Progressive cavity pumps (PCPs) are a special type of rotary positive displacement pumps. PCP was first introduced in petroleum engineering as an artificial lift method in 1970's, and is becoming a popular lift tool for its advantages of broader applications, less maintenance, and higher efficiency. PCP performances have been studied for many years, but no published paper has discussed the relation of pump performances with well performances systematically.

This paper analyzes the system performances of PCP wells. Using nodal analysis method, the paper presents algorithms and procedures to design pump rotational speed and production rate from well inflow and outflow performances. For the effect of viscosity on pump volumetric slip, unlike traditional methods of trying to set up a general correlation for all PCP types, the paper propose a method to correct the effect of viscosity on each pump's catalog performance curves, and demonstrates how to use the corrected performances to design the pumping of viscous fluid.

By unfolding a PCP cavity and using simplified slot flow, this paper presents correlations to determine the critical pump intake pressures for filling pump cavity completely for Newtonian and non-Newtonian fluids.

The presented algorithms can be used not only to design a PCP well for pump rotational speed and production rate, but also to analyze the performance of a PCP pumping well. The presented correlations of the viscosity effect on slippage and the critical pump intake pressure are useful in PCP design and system analysis.
Computational Modeling of the Three-Dimensional Flow in a Metallic Stator Progressing Cavity Pump
Authors: Paladino Emilio E. , Lima João A. , Almeida Rairam F.C. , Assmann Benno W.
Published: April 2008

This work presents a novel computational model for the 3D flow in a rigid stator Progressing Cavity Pump (PCP), using an element based finite volume method, which includes the relative motion between rotor and stator. Usual flow models in PCPs consider a Poiseuille flow along the seal lines, i.e., along the positive clearance between cavities in order to predict the internal slip and then, the volumetric efficiency for different pressures, rotations and fluid viscosities. Furthermore, some attempts for more detailed models including computational solutions for the flow in simplified geometries can be encountered in literature. These approaches include, treating cavities as parallel plates or computing the flow between two static cavities, in all cases considering steady state flow, which is a strong hypothesis in this case. Nevertheless no models considering the solution for the full transient 3D Navier-Stokes equations and the relative motion between rotor and stator were encountered. The main challenge at this point was the imposition of the mesh motion and mesh generation process, mainly, because of the mesh quality control (element distortion) in regions near the seal lines, or in the clearance regions between rotor and stator.

The model developed is capable to predict accurately the volumetric efficiency and the viscous looses as well as provide detailed information of pressure and velocity fields inside this device. Furthermore, the present model could be used to predict the hydraulic performance of an elastomeric progressing cavity pump after stator wear or deformation and allow for the development of a computational model for the fluid-structure interaction which permits the analysis of the non-rigid stator case.