bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of fluids in migmatites: CO2‐H2O fluid inclusions in leucosomes from the Deep Freeze Range migmatites (Terra Nova Bay, Antarctica)
Authors: GIORGETTI G. , FREZZOTTI M.‐L.E , PALMERI R. , BURKE E. A. J. 
Published: December 2004

ABSTRACT The metasedimentary sequence of the Deep Freeze Range (northern Victoria Land, Antarctica) experienced high‐T/low‐F metamorphism during the Cambro‐Ordovician Ross orogeny. The reaction Bt + Sil + Qtz = Grt + Crd + Kfs + melt was responsible for the formation of migmatites. Peak conditions were c. 700–750° C, c. 3.5–5 kbar and xH2Oc. 0.5).Distribution of fluid inclusions is controlled by host rock type: (1) CO2‐H2O fluid inclusions occur only in graphite‐free leucosomes; (2) CO2–CH4± H2O fluid inclusions are the most common type in leucosomes, and in graphite‐bearing mesosomes and gneiss; and (3) CO2–N2–CH4 fluid inclusions are observed only in the gneiss, and subordinately in mesosomes.CO2–H2O mixtures (41% CO2, 58% H2O, 1% Nad mol.%) are interpreted as remnants of a synmig‐matization fluid; their composition and density are compatible P–T–aH2O conditions of migmatization (c. 750° C, c. 4 kbar, xH2Oc. 0.5). CO2‐H2O fluid in graphite‐free leucosomes cannot originate via partial melting of graphite‐bearing mesosomes in a closed system; this would have produced a mixed CO2–CH4 fluid in the leucosomes by a reaction such as Bt + Sil + Qtz + C ± H2O = Grt + Crd + Kfs + L + CO2+ CH4. We conclude that an externally derived oxidizing CO2‐H2O fluid was present in the middle crust and initiated anatexis.High‐density CO2‐rich fluid with traces of CH4 characterizes the retrograde evolution of these rocks at high temperatures and support isobaric cooling (P–T anticlockwise path). In unmigmatized gneiss, mixed CO2–N2–CH4 fluid yields isochores compatible with peak metamorphic conditions (c. 700–750° C, c. 4–4.5 kbar); they may represent a peak metamorphic fluid that pre‐dated the migmatization.
Development and Positioning Reliability of a TMS Coil Holder for Headache Research
Authors: Chronicle Edward P. , Pearson A. Jane , Matthews Cheryl 
Published: December 2004

Objective.—Accurate and reproducible coil positioning is important for headache research using transcranial magnetic stimulation protocols. We aimed to design a transcranial magnetic stimulation coil holder and demonstrate reliability of test–retest coil positioning.Methods.—A coil holder was developed and manufactured according to three principles of stability, durability, and three‐dimensional positional accuracy. Reliability of coil positioning was assessed by stimulating over the motor cortex of four neurologically normal subjects and recording finger muscle responses, both at a test phase and a retest phase several hours later.Results.—In all four subjects, repositioning of the transcranial magnetic stimulation coil solely on the basis of coil holder coordinates was accurate to within 2 mm.Conclusions.—The coil holder demonstrated good test–retest reliability of coil positioning, and is thus a promising tool for transcranial magnetic stimulation‐based headache research, particularly studies of prophylactic drug effect where several laboratory visits with identical coil positioning are necessary.
Migraine Therapy: A Survey of Pharmacists' Knowledge, Attitudes, and Practice Patterns
Authors: Wenzel Richard G. , Lipton Richard B. , Diamond Merle L. , Cady Roger 
Published: December 2004

Objective.—Study pharmacists' knowledge, attitudes, and practice patterns with regard to migraine therapy.Background.—Pharmacists interact with headache sufferers at least 53,000 times daily, thus are well positioned to improve the less than optimal medication management of these disorders.Methods.—Two hundred self‐administered surveys, distributed at a migraine symposium, assessing pharmacists' demographic characteristics and level of agreement or disagreement with treatment approaches were conducted.Results.—A total of 171 useable surveys (86%) were received. Of the sample, 35% were community pharmacists, 29% were hospital pharmacists, and the remainder were from other work environments. Exclusively among community pharmacists, 80% feel that headache is an important part of their practice, 85% make between one and five over‐the‐counter (OTC) headache product suggestions per day, and 12% make six or more daily OTC recommendations. Among all the sample's pharmacists, more than half feel migraine patients should try OTC drugs prior to prescription medications, only half ask patients about headache‐related morbidity, and one‐third feel migraine‐specific medications should be reserved only for patients who initially fail nonspecific drugs. Few pharmacists utilize published migraine treatment guidelines. Approximately two‐thirds of pharmacists do not feel migraine is a neurobiological illness. The majority is comfortable with their ability to identify people needing a physician referral.Conclusions.—Our results show pharmacists, particularly those in community pharmacies, interact with headache sufferers multiple times daily. Most pharmacists were neither familiar with nor practice migraine therapies endorsed by evidence‐based guidelines. Further training of pharmacists is warranted.
Executive Control Mediates Memory's Association with Change in Instrumental Activities of Daily Living: The Freedom House Study
Authors: Royall Donald R. , Palmer Raymond , Chiodo Laura K. , Polk Marsha J. 
Published: December 2004

Objectives: To assess the relative independent contribution of changes in executive control function (ECF) and memory to changes in functional status.Design: Three‐year longitudinal cohort study.Setting: A comprehensive care retirement community.Participants: Five hundred forty‐seven noninstitutionalized people aged 70 and older.Measurements: The California Verbal Learning Test (CVLT) and Executive Interview (EXIT25). Functional status was assessed using instrumental activities of daily living (IADLs). Latent growth curves of CVLT, EXIT25, and IADLs were modeled. The rate of change in IADLs (adjusted for baseline IADLs and cognition) was regressed on the rate of change in each cognitive measure. Models were also adjusted for baseline age, level of care, and comorbid illnesses.Results: There was significant variability around the baseline means and slopes for all variables. The rate of change in EXIT25 was independently correlated with the rate of change in IADLs (correlation coefficient (r)=−0.52, P<.001). This remained significant after adjusting for baseline EXIT25 scores, IADLs, age, comorbid disease, and level of care. The EXIT25's effect on the rate of change in IADLs was stronger than those of age, baseline IADLs, comorbid disease, or level of care. The rate of change in CVLT scores was not significantly associated with the rate of change in IADLs.Conclusion: ECF is a strong, significant, and independent correlate of functional status in normal aging. In contrast, decline in memory, as measured using the CVLT, has no independent association with the rate of change in functional status. This suggests that amnestic mild cognitive impairment can be associated with dementia only though the subsequent or comorbid development of ECF impairment.
Drop Attacks in Older Adults: Systematic Assessment Has a High Diagnostic Yield
Authors: Parry Steve W. , Kenny Rose Anne 
Published: December 2004

Objectives: To investigate the causes of recurrent drop attacks in older patients with a comprehensive battery of investigations in the largest series reported to date.Design: Observational with mean followup of 18 months.Setting: Inner city emergency department and tertiary facility in Newcastle upon Tyne, United Kingdom.Participants: Ninety‐three consecutive patients aged 55 and older with three or more drop attacks in the 6 months before evaluation.Methods: Subjects underwent a comprehensive diagnostic evaluation, with particular attention to traditional (e.g., gait and balance abnormalities, medications) and more recently identified (e.g., carotid sinus hypersensitivity) risk factors for drop attacks.Results: Subjects tended to be older (mean age±standard deviation 77.4±9.0) and female (70; 75%) and to have a mean of 10.4 drop attacks before evaluation. Fifty‐three (57%) had suffered soft tissue injuries needing medical attention and 32 (34%) fractures secondary to drop attacks. An attributable diagnosis was achieved in all but nine subjects (90%). Cardiovascular diagnoses (49; 53%) were most commonly implicated, with neurological (27; 29%) and gait and balance abnormalities (17; 18%) and drug‐related causes (11; 12%) providing the majority of the remaining diagnoses.Conclusion: Drop attacks in older subjects are associated with high levels of morbidity and healthcare resource utilization. Attributable diagnoses are achievable in the majority of cases with a systematic investigative approach. The high diagnostic yield more than justifies the approach described.
Treatment Intensity and Outcome of Patients Aged 80 and Older in Intensive Care Units: A Multicenter Matched‐Cohort Study
Authors: Boumendil Ariane , Aegerter Philippe , Guidet Bertrand ,   the CUB‐Rea Network
Published: December 2004

Objectives: To determine whether patients aged 80 and older have similar treatment intensity to that of younger patients in the intensive care unit (ICU).Design: Multicenter, matched‐cohort study.Setting: Data were extracted from a multicenter database with 36 ICUs in the Paris area (France) during a 4‐year period (1997–2000).Participants: Three thousand one hundred seventy‐five patients aged 80 and older (oldest‐old) were retrospectively matched to 3,175 patients aged 65 to 79 (young‐old).Measurements: The matching criteria were severity status on admission (±2) (assessed using a corrected Simplified Acute Physiology Score II leaving out age points), Charlson Comorbidity Index, type of admission (surgical vs medical), sex, admission to same ICU, and year of ICU admission. The underlying condition was classified using the McCabe classification. The functional status was assessed using the Knaus classification. The ICU workload was assessed using the OMEGA scoring system.Results: Total and daily workload were lower in the oldest‐old than in matched young‐old patients. Estimated mean direct medical cost per stay was approximately $1,280 lower for oldest‐old patients. Older patients received less mechanical ventilation (adjusted odds ratio (AOR)=0.69, 95% confidence interval (CI)=0.61–0.78), less tracheostomy (AOR=0.37, 95% CI=0.28–0.50), and less renal support (AOR=0.52, 95% CI=0.41–0.66) than matched young‐old patients. Oldest‐old patients had a shorter length of ICU stay than matched young‐old patients and the same length of post‐ICU stay.Conclusion: Oldest‐old patients receive less treatment in the ICU than young‐old patients even after adjustment for severity of illness.
Prestorage leukoreduction and low‐temperature filtration reduce hemolysis of stored red cell concentrates
Authors: Gyongyossy‐Issa M.I.C. , Weiss S.L. , Sowemimo‐Coker S.O. , Garcez R.B. , Devine D.V. 
Published: December 2004

BACKGROUND:  Universal prestorage leukoreduction in Canada created the perception that stored red cells (RBCs) are more hemolyzed than their unfiltered predecessors. A pool‐split design tested the effects of leukoreduction on hemolysis of stored RBCs.STUDY DESIGN AND METHODS:  Two ABO‐matched units were pooled, divided, and then processed into leukoreduced (LR) and nonleukoreduced (NLR) units with the Pall LT‐WB or RC‐PL systems and sampled during standard processing and storage for testing of sterility, counts, hemolysis, and osmotic fragility.RESULTS:  Room temperature (RT) filtration of 10 pairs of LT‐WB‐LR and ‐NLR units showed significantly different percentage of hemolysis (0.39%) and osmotic fragility (0.643%) at 42 days. Cold‐stored and ‐filtered units (2 days at 4°C before processing) were less hemolyzed, but showed a similar proportional decrease of hemolysis in LR units (0.13% vs. 0.25% at 42 days). RBCs from RC‐PL systems showed the lowest hemolysis although there was a filtration effect (0.05% vs. 0.12%, 42 days). Osmotic fragility paralleled hemolysis. Segment samples gave inaccurate results. Two‐day prefiltration cold storage reduced hemolysis from 0.36 to 0.07 percent (42 days, p < 0.001). RT‐LR hemolysis became significantly higher by Day 10 and 4°C LR by Day 12. NLR units showed hemolysis by Day 7. LR units filtered cold were less hemolyzed (p < 0.05) than RT‐LR but osmotic fragility was unchanged.CONCLUSIONS:  LR‐RBCs prepared by any of three methods (LT‐WB, RT or cold; RC‐PL), filtered at 4°C, were less hemolyzed during storage than nonfiltered concentrates: 4°C leukoreduction is beneficial for RBCs and does not cause hemolysis or enhance fragility.
Recombinant factor VIIa for intractable blood loss after cardiac surgery: a propensity score–matched case‐control analysis
Authors: Karkouti Keyvan , Beattie W. Scott , Wijeysundera D.N. , Yau Terrence M. , McCluskey Stuart A. , Ghannam Mohammed , Sutton David , Van Rensburg Adriaan , Karski Jacek 
Published: December 2004

BACKGROUND:  Cardiac surgery is occasionally complicated by massive blood loss that is refractory to standard hemostatic interventions. Recombinant factor VIIa (rF‐VIIa) is being increasingly used as rescue therapy in such cases, but little information is available on its safety and efficacy for this indication.STUDY DESIGN AND METHODS:  The outcomes of the first 51 cardiac surgery patients who received rF‐VIIa for intractable blood loss (from November 2002 to February 2004) at a single institution according to a standardized clinical guideline were compared to 51 matched control patients, with the control patients identified from a large database and matched based on the propensity for massive blood loss.RESULTS:  Blood loss and blood product usage were significantly decreased after 2.4 to 4.8 mg of rF‐VIIa. In those treated after sternal closure (n = 32), there was a significant reduction in blood loss from the hour before to the hour after treatment: 100 (70, 285) mL (median [25th, 75th percentiles]; p < 0.0001). Except for a slower postoperative recovery and higher incidence of acute renal dysfunction, the adverse event rates were similar between the rF‐VIIa‐treated patients and their matched controls.CONCLUSIONS:  These results suggest that rF‐VIIa may be an effective rescue therapy for patients with intractable hemorrhage after cardiac surgery. A clinically important risk of stroke or other major thrombotic complications could not be ruled out by our study. Controlled clinical trials with adequate power to detect the impact of rF‐VIIa therapy on morbidity and mortality therefore are necessary before one can recommend its routine use in patients undergoing cardiac surgery who have excessive bleeding.
Implant design and interface force transfer
Authors: Cehreli Murat , Duyck Joke , Cooman Michel De , Puers Robert , Naert Ignace 
Published: December 2004

AbstractObjectives: To compare stress and strain magnitudes of butt‐joint and internal‐cone oral implants in a bone simulant.Material and methods: Photoelastic and strain‐gauged models of solitary Brånemark®, ITI® and Astra Tech® implants were obtained. Vertical and 20° oblique forces of 100 and 150 N were applied on the abutments in separate load cases. Isochromatic fringe patterns around implants were observed and photographed in the field of a polariscope. Strain‐gauge measurements were performed and principal strains induced around implants were calculated.Results: Isochromatic fringe orders of all designs were similar under both loading conditions (P>0.05). Strains around Brånemark® implants were lower than around Astra Tech® and ITI® implants, particularly under vertical loads. The latter implants had similar strain magnitudes (P>0.05), although strains around the conical Astra Tech® implant were lower under vertical load.Conclusions: Butt‐joint and internal‐cone oral implants have similar force distribution characteristics. The implant–abutment mating design is not a decisive factor affecting stress and strain magnitudes in a bone simulant.
Histomorphometrical and clinical comparison of submerged and nonsubmerged implants subjected to experimental peri‐implantitis in dogs
Authors: Zechner Werner , Kneissel Michaela , Kim Syngcuk , Ulm Christian , Watzek Georg , Plenk Hanns 
Published: December 2004

AbstractObjectives: Soft and hard tissue healing around submerged and nonsubmerged versions of one dental implant design was evaluated in an experimental canine peri‐implantitis model.Material and methods: Forty‐eight c.p. Ti‐implants with integrated (one‐piece=OPI) or screw‐on (two‐piece=TPI) abutments were inserted in edentulous mandibles of eight beagle dogs, one OPI and one TPI with connected abutments for nonsubmerged and one TPI without abutment (SMI) for submerged healing. After 3 months, all implants were functionally loaded, and at 4 months peri‐implantitis was ligature‐induced in one jaw side. Intravital polyfluorochrome labeling, monthly conventional radiography and gingival probing of all 48 implants were performed until sacrifice 8 months postimplantation. Undecalcified ground sections in the bucco‐lingual and mesio‐distal planes of four dogs (23 implants, one implant lost) were evaluated by light and fluorescence microscopy. The immunohistochemical and SEM‐vascular corrosion cast results of the four other dogs (24 implants) will be reported elsewhere. Levels of alveolar bone‐to‐implant contact (ABICL), alveolar crest (ACL) and junctional epithelium‐to‐implant contact were determined by computer‐assisted histometry. Peri‐implant alveolar bone loss (=saucerization) was assessed on the radiographs and calculated as ACL minus ABICL from histometric data.Results: Around SMIs and OPIs without ligature less plaque adhesion and lower gingival indices were found when compared to TPIs. Radiologically, all ligatured, but also some nonligatured implants showed alveolar bone loss. Histometry demonstrated reduced ABICL around all these implants. Saucerization was more pronounced on the lingual and mesio‐distal sides. Particularly around TPIs, bone resorption was still active or bone formation was impaired on fluorochrome labeling. Only around SMIs and one OPI without ligature continuing alveolar bone formation reflected by gains in ABICL were found.Conclusion: The clinical and histometric results of this study demonstrate that healing of submerged SMIs was not impaired by the two‐stage procedure, resulting in equally good healing as around nonsubmerged OPIs. However, peri‐implantitis plaque‐induced by ligature and/or dilated abutment connection microgaps in TPIs affected alveolar bone‐to‐implant contacts more than transmucosal or submerged healing mechanisms.
Bioactive glass granules as a bone adjunctive material in maxillary sinus floor augmentation
Authors: Turunen Tia , Peltola Juha , Yli‐Urpo Antti , Happonen Risto‐Pekka 
Published: December 2004

AbstractObjectives: Bilateral sinus floor augmentation procedure was performed in 17 patients to study the effect of bioactive glass (BG) granules mixed with autologous bone (AB) chips on bone regeneration. The posterior part of 17 maxillary sinus was augmented with a 1 : 1 mixture of BG granules (∅ 800–1000 μm) and AB chips harvested from the iliac crest (BG–AB group). The anterior parts of the same sinus and the contralateral sinus, serving as a control (AB group), were filled with AB chips alone. Trephine biopsies for histological, scanning electron microscopy (SEM), and energy dispersive X‐ray (EDX) analyses were taken from the posterior part of the sinus after 21–34 weeks at the time of insertion of dental implants. Additionally, six biopsies were taken from the BG–AB group and four biopsies were taken from the AB group in connection with abutment operation at 49–62 weeks.Results: Histological evaluation revealed lamellar bone growth in all the specimens. Although most of the BG granules were without bone contact in the majority of the patients in the BG–AB group, the bone lamellae were thicker than observed in the AB group. In the contact areas, bone was growing along the glass surface connecting the particles together. Histomorphometrical analysis carried out from the SEM images at 21–34 weeks revealed 26% and 25% bone in the BG–AB and the AB group, respectively. Corresponding figures for 49–62 weeks were 29% for the BG–AB group and 25% for the AB group. Bone–BG complex, i.e. the granules with intimate contact with bone, occupied 34% of the area measured at 21–34 weeks and 31% at 49–62 weeks. EDX analysis showed a tight contact and chemical bonding between the glass and bone. As a sign of dissolution, a few small Si‐depleted areas were present in some BG granules at 21–34 weeks, while more and larger Si‐free areas were observed in the granules at 49–62 weeks.Conclusion: The results indicate that BG granules (S53P4) can be used together with AB chips for sinus floor augmentation procedure, thus decreasing the amount of bone needed. Further studies concerning especially the biomechanical properties of the BG–AB complex with dental implants are needed.
Deformation at the implant interface to prosthetic superstructure: an interferometric approach
Authors: Wahl Gerhard , Lang Hermann 
Published: December 2004

Abstract:Dental implants are deformed by masticatory forces. These deformations may affect the implant, the prosthetic superstructure or, in particular, the interfaces between the implant and the superstructure. The resulting changes in the geometrical relationships may lead to gap formation in this region. The objective of the present pilot study was to present an interferometric method for the direct recording and quantitative three‐dimensional analysis of load‐induced dynamic implant deformation. Three implant screws of 4.1 mm diameter were loaded using a piezoelectric device. The results showed that the screws itself exhibited a homogeneous deformation pattern, whereas implants with screw‐retained superstructures demonstrated dislocations of the crown and resulting gap formations (0.27±0.37 μm – mean±SD; max: 0.82 μm). The results supported the hypothesis that the high precision of prefabricated abutments is adversely affected by dynamic deformations under functional loading.
Stimulating effect of implant loading on surrounding bone
Authors: Mellal A. , Wiskott H. W. A. , Botsis J. , Scherrer S. S. , Belser U. C. 
Published: December 2004

Abstract:  A number of algorithms have been proposed to model the adaptive behavior of bone under load. However, the predictions of several models have neither been compared nor have they been systematically related to in vivo data. To this end, the stress states of loaded implant–bone interfaces were analyzed before and after osseointegration using finite element (FE) techniques.In a preliminary step, an FE mesh of a cylindrical implant encased in a cancellous core surrounded by a cortical layer was constructed, and the stresses and strains that developed at the interface were determined. The implant was loaded with 100 N vertical and 30 N lateral loads. Using this structure, the peak compressive and tensile stresses were determined. Then bone remodeling predictions were assessed using three different models: von Mises equivalent strain, strain energy density and effective stress. Finally, a systematic search of the literature was conducted to relate the numerical predictions to existing in vivo data.The FE simulations led to the following conclusions: (1) calculated compressive stresses were lower than the ultimate compressive stresses of cortical and cancellous bone. (2) Calculated tensile stresses were generally superior to experimental data on the tensile strength of the bone–implant interface. (3) With one exception, the predictions of all models were homogeneously grouped on the stimulus scales. (4) The predictions of the models as to bone gain or loss were not consistent and at times contradictory. It is hypothesized that this effect is linked to a lazy zone that is too narrow. With respect to the application of the numerical models to in vivo data, peak strains and strain energy densities were consistent with in vivo data. No in vivo data were found that supported effective stress as a stimulus.