bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk Factors for Potentially Harmful Informal Caregiver Behavior
Authors: Beach Scott R. , Schulz Richard , Williamson Gail M. , Miller L. Stephen , Weiner Myron F. , Lance Charles E.
Published: January 2005

Objectives: Caring for a sick or disabled relative has been linked to compromised caregiver health, and risk factors for negative caregiver outcomes have been studied extensively, but little attention has been given to care recipient and caregiver health as risk factors for potentially harmful behavior by informal caregivers. This article explores such risk factors.

Design: Structured interviews from baseline assessment of the Family Relationships in Late Life Study.

Setting: Three U.S. communities.

Participants: Referred, volunteer sample of 265 caregiver/care recipient dyads. Caregivers were primarily responsible for care of an impaired, community‐residing family member aged 60 and older and providing help with at least one activity of daily living (ADL) or two instrumental activities of daily living (IADLs).

Measurements: Self‐reported care recipient demographics, cognitive status, need for care, and self‐rated health; self‐reported caregiver demographics, cognitive status, amount of care provided, self‐rated health, physical symptoms, and depression. Care recipient reports of potentially harmful caregiver behavior, including screaming and yelling, insulting or swearing, threatening to send to a nursing home, and withholding food, were the main outcome variable.

Results: The following were significant risk factors for potentially harmful caregiver behavior: greater care recipient ADL/IADL needs (odds ratio (OR)=1.12, 95% confidence interval (CI)=1.03–1.22), spouse caregivers (vs others; OR=8.00, 95% CI=1.71–37.47), greater caregiver cognitive impairment (OR=1.20, 95% CI=1.04–1.38), more caregiver physical symptoms (OR=1.07, 95% CI=1.01–1.13), and caregivers at risk for clinical depression (OR=3.47, 95% CI=1.58–7.62).

Conclusion: Potentially harmful caregiver behavior is more likely in spouse caregiving situations and when care recipients have greater needs for care and caregivers are more cognitively impaired, have more physical symptoms, and are at risk for clinical depression. This risk profile is similar to that for negative caregiver outcomes.
Falls Documentation in Nursing Homes: Agreement Between the Minimum Data Set and Chart Abstractions of Medical and Nursing Documentation
Authors: Hill‐Westmoreland Elizabeth E. , Gruber‐Baldini Ann L.
Published: January 2005

Objectives: To assess the agreement between falls as recorded in the Minimum Data Set (MDS) and fall events abstracted from chart documentation of elderly nursing home (NH) residents.

Design: Secondary analysis of data from a longitudinal panel study.

Setting: Fifty‐six randomly selected NHs in Maryland stratified by facility size and geographic region.

Participants: Four hundred sixty‐two NH residents, aged 65 and older, in NHs for 1 year.

Measurements: Falls were abstracted from resident charts and compared with MDS fall variables. Fall events data obtained from other sources of chart documentation were matched for the corresponding periods of 30 and 180 days before the 1‐year MDS assessment date.

Results: For a 30‐day period, concordance between the MDS and chart abstractions of falls occurred in 65% of cases, with a kappa coefficient of 0.29 (P<.001), indicating fair agreement. Concordance occurred between the sources for 75% of cases for a 180‐day period, with a kappa of 0.50 (P<.001), indicating moderate agreement. During the 180‐day period, chart abstractions showed that 49% of the sample fell, whereas the MDS revealed that only 28% fell. An analysis of residents whose falls the MDS missed indicated that these residents had significantly more activity of daily living impairment and significantly less unsteady gait and cane/walker use.

Conclusion: The MDS underreported falls. Nurses completing MDS assessments must carefully review residents' medical records for falls documentation. Future studies should use caution when employing MDS data as the only indicator of falls.
Postoperative Pain Management in Elderly Patients: Correlation Between Adherence to Treatment Guidelines and Patient Satisfaction
Authors: Sauaia Angela , Min Sung‐joon , Leber Chris , Erbacher Kathleen , Abrams Fredrick , Fink Regina
Published: January 2005

Objectives: To evaluate pain management satisfaction in elderly postoperative patients; to define pain management strategies documented in the medical record (MR) that predict patient satisfaction.

Design: Prospective cohort.

Setting: Eight urban hospitals.

Participants: Three hundred twenty‐two postsurgical patients aged 65 and older.

Measurements: Patients were surveyed regarding satisfaction with pain management in the first 24 hours postsurgery and the survey results summarized in a score. Pain management variables (patient education, pharmacological and nonpharmacological interventions, demographic variables, and surgery and anesthesia information) were abstracted from their MR. The correlation between the satisfaction score and MR variables was assessed using linear regression.

Results: Sixty‐two percent of patients experienced severe postoperative pain, yet 87% reported being satisfied with the treatment. The mean satisfaction score±standard deviation was 59.3±10.8 (range 10.6–84.3; potential range 0–100, higher score=higher satisfaction). MR variables explained 14% of the satisfaction score variation. The worst pain intensity in the first 24 hours postsurgery as documented in the MR was the most powerful predictor of satisfaction. Other predictors associated with satisfaction were younger age, male sex, preoperative education, surgery type (laparotomy/thoracotomy patients were more satisfied than orthopedic patients), shorter recovery room stay, analgesic given through oral route, and morphine (compared with other opioids).

Conclusion: Pain in elderly surgical patients remains undermanaged. Simple strategies such as emphasizing preoperative education may have a large effect in pain management. This study developed a validated patient satisfaction score and a MR instrument to assist in monitoring pain management quality.
A Chart‐Based Method for Identification of Delirium: Validation Compared with Interviewer Ratings Using the Confusion Assessment Method
Authors: Inouye Sharon K. , Leo‐Summers Linda , Zhang Ying , Bogardus Sidney T. , Leslie Douglas L. , Agostini Joseph V.
Published: January 2005

Objectives: To validate a chart‐based method for identification of delirium and compare it with direct interviewer assessment using the Confusion Assessment Method (CAM).

Design: Prospective validation study.

Setting: Teaching hospital.

Participants: Nine hundred nineteen older hospitalized patients.

Measurements: A chart‐based instrument for identification of delirium was created and compared with the reference standard interviewer ratings, which used direct cognitive assessment to complete the CAM for delirium. Trained nurse chart abstractors were blinded to all interview data, including cognitive and CAM ratings. Factors influencing the correct identification of delirium in the chart were examined.

Results: Delirium was present in 115 (12.5%) patients according to the CAM. Sensitivity of the chart‐based instrument was 74%, specificity was 83%, and likelihood ratio for a positive result was 4.4. Overall agreement between chart and interviewer ratings was 82%, kappa=0.41. By contrast, using International Classification of Diseases, Ninth Revision, Clinical Modification, administrative codes, the sensitivity for delirium was 3%, and specificity was 99%. Independent factors associated with incorrect chart identification of delirium were dementia, severe illness, and high baseline delirium risk. With all three factors present, the chart instrument was three times more likely to identify patients incorrectly than with none of the factors present.

Conclusion: A chart‐based instrument for delirium, which should be useful for patient safety and quality‐improvement programs in older persons, was validated. Because of potential misclassification, the chart‐based instrument is not recommended for individual patient care or diagnostic purposes.
Evaluating Immediate and Long‐Range Effect of a Geriatric Clerkship Using Reflections and Ratings from Participants as Students and as Residents
Authors: Powers Cathey L. , Allen Ruth M. , Johnson Virginia A. , Cooper‐Witt Christina M.
Published: January 2005

This article describes a longitudinal study developed to assess perceived usefulness of a mandatory geriatric clerkship from the perspective of junior students completing the newly initiated program in 1998–1999 and 1999–2000 and these same students as second‐ or third‐year residents. End‐of‐clerkship student evaluations were compared with follow‐up resident surveys of those same students to identify the utility of information provided and strengths and weaknesses of the initial course experience. Students participated in hospice, outpatient clinics, nursing homes, and transitional care venues during their clerkship experience at the Donald W. Reynolds Department of Geriatrics, College of Medicine, University of Arkansas for Medical Sciences. Two hundred eighty‐five student evaluations were collected, and 143 resident surveys were returned. Quantitative and qualitative data from students and residents corroborated each other in identifying strengths and weaknesses of the clerkship. Hospice information was successfully incorporated into residency practice. In contrast, outpatient clinic, nursing home, and transitional care segments of the clerkship were perceived as inadequate. Survey responses validated faculty changes that were initiated in the following years. These changes use settings and patients that more accurately mirror those seen in typical resident encounters.
A mechanical comparison of veterinary linear external fixation systems
Authors: White David T. , Bronson Dwight G. , Welch Robert D.
Published: January 2005

Objective—To compare the fixation rigidity of recently developed external fixation systems (EFSs) to that of the traditional Kirschner‐Ehmer (KE) system.

Study Design—In vitro biomechanical study.

Sample Population—Five different EFSs (KE, Secur‐U, small SK carbon fiber, small SK titanium, large SK carbon fiber) were assembled into 7 frame geometries to stabilize Delrin plastic rods with a 1‐cm gap.

Methods—External skeletal fixation (ESF) constructs were tested in axial compression, torsion, medial‐lateral bending, and cranial‐caudal bending. Testing was conducted within the elastic range of each fixator. Mean stiffness in each mode was determined from the slope of the linear portion of the load‐deformation curve. Comparison of stiffness values of each EFS within each loading mode and frame type was performed with 1‐way analysis of variance (P< .05).

Results—Mean stiffness values were significantly higher for the large SK EFS in all frame types compared with KE but were equal in torsional stiffness in the double‐bar type 1a frame. The small SK EFS with titanium connecting bar had greater stiffness than the KE in all modes for frame types Ia, Ia‐accessory bar, and II‐modified. No overall difference was detected between the KE EFS and the small SK with carbon fiber rod. The stiffness of the Secur‐U type Ia frame with augmentation plate was significantly greater than the KE type Ia with accessory bar.

Conclusions—The newer external fixation systems evaluated in this study provided fixation rigidity equal to or greater than that of the KE system.

Clinical Relevance—EFSs with increased frame rigidity should permit the use of less complex frame designs while providing fracture stability.
Thoracoscopic treatment of bullous emphysema in 3 dogs
Authors: Brissot Herve N. , Dupre Gilles P. , Bouvy Bernard M. , Paquet Laurent
Published: January 2005

Objective—To report thorascopic partial lobectomy for treatment of bullous emphysema in dogs.

Study Design—Prospective clinical study.

Animals—Three dogs with spontaneous pneumothorax.

Methods—Thoracoscopy without pulmonary exclusion was used to identify bulla. The thorascope was introduced into the thorax lateral to the xyphoid process, and instrument portals were made at different levels along the thoracic wall between the third and tenth intercostal spaces. The thorascope was passed through the mediastinum to view the opposite pleural cavity. After identification of bullae, the affected lung was excised using an endoscopic stapler, and the incision line was checked for air leakage. Thoracic drains were used for air aspiration for 2 days after surgery.

Results—Bullae were confirmed histologically as emphysematous lesions. Lung inflation did not interfere with identification of bullae or with surgery. All dogs had full recovery without recurrence for 18 to 29 months after surgery.

Conclusions—Identification and ablation of bulla can be performed thoracoscopically without pulmonary exclusion in dogs.

Clinical Relevance—Thoracoscopy offers several advantages compared with thoracotomy for treatment and diagnosis of idiopathic pneumothorax, including ease of identification of bullae and reduced postoperative pain and morbidity.
Laryngoplasty with ventriculectomy or ventriculocordectomy in 104 draft horses (1992–2000)
Authors: Kraus Beth M. , Parente Eric J. , Tulleners Eric P.
Published: January 2005

Objective—To evaluate efficacy and safety of laryngoplasty with vetriculectomy (VE) or ventriculocordectomy (VCE) for treatment of laryngeal hemiplegia (LH) in draft horses.

Study Design—Retrospective study.

Sample Population—One hundred four draft horses used for competitive hitch competitions.

Methods—Medical records and postoperative endoscopy for competitive hitch draft horses diagnosed with left LH and treated with laryngoplasty and VE or VCE between January 1992 and December 2000 were reviewed. Follow‐up information was obtained from telephone interviews with owners and trainers, and performance scores of 1 to 3 were assigned in which 1 was defined as a horse that was unable to perform (abnormal respiratory noise with or without exercise intolerance), 2 was able to perform but not for its intended use (exercise tolerant but abnormal respiratory noise), and 3 was performing as expected for its intended use (exercise tolerant, no abnormal respiratory noise).

Results—One hundred four horses that had 111 laryngoplasty procedures were included. All horses had preoperative performance scores of 1. Follow‐up information was available for 79 horses. Improvement in postoperative performance (exercise tolerant, with or without abnormal respiratory noise) was reported in 92% of horses. Respiratory noise was eliminated in 72% (57 horses) of horses. Postoperative performance scores were the following: 3 in 57 (72%) horses, 2 in 16 (20%) horses, and 1 in 6 (8%) horses. There was no significant difference in postoperative performance based on preoperative grade of LH. There was a trend for horses with ≥70% of possible maximal abduction postoperatively to have a performance score of 3. Postanesthetic complications included prolonged recovery (4 horses, 4%) and myopathy or neuropathy (7 horses, 7%). One of these horses was killed because it did stand; triceps myopathy and encephalopathy were confirmed on necropsy.

Conclusions—Laryngoplasty with VE or VCE is an effective and safe procedure for the treatment of LH in the draft horse. Repeat laryngoplasty can be performed successfully, with good performance outcome after laryngoplasty failure. Complications associated with general anesthesia and laryngoplasty in draft horses are higher than reported for light breed horses under similar conditions.

Clinical Relevance—For LH, laryngoplasty with VCE or VE under general anesthesia is recommended to eliminate abnormal respiratory noise and improve performance in most competitive hitch draft horses.
Pasteurized tumoral autograft and adjuvant chemotherapy for the treatment of canine distal radial osteosarcoma: 13 cases
Authors: Morello Emanuela , Vasconi Elisabetta , Martano Marina , Peirone Bruno , Buracco Paolo
Published: January 2005

Objective—To report outcome in 13 dogs with distal radial osteosarcoma, without evidence of metastasis, treated by a combination of adjuvant chemotherapy and a pasteurized autograft limb‐sparing procedure.

Study Design—Prospective clinical study.

Animals—Thirteen dogs with distal radial osteosarcoma.

Methods—Limb‐sparing procedure was performed using an autograft from the excised tumoral segment, pasteurized at 65°C for 40 minutes. Adjuvant chemotherapy (cisplatin or cisplatin and doxorubicin) was administered in all dogs.

Results—Mean and median survival times were 531 and 324 days, respectively (range, 180 to 1,868 days). Overall survival was 100% at 6 months, 50% at 12 months, 44% at 18 months, and 22% at 24 months. Lung metastasis occurred in 5 (38%) dogs. Observed complications were local recurrence (2 dogs, 15%), allograft infection (4 dogs, 31%), and implant failure (3 dogs, 23%). Limb function was good in 12 dogs (92%) and fair in 1 dog.

Conclusions—Pasteurized bone autograft derived from the tumoral bone segment was an effective alternative to cortical bone allograft for limb sparing in canine distal radial osteosarcoma, in terms of feasibility, pattern of healing, complications, and survival.

Clinical Relevance—Use of a pasteurized bone autograft eliminates the need for a canine bone allograft bank and has the added advantage of good fit to the recipient site.
Short‐term outcome after total elbow arthroplasty in dogs with severe, naturally occurring osteoarthritis
Authors: Conzemius Michael G. , Aper Rhonda L. , Corti Lisa B.
Published: January 2005

Objective—To evaluate limb function in client‐owned dogs before and after total elbow arthroplasty (TEA) for severe, naturally occurring osteoarthritis (OA).

Study Design—Prospective clinical evaluation comparing limb function before and after surgery.

Animals—Twenty adult, large breed dogs with elbow OA.

Methods—Physical, radiographic, and force platform gait examinations were performed on all dogs before surgery. TEA was performed, and examinations were repeated at 3, 6, and 12 months after surgery. Pre‐ and postoperative findings were compared.

Results—TEA led to a satisfactory outcome in 16 dogs. In dogs with a satisfactory outcome, function in the operated limb increased over time, with mean peak vertical force (PVF) and vertical impulse (VI) 1 year after surgery being nearly twice the presurgical value. Serious complications encountered included infection (n = 2), luxation (n = 1), and fracture of the humeral condyle (n = 1).

Conclusions—Although TEA, as presented, has significant limitations, it can be successfully performed in dogs with naturally occurring elbow OA. Improvements in technique and implant design should lead to improved prognosis.

Clinical Relevance—Based on 1‐year data, TEA can be successfully performed in dogs and should be considered as a treatment alternative for adult dogs with lameness from severe OA of the elbow joint.
Biomechanical investigation of the association between suspensory ligament injury and lateral condylar fracture in thoroughbred racehorses
Authors: Le Jeune Sarah S. , Macdonald Melinda H. , Stover Susan M. , Taylor Ken T. , Gerdes Max
Published: January 2005

Objective—To determine whether partial transection of the medial branch of the suspensory ligament (MBSL) alters equine third metacarpal bone (MC3) condylar surface strains and forelimb, distal joint angles in a manner consistent with promotion of lateral condylar fracture.

Study Design—In vitro biomechanical experiment.

Sample Population—Right forelimbs from 7 Thoroughbred horse cadavers.

Methods—Lateral and medial MC3 condylar, dorsal and abaxial, bone surface strains and distal joint angles were measured both before and after partial transection of the MBSL during in vitro axial limb compression. Dorsal, principal bone strains and abaxial, uniaxial, and proximodistal strains were compared before and after MBSL partial transection at 1,400‐, 3,000‐, and 5,600‐N loads.

Results—Bone strains increased in all locations with increasing axial load. All lateral condylar bone strains were significantly higher, and abaxial surface medial condylar bone strain was significantly lower, after partial transection of the MBSL. Respective distal joints became more flexed or extended as axial load increased but were not significantly different after partial transection of the MBSL.

Conclusions—Partial transection of the MBSL increases in vitro MC3 lateral condylar bone surface strains.

Clinical Relevance—Loss of integrity of the medial branch of the suspensory ligament could increase the risk for lateral condylar fracture in Thoroughbred horses by amplifying bone strain in the lateral condyle.
Lymphocyte Sub‐populations in Gestational Diabetes
Authors: Mahmoud Fadia , Abul Habib , Omu Alexander , Haines David
Published: January 2005

Problem:  We hypothesize that the normal immunologic responses by the maternal immune system during pregnancy are not as well‐regulated in gestational diabetes (GD) patients as in healthy pregnant women.

Method of study:  Using two‐color flow cytometry we evaluated frequencies of peripheral blood lymphocytes in 20 GD patients being treated with insulin; 43 GD patients treated with dietary therapy but no insulin; 44 women experiencing normal pregnancies; and 48 non‐pregnant women.

Results:  When compared with healthy pregnant women, both GD cohorts showed higher percentages CD4+CD25+ (P < 0.05), CD4+CD45RO+ (P < 0.05) and CD4+CD29+ (P < 0.01) but lower percentages of CD4+CD45RA+ (P < 0.05). Higher percentages of the activated phenotypes CD8+CD25+ and CD8+HLA‐DR+ cells in the diet‐treated cohort and CD4+HLA‐DR+ cells in insulin‐treated GB cohort, were observed compared with healthy pregnant subjects (P < 0.05).

Conclusions:  Expanded populations of activated peripheral blood T cells are associated with GD, suggesting that normal maternal immunosuppression is less effective in GD‐afflicted women.
Changes in Immune Cell Distribution and IL‐10 Production are Regulated through Endometrial IP‐10 Expression in the Goat Uterus
Authors: Imakawa Kazuhiko , Nagaoka Kentaro , Nojima Hisashi , Hara Yasuhiro , Christenson Ronald K.
Published: January 2005

Problem:  Changes in distribution or redistribution of immune cells are required for the establishment and maintenance of pregnancy, but these changes during early pregnancy have been poorly understood in the ruminant ungulates. Expression of a chemokine, interferon‐γ (IFN‐γ)‐inducible protein 10 kDa (IP‐10, CXCL10), was identified in the endometrium of pregnant goats. Population and/or distribution of endometrial immune cells and their cytokine productions could be regulated by IP‐10 during the period of pregnancy establishment.

Method of study:  Using reverse transcriptase‐polymerase chain reaction (RT‐PCR), expression of IP‐10, IFN‐γ, tumor necrosis factor‐α, interleukin‐10 (IL‐10), CXCR3 mRNA and leukocyte cell surface markers, CD4, CD8, CD11b and CD45 mRNA during the caprine early pregnancy was investigated. The ability of IP‐10 to stimulate peripheral blood mononuclear cells (PBMCs) migration was demonstrated using a chemotaxis assay. Changes in migration of PBMCs’ immune cell population and cytokine expressions with IP‐10 stimulation were investigated using flow cytometry and RT‐PCR respectively.

Results:  Levels of IP‐10, IL‐10, CD4 and CD11b mRNA, and the number of CD4 and CD11b positive cells in pregnant goat endometrium were higher than those of cyclic goat endometrium. Migration of PBMCs was stimulated by recombinant caprine IP‐10, and the effect was significantly reduced by neutralization with the use of an anti‐IP‐10 antibody. In the flow cytometric and RT‐PCR analyses, migrated cells stimulated by IP‐10 increased the expression of IL‐10 and CD11b mRNA. Furthermore, IP‐10 could stimulate the expression of IL‐10 mRNA from PBMCs.

Conclusion:  Endometrial chemokine IP‐10 could regulate IL‐10 production by resident and possibly migrated cells expressing CD11b, probably natural killer cells, and these changes may result in immune environments of the uterus suitable for conceptus implantation in ruminants.
Apoptosis in the regenerate produced by mandibular osteodistraction in the mature rat*
Authors: Liu ZJ , Anderson MW , Gu GM , King GJ
Published: January 2005

Structured Abstract

Authors – Liu ZJ, Anderson MW, Gu GM, King GJ

Objective – Little is known about the contribution of apoptosis to the formation of the regenerate in distraction osteogenesis. This study investigated the role of apoptosis in the regulation of osteogenesis in relation to mandibular distraction rate and recovery time.

Methods – One hundred and twenty‐nine 3‐month rats received unilateral mandibular ramus osteotomy and distraction device placement. After 3‐day latency, these were distracted for 5 days. The slow group was distracted a total of 1 mm (0.2 mm/day), the moderate 2 mm (0.4 mm/day), the rapid 3 mm (0.6 mm/day), and the sham was not distracted (0.0 mm/day). Eight to nine rats from each group were killed at 6 (mid‐distraction), 10 (early‐consolidation), 24 (mid‐consolidation) and 38 (late‐consolidation) days following device placement. Baseline data were obtained from an additional eight rats killed at day 3 (end of latency). Sagittal sections (7 μm) of the harvested hemi‐mandibles were embedded in paraffin, double‐stained with the DeadEndTM Colorimetric TUNEL system for apoptotic cells and tartrate‐resistant acid phosphatase for osteoclasts. Cell counts of apoptotic cells and osteoclasts (apoptotic or otherwise) were preformed at 40× magnification using a calibrated grid at the middle regions of the caudal, central and rostral parts of the distraction gap. Counting reproducibility was verified as <13%.

Results – Counts from all three regions were combined because no significant regional difference was found. The majority of the fibrous matrix regenerate was seen at days 6 and 10 while osseous regenerate occurred mainly at days 24 and 38. Significantly higher levels of apoptotic activity were seen at day 24. Apoptotic osteoclasts also peaked at day 24. Apoptotic cell numbers in the slow and moderate groups most closely followed the pattern of the sham in which the apoptosis activity peaked at days 10 or 24. However, those in the rapid group showed delayed peaks at days 24 or 38.

Conclusions – The transition from fibrous to osseous regenerate during mandibular distraction osteogenesis is accompanied by an increase in cell clearance via apoptosis. A slow to moderate distraction rate allows for the most typical pattern of bone healing while a rapid rate prolongs the healing process.
Leishmanicidal Activity of Edelfosine, Miltefosine and Ilmofosine
Authors: Azzouz Samira , Maache Mimoun , Garcia Ramon Gil , Osuna Antonio
Published: January 2005

Abstract: The anti‐proliferative action of three alkyl‐lysophospholipid derivatives, edelfosine (ET‐OCH), miltefosine (Hexadecylphosphocholine), and ilmofosine (BM 14.440) has been studied on the promastigotes and amastigotes of Leishmania donovani. The effect of the three drugs has previously been studied, but the action mode was not clearly elucidated. In this study the effect on the intracellular amastigote forms was evaluated by two different methods: the traditional method, counting the amastigotes within the macrophages stained with Giemsa; and by a new method, staining the nuclear macrophages and amastigotes with ethidium bromide and counting the different population by flow cytometry. This new method, based on the flow cytometry, shows an advantage for evaluating the anti‐proliferative effects in intracellular parasites. The ED50 were calculated for the drug activity after 72 hr, and for the three alkyl‐lysophospholipid derivatives it were in the range of 26.73–33.31 μM against promastigotes and in the range of 16.46–23.16 against amastigotes. Also, studying the effect against macrophages J774A1, the ED50 were in the range of 24.28–26.38 μM. The effect of the alkyl‐lysophospholipids in the macromolecular biosynthesis of the Leishmania donovani, was studied comparing the incorporation of labelled analogues ([3H] thymidine, [3H] uridine and [3H] leucine), respectively, in the DNA, RNA, and proteins of the flagellates treated. Miltefosine was the most active of the alkyl‐lysophospholipids, especially in the inhibition of the RNA synthesis. The three compounds studied show high in vitro activity against L. donovani promastigotes and amastigotes.
Comparison of Carcinogen Hazard Characterisation Based on Animal Studies and Epidemiology
Authors: Sanner Tore , Dybing Erik
Published: January 2005

Abstract: Recently we have described a simple method for quantitative risk assessment of non‐threshold carcinogens based on the dose descriptor T25. In the present report quantitative hazard estimates calculated with the T25 method have been compared with results obtained using quantitative methods based on epidemiological studies. “Known” and “Likely/Probably” human carcinogens were identified from the US EPA database IRIS. In cases were the hazard characterisation was performed on the basis of epidemiological studies, the IARC monographs were used to identify animal studies by oral or inhalation exposure suitable for hazard characterisation by the T25 method. Six agents were identified: benzene, benzidine, 1,3‐butadiene, cadmium, nickel subsulfide and vinyl chloride for which US EPA had made their hazard estimation based on epidemiological data. Animal data suitable for hazard characterisation were also available. For comparing hazard characterisations based on epidemiological and animal data, it was pragmatically decided to do this by comparing the chronic doses expressed as those representing a lifetime cancer hazard of 10−3. In all cases the difference between the chronic doses determined from animal studies by the T25 method differed from those determined from epidemiological studies by a factor of less than three. Although a limited number of carcinogens were studied, the results demonstrate a very good agreement between the hazard characterisation based on epidemiological data and animal experiments over a range of more than 104.
Screening of Antioxidants from Medicinal Plants for Cardioprotective Effect against Doxorubicin Toxicity
Authors: Wattanapitayakul Suvara K. , Chularojmontri Linda , Herunsalee Angkana , Charuchongkolwongse Suphan , Niumsakul Somchit , Bauer John A.
Published: January 2005

Abstract: Doxorubicin is an important and effective anticancer drug widely used for the treatment of various types of cancer but its clinical use is limited by dose‐dependent cardiotoxicity. Elevated tissue levels of cellular superoxide anion/oxidative stress are a mechanism by which doxorubicin‐induced cardiotoxicity. Selected medicinal plant extracts were tested for their antioxidant capacity and cardioprotective effect against doxorubicin‐induced cardiotoxicity. The cardiac myoblasts H9c2 were incubated with the antioxidants ascorbic acid, trolox, N‐acetylcysteine or selected medicinal plant extracts including; 1) ethanolic extracts from Curcuma longa L‐EtOH Phyllanthus emblica L‐EtOH, and Piper rostratum Roxb‐EtOH; and 2) water extracts from Curcuma longa L‐H2O and Morus alba L‐H2O. The cardioprotective effects of these extracts were evaluated by crystal violet cytotoxicity assay. IC50s of doxorubicin were compared in the presence or absence of ascorbic acids, trolox, N‐acetylcysteine or plant extracts. Morus alba L‐H2O showed the highest antioxidant properties evaluated by ferric reducing/antioxidant power assay. Ascorbic acid and N‐acetylcysteine had modest effects on the protection of doxorubicin‐induced cytotoxicity while trolox showed insignificant protective effect. All plant extracts protected cardiac toxicity at different degrees except that Curcuma longa L‐EtOH had no protective effect. Phyllanthus emblica‐EtOH (100 μg/ml) showed the highest cardioprotective effect (∼12‐fold doxorubicin IC50 increase). The data demonstrate that antioxidants from natural sources may be useful in the protection of cardiotoxicity in patients who receive doxorubicin.
Application of the Conservation Element and Solution Element Method in Numerical Modeling of Three-Dimensional Heat Conduction With Melting and/or Freezing
Authors: Ayasoufi Anahita , Keith Theo G. , Rahmani Ramin K.
Published: January 2005

The conservation element and solution element (CE/SE) method, an accurate and efficient explicit numerical method for resolving moving discontinuities in fluid mechanics problems, is used to solve three-dimensional phase-change problems. Several isothermal phase-change cases are studied and comparisons are made to existing analytical solutions. The CE/SE method is found to be accurate, robust, and efficient for the numerical modeling of phase-change problems.
Film Condensation of Saturated Vapor Over Horizontal Noncircular Tubes With Progressively Increasing Radius of Curvature Drawn in the Direction of Gravity
Authors: Dutta Arijit , Som S. K. , Das P. K.
Published: January 2005

A theoretical study has been made to determine the heat transfer coefficient in film condensation of slowly downward flowing saturated vapor over horizontal noncircular tubes with progressively increasing radius of curvature drawn in the direction of gravity. The noncircular tube profile considered for the present work, is an equiangular spiral described by a curve in polar coordinate as Rp=aemθ (a and m being parametric constants). Nusselt number in case of noncircular tube has been determined on the basis of an equivalent diameter of a circular tube that equals the surface area of the noncircular tube with that of the circular one. It has been recognized that both the local Nusselt number Nuθ and average Nusselt number Nu¯ become a function of m, Ra/Ja1/4 and Nσ=σ/ρ−ρgR2. An enhancement in heat transfer coefficient has been observed in case of a noncircular tube over that of a circular tube of same surface area because of the combined effect of gravity force component and surface tension driven favourable pressure gradient in the direction of flow of the liquid film. The relative weightage of both the components in the enhancement of heat transfer has been reported. An estimation of pressure drop of cooling liquid flowing through the circular and noncircular tubes of same surface area has been made to compare the values against the enhancement in heat transfer rate.
Effect of Boundary Wall Conditions on Heat Transfer for Fully Opened Tilted Cavity
Authors: Chakroun Walid
Published: January 2005

An experimental investigation was performed to study the effect of wall conditions as well as the tilt angle on heat transfer for fully opened tilted cavity. The cavity has a rectangular shape with a square cross section. One side is fully opened to the ambient, permitting air to flow inside the cavity by virtue of buoyancy. The cavity was selected to be long enough to simulate two-dimensional natural convection. Seven cases with different wall configurations were examined: (a) three of which with only one wall heated and the other two were insulated, (b) three of which with two walls heated and the other one was insulated, and (c) a case with all walls were heated. The heated walls were maintained at constant heat flux, which correspond to a constant Grashof number of 1.3×108. In each case, the cavity was rotated over a range of ±90 deg (measured from the vertical direction) in 15 deg increments. It was concluded that tilt angle, wall configuration, and the number of heated walls are all factors that strongly affect the convective heat transfer coefficient between the cavity and the ambient air. Empirical correlations were provided to predict the average Nusselt number at different inclination angles for all seven cases. It was found that the correlations could predict the result to within 4 to 10 percent, depending on the inclination angle and the case considered.
Optimal Design for PPF Heat Sinks in Electronics Cooling Applications
Authors: Chen Han-Ting , Horng Jenn-Tsong , Chen Po-Li , Hung Ying-Huei
Published: January 2005

An effective method for predicting and optimizing the thermal performance of heat sinks with Parallel-Plain Fin under a given design constraint of pressure drop has been successfully developed in the study. The thermal and hydrodynamic performance analyzers for PPF heat sinks have been developed. A screening experimental design using the Taguchi method is performed to determine key factors that are critical to the design and screen out unimportant design factors; and a Response Surface Methodology is then applied to establish analytical models for the thermal resistance and pressure drop in terms of the key design factors with a CCD experimental design. By employing the Sequential Quadratic Programming technique, a series of constrained optimal designs can be efficiently performed. Comparisons between these predicted optimal designs and those evaluated by the theoretical calculations are made with satisfactory agreement.
Chimney Effect on Natural Air Cooling of Electronic Equipment Under Inclination
Authors: Kitamura Yoji , Ishizuka Masaru
Published: January 2005

With the rapid increase of the power dissipation density in modern electronic equipment, the cooling design of electronic equipment becomes increasingly important. For widely used forced-convection air-cooled systems, the reliability of and the acoustic noise of the fan present serious concerns as the air velocity is increased to enhance the cooling capacity. Thus, the interest in natural-convection air cooling is growing to take advantage of low noise and energy savings inherent in that cooling mode. One method of promoting the capacity of natural air cooling is to incline the electronics casing, thereby, induce draft air by what is called the chimney effect. However, the effect of inclination on thermal behavior and cooling capacity has not yet been fully understood due to the involvement of many parameters in driving the draft air. This paper presents the results of experimental and numerical studies on the effect of casing inclination on the temperature rise across the casing. The numerical simulation was implemented to find out the thermal behavior inside a thin electronic casing. The simulation results are in good agreement with the experiment data. A thermal design guide is obtained regarding how the cooling effect is improved by increasing the inclination angle.
Thermal Performance Optimization of Radio Frequency Packages for Wireless Communication
Authors: Chiriac Victor Adrian , Lee Tien-Yu Tom , Hause Vern
Published: January 2005

The increasing trend in power levels and associated densities leads to the need of design thermal optimization, either at the module level or at the system (module-board stack-up) level. The wireless communication industry is facing multiple challenges as it tries to promote smaller, faster and cost-effective packages, yet trying to cope with potential thermal bottlenecks. The present study investigates a family of packages, whose thermal and electrical performances are far superior to the classic (standard) packages. A three-dimensional conjugate numerical study was conducted to evaluate the thermal performance of gallium arsenic die packaged in quad flat no-lead (QFN) packages for various wireless and networking applications. Two different QFN packages are investigated: a standard package and a power package (PQFN) with thicker leadframe and solder die attach. The thermal impact of die attach material, leadframe thickness, die pad size, and board structure is evaluated and provides valuable information for product designers. Two powering scenarios are investigated: (1) one for standard operating parameters and (2) an alternative for extreme operating powering scenarios. Results indicate that the peak temperature reached on the die for 3×3 mm QFN under normal powering conditions is ∼138.5 °C (or 119 °C/W junction-to-air thermal resistance), while for the extreme scenario, the junction temperature is ∼186 °C (or 125 °C/W junction-to-air thermal resistance). In both cases, the top Au metal layer has a limited impact on lateral heat spreading. Under extreme powering conditions, the 5×5 mm PQFN package reaches a peak temperature of ∼126 °C (66 °C/W thermal resistance). A ∼32% reduction in peak temperature is achieved with the 5×5 PQFN package. The improvement is mainly due to the larger package size, high conductivity die attach material, thicker leadframe, and additional board thermal vias. A parametric study shows that the increase in leadframe thickness from 0.2 mm (8 mils) to 0.5 mm (20 mils) in the QFN package will lead to only 3% reduction in peak temperature. By comparison, for both packages, the die attach material (conductive epoxy versus solder) will have a significant impact on the overall reduction in peak temperature (∼12%). Experimental measurements using an infrared microscope are performed to validate the numerical results. The results indicate good agreement (∼6% discrepancy) between the numerical model and the measurement.
Determination of Temperatures and Heat Fluxes on Surfaces and Interfaces of Multidomain Three-Dimensional Electronic Components
Authors: Dennis Brian H. , Han Zhen-xue , Dulikravich George S.
Published: January 2005

A finite element method (FEM) formulation for the prediction of unknown steady boundary conditions in heat conduction for multidomain three-dimensional (3D) solid objects is presented. The FEM formulation is capable of determining temperatures and heat fluxes on the boundaries where such quantities are unknown, provided such quantities are sufficiently overspecified on other boundaries. An inverse finite element program has been previously developed and successfully tested on 3D simple geometries. The finite element code uses an efficient sparse matrix storage scheme that allows treatment of realistic 3D problems on personal computer. The finite element formulation also allows for very straightforward treatment of geometries composed of many different materials. The inverse FEM formulation was applied to the prediction of die-junction temperature distribution in a simple ball grid array electronic package. Examples are presented with simulated measurements, which include random measurement errors. Regularization was applied to control numerical error when large measurement errors were added to the overspecified boundary conditions.
Dynamic Reduced Electrothermal Model for Integrated Power Electronics Modules (IPEM)
Authors: Herna´ndez-Mora M. , Gonza´lez J. E. , Ve´lez-Reyes M. , Ortiz-Rodrı´guez J. M. , Pang Y. , Scott E.
Published: January 2005

Background: This paper presents a reduced mathematical model using a practical numerical formulation of the thermal behavior of an integrated power electronics module (IPEM). This model is based on the expanded lumped thermal capacitance method (LTCM), in which the number of variables involved in the analysis of heat transfer is reduced only to time. Method of Approach: By applying the LTCM, a simple, nonspatial, but highly nonlinear model is obtained for the case of the IPEM Generation II. Steady and transient results of the model are validated against results from a three-dimensional, transient thermal analysis software tool, FLOTHERM™ 3.1. The electrothermal coupling was obtained by implementing the reduced-order thermal model into the SABER™ circuit simulator. Two experimental setups, for low- and high-speed thermal responses, were developed and used to calibrate the reduced model with actual data. Results: The comparison of the LTCM model implemented in a Generation II IPEM with FLOTHERM 3.1 results compared very favorably in terms of accuracy and efficiency, reducing the computational time significantly. Additional validations of the reduced thermal model were made using experiment data for the low-speed thermal response at different constant powers, and good agreement was demonstrated in all cases. A comparison between SABER™ simulations, which incorporated the proposed LTCM, and the fast thermal experimental response results is also presented to validate the dynamic electrothermal model response, and excellent agreement was found for this case. Conclusions: The good agreement found for all three cases presented, the three-dimensional, transient numerical formulation, and the low- and high-speed experimental data indicates that reduced electrothermal models are an excellent alterative for design methodologies of new generations of IPEMs.
Methodology for an Integrated (Electrical/Mechanical) Design of PWBA
Authors: Ahn Wonkee , Agonafer Dereje , Novotny Shlomo
Published: January 2005

This paper describes a general methodology of how electrical circuit design data are mapped into an intermediate analyzable representation that supports the information requirement of several thermomechanical analyses, including product optimization/idealization. This paper describes other issues encountered, such as how to integrate product data that spans more than one tool, how to modify and add analysis data necessary during analysis, and how to use data stored in the analysis module from different programing environments. The advantage this process offers is also described by considering a PWBA (Printed Wiring Board Assembly) design, such as layout and layup in an electrical design system.
An Analytical Study of the Optimized Performance of an Impingement Heat Sink
Authors: Sathe S. B. , Sammakia B. G.
Published: January 2005

The results of a study of a new and unique high-performance air-cooled impingement heat sink are presented. An extensive numerical investigation of the heat sink performance is conducted and is verified by experimental data. The study is relevant to cooling of high-power chips and modules in air-cooled environments and applies to workstations or mainframes. In the study, a rectangular jet impinges on a set of parallel fins and then turns into cross flow. The effects of the fin thickness, gap nozzle width and fin shape on the heat transfer and pressure drop are investigated. It is found that pressure drop is reduced by cutting the fins in the central impingement zone without sacrificing the heat transfer due to a reduction in the extent of the stagnant zone. A combination of fin thicknesses of the order of 0.5 mm and channel gaps of 0.8 mm with appropriate central cutout yielded heat transfer coefficients over 1500 W/m2 K at a pressure drop of less than 100 N/m2, as is typically available in high-end workstations. A detailed study of flow-through heat sinks subject to the same constraints as the impingement heat sink showed that the flow-through heat sink could not achieve the high heat transfer coefficients at a low pressure drop.
Experimental and Numerical Thermal Transient Behavior of Chips in a Liquid Channel During Loss of Pumping Power
Authors: Tso C. P. , Tou K. W. , Bhowmik H.
Published: January 2005

Both transient and steady-state experiments are performed to study the single-phase heat transfer characteristics on an array of four in-line, flush-mounted simulated chips in a vertical rectangular channel. Water is the coolant media, and the flow covers the wide range of laminar regimes with the Reynolds number, based on heat source length, from 800 to 2625. The effect of heat fluxes, coolant flow rates, and geometric parameters (such as chip configuration number) are investigated. The operation is extended to study the transient natural convection during an accidental stoppage of coolant flow due to loss of pumping power. Results compare favorably with those obtained from three-dimensional numerical calculations. The transient correlation recommended is Nul=0.3Fo−0.2Ral*1/4.