bluuebunny/crossref_metadata_2025_split huggingface dataset:
Issues and Challenges of Chemical Mechanical Polishing for Nano-scale Memory Manufacturing
Authors: Ryu Choon Kun , Shin Jonghan , Park Hyungsoon , Kwak Nohjung , Hong Kwon , Park Sungki 
Published: March 2010

AbstractAs the design rule of memory devices is scaled down to nanoscale, the number of the CMP process has increased considerably due to the complexity of integration scheme. The CMP for isolation has increased significantly because the isolation process of metal contact plugs and damascene metallization at nanoscale has been successfully enabled by the CMP. The CMP selectivity, which depends strongly on the chemistry of the slurry, must be tuned for the various new materials. Recently, in order to get over the limitation in lateral shrinkage of the memory device, several emerging applications have been investigated extensively. A vertical integration needs the new CMP process such as high removal rate Cu CMP. Next generation memories need the CMP process for new materials such as GeSbTe, conductive oxide, and magnetic materials. Since any nano-size scratch will be a killer defect at the nanoscale memory, both the CMP equipment and the consumables must be maintained with tighter degree of control specifications.
Role of Phosphoric Acid in Copper Electrochemical Mechanical Planarization Slurries
Authors: Aksu Serdar 
Published: March 2010

AbstractIn this paper, the electrochemical behavior of copper in aqueous solutions containing phosphoric acid (H3PO4) is investigated to elucidate the role of H3PO4 in the Cu ECMP slurries. Aqueous solubility and potential-pH diagrams were constructed for copper-phosphate-water system. Good correlations were found between the diagrams and the experimental polarization data. It was found that H3PO4 might not able to sufficiently increase the solubility of copper alone. A complexing agent is needed to ensure the high solubility of copper, especially as the slurry pH and dissolved copper concentration increase. Specific conductance measurements revealed that phosphoric acid was the key constituent responsible for increasing the conductivity of the ECMP electrolyte. In situ electrochemical polarization experiments showed that the planarization mechanism during the ECMP process was similar to that observed in conventional copper CMP.
CMP for High Mobility Strained Si/Ge Channels
Authors: Sawano Kentarou , Shiraki Yasuhiro , Nakagawa Kiyokazu 
Published: March 2010

AbstractSi/Ge heterostructures are one of the most promising performance boosters for next generation CMOS circuits. Lattice mismatch between Si and Ge enables us to manipulate lattice strain, that is, strain engineering is possible. The strain highly alters band structures and gives rise to band splitting and/or effective mass reduction, which brings significant mobility enhancement of the carriers in the strained channel.High mobility channels such as strained-Si and strained-Ge can be formed on strain-relaxed SiGe buffer layers called SiGe virtual substrates (VS). Since the property of the SiGe VS directly affects that of the overgrown channel layer, creating high-quality SiGe VS is highly required to obtain high performance devices. One critical problem is a very large surface roughness arising on the SiGe VS. So-called crosshatch pattern appears on the surface, irrespective of growth methods. Since strain field coming from the underlying misfit dislocation arrays is responsible for this roughness formation, it is very difficult to create a roughness-free surface.To overcome this problem, we employed chemical mechanical planarization (CMP) for the purpose of eliminating the roughness. Since CMP is established technology for Si wafer production, it is reasonably applicable to SiGe. Adopting the similar process as Si CMP, we demonstrated that an initial roughness of larger than 10 nm was reduced considerably down to less than 1 nm.Post-CMP cleaning is an additional issue of great importance for regrowth of device channel structures. We found that the roughness increased during post-CMP cleaning process due to laterally nonuniform etching rate of the SiGe surface. To overcome this, we optimized the cleaning procedure, especially cleaning solution, and successfully obtained very smooth surface with RMS roughness of less than 0.4 nm, the lowest value ever obtained for SiGe surfaces.The planarized SiGe VS was applied to strained channel structures. Strained Si modulation doped structure was fabricated on the planarized SiGe VS with a Ge concentration of 30 %. The electron Hall mobility obtained from the structure with CMP was 4 times higher than the reference structure without CMP, which is a clear evidence that the roughness-related carrier scattering can be well suppressed by the planarization. Strained Ge channel modulation doped structure was also fabricated on the SiGe VS with much higher Ge concentration (65 %). Although the roughness was much larger than 10 nm due to the high Ge concentration, the surface smoothness less than 1 nm was obtained by CMP. As a result, hole mobility enhancement factor over the reference sample without CMP was found to reach as high as 8 at low temperature and 1.8 at room temperature. These results clearly indicate that CMP is very promising technology for high performance strained Si/Ge based CMOS circuit.
Implant Bone Rings. One-Stage Three-Dimensional Bone Transplant Technique: A Case Report
Authors: Stevens Mark R. , Emam Hany A. , Alaily Mahmoud E. L. , Sharawy Mohamed 
Published: March 2010

Abstract
A variety of techniques and materials has been used to provide the structural base of bone and soft tissue support for dental implants. Alveolar bone augmentation techniques include different surgical approaches such as guided bone regeneration, onlay grafting, interpositional grafting, distraction osteogenesis, ridge splitting, and socket preservation. In the case presented, a technique was used to augment the alveolar bone three-dimensionally with autologous “bone rings” and immediate implant placement in a 1-stage procedure following teeth extraction. Bone rings (circular osteotomies) were outlined at the symphysis area using trephine burs, and a central osteotomy for implant placement was done before its removal. The rings were then removed and sculptured to fit the extraction socket; this was followed by screwing the implant through the ring, gaining its primary stability from the prepared basal bone.
Interim Endodontic Therapy for Alveolar Socket Bone Regeneration of Infected Hopeless Teeth Prior to Implant Therapy
Authors: Rass Marwan Abou 
Published: March 2010

AbstractThe immediate placement of implants in the fresh extraction sockets of infected teeth with periradicular and periapical lesions is contraindicated because of both the infection and the loss of architecture required for proper implant placement. There are 4 approaches for implant replacement of a hopeless tooth with lesions: (1) extraction and delayed implant placement; (2) extraction, debridement, guided bone regeneration (GBR), guided tissue regeneration (GTR), and delayed implant placement; (3) extraction, intrasocket debridement, and immediate implant placement; or (4) extraction, debridement, GBR, GTR, and simultaneous implant placement. The extraction of such hopeless teeth often results in large bone and soft tissue defects that are difficult to repair. This article introduces an alternative approach: interim endodontic implant site preparation, defined as a transitional, surgical, or nonsurgical endodontic treatment to regenerate the hopeless tooth bone defects and prepare the site for proper implant placement. This article describes 3 distinct interim endodontic protocols used to manage 5 patients, all of whom had severely infected hopeless teeth with large lesions and were treatment planned for implant replacement: the first, interim nonsurgical endodontic treatment to restore the normal anatomy of the infected hopeless tooth; the second, interim surgical endodontics on the hopeless tooth with preexisting endodontic treatment to regenerate apical bone for primary implant stability, thus avoiding the involvement of the maxillary sinus and other critical anatomic structures; and the third, interim surgical endodontics on the hopeless tooth with preexisting endodontic treatment to confine the size of the osseous defect and simplify the GBR and GTR procedures. The outcome of interim endodontic treatment on these 5 patients demonstrated that tooth extraction would have been a less predictable approach. The interim treatment changed the overall direction of the patients' dental care. When treated, these hopeless teeth served many preventive, biologic, and esthetic functions. The infections of the alveolar sockets were eliminated, the alveolar bone defects were repaired through normal bone regeneration, and sockets anatomies were maintained or restored. Furthermore, the patients were spared maxillary sinus surgery and the possible complications resulting from major GBR and GTR procedures. In summary, the interim treatment facilitated tooth extraction and immediate implant placement.
Histologic Analysis of the Oral Mucosa Lining Osseointegrated Implant Cover Screws: A Study in Humans
Authors: Nahas André Alan , Dechichi Paula , de Magalhães Denildo , Vieira Andreia Espíndola 
Published: March 2010

Abstract
Osseointegrated dental implants are inserted into the alveolar ridge, and for them to function as tooth replacements, the surrounding tissues need to adapt to them. Just as with teeth, dental implants traverse the oral mucosa and have access to the contaminated environment of the oral cavity. Therefore, periodontal and peri-implant tissues are important for establishing a protective barrier. The aim of the present study was to perform a histologic analysis of the mucosa surrounding osseointegrated implant cover screws. For this study, 17 mucosal specimens were obtained from 12 patients during the second surgical session for implant exposure to the oral environment. After histologic preparation, specimens were sectioned perpendicularly to the mucosal surface to a thickness of about 3 µm, stained with 1% toluidine blue, and examined under light microscopy. All specimens showed a keratinized, stratified, squamous epithelium with well-defined strata. In the lamina propria, unorganized dense connective tissue was noted in the reticular layer, and in 4 samples, a chronic inflammatory infiltrate was seen in this region. The papillary layer presented tall connective papillae consisting of loose connective tissue. The results of this study confirm the hypothesis that the mucosa that conceals osseointegrated implant cover screws has the same morphologic characteristics as the alveolar masticatory mucosa. Furthermore, clinical conditions of normality in peri-implant tissues may not coincide with situations of histologic normality.
Use of Ultrasound in the Management of Thyroid Cancer
Authors: Lew John I. , Solorzano Carmen C. 
Published: March 2010

AbstractThe use of ultrasound for thyroid cancer has evolved dramatically over the last few decades. Since the late 1960s, ultrasound has become essential in the examination of the thyroid gland with the increased availability of high-frequency linear array transducers and computer-enhanced imaging capabilities of modern day portable ultrasound equipment in a clinic- or office-based setting. As a noninvasive, rapid, and easily reproducible imaging study, ultrasound has been demonstrated to have a broadened utility beyond the simple confirmation of thyroid nodules and their sizes. Recently, office-based ultrasound has become an integral part of clinical practice, where it has demonstrated overwhelming benefits to patients being evaluated and treated for thyroid cancer. Ultrasound has become useful in the qualitative characterization of thyroid nodules based on benign or malignant features. On the basis of such classifications and the relative risk for thyroid malignancy, the need for ultrasound-guided fine-needle aspiration, preoperative and intraoperative staging, lymph node mapping, and the extent of surgery can subsequently be determined. Furthermore, ultrasound has additional value in the surveillance of patients treated for thyroid cancer.
Effects of Menstrual Cycle on Periodontal Health and Gingival Crevicular Fluid Markers
Authors: Becerik Sema , Özçaka Özgün , Nalbantsoy Ayşe , Atilla Gül , Celec Peter , Behuliak Michal , Emingil Gülnur 
Published: March 2010

Background: Fluctuations in sex steroid hormones, which are also noticeable through the menstrual cycle of women, may impact periodontal health. The aim of this study is to evaluate the effect of hormonal changes occurring in the menstrual cycle on gingival inflammation and the gingival crevicular fluid (GCF) levels of interleukin 6 (IL‐6), prostaglandin E2 (PGE2), tissue plasminogen activator (t‐PA), and plasminogen activator inhibitor‐2 (PAI‐2).Methods: Twenty‐five gingivitis patients and 25 periodontally healthy subjects having regular menstrual cycles were seen at menstruation (ME) (1 to 2 days of menstruation), ovulation (OV) (12 to 14 days), and premenstrual phases (PM) (22 to 24 days). GCF and saliva samples were collected and clinical parameters including plaque index and bleeding on probing were recorded at each menstrual phase. Salivary estrogen and progesterone levels were analyzed to determine exact menstrual cycle days. GCF levels of IL‐6, PGE2, t‐PA, and PAI‐2 were measured by enzyme‐linked immunosorbent assay.Results: The percentages of sites with bleeding on probing were significantly higher in ME (60.85 ± 18.36) and OV (58.92 ± 25.04) than in the PM (40.12 ± 20.10) phase in the gingivitis group (P <0.001; repeated measures analysis of variance), whereas it was similar for all phases in the healthy group (P >0.05; repeated measures analysis of variance). GCF levels of IL‐6 were significantly elevated in gingivitis patients compared to healthy subjects in all phases (P = 0.004, P = 0.041, and P = 0.046 for ME, OV, and PM, respectively; Mann‐Whitney U test). GCF levels of IL‐6, PGE2, t‐PA, and PAI‐2 were unchanged in different menstrual phases in both groups (P >0.05; Friedman test).Conclusion: The present study suggests that changes in the sex steroid hormones during menstrual cycles might have a limited effect on the inflammatory status of gingiva, but GCF cytokine levels were not affected.
Changing Patterns in Health Behaviors and Risk Factors Related to Cardiovascular Disease Among American Indians and Alaska Natives
Authors: Jernigan Valarie Blue Bird , Duran Bonnie , Ahn David , Winkleby Marilyn 
Published: March 2010

Objectives. We assessed changes in cardiovascular disease–related health outcomes and risk factors among American Indians and Alaska Natives by age and gender. Methods. We used cross-sectional data from the 1995 to 1996 and the 2005 to 2006 Behavioral Risk Factor Surveillance System. The respondents were 2548 American Indian and Alaska Native women and men aged 18 years or older in 1995–1996 and 11 104 women and men in 2005–2006. We analyzed the prevalence of type 2 diabetes, obesity, hypertension, cigarette smoking, sedentary behavior, and low vegetable or fruit intake. Results. From 1995–1996 to 2005–2006, the adjusted prevalence of diabetes among American Indians and Alaska Natives increased by 26.9%, from 6.7% to 8.5%, and obesity increased by 25.3%, from 24.9% to 31.2%. Hypertension increased by 5%, from 28.1% to 29.5%. Multiple logistic models showed no meaningful changes in smoking, sedentary behavior, or intake of fruits or vegetables. In 2005–2006, 79% of the population had 1 or more of the 6 risk factors, and 46% had 2 or more. Conclusions. Diabetes, obesity, and hypertension and their associated risk factors should be studied further among urban, rural, and reservation American Indian and Alaska Native populations, and effective primary and secondary prevention efforts are critical.
The effect of co-existing solutes on arsenate removal with hydrotalcite compound
Authors: Kiso Y. , Jung Y. J. , Yamamoto H. , Oguchi T. , Kuzawa K. , Yamada T. , Kim S. S. , Ahn K. H. 
Published: March 2010

Hydrotalcite (HTAL-Cl), an inorganic anion exchanger, is of use as an adsorbent for the removal of arsenate (As(V)) in water systems. The adsorption properties of HTAL-Cl for As(V) and the effects of co-existing anions on the As(V) removal performance were investigated in this work. Under the conditions of pH≥4, the adsorption capacity for As(V) gradually decreased with an increase of pH, but As(V) was removed effectively within the range of pH = 5–8. Co-existing anions interfered As(V) removal, and the effect decreased in the order of HPO42− &gt; HCO3− &gt; SO42− &gt; Cl−. In binary solute systems containing phosphate and As(V), the maximum adsorption capacity of HTAL-Cl was 0.95 mmol g−1 for phosphate and 0.65 mmol g−1 for As(V): the total of these values corresponded to the maximum adsorption capacity for As(V) in single solute systems. The adsorption isotherms in these binary solute systems were approximated by the following modified Langmuir equations:
As(V): qAs=18.7√CAs/1 + 21.5√CP + 12.8√CAs, phosphate : qP = 33.1√CP/ 1+ 21.5√CP+ 12.8√CAs
The column adsorption experiments showed that the adsorbed As(V) was released by the phosphate adsorption, because phosphate was adsorbed more strongly on HTAL-CL than As(V).
An assessment of oxygen transfer efficiency in a gas permeable hollow fibre membrane biological reactor
Authors: Soreanu G. , Lishman L. , Dunlop S. , Behmann H. , Seto P. 
Published: March 2010

The clean water oxygen transfer efficiency (OTE) of a full scale non-porous hollow fibre gas permeable (GP) membrane (surface area of 500 m2) was evaluated at inlet air pressures of 1.2, 1.4, and 1.8 atm using two established testing methods. To form a basis of comparison with traditional aeration technologies, additional testing was done with conventional aerators (fine bubble and coarse bubble diffusers) replacing the GP membrane. OTE can be established based on the re-aeration of deoxygenated water or by monitoring the catalytic oxidation of a sodium sulphite (Na2SO3) solution. In this study, OTE values determined by sulphite oxidation (SOTES) were consistently higher than those established during re-aeration (SOTER) suggesting that the chemical reaction was enhancing the mass transfer. The chemical reaction was sufficiently fast in the case of the GP membrane, that the gas phase limited the mass transfer. The GP membrane operating at 1.2 atm had a SOTES of 70.6% and a SOTER of 52.2%.
SOTER for the coarse bubble and fine bubble diffusers were 3.8% and 23.6%, respectively. This is comparable to the manufacturer's values, corrected for depth of 3.4% and 18.3%, respectively. Particularly, the derived OTE values were used to evaluate differences in energy consumption for a conventional treatment plant achieving carbon removal and nitrification. This analysis highlights the potential energy efficiency of GP membranes, which could be considered for the design of the membrane modules.
Effect of Endogenous GLP-1 on Insulin Secretion in Type 2 Diabetes
Authors: Salehi Marzieh , Aulinger Benedict , Prigeon Ronald L. , D'Alessio David A. 
Published: March 2010

OBJECTIVE
The incretins glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) account for up to 60% of postprandial insulin release in healthy people. Previous studies showed a reduced incretin effect in patients with type 2 diabetes but a robust response to exogenous GLP-1. The primary goal of this study was to determine whether endogenous GLP-1 regulates insulin secretion in type 2 diabetes.

METHODS
Twelve patients with well-controlled type 2 diabetes and eight matched nondiabetic subjects consumed a breakfast meal containing d-xylose during fixed hyperglycemia at 5 mmol/l above fasting levels. Studies were repeated, once with infusion of the GLP-1 receptor antagonist, exendin-(9–39) (Ex-9), and once with saline.

RESULTS
The relative increase in insulin secretion after meal ingestion was comparable in diabetic and nondiabetic groups (44 ± 4% vs. 47 ± 7%). Blocking the action of GLP-1 suppressed postprandial insulin secretion similarly in the diabetic and nondiabetic subjects (25 ± 4% vs. 27 ± 8%). However, Ex-9 also reduced the insulin response to intravenous glucose (25 ± 5% vs. 26 ± 7%; diabetic vs. nondiabetic subjects), when plasma GLP-1 levels were undetectable. The appearance of postprandial ingested d-xylose in the blood was not affected by Ex-9.

CONCLUSIONS
These findings indicate that in patients with well-controlled diabetes, the relative effects of enteral stimuli and endogenous GLP-1 to enhance insulin release are retained and comparable with those in nondiabetic subjects. Surprisingly, GLP-1 receptor signaling promotes glucose-stimulated insulin secretion independent of the mode of glucose entry. Based on rates of d-xylose absorption, GLP-1 receptor blockade did not affect gastric emptying of a solid meal.
Novel Assay of Metformin Levels in Patients With Type 2 Diabetes and Varying Levels of Renal Function
Authors: Frid Anders , Sterner Gunnar N. , Löndahl Magnus , Wiklander Clara , Cato Anne , Vinge Ellen , Andersson Anders 
Published: March 2010

OBJECTIVE
To study trough levels of metformin in serum and its intra-individual variation in patients using a newly developed assay.

RESEARCH DESIGN AND METHODS
Trough serum levels of metformin were measured once using liquid chromatography–tandem mass spectrometry (LCMSMS) in 137 type 2 diabetic patients with varying renal function (99 men) and followed repeatedly during 2 months in 20 patients (16 men) with estimated glomerular filtration rate (eGFR) &lt;60 ml/min/1.73 m2 body surface.

RESULTS
Patients with eGFR &gt;60, 30–60, and &lt;30 ml/min/1.73 m2 had median trough metformin concentrations of 4.5 μmol/l (range 0.1–20.7, n = 107), 7.71 μmol/l (0.12–15.15, n = 21), and 8.88 μmol/l (5.99–18.60, n = 9), respectively. The median intra-individual overall coefficient of variation was 29.4% (range 9.8–74.2).

CONCLUSIONS
Determination of serum metformin with the LCMSMS technique is useful in patients on metformin treatment. Few patients had values &gt;20 μmol/l. Metformin measurement is less suitable for dose titration.