bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of Gastric Cancer Cell Adhesion in Nude Mice by Inraperitoneal Phospholipids
Authors: Jansen Marc , Treutner Karl‐Heinz , Jansen Petra Lynen , Zuber Sebastian , Otto Jens , Tietze Lothar , Schumpelick Volker
Published: May 2005

Adhesion of tumor cells to mesothelial cells or extracellular matrix components is a pivotal step in developing peritoneal dissemination after gastric cancer. As phospholipids were found to reduce adhesion formation, especially at sites of peritoneal lesions, we assessed the inhibition of attachment of NUGC‐4 gastric cancer cells by local treatment with phospholipids to the peritoneum in nude mice. Gastric cancer cells (1×l06) suspended in either normal saline (controls) or phospholipid suspension 75 mg/kg body weight (PL75) or 150 mg/kg (PL150) were injected intraperitoneally into 90 female BALB/c nu/nu mice. The treatment groups were subdivided into animals with defined peritoneal lesions and animals without lesions. After 30 days the extent of peritoneal carcinosis and the Peritoneal Cancer Index were evaluated. Statistical analysis was performed with two factorial ANOVAs. The level of significance was adjusted according to Bonferrorni (α = 0.00278). During a 90‐day observation period the survival rate was determined using the log rank test.

After 30 days the intraperitoneal tumor volume was reduced by PL150 up to 0.6 ml (SEM 0.16) and 0.48 ml (SEM 0.09) in mice with peritoneal lesions compared to 0.9 ml (SEM 0.2) and 0.9 ml (SEM 0.1) in the control group (P = 0.04). The mean area of tumor adhesion amounted to 145 mm2 (SEM 17) (P = 0.08) and 164 mm2 (SEM 32.8) (P = 0.049) with peritoneal lesions after treatment with PL150 [controls: 216 mm2 (SEM 28.5) and 245 mm2 (SEM 29.3)]. The peritoneal cancer index was 16.4 (SEM 1.7) in the control group and 9 (SEM 1.68) with PL150 (P = 0.0002). In the subgroup with peritoneal lesions, the respective values were as follows: controls: 20.8 (SEM 0.85); PL 150:14.3 (SEM 1.07) (P = 0.0001). We found a prolonged survival rate after treatment with PL150. However, this effect was not significantly different to that seen in the control group. Treatment with PL75 had no significant influence. Phospholipids may be an efficacious and economic tool for reducing peritoneal tumor cell adhesion and consequently the development of peritoneal carcinosis after resection of gastric cancer.
Safe and Rapid Laparoscopic Access—a New Approach
Authors: Antevil Jared L. , Bhoyrul Sunil , Brunson Mathew E. , Vierra Mark A. , Swadia Nayan D.
Published: May 2005

Despite numerous recent technical advances in minimally invasive surgical technique, the potential exists for serious morbidity during initial laparoscopic access. Safe access depends on adhering to well‐recognized principles of trocar insertion, knowledge of abdominal anatomy, and recognition of hazards imposed by previous surgery. Applying these principles, we describe a safe, rapid, and cost‐effective technique for laparoscopic access using readily available instruments. This technique emphasizes identification and incision of the point at which the midline abdominal fascia is fused with the base of the umbilicus, and the importance of the application of countertraction directly at the point of insertion. This method allows penetration under direct vision with minimal controlled axial force, and without the requirement for fascial sutures or other cumbersome aspects of the traditional open technique. While previous reports describe techniques for laparoscopic access entry based on similar anatomic and surgical principles, we describe an alternative method not yet discussed in the surgical literature.
Clinical Significance of Occult Metastatic Melanoma in Sentinel Lymph Nodes and Other High‐risk Factors Based on Long‐term Follow‐up
Authors: Leong Stanley P.L. , Kashani‐Sabet Mohammed , Desmond Renee A. , Kim Robert P. , Nguyen Dennis H. , Iwanaga Kensho , Treseler Patrick A. , Allen Robert E. , Morita Eugene T. , Zhang Yuting , Sagebiel Richard W. , Soong Seng‐Jaw
Published: May 2005

Selective sentinel lymphadenectomy (SSL) following preoperative lymphoscintigraphy is the most significant recent advance in the management of patients with primary melanoma. This study evaluates the prognostic value of sentinel lymph node (SLN) status and other risk factors in predicting survival and recurrence in patients with primary cutaneous melanoma. From October 1993 to July 1998 a series of 412 patients with primary invasive melanoma underwent SSL at the UCSF/ Mt. Zion Melanoma Center. The outcome of 363 evaluable patients is summarized in this study. The factors related to survival and disease recurrence were analyzed by Cox proportional hazard regression models. The overall incidence of patients with positive SLNs was 18%. Over a median follow‐up of 4.8 years, the overall mortality rate in patients with primary cutaneous melanoma was 18.7%, and 74 recurrences occurred (20.4%). Mortality was significantly related to SLN status [HR = 2.06; 95% Confidence interval (CI) 1.18, 3.58], angiolymphatic invasion (HR = 2.21; 95% CI 1.08, 4.55), ulceration (HR = 1.79; 95% CI 1.02, 3.15), mitotic index (HR =1.38; 95% CI 1.01, 1.90), and tumor thickness (HR = 2.20, 95% CI 1.21, 3.99). Factors significantly related to disease‐free survival included SLN status (HR = 2.09; 95% CI 1.31, 3.34), tumor thickness (HR = 1.89; 95%. CI 1.20,2.98), and age (HR= 1.26 95% CI 1.08, 1.47). SLN status was the most significant factor for melanoma recurrence and death. Other important predictors include tumor thickness, ulceration, lymphatic invasion, and mitotic index.
ACare: A communication training program for shared decision making along a life-limiting illness
Authors: WEINER JOSEPH S. , COLE STEVEN A.
Published: May 2005

Objective: This article describes an innovative 8-h training program that provides clinicians with the competencies necessary to conduct efficient, effective, and compassionate advance care planning discussions throughout the trajectory of life-limiting illnesses.

Method: The Advance Care Training Program (ACare) includes 6 h of group workshops and 2 h of one-on-one faculty–learner interaction. In this article, we describe the (1) objectives of ACare; (2) structure, training procedures, and educational rationale of ACare training; and (3) educational outcome studies in progress.

Results: ACare training in various forms has already been provided to over 100 medical professionals (medical students, medical residents, oncology and geriatric fellows, medical attendings, social workers, and nurses). Formative outcome data indicate considerable trainee satisfaction. Emerging summative outcome data indicate improved skills.

Significance of results: Widespread adoption of the program could increase the frequency and quality of advance care planning discussions between patients with life-limiting illnesses, their health care providers, and families.
Giving support and getting help: Informal caregivers' experiences with palliative care services
Authors: CAIN ROY , MACLEAN MICHAEL , SELLICK SCOTT
Published: May 2005

Objective: Palliative care services have made significant contributions to those needing end-of-life care, but the effect of these services on informal caregivers is less clear. This article reviews the literature and examines the influences of palliative care services on caregivers of people who are dying of cancer, HIV-related illnesses, and illnesses of later life.

Methods: Based on questions that we developed from the literature review, we conducted six focus groups in Toronto, Thunder Bay, and Ottawa, Canada, with informal caregivers about their experiences with caregiving and with palliative care services.

Results: We outline the major themes relating to the 42 focus group participants' experiences of giving support and getting help.

Significance of results: Our findings help us better understand the common concerns of caregivers of terminally ill seniors, people with HIV/AIDS, and people with cancer. The article discusses the implications of participants' experiences for palliative care service providers.
Clarifying “meaning” in the context of cancer research: A systematic literature review
Authors: LEE VIRGINIA , COHEN S. ROBIN , EDGAR LINDA , LAIZNER ANDREA M. , GAGNON ANITA J.
Published: May 2005

Objectives: This article synthesizes the published literature related to the construct of meaning in the adult cancer population.

Methods: The databases CancerLit, CINAHL, Medline, PsychINFO, and the Journal of Psychosocial Oncology and PsychoOncology were searched to identify all studies related to meaning. The methodological aspects of all studies are described and the conceptual aspects are summarized only from those studies that met criteria for methodological rigor and validity of findings. The definitions forglobal meaning, appraised meaning,search for meaning, andmeaning as outcomeas proposed by Park and Folkman were used to interpret the findings.

Results: Of 44 studies identified, 26 met the criteria for methodological rigor. There is strong empirical and qualitative evidence of a relationship between meaning as an outcome of and psychosocial adjustment to cancer.

Significance of results: The qualitative findings are considered useful for the development of psychosocial interventions aimed at helping cancer patients cope with and even derive positive benefit from their experience. However, variations in the conceptual and operational definitions, frequent reliance on homogeneous and convenience sampling, and the lack of experimental designs are considered to be methodological limitations that need to be addressed to advance the study of meaning in the context of cancer.
Spirituality, meaning, and transcendence
Authors: BRYSON KENNETH A.
Published: May 2005

End-of-life care provides an opportunity to help a patient find meaning in the experience of dying. This is a challenge because the experience of dying can rob a patient of meaning. The first step is to look at death as being a process of life rather than an event. This is brought about by welding the broken pieces of the mind–body connection. Medicine cannot always fix broken pieces, but spiritual welding always puts us back together again. Compassionate end-of-life care helps a patient connect spirituality with the search for meaning and transcendence.
Application of the effective medium approximation for determining water contents through GPR in coarse‐grained soil materials
Authors: Fiori A. , Benedetto A. , Romanelli M.
Published: May 2005

We investigate the relation between the dielectric constant of soils and their volumetric water content to be used in non‐invasive measures of water content, like Ground Penetrating Radar (GPR). After modeling the porous medium as a Multi Indicator structure, we derive the effective permittivity of the soil as function of the water content by adopting the effective medium approximation. The derived formula is tested against controlled, laboratory experiments.
Source fault structure of the 2003 Bam earthquake, southeastern Iran, inferred from the aftershock distribution and its relation to the heavily damaged area: Existence of the Arg‐e‐Bam fault proposed
Authors: Nakamura Takeshi , Suzuki Sadaomi , Sadeghi Hossein , Fatemi Aghda Seyed Mahmoud , Matsushima Takeshi , Ito Yoshihiro , Hosseini Sayyed Keivan , Gandomi Arash Jafar , Maleki Mehdi
Published: May 2005

We investigate the hypocenter distribution of aftershocks of the December 26, 2003 Bam earthquake Mw 6.5 by using a temporal seismic network. The hypocenters distribute linearly over about 20 km in parallel with a line 3.5 km west of the geological Bam fault and extend from the south of Bam city to the heavily damaged area in the eastern part of the city including the historical mud brick citadel “Arg‐e‐Bam”. Based on the hypocenter distribution, we propose a schematic 3‐D structural model of a new fault that we have named the Arg‐e‐Bam fault. We suggest that the Bam earthquake occurred not in the Bam fault but in the Arg‐e‐Bam fault. Bam city is located just above northern part of the Arg‐e‐Bam fault and also on the rupture propagation direction from the asperity. This may be one of the main reasons why eastern part of Bam city suffered the heaviest damage.
Magnetic properties of spin valves with antiferromagnetic CrMnPt deposited at various Ar pressures
Authors: Park Gi Back , Song Jin-Oh , Lee Seong-Rae
Published: May 2005

The dependence of the giant magnetoresistance (MR) ratio and exchange bias field (Hex) on the argon deposition pressure (PAr) of antiferromagnetic CrMnPt film for top spin valves was investigated. The MR ratio was enhanced from 5.0% to 8.3% as the PAr of CrMnPt film increased from 2to15mTorr. Hex also increased from 150to300Oe. These significant enhancements in the magnetic properties were correlated with microstructural changes and body-centered-tetragonal (bct) phase change reaction in the antiferromagnetic film. The bct phase change was promoted at high PAr because of the microstructural defects. The blocking temperature (TB) and the exchange anisotropy energy (Jex) were higher at high PAr owing to the promotion of bct phase change.
Direction control of anisotropy in the soft-magnetic underlayer for L1 Fe–Pt perpendicular media
Authors: Suzuki Toshio
Published: May 2005

Induced anisotropy of soft-magnetic underlayers (SUL) were pinned to radial and circumferential directions in double-layered perpendicular media, and effects of the directions on recording properties were studied for Fe–Pt media. A medium with the SUL of radial anisotropy showed a sharper cross-track profile than that of a medium with the SUL of circumferential anisotropy. Furthermore, signal-to-noise ratio (SNR) of the former was found to be 4dB higher than that of the latter at 500kfrpi. A SUL of radial anisotropy with an anisotropy-dispersion narrower could result in suppressing the fluctuation of write-field gradient and lead to further high SNR.
Magnetoresistive sensors with perpendicular magnetic anisotropy
Authors: Ding Yunfei , Judy Jack H. , Wang Jian-Ping
Published: May 2005

A magnetoresistive (MR) read sensor design for magnetic recording has been proposed in an attempt to solve the magnetization distribution and thermal stability problems of nanometer-scale read sensors. In this design, the free layer has a perpendicular-to-plane easy axis and the reference layer has an in-plane easy axis. The giant-magnetoresistive film with this structure is demonstrated in which the free layer is a [CoFe∕Pt]n multilayer. The structure of the [CoFe∕Pt]n multilayer has to be optimized so that the magnetic properties of the free layer can meet the requirements of a MR read head.
Determination and reduction of ion-beam etching induced magnetic dead layer
Authors: Si Weimin , Williams Kurt , Campo Mark , Mao Ming , Devasahayam Adrian , Lee Chih-Ling
Published: May 2005

NiFe films with different thicknesses as were etched under several Ar+-ion-beam energy conditions. The functional dependence of the saturation magnetic flux on the remaining NiFe film thickness was used to determine the magnetic dead layer (MDL) thickness (tMDL). A tMDL of 24Å was generated in the NiFe films etched using a 1200-eV Ar+-ion beam. A dual-energy (1200eV∕400eV) etching process was found to be effective in reducing tMDL to 16Å without much throughput loss. A combination of optimal etching depth with an appropriate ion-beam energy is necessary in minimizing tMDL. The mechanism of MDL formation is discussed in terms of oxidation and surface roughening of the NiFe films.
Magnetoresistive random access memory operation error by thermally activated reversal (invited)
Authors: Yamamoto Tetsuya , Kano Hiroshi , Higo Yutaka , Ohba Kazuhiro , Mizuguchi Tetsuya , Hosomi Masanori , Bessho Kazuhiro , Hashimoto Minoru , Ohmori Hiroyuki , Sone Takeyuki , Endo Keitaro , Kubo Shinya , Narisawa Hiroaki , Otsuka Wataru , Okazaki Nobumichi , Motoyoshi Makoto , Nagao Hajime , Sagara Tsutomu
Published: May 2005

The reliability in magnetoresistive random access memory (MRAM) write operation was investigated for both toggle and asteroid memory chips developed with 0.18μm CMOS process. Thermally activated magnetization reversal, being the dominant origin of the intrinsic write error, was studied theoretically and experimentally. For asteroid MRAM, the bit line or word line disturbing error on half selected bits was proved to have significant effect on the write operation margin, even in the ideal case free from bit-to-bit switching field distribution and the hysteresis loop shift. For toggle MRAM, on the other hand, the dominant origin of the error occurs for selected bits, although its impact is much smaller than in the case of asteroid MRAM. As was expected from the estimation based on the single domain model, more than 10mA operation margin with the error rate of <10−9, which is sufficiently small for semiconductor IC memory, was achieved for the toggle MRAM.
Nanoscale air bearing modeling via lattice Boltzmann method
Authors: Kim Woo Tae , Jhon Myung S. , Zhou Yong , Staroselsky Ilya , Chen Hudong
Published: May 2005

As spacing between the two solid surfaces in operating condition becomes much smaller than the mean free path of the air, continuum-based Navier–Stokes equation is no longer valid and one has to use a modified Reynolds equation (MRE) in simulating high Knudsen number air bearing. This MRE, which stems from the linearized Boltzmann transport equation with Bhatnagar–Gross–Krook approximation via the appropriate choice of the boundary condition, has the advantages of calculating the pressure distribution in a nanoscale confined gaseous system. In this paper, we provide a methodology based on the lattice Boltzmann method (LBM), which could enhance the computational capability of nanoscale confined gaseous system by calculating both velocity and pressure fields simultaneously. The advantage of transient and parallel nature makes this LBM an attractive tool for the next generation air bearing design. Furthermore, LBM is suitable for hybridization with lubricant morphology as well as multiscale modeling including entire disk flow analysis. We demonstrate the feasibility of this LBM by using first-order slip model as a case study. Hybridization with database established by Kang et al. [S.-C. Kang, R. M. Crone, and M. S. Jhon, J. Appl. Phys. 85, 5594 (1999)] can be performed via the similar procedure reported here to develop the state-of-the-art slider design software.
Real-time optimal torque control of fault-tolerant permanent magnet brushless machines
Authors: Max L. , Wang J. , Atallah K. , Howe D.
Published: May 2005

The paper describes issues that are pertinent to control system hardware and software design for the real-time implementation of an optimal torque control strategy for fault-tolerant permanent magnet brushless ac drives, and reports experimental results. The influence of the current control loop bandwidth and pulse width modulation on the torque ripple are investigated and quantified.
Intermolecular force, surface roughness, and stability of head-disk interface
Authors: Li Hui , Liu Bo , Hua Wei , Chong Tow-Chong
Published: May 2005

To achieve 1-Tb∕in.2 magnetic recording areal density, the head/disk spacing, or the flying height (FH) of the slider has to be reduced to 2–3nm and the disk surface roughness and the slider air bearing surface (ABS) roughness need to be well considered when the flying height is in such a regime. This paper presents authors’ efforts in further study of the intermolecular force effects with the surface roughness in consideration and the investigation of the contact force caused by the surface roughness effects. A probability model is built to simulate the intermolecular force and the contact force, and these two forces are introduced into the modified compressible Reynolds equation governing the air bearing pressure of the slider. The simulation results show that the effects of slider/disk roughness on the intermolecular force are negligible. On the other hand, surface roughness plays important roles in the contact force and the contact vibration. Reducing the roughness of both the slider and the disk surfaces is the best solution for reducing the contact force. Moreover, reducing the disk roughness can still significantly reduce the contact force, if the roughness reduction of the slider surface cannot be at the same pace of the disk surface roughness.
In situ high temperature magnetic force microscope analysis of thermal stability in the granular-type FePt–MgO double-layered perpendicular recording media
Authors: Singh Amarendra K. , Zhang Zhengang , Yin Jinhua , Suzuki Takao
Published: May 2005

Thermal stability of written bits with different linear densities on granular-type FePt–MgO double-layered perpendicular magnetic recording media has been investigated by magnetic force microscope (MFM) technique, equipped with an in situ heating system up to 200°C. Within the measurement time scale (∼6h), there is no observable degradation in 50- and 100-kfci bits even at 200°C indicating good thermal stability of FePt media, while in 10-kfci bits some reversed domains are found at high temperatures in the center region of the bits due to the presence of strong demagnetizing field. The average MFM signal extracted from MFM images at high temperature is interpreted based on the temperature-dependent magnetic anisotropy (Ku) behavior of the FePt media.
Numerical simulation of slider temperature rise caused by read/write current
Authors: Li Hui , Liu Bo , Chong Tow-Chong
Published: May 2005

The Joule heat caused by read/write operation leads to nanodeformation of slider body and variation of head-disk spacing. In this work, the heat transferring between slider and disk surfaces is numerically simulated based on an unstructured adaptive triangular mesh method and the Voronoi polygons control volume method. Results suggest that the heat transferring between slider and disk surfaces plays a very important role in determining the final temperature value and distribution over slider’s air-bearing surface (ABS). Furthermore, the writing operation, due to its high writing current, is of significant thermal effects to both writing head and MR sensor. The temperature distribution over the air bearing surface is asymmetrical and depends on the air bearing pressure and heat flux distribution. Also, higher slider flying speed increases the heat transferring between slider and disk surface. Furthermore, it is noticed that the heat conduction dominates the heat transferring between slider and disk surfaces. Good agreements are obtained between the present calculation and the reported experimental results.
Composite perpendicular magnetic recording media using [Co∕PdSi]n as a hard layer and FeSiO as a soft layer
Authors: Shen W. K. , Bai J. M. , Victora R. H. , Judy J. H. , Wang Jian-Ping
Published: May 2005

We fabricated the composite perpendicular magnetic recording (PMR) media successfully for the first time by combining a nanogranular FeSiO soft layer and a [Co∕PdSi]n hard layer. PdSi spacing layer (0–4nm) was used to study the exchange coupling effects between the FeSiO(5nm) and the [Co(0.26nm)∕Pd(1nm)]14 layers in the composite films. Proper coupling occurs when PdSi interlayer is ∼0.5nm. Significant lowering of the coercivity is observed for the composite PMR medium while still maintaining good thermal stability. The results prove the possibility to fabricate a writable PMR medium having an ultrahigh magnetic anisotropy constant Ku value.
Vapor deposition of strongly bonded hydrocarbon films on diamondlike carbon surfaces
Authors: Choi Junho , Kato Takahisa , Ikeyama Masami
Published: May 2005

In this report, we describe the deposition of strongly bonded hydrocarbon films (1-decanol and decanoic acid) on carbon surfaces by a vacuum vapor deposition technique. From the contact angle test and x-ray photoelectron spectroscopy measurement results, we conclude that the hydrocarbon molecules having hydroxyl or carboxyl end groups can be strongly bonded on carbon surfaces by vapor deposition. It is related to the electrostatic interaction between hydroxyl or carboxyl end groups and unsaturated electrons on carbon surfaces. The friction measurements results are also discussed.
Temperature variation of the fluctuation field in Co∕Pt
Authors: Rao S. , Torre E. Della , Bennett L. H. , Seyoum H. M. , Watson R. E.
Published: May 2005

Measurements of the fluctuation field of a perpendicular Co∕Pt multilayer medium was carried out from 4K to room temperature, using a procedure that for each holding field matches, in log-time, the aftereffect curve with the major loop. This is done by translation and scaling using the entire curve. The fluctuation field at each temperature is obtained from the slope of the required translation as a function of the holding field. The fluctuation field is directly proportional to the absolute temperature below the Bose condensation temperature, TBE, has a sharp peak at the TBE, then decreases until it approaches a constant value asymptotically from below for higher temperatures. This paper presents both the technique used to obtain this data and a theory of this magnetic aftereffect.
Sensitivity analysis of write field with respect to design parameters for perpendicular recording heads
Authors: Liu Z. J. , Li J. T. , Long H. H.
Published: May 2005

In this article, an analytical solution for the write field distribution in perpendicular recording system is presented. The field distribution in soft underlayer has been taken into consideration. The computed results agree well with numerical simulations. To investigate the influence of the leading design parameters on the write field characteristics, the sensitivity analysis based on response surface methodology is carried out. Besides, the effect of the soft underlayer on the write field is also studied to provide guidelines for the perpendicular recording head design.
Effect of H2 sputter gas on interfacial mixing in spin valves
Authors: Ahn Whang-Gi , Lee Seong-Rae
Published: May 2005

We introduced the use of hydrogen during the deposition of spin valves to achieve better control of interfacial mixing, especially for bottom spin valves (B-SV). The hydrogen was introduced during deposition of the CoFe or IrMn layer depending on whether it was a B-SV or a top spin valve (T-SV). The magnetoresistance ratio and Hex increased to 15% and 30%, respectively, when hydrogen (10vol%) was introduced for a B-SV. By contrast, the hydrogen effect for a T-SV was small. Using hydrogen (10vol%), the surface of the SV was smoother (1.01nm) than without hydrogen (1.94nm). In addition, the SV with hydrogen had a well-developed (111) texture and larger grains. By introducing hydrogen, we could control the microstructure and reduce the intermixing between CoFe and IrMn, especially for B-SVs.
A high-performance linear magnetic gear
Authors: Atallah K. , Wang J. , Howe D.
Published: May 2005

Currently, the demand for high force density linear actuators is being met almost exclusively by employing a leadscrew and nut to transform rotary to linear motion. The paper describes an alternative technology, viz., a linear magnetic gear, which employs rare-earth magnets, and which simulation studies have shown to have a highly competitive force density.
Reducing average grain and domain size in high-coercivity Co∕Pd perpendicular magnetic recording media through seedlayer engineering
Authors: Speetzen N. J. , Stadler B. J. H.
Published: May 2005

InSn seedlayers for Co∕Pd multilayered media were engineered using dopants (Pd, O) to achieve grain size of 7.8±1.8nm(σ=23%) and virgin magnetic cluster size of less than 65nm. HN=−5kOe and Hc=12.2kOe make this media promising for extremely high-density recording. These parameters were all realized with room-temperature depositions without annealing. Media with O-doped 2-nm InSn seedlayers without other adhesion layers achieved Hc=6.2kOe, which will be beneficial in reducing spacing loss. There is evidence that the engineered seedlayers also reduce the anisotropy dispersion and therefore the switching field distributions of these media.
Magnetic annealing of plated high saturation magnetization soft magnetic FeCo alloy films
Authors: Sun N. X. , Mehdizadeh S. , Bonhote C. , Xiao Q. F. , York B.
Published: May 2005

Plated high saturation magnetization soft magnetic FeCo films were annealed in magnetic field; their stress, microstructure, and magnetic properties were investigated. The FeCo films consistently showed a reduced tensile stress after magnetic annealing at temperatures above 255°C. The annealing temperature was found to be the primary factor in reducing the tensile stress, while annealing time was secondary. The FeCo films showed improved soft magnetic properties when subjected to an easy axis annealing with reduced coercivities along both the easy axis and hard axis. Hard axis annealing on these FeCo films caused a switched easy and hard axis in these films when the annealing temperature is above 255°C.
Dependence of the pole-tip remanence on the medium magnetization state underneath the trailing shield of a perpendicular write head
Authors: Zhou Yuchen , Zhu Jian-Gang
Published: May 2005

Understanding the physical mechanisms responsible for the write head pole-tip remanence is critical for making perpendicular recording a practically viable technology. In this paper, one of these mechanisms is explored in detail by using a contact scanning recording tester. The pole-tip remanence of unlaminated perpendicular write heads is studied by varying the magnetization states underneath the trailing shield. It is found that the net medium magnetization underneath the trailing shield acts effectively as magnetomotive force in the head-soft underlayer magnetic flux circuit. A clear correlation between the pole-tip remanence and the medium magnetization state is demonstrated and characterized. The medium magnetization facilitates the head remanence effectively, resulting in significant erasure after write. The stiffness of the remanence shows a clear dependence on the current amplitude of the prior writing. The large physical dimension of the trailing shield makes the effect of medium magnetization significantly nonlocal.
Magnetic properties and domain structure of highly coercive Au∕FePt films
Authors: Tsai Jai-Lin , Yuan Fu-Te , Chen Shi-Kun
Published: May 2005

The magnetic properties of highly ordered Au∕FePt films were studied. The film morphology was controlled by varying the thickness of the FePt layer while the thickness of the Au cap layer was fixed at 60 nm. We prepared the highly coercive Au∕FePt films with surface morphology ranging from continuous films to island structure and magnetic domains structure changing from stripe multidomain to single-domain structure, respectively, with a critical FePt thickness 60 nm. The particles are slightly coalesced with nearly ellipsoidal shape as the thickness is larger than 60 nm. In thinner FePt layer such as 20 nm, single-domain particle was observed clearly in magnetic force microscopy image. The huge coercivity up to 27 kOe was measured at room temperature with thickness 10 nm. According to the temperature dependence on coercivity, the domain wall displacement plays an important role in Au∕FePt (90 nm) bilayer. However, magnetic incoherent rotation is significantly in Au∕FePt (10 nm) bilayer.
Boundary line of the transition into the pseudogap state in thulium cuprates
Authors: Amitin E. B. , Zhdanov K. R. , Blinov A. G. , Kameneva M. Yu. , Kovalevskaya Yu. A. , Kozeeva L. P. , Paukov I. E.
Published: May 2005

Precision measurements of the heat capacity of 1-2-3 thulium cuprates with oxygen content ranging from 6.3 to 6.92 were performed in the temperature range 6–300 K. Analysis of the experimentl data showed anomalies in the temperature dependence of the electronic heat capacity. It is conjectured that the anomalies are due to a transition from the normal metallic into the pseudogap state.
Natural behavior of the magnetization under spontaneous reorientation: TmFeO3, ErFeO3
Authors: Tsymbal L. T. , Bazaliı̆ Ya. B. , Kakazeı̆ G. N. , Nepochatykh Yu. I. , Wigen P. E.
Published: May 2005

A SQUID magnetometer is used to study the behavior of the magnetization of TmFeO3 single crystals along the a and c principal crystallographic axes in the Γ4–Γ24–Γ2 spin reorientation range. The temperature dependences are obtained as the moduli of the magnetization vector M and its turn angle θ in the reorientation range. The results are compared with the same results for ErFeO3. It is shown that even though the experimental dependences |M|(T) and θ(T) are qualitatively different in TmFeO3 and ErFeO3 they can all be convincingly described on the basis of a modified mean-field theory previously proposed by the authors. Since the theoretical analysis does not include any parameters which are not known from experiment, the agreement between theory and experiment confirms that the model proposed for describing Γ4–Γ24–Γ2 phase transitions in orthoferrites is a general model. Dedicated to E. S. Borovik—Scientist and Humanitarian “Who can say what influence the silent presence of one person has on another?” Walter De la Mar
Low-temperature deviations from Bloch’s law in BaFe12O19 hexaferrite
Authors: Bezlepkin A. A. , Kuntsevich S. P.
Published: May 2005

The NMR method is used to study the temperature variations of local fields on 57Fe nuclei in the octahedral positions 12k, 4f2, and 2a of the iron ions in the ferrite BaFe12O19. The possibility of applying Bloch’s spin-wave theory to describe the temperature variations of the local fields on the iron nuclei is examined. Deviations from Bloch’s 3/2 power law are found in the temperature range 4.2–77 K. These deviations cannot be described on the basis of the behavioral characteristics due to the presence of an energy gap in the acoustic magnon spectrum.
Fluctuations and nonuniformities in strongly correlated electronic systems
Authors: Boyarskiı̆ L. A. , Gabuda S. P. , Kozlova S. G.
Published: May 2005

A general approach to describing a number of phenomena in strongly correlated electronic systems is examined. These phenomena are united by the fluctuation nature of the effects and the presence (or appearance) of nonuniform charge and/or spin densities. The following problems are discussed: the nature of ferromagnetism in d metals; the reasons for the appearance of metallic conductivity in oxides of heavy p metals; and, the nature of the pseudogap state in high-temperature superconductors.
Spin-orbit interaction in thin bismuth films
Authors: Komnik Yu. F. , Berkutov I. B. , Andrievskiı̆ V. V.
Published: May 2005

The magnetic-field dependences of the resistance of thin (100–700 Å thick) bismuth films at low temperatures are analyzed using quantum corrections to the conductivity with weak electron localization. It is shown that the spin-orbit scattering time τso is much shorter than the phase relaxation time τφ of the electrons (the case of a strong spin-orbit interaction). It is found that τso tends to increase with the film thickness. This shows that the surface scattering of the electrons plays a dominant role in spin-orbit processes. Apparently, strong spin relaxation in the presence of surface scattering is due to the gradient of the internal crystal-field potential near the surface of the metal, resulting in lifting of the spin degeneracy and in the appearance of a spin gap (Rashba mechanism).
Stereochemistry of 1,2-dichloroethane adsorbed on Pt(111)
Authors: Aoki M. , Ohashi Y. , Masuda S. , Ojima S. , Ueno N.
Published: May 2005

The rotational isomerism of 1,2-dichloroethane (DCE, CH2ClCH2Cl) adsorbed on Pt(111) was studied in the temperature range of 35–100 K using high-resolution electron energy loss spectroscopy and metastable atom electron spectroscopy. In the coverage below monolayer the physisorbed and chemisorbed species coexist at 35 K in the gauche and slightly distorted trans form, respectively. Owing to the direct Pt–Cl interactions, the nonbonding Cl 3p states of the chemisorbed DCE are split off, giving rise to degradation in symmetry from the pure trans form (C2h). The physisorbed gauche conformers are arranged with the C2 axis parallel (or heavily tilted) to the substrate and converted irreversibly to the pseudo-trans form by heating at 70 K. In the multilayer, the trans and gauche conformers exist at 35 K, where the former population is increased with increasing layer thickness. Upon annealing the bilayer at 80 K, the irreversible conversion takes place to yield a higher population of the gauche conformer in the topmost layer. The conformational stabilities and mutual changes of DCE adsorbed on a metal surface are discussed in terms of intramolecular rotational potential.
Magic angle spinning and static oriented sample NMR studies of the relaxation in the rotating frame of membrane peptides
Authors: Farès Christophe , Qian Jin , Davis James H.
Published: May 2005

To demonstrate the influence of motions with medium-to-slow correlation times (milliseconds to nanoseconds), a systematic study of the spin-lattice relaxation in the rotating frame was conducted for several nuclei (H1, C13, and N15) in small membrane polypeptides, either in oriented or magic angle spinning samples. This study not only assesses the validity of some motional models, but also characterizes the magnetization relaxation rates crucial for the design of polarization transfer experiments. It was found that relaxation time constant (T1ρ) values on the order of 10−3–10−2s for backbone nuclei and their dependence on sample orientation are consistent with the model of transmembrane polypeptides undergoing axial diffusion (τc∼10−8–10−7s) and small amplitude off-axis reorientation (τc∼10−6–10−5s).
The effect of solvent size on physical gelation in triblock copolymer solutions
Authors: Li Yunqi , Sun Zhaoyan , Su Zhaohui , Shi Tongfei , An Lijia
Published: May 2005

The gelation of physically associating triblock copolymers in a good solvent was investigated by Monte Carlo simulation, and the effect of the solvent size on the gelation was discussed in detail. The solvent size can greatly affect the conformation distribution of the polymer chains, the size distribution of the micelle, and the mechanism of the gelation on microscale, mesoscale, and macroscale. Our results indicate that the effect of the solvent size on the physical gelation exhibits three distinct regions. The gelation closely couples to the chain conformation transition when the solvent size is normal or quasinormal; the gelation occurs simultaneously with phase separation when the solvent size approaches the ideal end-to-end distance of the polymer chains; the gelation follows a glass transition mechanism upon increasing the solvent size to much larger than the ideal end-to-end distance of polymer chains. We also found that the volume fraction of the gel point can shift from 0.20 to 0.06, a range much broader than that reported in the literature.
MHD α2-dynamo, Squire equation and PT-symmetric interpolation between square well and harmonic oscillator
Authors: Günther Uwe , Stefani Frank , Znojil Miloslav
Published: May 2005

It is shown that the α2-dynamo of magnetohydrodynamics, the hydrodynamic Squire equation as well as an interpolation model of PT-symmetric quantum mechanics are closely related as spectral problems in Krein spaces. For the α2-dynamo and the PT-symmetric model the strong similarities are demonstrated with the help of a 2×2 operator matrix representation, whereas the Squire equation is reinterpreted as a rescaled and Wick-rotated PT-symmetric problem. Based on recent results on the Squire equation the spectrum of the PT-symmetric interpolation model is analyzed in detail and the Herbst limit is described as spectral singularity.
Spin-polarized electron tunneling across magnetic dielectric
Authors: Shvets I. V. , Grigorenko A. N. , Novoselov K. S. , Mapps D. J.
Published: May 2005

This letter deals with a magnetic tunnel junction having spin filtering by a magnetic barrier. We performed experiments in which a relatively strong external field rotates magnetizations of both ferromagnetic electrodes in the tunnel junction with the magnetic barrier simultaneously so that the two are always parallel to each other. The tunnel magnetoresistance induced in this way was over 16% at 300K. The angular dependency of the tunnel current on the layer magnetizations indicates that the barrier contains antiferromagnetic oxide. To achieve the described effect the magnetic electrode of the junction was oxidized prior to forming the Al2O3 layer.
High-differential-quantum-efficiency, long-wavelength vertical-cavity lasers using five-stage bipolar-cascade active regions
Authors: Koda R. , Wang C. S. , Lofgreen D. D. , Coldren L. A.
Published: May 2005

We present five-stage bipolar-cascade vertical-cavity surface-emitting lasers emitting at 1.54μm grown monolithically on an InP substrate by molecular beam epitaxy. A differential quantum efficiency of 120%, was measured with a threshold current density of 767A∕cm2 and voltage of 4.49V, only 0.5V larger than 5×0.8V, the aggregate photon energy. Diffraction loss study on deeply etched pillars indicates that diffraction loss is a major loss mechanism for such multiple-active region devices larger than 20μm. We also report a model on the relationship of diffraction loss to the number of active stages.
Low-resistance and highly transparent Ni/indium-tin oxide ohmic contacts to phosphorous-doped p-type ZnO
Authors: Kang Soon-Hyung , Hwang Dae-Kue , Park Seong-Ju
Published: May 2005

The use of a Ni (50 Å)/indium tin oxide (ITO) (500 Å) bilayer scheme for low-resistance and transparent ohmic contacts to phosphorous doped p-type ZnO was investigated. Ni/indium tin oxide (ITO) (50/500 Å) layers were prepared by electron-beam evaporation. Although the as-deposited Ni/ITO contact was highly resistant and opaque, contact resistance and transparency were greatly improved by a thermal annealing process. A specific contact resistance as low as 6.2×10−5Ωcm2 was obtained after thermal annealing at 400 °C for 1 min under an N2 ambient. The measured light transmittance of the Ni/ITO (50/500 Å) bilayer on p-type ZnO was determined to be above 80% at a wavelength of 400–600 nm. These results strongly indicate that the use of a Ni/ITO has considerable promise for ZnO-based optical devices.
Temperature dependence of electrical conductance in single-crystalline boron nanobelts
Authors: Kirihara K. , Wang Z. , Kawaguchi K. , Shimizu Y. , Sasaki T. , Koshizaki N. , Soga K. , Kimura K.
Published: May 2005

We studied electrical transport in single-crystalline boron nanobelts with α-tetragonal crystalline structure. We obtained ohmic contacts to the boron nanobelts by metal electrodes of Ni∕Au bilayer. From the temperature dependence of electrical conductance, we found that the boron nanobelt is a semiconductor. The electrical conductivity was of the order of 10−3(Ωcm)−1 at 295 K. Fitting the results to variable-range-hopping conduction revealed a high density of localized states at the Fermi level compared with bulk β-rhombohedral boron.
Liquid-crystal imaging of molecular-tilt ordering in self-assembled lipid tubules
Authors: Zhao Yue , Mahajan Nidhi , Lu Ruibo , Fang Jiyu
Published: May 2005

Self-assembled cylindrical tubules of chiral phospholipids are interesting supramolecular structures. Understanding the molecular-tilt order is a key step in controlling the size and shape of the tubules and designing new functional materials. The current theories based on the chiral interactions, coupled with molecular tilt, have predicted that the tubules could have both uniform and modulated tilt states. Here, we image the molecular-tilt order in the self-assembled tubules of a chiral phospholipid by using liquid crystals as an optical amplification probe. We demonstrate that the organization of the molecular-tilt azimuth in the lipid tubules can induce an azimuthal orientation in the liquid crystals. Both uniform and modulated tilt states of the lipid tubules are observed after liquid-crystal optical amplification.
The frequencies of calcium oscillations are optimized for efficient calcium-mediated activation of Ras and the ERK/MAPK cascade
Authors: Kupzig Sabine , Walker Simon A. , Cullen Peter J.
Published: May 2005

Ras proteins are binary switches that, by cycling through inactive GDP- and active GTP-bound conformations, regulate multiple cellular signaling pathways, including those that control growth and differentiation. For some time, it has been known that receptor-mediated increases in the concentration of intracellular free calcium ([Ca
2+
]
i
) can modulate Ras activation. Increases in [Ca
2+
]
i
often occur as repetitive Ca
2+
spikes or oscillations. Induced by electrical or receptor stimuli, these repetitive Ca
2+
oscillations increase in frequency with the amplitude of receptor stimuli, a phenomenon critical for the induction of selective cellular functions. Here, we show that Ca
2+
oscillations are optimized for Ca
2+
-mediated activation of Ras and signaling through the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) cascade. We present additional evidence that Ca
2+
oscillations reduce the effective Ca
2+
threshold for the activation of Ras and that the oscillatory frequency is optimized for activation of Ras and the ERK/MAPK pathway. Our results describe a hitherto unrecognized link between complex Ca
2+
signals and the modulation of the Ras/ERK/MAPK signaling cascade.
Serum protein markers for early detection of ovarian cancer
Authors: Mor Gil , Visintin Irene , Lai Yinglei , Zhao Hongyu , Schwartz Peter , Rutherford Thomas , Yue Luo , Bray-Ward Patricia , Ward David C.
Published: May 2005

Early diagnosis of epithelial ovarian cancer (EOC) would significantly decrease the morbidity and mortality from this disease but is difficult in the absence of physical symptoms. Here, we report a blood test, based on the simultaneous quantization of four analytes (leptin, prolactin, osteopontin, and insulin-like growth factor-II), that can discriminate between disease-free and EOC patients, including patients diagnosed with stage I and II disease, with high efficiency (95%). Microarray analysis was used initially to determine the levels of 169 proteins in serum from 28 healthy women, 18 women newly diagnosed with EOC, and 40 women with recurrent disease. Evaluation of proteins that showed significant differences in expression between controls and cancer patients by ELISA assays yielded the four analytes. These four proteins then were evaluated in a blind cross-validation study by using an additional 106 healthy females and 100 patients with EOC (24 stage I/II and 76 stage III/IV). Upon sample decoding, the results were analyzed by using three different classification algorithms and a binary code methodology. The four-analyte test was further validated in a blind binary code study by using 40 additional serum samples from normal and EOC cancer patients. No single protein could completely distinguish the cancer group from the healthy controls. However, the combination of the four analytes exhibited the following: sensitivity 95%, positive predictive value (PPV) 95%, specificity 95%, and negative predictive value (NPV) 94%, a considerable improvement on current methodology.