bluuebunny/crossref_metadata_2025 huggingface dataset:
Thalidomide for the treatment of multiple myeloma
Authors: Hattori Yutaka , Iguchi Toyotaka
Published: August 2004

ABSTRACT  Although thalidomide was withdrawn in the 1960s after its teratogenic property was recognized, it was subsequently found that this drug possesses immunomodulatory and anti‐inflammatory effects. Recent studies have also demonstrated that thalidomide has antineoplastic activity via an antiangiogenic mechanism. Observations in the late 1990s that the microenvironment in the bone marrow plays a role in tumor progression in multiple myeloma provided an impetus to use thalidomide for the treatment of this disease. It is known that thalidomide monotherapy is effective in one‐third of refractory cases, and in combination with glucocorticoids and/or antineoplastic drugs, thalidomide provides a response rate of more than 50%. Thus, thalidomide therapy is considered a standard approach for the treatment of relapsed and refractory myeloma. The exact mechanism of the antimyeloma effect of thalidomide is not yet clearly understood. Anti‐angiogenic effects, direct activity in tumor cells such as the induction of apoptosis or G1 arrest of the cell cycle, the inhibition of growth factor production, the regulation of interactions between tumor and stromal cells, and the modulation of tumor immunity have been considered as possible mechanisms. In addition to its teratogenicity, the adverse effects of thalidomide have been general symptoms such as somnolence and headache, peripheral neuropathy, constipation, skin rash, and other symptoms. Although these adverse effects are generally reversible and mild, grade 3 and 4 toxicities such as peripheral neuropathy, deep venous thrombosis, neutropenia, and toxic dermal necrosis have occasionally been reported. The application of thalidomide therapy in patients with multiple myeloma is being broadened to include not only cases of refractory myeloma, but also previously untreated cases, as well as for maintenance therapy after hematopoietic stem cell transplantation and for the treatment of other hematological diseases. The safe use of this drug will depend on the establishment of diagnostic and treatment guidelines. In addition, the establishment of a nation‐wide regulation system is urgently needed in Japan.
Novel alternative splicing of human faciogenital dysplasia 1 gene
Authors: Yanagi Kumiko , Kaname Tadashi , Chinen Yasutsugu , Naritomi Kenji
Published: August 2004

ABSTRACT  The human faciogenital dysplasia 1 (FGD1) gene product plays an important role in morphogenesis. Its dysfunction causes Aarskog–Scott syndrome (MIM ♯305400). To characterize the FGD1, we investigated its expression by RT–PCR and Southern blot analysis in normal tissues. We found novel alternative forms of the FGD1. One has a novel exon located in intron 8, named exon 8B (8B FDG1) and the other has an exon in intron 7, exon 7B (7B FGD1). The 8B FDG1 is expressed strongly in the brain, testis, spinal cord, trachea and stomach, and weakly in the thymus and lymphocytes. However, expression of the 7B FGD1 is weak and restricted in the testis and salivary gland. Insertion of each novel exon results in production of a premature termination codon, respectively, and the predicted proteins generated from them have only a proline‐rich domain and an incomplete DH domain which potentially compete with the wild type of FGD1.
Analysis of fetal DNA from maternal peripheral blood by lectin‐polymerase chain reaction–single strand conformation polymorphism
Authors: Shinya Masaru , Okamoto Aikou , Sago Haruhiko , Saito Misato , Akiyama Yoshiaki , Kitagawa Michihiro , Tanaka Tadao
Published: August 2004

ABSTRACT  Fetal nucleated cells in maternal peripheral blood are a non‐invasive source of fetal DNA for prenatal genetic diagnosis. However, the number of fetal cells present in maternal peripheral blood is very small. Therefore, fetal cell enrichment is generally considered necessary to allow detection and subsequent genetic analysis of the rare fetal cells. In the study presented here, we performed fetal cell separation from maternal blood using galactose‐specific lectin to concentrate fetal nucleated red blood cells (FNRBCs), and attempted paternal diagnosis using polymerase chain reaction–single strand conformation polymorphism (PCR–SSCP). Fetal cell separation was performed using galactose‐specific lectin on a PV‐MeA coated slide. Twenty cells consisting of an NRBC and its surrounding 19 maternal cells were collected using laser microdissection for stable DNA amplification. DNA analysis was performed using three sequence tagged site markers (D13S270, D17S5, and D18S474) by PCR–SSCP. All seven cases were informative because they showed heterozygosity at least one locus in D13S270, D17S5, or D18S474, and paternal‐specific bands were detected in all cases. These results suggest that our proposed lectin‐laser–micromanipulation–PCR–SSCP method may contribute to the development of prenatal diagnosis.
Studies on protocadherin‐2 expression in the human fetal central nervous system
Authors: Omi Hiroko , Kitagawa Michihiro
Published: August 2004

ABSTRACT  Protocadherin (Pcad) is a group of molecules obtained by polymerase chain reaction (PCR) utilizing the sequence that is well preserved in the extracellular domain of cadherin. Sano et al. analyzed Pcad (PC42,43) that had been cloned from rats, and found that it basically had homology to cadherin, but contained more than six cadherin repeats with a completely different intracellular domains (Sano et al. 1993). In the present study, of the Pcad (Pcad‐1,2) cloned from a human cDNA library, as‐yet‐unspecified Pcad‐2 was analyzed for expression in the human fetal central nervous system (CNS). Northern blot analysis of adult human tissue showed that Pcad‐2 was expressed in the brain and the placenta, and that Pcad‐2 mRNA was expressed in actively dividing neural tumor cell lines. Monoclonal antibodies against Pcad‐2 were then made, and the CNS of fetuses were immunohistochemically stained. The expression was hardly visible at the 6th week of pregnancy, and began to become visible along the nerve fiber in the brain stem at the 8th week, and spread over the entire brain at the 11th week. At the 18th week, however, expression in the nerve fascicles, which had been visible by that time, was no longer visible or had decreased. These results suggest that Pcad‐2 appears relatively early in the critical stage of development of the fetal CNS, and is involved in the induction, fasciculation, and extension of axons.
Increased Mental Health Needs and New Roles in School Communities
Authors: Hootman Janis , Houck Gail M. , King Mary Catherine
Published: August 2004

TOPIC Mental health issues and partnership roles in school communities.

PURPOSE To heighten the awareness of healthcare providers about the multiple mental health conditions students bring into school communities and the impact of these conditions on students' ability to learn; to encourage partnering between healthcare providers and educators to support students in achieving academic and developmental success.

SOURCES Literature review and authors' experiences with assessment of and intervention with school‐age children presenting with impaired mental health.

CONCLUSIONS Health and education systems must increase their partnerships on behalf of children for a healthy future.
Anxiety, Somatic Complaints, and Depressive Symptoms in Rural Adolescents
Authors: Puskar Kathryn R. , Sereika Susan M. , Haller Linda L.
Published: August 2004

PROBLEM Undiagnosed and untreated anxiety in adolescents is often associated with greater rates of mood and behavior problems, somatic complaints, and risk for future psychiatric disorders.

METHODS A self‐report anxiety instrument was administered as part of a community survey of 466 rural adolescents.

FINDINGS Anxiety symptoms were strongly correlated with both physical complaints and depression. Females had higher scores for total anxiety and the anxiety subtypes of generalized anxiety disorder, separation anxiety disorder, panic disorder, social phobia, and school phobia.

CONCLUSIONS Implications for nursing practice are provided.
Culturally Competent Mental Health Care for Puerto Rican Children
Authors: Berrios Carmen
Published: August 2004

TOPIC Mental health care for Puerto Rican children.

PURPOSE To explore the cultural background of Hispanics, present relevant definitions, and review and critique selected literature relevant to culturally competent mental health care of Puerto Rican children.

SOURCES OF DATA Published literature.

CONCLUSIONS Cross‐cultural research is important to raise the consciousness of nursing professionals, expose them to other realities, and provide opportunities to establish culturally relevant treatment modalities.
Actual and Potential Violence: Communities Gripped in the Culture of Fear
Authors: Yearwood Edilma L.
Published: August 2004

The goal of Culture Bound is to explore topics related to the impact of culture on psychiatric/mental health nursing practice, research, and education.
Prevalence of Psychopathology in Preschool‐Age Children
Authors: McDonnell Mary Ann , Glod Carol
Published: August 2004

PROBLEMLittle is known about psychopathology in preschool‐age children.

METHODSA review of representative studies of psychiatric disorders in preschoolers.

FINDINGSSample sizes ranged from 104 to 3,860 subjects, ages 1 to 9 years. Prevalence rates of psychiatric disorders varied from 0.1% to 26.4%; high rates of co‐morbidity were reported.

CONCLUSIONSStudies addressing psychiatric disorders in preschoolers are extremely limited. Future research is needed to improve the diagnosis, treatment, and outcomes in preschool‐age children.
Cries From the Morgue
Authors: Clements Paul T. , Weisser Susan M.
Published: August 2004

TOPIC Family member homicide.

PURPOSE To explore the unique facets of bereavement for a family member of a homicide victim in order to assist clinicians during assessment, evaluation, and intervention with children.

SOURCES The authors' experience in working with children at a child grief center and published literature.

CONCLUSIONS Children experience grief uniquely and use differing methods of coping and adaptation. Knowledge of these differences can assist clinicians with promotion of adaptive coping and grieving in children who have been exposed to murder.
Adjustment Difficulties of Adolescents With Sickle Cell Disease
Authors: Pinckney Rosie B. , Stuart Gail W.
Published: August 2004

TOPIC The psychosocial factors that affect adolescents with sickle cell disease (SCD).

PURPOSE To explore whether specific psychosocial factors can provide clues to the future adjustment of this population.

SOURCES Ovid Web, Medline, Psychinfo, and CINAHL databases for the years 1997 to 2001.

CONCLUSIONS Promoting effective psychosocial functioning is as important as managing the medical aspects of SCD, yet this is an area of care that is commonly overlooked. Nurses, therefore, have an opportunity to have a significant impact on the lives of adolescents with SCD if they intervene in ways to promote both biological and psychosocial adjustment.
Identifying Competence in the Context of the Pediatric Anogenital Exam
Authors: Waibel‐Duncan Mary Katherine
Published: August 2004

PROBLEM Appraisals of and concerns about the pediatric anogenital exam in order to promote a better understanding of predisposing factors that may underlie some people's adjustment to these exceptional circumstances.

METHODS Thirty‐three girls ages 8–15 and 82 adult guardians rated their acute exam appraisals and concerns using a 5‐point Likert‐type scale. Data were collected immediately after the anogenital exam at a pediatric outpatient clinic specializing in medical evaluations following allegations of child sexual abuse.

FINDINGS Participants reported relatively low levels of acute exam concerns as well as relatively high appraisals of the exam's importance and desirability, their ability to emotionally tolerate the exam, and optimism regarding the event's potential amelioration.

CONCLUSIONS Data suggested the presence of specific competencies that may be instrumental in safeguarding children's and adult guardians' psychological well‐being in the context of the pediatric anogenital exam.
Relationships Among Personal Space Boundaries, Peer Acceptance, and Peer Reputation in Adolescents
Authors: Stiles Anne Scott , Raney Thomas J.
Published: August 2004

PROBLEM Peer relationships are important to the health of adolescents who are at a developmental period of moving from parental influence to potentially dangerous peer influence. Interpersonal communication processes are logical antecedents of peer relationships. However, research in this area with adolescent populations is limited.

METHODS Exploratory descriptive study using observational technique to collect nonverbal and verbal communication data on adolescents (N = 28). Observer ratings of personal boundaries and peer acceptance were correlated with anonymous peer ratings of sociability/leadership, aggressiveness/disruptiveness, and sensitivity/isolation, with comparisons made between males and females.

FINDINGS Boundaries are related to peer acceptance and peer reputation and are interpreted differently in males and females.

CONCLUSIONS This study provides beginning evidence of the usefulness of Personal Space Boundary Theory in understanding adolescent behavior.
Where is the “Community” in Community Treatment?
Authors: Yearwood Edilma L.
Published: August 2004

The goal of this column is to explore topics related to the impact of culture on psychiatric/mental health nursing practice, research, and education.
Development of Child and Adolescent Psychiatric Nursing Practice in Korea, 1980–2000
Authors: Im Sook‐Bin , Kim Jung‐Lim , Ju Se‐Jin , Kwon Mi‐Kyung , Kim Ju‐Hee , Kwon Ji‐Hyang , Lee So‐Woo
Published: August 2004

PROBLEMAlthough the need for mental health services for children and youth is on the rise in Korea, there are no data available regarding the current status of psychiatric nurses working with children and adolescents.

METHODSDescriptive statistics were used to analyze questionnaires from 324 respondents.

FINDINGSOnly 5% of psychiatric nurses in Korea are working at child and adolescent–specific programs. The level of nurses' roles and functions vary from simple to specialized.

CONCLUSIONSMore effort should be put into networking among nurses to exchange updated information and to share nursing strategies and strengthen college education for further specialization and expansion of nursing roles in the various settings.
Effectiveness of a Comprehensive Psychoeducational Intervention With Pregnant and Parenting Adolescents: A Pilot Study
Authors: Thomas Deborah V. , Looney Stephen W.
Published: August 2004

PROBLEM Little is known about the effectiveness of a comprehensive psychoeducational intervention on depression, self‐esteem, and parenting attitudes/beliefs of at‐risk pregnant and parenting adolescents.

METHODS Adolescents (N = 41) attending either a residential treatment facility (RTF) or a rural alternative school (RAS) participated in a psychoeducational parenting group using Bavolek's Nurturing Program during Phase I. Phase II included health promotion issues, infant massage, and CPR.

FINDINGS Using the Parenting Semantic Differential and the AAPI‐2, there was significant improvement in parenting attitudes and beliefs. No significant change was found in self‐esteem.

CONCLUSIONS A comprehensive psychoeducational parenting group can be effective in changing parenting attitudes and beliefs, which suggests an ultimate improvement in health promotion and disease prevention in adolescent women and their children.
Using Freirean Empowerment for Health Education With Adolescents in Primary, Secondary, and Tertiary Psychiatric Settings
Authors: Rindner Ellen C.
Published: August 2004

TOPIC Engaging adolescents in health education through the application of Paulo Freire's three‐stage empowerment model in primary, secondary, and tertiary psychiatric settings.

PURPOSE To demonstrate how nurses can support adolescent autonomy and facilitate adolescent self and collective learning through group process, peer teaching, and development of critical thinking skills.

SOURCES A synthesis of nursing, medical, and health education literature resulted in identification of Freire's empowerment model and its application with adolescents in primary prevention settings.

CONCLUSIONS Adolescents in primary, secondary, and tertiary psychiatric settings can identify their health needs, make health choices, and take action to achieve them by using Freire's model.
In vivo human muscle structure and function: adaptations to resistance training in old age
Authors: Reeves N. D. , Narici M. V. , Maganaris C. N.
Published: August 2004

This study investigated changes in elderly muscle joint angle–torque relation induced by resistance training. Older adults were assigned to either training (n= 9, age 74.3 ± 3.5 years; mean ±s.d.) or to control groups (n= 9, age 67.1 ± 2 years). Leg‐extension and leg‐press exercises were performed three times per week for 14 weeks. Maximal isometric knee extension torque was measured across the knee joint angle range of movement. Vastus lateralis muscle architecture was examined in vivo using ultrasonography. The vastus lateralis muscle fascicle force was estimated from the measured joint torque, enabling construction of the fascicle length–force relation. Electromyographic (EMG) activity was measured from representative agonist and antagonist muscles. Training altered the angle–torque relation: (a) displacing it by 9–31% towards higher torque values (P < 0.05); and (b) shifting the optimal angle from 70 deg (corresponding torque: 121.4 ± 61 N m) before to 60 deg (134.2 ± 57.2 N m; P < 0.05) after training. Training also altered the fascicle length–force relation: (a) displacing it by 11–35% towards higher force values; and (b) shifting the optimal fascicle length from 83.7 ± 8 mm (corresponding force: 847.9 ± 365.3 N) before to 93.2 ± 12.5 mm (939.3 ± 347.8 N; P < 0.01) after training. The upward displacement of the angle–torque relation was mainly due to a training‐induced increase in agonist activation, whilst the shift in the optimal angle was associated with changes in muscle‐tendon properties.
Haemodynamic responses following intermittent supramaximal exercise in athletes
Authors: Crisafulli Antonio , Carta Celestino , Melis Franco , Tocco Filippo , Frongia Francesco , Santoboni Uberto M. , Pagliaro Pasquale , Concu Alberto
Published: August 2004

We aimed to investigate haemodynamics during active and passive recovery following repeated bouts of supramaximal exercise. Seven male athletes underwent two sessions of supramaximal exercise which consisted of a warm‐up and of five bouts of cycling at the maximum speed possible for 30 s against a resistance equivalent to 150% of the maximum workload achieved in a previous incremental test. Bouts were separated by 1 min of recovery and followed by 10 min of recovery which was either active (pedalling at 40 W) or passive (completely rest seated on the cycle). Haemodynamic variables were evaluated by means of impedance cardiography. Heart rate (HR), stroke volume (SV), cardiac output (CO), mean blood pressure (MBP), thoracic electrical impedance (Z0) as an inverse index of central blood volume, and systemic vascular resistance (SVR) were assessed. The main findings were that active recovery, with respect to passive recovery, induced higher changes from baseline in HR (+29.1 ± 4.5 versus+15.6 ± 2.9 beats min−1 at the 10th minute of recovery, P < 0.05), SV (+19.9 ± 5.6 versus–6.4 ± 3.3 ml, P < 0.01) and CO (+3.8 ± 1.2 versus+0.4 ± 0.2 l min−1, P < 0.01). Furthermore, MBP was similar between the two kinds of recovery despite an increase in Z0 during passive compared to active recovery. These results suggest that the faster haemodynamic recovery towards baseline and the decrease in cardiac preload during passive recovery may be successfully prevented by cardiovascular regulatory mechanisms which include an increase in SVR, thus avoiding a drop in blood pressure.
APPLICATION OF SUPERCRITICAL FLUIDS FOR FABRICATION OF FREE-STANDING NANOOBJECTS
Authors: CHEHOVSKIY A. V. , PRINZ V. Ya.
Published: August 2004

It is experimentally shown that, unlike evaporation drying, supercritical CO 2 drying makes it possible to obtain free-standing single-coil InGaAs / GaAs nanotubes and other nanoshells with wall thicknesses down to 1 nm without their deformation by capillary forces. The performed process optimization has allowed us to reduce tenfold the duration of the process for long nanotubes. For the first time, etching of sacrificial AlAs layers in supercritical media was performed.
SECOND NEAREST NEIGHBORS INTERACTION AND EQUILIBRIUM SHAPE OF STEPS ON KOSSEL CRYSTAL VICINAL SURFACE
Authors: KORSAKOV V. B. , SURIS R. A.
Published: August 2004

The structure of monoatomic steps on (001)-vicinal surface of Kossel crystal is investigated theoretically. We consider all step directions except for relatively small vicinities of <10>-directions. The structure of such steps at sufficiently low temperature is shown to be controlled only by interaction between second nearest neighbors. If this interaction is repulsive, steps have saw-like shape, while attractive interaction leads to straightening of steps. More general case of nonpairwise interactions is also considered.
MAGNETIC EPITAXIAL NANOSTRUCTURES FROM IRON AND NICKEL
Authors: MALIKOV I. V. , FOMIN L. A. , VINNICHENKO V. Yu. , MIKHAILOV G. M.
Published: August 2004

Magnetoresistance of a planar single crystalline Ni nanostructures has been measured at room and liquid helium temperatures. Bending GMR effect increases from 4% under diffusive to more than 200% under ballistic electron transport in cross-type nanostructures. Magnetoresistance measured for longitudinal and transverse magnetic fields are qualitatively different and explained by a nonsymmetrical magnetic domain structure in the central part of the cross.
NANOSCALE PERIODICAL STRUCTURES FABRICATED BY INTERFERENCE PHOTOLITHOGRAPHY
Authors: NESTEROV S. I. , MYAGKOV D. V. , PORTNOI E. L.
Published: August 2004

The possibility of periodical mask fabrication with elements of minimal size by means of interference photolithography is considered. The method is based on application of striped interference picture of coherent light for photoresist exposition. The investigation of inorganic photoresist based on chalcogenide glass As 2 S 3 reveals high resolution, sufficient contrast and vertical edge of the masks stripe. The influence of exposure dose and development parameters on photoresist profile are analyzed with the help of the method of computer simulation of the development process. The possibility of decreasing the effect of standing light wave by means of additional homogeneous light irradiation is demonstrated. The optimal conditions for minimum size elements fabrication are found, which enables fabrication of periodical grating with a 80-nm-wide line and two-dimensional periodical structures with pillars of 50 nm cross-section.
ORGANIZED PLANAR NANOSTRUCTURES VIA INTERFACIAL SELF-ASSEMBLY AND DNA TEMPLATING
Authors: KHOMUTOV G. B. , ANTIPINA M. N. , SERGEEV-CHERENKOV A. N. , RAKHNYANSKAYA A. A. , ARTEMYEV M. , KISIEL D. , GAINUTDINOV R. V. , TOLSTIKHINA A. L. , KISLOV V. V.
Published: August 2004

The methods are presented for fabrication of new nanoscale-organized planar inorganic nanostructures, ultrathin polymeric and nanocomposite films on solid substrates with incorporated nanosized functional and structural building blocks. The methods are based on interfacial synthesis and self-assembly, DNA templating and scaffolding. Ultimately thin monomolecular and multilayer ordered stable polymeric and nanocomposite films containing incorporated ligand-stabilized gold nanoclusters, interfacially in-film grown metallic ( Au , Pd ) nanoparticles and organized low-dimensional nanostructures were formed. N-alkylated derivatives of poly(4-vinilpyridine) were synthesized and used as water-insoluble amphiphilic polycations to form organized polymeric Langmuir monolayers and novel planar DNA/amphiphilic polycation complexes at the air–aqueous DNA solution interface. The extended net-like and quasi-circular toroidal condensed conformations of deposited planar DNA/amphiphilic polycation complexes were obtained in dependence on the amphiphilic polycation monolayer state during the DNA binding. Planar DNA/amphiphilic polycation complexes were used as nanotemplates for fabrication of organized planar bio-organic–inorganic hybrid nanostructures with ordered nanophase inorganic components (quasi-one-dimensional arrays of semiconductor (CdS) and iron oxide nanoparticles and nanorods) organized in planar matrix of deposited DNA/amphiphilic polycation complex film. The formed nanostructures were characterized by atomic force microscopy and transmission electron microscopy techniques.
NANOPATTERNING OF SILICON-BASED NANOSTRUCTURES BY AFM PROBE
Authors: SHEGLOV D. V. , NASTAUSHEV Yu. V. , LATYSHEV A. V. , ASEEV A. L.
Published: August 2004

Atomic force and reflection electron microscopes have been applied to investigate tip-induced local anodic oxidation of the titanium and silicon films. The number of parameters such as applied voltage, oxidation time, relative humidity and host material was under consideration. The special treatments were applied to reduce the roughness of the studied surfaces achieving the average roughness of the surface less than one angstrom. Some examples of nanostructures fabrication are demonstrated.
COERCIVITY OF SINGLE PINNING CENTER MEASURED BY HALL MICROMAGNETOMETRY
Authors: NOVOSELOV KOSTYA S. , DUBONOS SERGEY V. , MOROZOV SERGEY V. , BERGEN DIRK VAN DEN , MAAN JAN KEES , GEIM A. K.
Published: August 2004

Nanometer-scale movements of domain walls in uniaxial garnet films have been studied by means of micromagnetization measurements using miniature gold and semiconductor Hall probes. At helium temperatures the domain walls are found to move by discrete jumps, which we attribute to pinning on isolated defects, and we were able to measure local hysteresis loops associated with pinning on individual pinning centers. The temperature dependence of the coercive field of a single pinning center allowed us to evaluate the characteristic energy and characteristic volume of the pinning center.
LOCAL ELECTRONIC STRUCTURE OF N ATOMS IN Ga(In)AsN BY SOFT-X-RAY ABSORPTION AND EMISSION: OPTICAL EFFICIENCY
Authors: STROCOV V. N. , NILSSON P. O. , SCHMITT T. , CLAESSEN R. , EGOROV A. Yu, , USTINOV V. M. , ALFEROV Zh. I.
Published: August 2004

The local electronic structure of N atoms in Ga ( In ) AsN diluted alloys ( N concentration of 3%) is determined by soft-X-ray emission and absorption spectroscopies as element specific probes. The experimental spectra reflect the local 2p orbital-projected density-of-states of N impurities, the main recombination centers in Ga ( In ) AsN , which appears to deviate dramatically from crystalline GaN in both valence and conduction bands. In particular, we observe a N local charge transfer from the valence band maximum to deeper valence states, which fundamentally limits the optical efficiency of Ga ( In ) AsN , unless different N local environments are formed. The incorporation of In in large concentrations forms In -rich N local environments such as In 4 N , which become the main recombination centers in Ga ( In ) AsN due to a local decrease of the band gap. A k-conserving process of resonant inelastic X-ray scattering is discovered, which allows probing of the k-character of valence and conduction states despite the random alloy nature of Ga ( In ) AsN .
SNOM INVESTIGATION OF THE ELECTROMAGNETIC FIELD INTENSITY AND POLARIZATION DISTRIBUTION IN THE VICINITY OF NANOSTRUCTURES
Authors: BASHEVOY M. V. , EZHOV A. A. , MAGNITSKII S. A. , MUZYCHENKO D. A. , PANOV V. I. , TOURSYNOV J. S. , MALAKHOV D. V.
Published: August 2004

The experimental and calculated results of the investigation of electromagnetic field distribution including its polarization characteristics in the vicinity of the nanostructures are presented. The experimental investigation was realized by aperture type scanning near field optical microscopes (SNOMs) which operated in collection mode. Normal resolution which allows us to image down to 0.3 nm height surface steps was demonstrated for the shear force probe to surface gap control system of the SNOM. Theoretical computation of the electromagnetic field distribution was realized by finite-difference time-domain (FDTD) method. The experimental three-dimensional maps of intensity and polarization distribution as a result of light diffraction at nanoaperture in the metal screen, dielectric and metallized nanocylinders were obtained. The qualitative difference between the orthogonal polarized component distributions near nanoaperture was experimentally shown. The electromagnetic field concentration in the proximity of the dielectric nanocylinders was observed. This observation gives a good fit with the results of FDTD computations. A spiral type electromagnetic field distribution pattern was experimentally observed in the proximity of metallized nanocylinders, which is unexpected from both experimental and theoretical points of view.
DEPTH DEPENDENCE OF MAGNETIC AND ELECTRIC PROPERTIES IN GaMnAs LAYERS
Authors: KOEDER A. , FRANK S. , LIMMER W. , SCHOCH W. , AVRUTIN V. , SAUER R. , WAAG A. , PEINER E. , SCHLACHETZKI A.
Published: August 2004

We investigate the electronic and magnetic properties of ferromagnetic GaMnAs single layers as well as multilayer structures fabricated by low-temperature molecular beam epitaxy. The electrochemical capacitance–voltage profiling as well as Raman spectroscopy measurements in GaMnAs single layers reveal a vertical gradient in the carrier concentration and therefore a gradient in Curie temperature measured by superconducting quantum interference device. Detailed studies of carrier density and ferromagnetic transition before and after annealing of the layers are presented. We also report on an enhancement of the Curie temperature in GaMnAs / InGaMnAs superlattices, which is due to thin InGaMnAs or InGaAs films embedded into the GaMnAs layers. The pronounced increase of the Curie temperature is strongly correlated to the In concentration in the embedded layers. Curie temperatures up to 110 K are observed in such structures compared to 60 K in GaMnAs single layers grown under the same conditions. A further increase in TC up to 130 K can be achieved using post-growth annealing at temperatures near the growth temperature.
METALLIC AND SEMICONDUCTOR HALL MICROPROBES FOR WIDE TEMPERATURE RANGE APPLICATIONS
Authors: NOVOSELOV KOSTYA S. , MOROZOV SERGEY V. , DUBONOS SERGEY V. , MISSOUS M. , GEIM A. K.
Published: August 2004

We report on mesoscopic Hall sensors allowing accurate magnetization studies of submicron or nanometer-sized samples over a wide temperature range. Even at 300 K, the probes can reliably resolve local changes in dc field of ≈ 1 G with spatial resolution of ≈ 1 μm, which corresponds to a flux sensitivity of less than 0.1 ϕ0 (ϕ0=h/e is a flux quantum). The resolution increases 100 times at temperatures below 80 K. The capabilities of new micromagnetometers are demonstrated by measuring nm-scale movements of individual domain walls in a ferromagnet.
TERAHERTZ EMITTERS AND DETECTORS BASED ON SiGe NANOSTRUCTURES
Authors: KOLODZEY J. , ADAM T. N. , TROEGER R. T. , LV P.-C. , RAY S. K. , YASSIEVICH I. , ODNOBLYUDOV M. , KAGAN M.
Published: August 2004

Terahertz (THz) electroluminescence was produced by three different types of sources: intersubband transitions in silicon germanium quantum wells, resonant state transitions in boron-doped strained silicon germanium layers, and hydrogenic transitions from dopant atoms in silicon. The devices were grown by molecular beam epitaxy, fabricated by dry etching, and characterized by infrared spectroscopy. The absorption of THz was observed in silicon germanium quantum wells at energies corresponding to heavy hole and light hole intersubband transitions. These results suggest that SiGe nanotechnology is attractive for THz device applications.
ON A SUPERLATTICE BLOCH OSCILLATOR
Authors: ROMANOV Y. A. , ROMANOVA J. Y.
Published: August 2004

We examine the static and high-frequency differential conductivity of semiconductor superlattices having various miniband dispersion laws. Our analysis shows that the anharmonicity of Bloch oscillations leads to the occurrence of negative high-frequency differential conductivity at frequency multiples of the Bloch frequency. This effect can arise even in regions of positive static differential conductivity. To achieve terahertz field amplification, we propose to employ structures having miniband dispersion law with decreasing effective electron mass as energy increases.
HIGH-PERFORMANCE RIDGE-WAVEGUIDE MULTI-STACK (N=2, 5 AND 10)InAs/InGaAs/GaAs QUANTUM DOT LASERS of 1.3 μm RANGE
Authors: LIN G. , CHEN I. F. , LAY F. J. , CHI J. Y. , LIVSHITS D. A. , KOVSH A. R. , USTINOV V. M.
Published: August 2004

We have investigated light-current and spectral characteristics of 2-, 5- and 10-stack InAs / InGaAs / GaAs quantum dot (QD) ridge-waveguide lasers grown by MBE. Ultra-low threshold current of 1.43 mA was achieved for 2-stack QD laser. Simultaneous lasing at ground- and excited-states was observed. This effect is accounted for the finite time of carriers capture to the ground-state in QDs. Multi-stack QD structures enables to maintain continuous-wave (CW) ground-state lasing up to the current density of 100×Jth and to achieve the highest output power and efficiency ever recorded for any single-mode lasers of 1.3-μm-wavelength range.
SCANNING E-BEAM LONGITUDINALLY PUMPED RT OPERABLE LASER BASED ON MOVPE-GROWN GaInP/AlGaInP MQW STRUCTURE
Authors: BONDAREV V. Yu. , KOZLOVSKY V. I. , KRYSA A. B. , ROBERTS J. S. , SKASYRSKY Ya. K.
Published: August 2004

The 17- and 25-period Ga 0.5 In 0.5 P /( Al 0.7 Ga 0.3)0.5 In 0.5 P quantum well structures were grown by metalorganic vapor phase epitaxy on a GaAs substrate misoriented by 10° from (001) to (111)A. A microcavity with dielectric oxide mirrors was fabricated on the basis of each structure. Lasing at 619 nm (632 nm) with 0.7 W (6 W) output power was achieved under scanning electron beam longitudinal pumping at room temperature using the 17-period (25-period) structure. The threshold current density at a 40 keV electron energy was 8 A/cm 2. It is shown that low threshold and high power lasing requires the position of the QWs to coincide with the antinodes of the cavity mode, at the maximum of the gain spectrum due to the QW ground state.
BEHAVIOR OF ELECTRON STATES IN GaAs/AlGaAs DOUBLE QUANTUM WELL STRUCTURE WITH STRONGLY ASYMMETRIC BARRIERS IN AN EXTERNAL ELECTRIC FIELD
Authors: ALESHCHENKO Yu. A. , KAPAEV V. V. , KOPAEV Yu. V. , KOP'EV P. S. , USTINOV V. M. , ZHUKOV A. E.
Published: August 2004

The specific features of the behavior of electron states in GaAs / AlGaAs double quantum well structure with strongly asymmetric barriers in an external electric field have been studied both theoretically and experimentally. This structure is the principal part of the active element of a quantum unipolar laser proposed by us earlier, since it contains the lower laser subband possessing the property of 2D–3D transformation. The drastic variations in the photoluminescence peak intensity, FWHM, and area with field demonstrate the possibility of controlling the dimensionality of this subband.
E-BEAM PUMPED VCSEL ON MOVPE-GROWN HEXAGONAL CdSSe/CdS MQW STRUCTURE
Authors: KOZLOVSKY V. I. , BONDAREV V. Yu. , SANNIKOV D. A. , KUZNETSOV P. I. , YAKUSHCHEVA G. G. , O'DONNELL K. P. , TRAGER-COWAN C.
Published: August 2004

The first electron-beam pumped VCSEL was fabricated on CdSSe / CdS MQW structure grown by metalorganic vapor phase epitaxy on CdS substrate misoriented by 12–16° from (0001) towards (1010). Substrate misorientation results in more perfect surface morphology and intense cathodoluminesence. Lasing in the 535–590 nm spectral range was achieved at room temperature with different VCSELs. The laser power maximum of one VCSEL was as high as 2 W at RT, with electron energy 50 keV and current 1.7 mA. The threshold current was lower than that for the bulk CdSSe laser although the heterostructure used in the VCSEL has the type-II band alignment.
Relationship between visceral adiposity and intramyocellular lipid content in two rat models of insulin resistance
Authors: Korach-André M. , Gao J. , Gounarides J. S. , Deacon R. , Islam A. , Laurent D.
Published: August 2004

High visceral adiposity and intramyocellular lipid levels (IMCL) are both associated with the development of type 2 diabetes. The relationship between visceral adiposity and IMCL levels was explored in diet- and glucocorticoid-induced models of insulin resistance. In the diet-induced model, lean and fa/fa Zucker rats were fed either normal or high-fat (HF) chow over 4 wk. Fat distribution, IMCL content in the tibialis anterior (TA) muscle (IMCLTA), and whole body insulin resistance were measured before and after the 4-wk period. The HF diet-induced increase in IMCLTAwas strongly correlated with visceral fat accumulation and greater glucose intolerance in both groups. The increase in IMCLTAto visceral fat accumulation was threefold greater for fa/fa rats. In the glucocorticoid-induced model, insulin sensitivity was impaired with dexamethasone. In vivo adiposity and IMCLTAcontent measurements were combined with ex vivo analysis of plasma and muscle tissue. Dexamethasone treatment had minimal effects on visceral fat accumulation while increasing IMCLTAlevels ∼30% ( P < 0.05) compared with controls. Dexamethasone increased plasma glucose by twofold and increased the saturated fatty acid content of plasma lipids [fatty acid (CH2)n/ωCH3ratio +15%, P < 0.05]. The lipid composition of the TA muscle was unchanged by dexamethasone treatment, indicating that the relative increase in IMCLTAobserved in vivo resulted from a decrease in lipid oxidation. Visceral adiposity may influence IMCL accumulation in the context of dietary manipulations; however, a “causal” relationship still remains to be determined. Dexamethasone-induced insulin resistance likely operates under a different mechanism, i.e., independently of visceral adiposity.
Ghrelin regulates mitochondrial-lipid metabolism gene expression and tissue fat distribution in liver and skeletal muscle
Authors: Barazzoni Rocco , Bosutti Alessandra , Stebel Marco , Cattin Maria Rosa , Roder Elena , Visintin Luca , Cattin Luigi , Biolo Gianni , Zanetti Michela , Guarnieri Gianfranco
Published: August 2004

Ghrelin is a gastric hormone increased during caloric restriction and fat depletion. A role of ghrelin in the regulation of lipid and energy metabolism is suggested by fat gain independent of changes in food intake during exogenous ghrelin administration in rodents. We investigated the potential effects of peripheral ghrelin administration (two times daily 200-ng sc injection for 4 days) on triglyceride content and mitochondrial and lipid metabolism gene expression in rat liver and muscles. Compared with vehicle, ghrelin increased body weight but not food intake and circulating insulin. In liver, ghrelin induced a lipogenic and glucogenic pattern of gene expression and increased triglyceride content while reducing activated (phosphorylated) stimulator of fatty acid oxidation, AMP-activated protein kinase (AMPK, all P < 0.05), with unchanged mitochondrial oxidative enzyme activities. In contrast, triglyceride content was reduced ( P < 0.05) after ghrelin administration in mixed (gastrocnemius) and unchanged in oxidative (soleus) muscle. In mixed muscle, ghrelin increased ( P < 0.05) mitochondrial oxidative enzyme activities independent of changes in expression of fat metabolism genes and phosphorylated AMPK. Expression of peroxisome proliferator-activated receptor-γ, the activation of which reduces muscle fat content, was selectively increased in mixed muscle where it paralleled changes in oxidative capacities ( P < 0.05). Thus ghrelin induces tissue-specific changes in mitochondrial and lipid metabolism gene expression and favors triglyceride deposition in liver over skeletal muscle. These novel effects of ghrelin in the regulation of lean tissue fat distribution and metabolism could contribute to metabolic adaptation to caloric restriction and loss of body fat.
The metabolic “switch” AMPK regulates cardiac heparin-releasable lipoprotein lipase
Authors: An Ding , Pulinilkunnil Thomas , Qi Dake , Ghosh Sanjoy , Abrahani Ashraf , Rodrigues Brian
Published: August 2004

The “fuel gauge” AMP-activated protein kinase (AMPK) facilitates ATP production to meet energy demands during metabolic stress. Given the importance of lipoprotein lipase (LPL) in providing hearts with fatty acids (FA), the preferred substrate consumed by the heart, the objective of the present study was to investigate whether activation of AMPK influences LPL at its functionally relevant location, the coronary lumen. Hearts from overnight-fasted rats were first perfused with heparin to release LPL, and homogenates from these hearts were then used to measure total and phospho-AMPK-α by Western blotting. Manipulation of AMPK activity [with drugs like adenine 9-β-d-arabinofuranoside (Ara-A) and insulin (that inhibit) or perhexiline and oligomycin (that stimulate)] and its influence on LPL was also determined. Fasting augmented the activity of both AMPK and luminal LPL on immediate removal of hearts, effects that still remained even after in vitro perfusion of hearts for 1 h. Inhibition of AMPK in fasted hearts using an inhibitor like Ara-A or through provision of insulin markedly lowered the enhanced luminal LPL activity. In contrast, AMPK activators, like perhexiline and oligomycin, produced a significant elevation in heparin-releasable LPL activity. Thus, with fasting or drugs that influence AMPK, a strong correlation between this metabolic switch and cardiac LPL activity was established. Our data suggest that, in addition to its direct role in promoting FA oxidation, AMPK-mediated recruitment of LPL to the coronary lumen could represent an immediate compensatory response by the heart to guarantee FA supply.
Renal protection by a soy diet in obese Zucker rats is associated with restoration of nitric oxide generation
Authors: Trujillo Joyce , Ramírez Victoria , Pérez Jazmín , Torre-Villalvazo Ivan , Torres Nimbe , Tovar Armando R. , Muñoz Rosa M. , Uribe Norma , Gamba Gerardo , Bobadilla Norma A.
Published: August 2004

The obese Zucker rat is a valuable model for studying kidney disease associated with obesity and diabetes. Previous studies have shown that substitution of animal protein with soy ameliorates the progression of renal disease. To explore the participation of nitric oxide (NO) and caveolin-1 in this protective effect, we evaluated proteinuria, creatinine clearance, renal structural lesions, nitrites and nitrates urinary excretion (UNO2−/NO3V), and mRNA and protein levels of neuronal NO synthase (nNOS), endothelial NOS (eNOS), and caveolin-1 in lean and fatty Zucker rats fed with 20% casein or soy protein diet. After 160 days of feeding with casein, fatty Zucker rats developed renal insufficiency, progressive proteinuria, and renal structural lesions; these alterations were associated with an important fall of UNO2−/NO3V, changes in nNOS and eNOS mRNA levels, together with increased amount of eNOS and caveolin-1 present in plasma membrane proteins of the kidney. In fatty Zucker rats fed with soy, we observed that soy diet improved renal function, UNO2−/NO3V, and proteinuria and reduced glomerulosclerosis, tubular dilation, intersticial fibrosis, and extracapilar proliferation. Renal protection was associated with reduction of caveolin-1 and eNOS in renal plasma membrane proteins. In conclusion, our results suggest that renal protective effect of soy protein appears to be mediated by improvement of NO generation and pointed out to caveolin-1 overexpression as a potential pathophysiological mechanism in renal disease.
Redundant signaling mechanisms contribute to the vasodilatory response of the afferent arteriole to proteinase-activated receptor-2
Authors: Wang Xuemei , Hollenberg Morley D. , Loutzenhiser Rodger
Published: August 2004

We previously demonstrated that stimulation of proteinase-activated receptor-2 (PAR-2) by SLIGRL-NH2elicits afferent arteriolar vasodilation, in part, by elaborating nitric oxide (NO), suggesting an endothelium-dependent mechanism (Trottier G, Hollenberg M, Wang X, Gui Y, Loutzenhiser K, and Loutzenhiser R. Am J Physiol Renal Physiol 282: F891–F897, 2002). In the present study, we characterized the NO-independent component of this response, using the in vitro perfused hydronephrotic rat kidney. SLIGRL-NH2(10 μmol/l) dilated afferent arterioles preconstricted with ANG II, and the initial transient component of this response was resistant to NO synthase (NOS) and cyclooxygenase inhibition. This NO-independent response was not prevented by treatment with 10 nmol/l charybdotoxin and 1 μmol/l apamin, a manipulation that prevents the endothelium-derived hyperpolarizing factor (EDHF)-like response of the afferent arteriole to acetylcholine, nor was it blocked by the addition of 1 mmol/l tetraethylammonium (TEA) or 50 μmol/l 17-octadecynoic acid, treatments that block the EDHF-like response to bradykinin. To determine whether the PAR-2 response additionally involves the electrogenic Na+-K+-ATPase, responses were evaluated in the presence of 3 mmol/l ouabain. In this setting, SLIGRL-NH2induced a biphasic dilation in control and a transient response after NOS inhibition. The latter was not prevented by charybdotoxin plus apamin or by TEA alone but was abolished by combined treatment with charybdotoxin, apamin, and TEA. This treatment did not prevent the NO-dependent dilation evoked in the absence of NOS inhibition. Our findings indicate a remarkable redundancy in the signaling cascade mediating PAR-2 -induced afferent arteriolar vasodilation, suggesting an importance in settings such as inflamation or ischemia, in which vascular mechanisms might be impaired and the PAR system is thought to be activated.
Na+-induced inward rectification in the two-pore domain K+channel, TASK-2
Authors: Morton Michael J. , Chipperfield Sarah , Abohamed Abdulrahman , Sivaprasadarao Asipu , Hunter Malcolm
Published: August 2004

TASK-2 is a member of the two-pore domain K+(K2P) channel family that is expressed at high levels in several epithelia, including the proximal tubule. In common with the other TASK channels, TASK-2 is sensitive to changes in extracellular pH. We have expressed human TASK-2 in Chinese hamster ovary cells and studied whole cell and single-channel activity by patch clamp. The open probability of K2Pchannels is generally independent of voltage, yielding linear current-voltage ( I- V) curves. Despite these properties, we found that these channels showed distinct inward rectification immediately on the establishment of whole cell clamp, which became progressively less pronounced with time. This rectification was due to intracellular Na+but was unaffected by polyamines or Mg2+(agents that cause rectification in Kir channels). Rectification was concentration- and voltage-dependent and could be reversibly induced by switching between Na+-rich and Na+-free bath solutions. In excised inside-out patches, Na+reduced the amplitude of single-channel currents, indicative of rapid block and unblock of the pore. Mutations in the selectivity filter abolished Na+-induced rectification, suggesting that Na+binds within the selectivity filter in wild-type channels. This sensitivity to intracellular Na+may be an additional potential regulatory mechanism of TASK-2 channels.