A Novel Micro Cold Atmospheric Plasma Device for Glioblastoma Both In Vitro and In Vivo.

: Cold atmospheric plasma (CAP) treatment is a rapidly expanding and emerging technology for cancer treatment. Direct CAP jet irradiation is limited to the skin and it can also be invoked as a supplement therapy during surgery as it only causes cell death in the upper three to five cell layers. However, the current cannulas from which the plasma emanates are too large for intracranial applications. To enhance efficiency and expand the applicability of the CAP method for brain tumors and reduce the gas flow rate and size of the plasma jet, a novel micro-sized CAP device (µCAP) was developed and employed to target glioblastoma tumors in the murine brain. Various plasma diagnostic techniques were applied to evaluate the physics of helium µCAP such as electron density, discharge voltage, and optical emission spectroscopy (OES). The direct and indirect effects of µCAP on glioblastoma (U87MG-RedFluc) cancer cells were investigated in vitro. The results indicate that µCAP generates short- and long-lived species and radicals (i.e., hydroxyl radical (•OH), hydrogen peroxide (H2O2), and nitrite (NO2 −), etc.) with increasing tumor cell death in a dose-dependent manner. Translation of these findings to an in vivo setting demonstrates that intracranial µCAP is effective at preventing glioblastoma tumor growth in the mouse brain. The µCAP device can be safely used in mice, resulting in suppression of tumor growth. These initial observations establish the µCAP device as a potentially useful ablative therapy tool in the treatment of glioblastoma

Optical absorption and single-particle excitations in the 2D Holstein t-J model

To discuss the interplay of electronic and lattice degrees of freedom in systems with strong Coulomb correlations we have performed an extensive numerical study of the two-dimensional Holstein t-J model. The model describes the interaction of holes, doped in a quantum antiferromagnet, with a dispersionsless optical phonon mode. We apply finite-lattice Lanczos diagonalization, combined with a well-controlled phonon Hilbert space truncation, to the Hamiltonian. The focus is on the dynamical properties. In particular we have evaluated the single-particle spectral function and the optical conductivity for characteristic hole-phonon couplings, spin exchange interactions and phonon frequencies. The results are used to analyze the formation of hole polarons in great detail. Links with experiments on layered perovskites are made. Supplementary we compare the Chebyshev recursion and maximum entropy algorithms, used for calculating spectral functions, with standard Lanczos methods.Comment: 32 pages, 12 figures, submitted to Phys. Rev.

Hole concentration and phonon renormalization in Ca-doped YBa_2Cu_3O_y (6.76 < y < 7.00)

In order to access the overdoped regime of the YBa_2Cu_3O_y phase diagram, 2% Ca is substituted for Y in YBa_2Cu_3O_y (y = 7.00,6.93,6.88,6.76). Raman scattering studies have been carried out on these four single crystals. Measurements of the superconductivity-induced renormalization in frequency (Delta \omega) and linewidth (\Delta 2\gamma) of the 340 cm^{-1} B_{1g} phonon demonstrate that the magnitude of the renormalization is directly related to the hole concentration (p), and not simply the oxygen content. The changes in \Delta \omega with p imply that the superconducting gap (\Delta_{max}) decreases monotonically with increasing hole concentration in the overdoped regime, and \Delta \omega falls to zero in the underdoped regime. The linewidth renormalization \Delta 2\gamma is negative in the underdoped regime, crossing over at optimal doping to a positive value in the overdoped state.Comment: 18 pages; 5 figures; submitted to Phys. Rev. B Oct. 24, 2002 (BX8292

Contribution of transcriptional regulation to natural variations in Arabidopsis

BACKGROUND: Genetic control of gene transcription is a key component in genome evolution. To understand the transcriptional basis of natural variation, we have studied genome-wide variations in transcription and characterized the genetic variations in regulatory elements among Arabidopsis accessions. RESULTS: Among five accessions (Col-0, C24, Ler, WS-2, and NO-0) 7,508 probe sets with no detectable genomic sequence variations were identified on the basis of the comparative genomic hybridization to the Arabidopsis GeneChip microarray, and used for accession-specific transcriptome analysis. Two-way ANOVA analysis has identified 60 genes whose mRNA levels differed in different accession backgrounds in an organ-dependent manner. Most of these genes were involved in stress responses and late stages of plant development, such as seed development. Correlation analysis of expression patterns of these 7,508 genes between pairs of accessions identified a group of 65 highly plastic genes with distinct expression patterns in each accession. CONCLUSION: Genes that show substantial genetic variation in mRNA level are those with functions in signal transduction, transcription and stress response, suggesting the existence of variations in the regulatory mechanisms for these genes among different accessions. This is in contrast to those genes with significant polymorphisms in the coding regions identified by genomic hybridization, which include genes encoding transposon-related proteins, kinases and disease-resistance proteins. While relatively fewer sequence variations were detected on average in the coding regions of these genes, a number of differences were identified from the upstream regions, several of which alter potential cis-regulatory elements. Our results suggest that nucleotide polymorphisms in regulatory elements of genes encoding controlling factors could be primary targets of natural selection and a driving force behind the evolution of Arabidopsis accessions

Current applications and future potential for bioinorganic chemistry in the development of anticancer drugs

This review illustrates notable recent progress in the field of medicinal bioinorganic chemistry as many new approaches to the design of innovative metal-based anticancer drugs are emerging. Current research addressing the problems associated with platinum drugs has focused on other metal-based therapeutics that have different modes of action and on prodrug and targeting strategies in an effort to diminish the side-effects of cisplatin chemotherapy

Threshold electronic structure at the oxygen K edge of 3d transition metal oxides: a configuration interaction approach

It has been generally accepted that the threshold structure observed in the oxygen K edge X-ray absorption spectrum in 3d transition metal oxides represents the electronic structure of the 3d transition metal. There is, however, no consensus about the correct description. We present an interpretation, which includes both ground state hybridization and electron correlation. It is based on a configuration interaction cluster calculation using a MO6 cluster. The oxygen K edge spectrum is calculated by annihilating a ligand hole in the ground state and is compared to calculations representing inverse photoemission experiments in which a 3d transition metal electron is added. Clear differences are observed related to the amount of ligand hole created in the ground state. Two "rules" connected to this are discussed. Comparison with experimental data of some early transition metal compounds is made and shows that this simple cluster approach explains the experimental features quite well.Comment: 10 pages, submitted to Phys. Rev. B, tried to make a better PS file

Pressure induced high-spin to low-spin transition in FeS evidenced by x-ray emission spectroscopy

We report the observation of the pressure-induced high-spin to low-spin transition in FeS using new high-pressure synchrotron x-ray emission spectroscopy techniques. The transition is evidenced by the disappearance of the low-energy satellite in the Fe K$\beta$ emission spectrum of FeS. Moreover, the phase transition is reversible and closely related to the structural phase transition from a manganese phosphide-like phase to a monoclinic phase. The study opens new opportunities for investigating the electronic properties of materials under pressure.Comment: ReVTeX, 4 pages, 3 figures inserted with epsfig. minor modifications before submission to PR

Physical origin of the buckling in CuO2_2: Electron-phonon coupling and Raman spectra

It is shown theoretically that the buckling of the CuO$_{2}$ planes in certain cuprate systems can be explained in terms of an electric field across the planes which originates from different valences of atoms above and below the plane. This field results also in a strong coupling of the Raman-active out-of-phase vibration of the oxygen atoms ($B_{1g}$ mode) to the electronic charge transfer between the two oxygens in the CuO$_{2}$ plane. Consequently, the electric field can be deduced from the Fano-type line shape of the $B_{1g}$ phonon. Using the electric field estimated from the electron-phonon coupling the amplitude of the buckling is calculated and found to be in good agreement with the structural data. Direct experimental support for the idea proposed is obtained in studies of YBa$_{2}$Cu$_{3}$O$_{6+x}$ and Bi$_{2}$Sr$_{2}$(Ca$_{1-x}$Y$_{x}$)Cu$_{2}$O$_{8}$ with different oxygen and yttrium doping, respectively, including antiferromagnetic samples. In the latter compound, symmetry breaking by replacing Ca partially by Y leads to an enhancement of the electron-phonon coupling by an order of magnitude.Comment: 12 pages, 4 figures, and 1 tabl

Efficacy of acupuncture for chronic low back pain: protocol for a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Chronic back pain is a major public health problem and the primary reason patients seek acupuncture treatment. Therefore, an objective assessment of acupuncture efficacy is critical for making informed decisions about its appropriate role for patients with this common condition. This study addresses methodological shortcomings that have plagued previous studies evaluating acupuncture for chronic low back pain.</p> <p>Methods and Design</p> <p>A total of 640 participants (160 in each of four arms) between the ages of 18 and 70 years of age who have low back pain lasting at least 3 months will be recruited from integrated health care delivery systems in Seattle and Oakland. They will be randomized to one of two forms of Traditional Chinese Medical (TCM) acupuncture needling (individualized or standardized), a "control" group (simulated acupuncture), or to continued usual medical care. Ten treatments will be provided over 7 weeks. Study participants and the "Diagnostician" acupuncturists who evaluate participants and propose individualized treatments will be masked to the acupuncture treatment actually assigned each participant. The "Therapist" acupuncturists providing the treatments will not be masked but will have limited verbal interaction with participants. The primary outcomes, standard measures of dysfunction and bothersomeness of low back pain, will be assessed at baseline, and after 8, 26, and 52 weeks by telephone interviewers masked to treatment assignment. General health status, satisfaction with back care, days of back-related disability, and use and costs of healthcare services for back pain will also be measured. The primary analysis comparing outcomes by randomized treatment assignment will be analysis of covariance adjusted for baseline value. For both primary outcome measures, this trial will have 99% power to detect the presence of a minimal clinically significant difference among all four treatment groups and over 80% power for most pairwise comparisons. Secondary analyses will compare the proportions of participants in each group that improve by a clinically meaningful amount.</p> <p>Conclusion</p> <p>Results of this trial will help clarify the value of acupuncture needling as a treatment for chronic low back pain.</p> <p>Trial registration</p> <p>Clinical Trials.gov NCT00065585.</p