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Full-Text Articles in Physical Sciences and Mathematics

Photovoltages In Polycrystalline Mosaic Solar Cells, Steluta A. Dinca, Eric A. Schiff Jul 2021

Photovoltages In Polycrystalline Mosaic Solar Cells, Steluta A. Dinca, Eric A. Schiff

Chemistry - All Scholarship

In some thin-film solar cells the light-absorbing layer is a mosaic of crystalline grains whose boundaries run from the back to the front of the cell. We used the semiconductor modeling software Sesame to do numerical calculations of the optoelectronic properties of such cells assuming that recombination of minority photocarriers occurs primarily at the grain boundaries. The work complements analytical results for diffusion-limited recombination at grain boundaries and dislocations. We chose idealized n-CdS/p-CdTe solar cells for illustration. We find that the open-circuit voltage, Voc, under illumination declines logarithmically with increasing ratio D/θ2, where D is the …


Understanding How The Platinum Anticancer Drug Carboplatin Works: From The Bottle To The Cell, Anthony J. Di Pasqua, Jerry Goodisman, James C. Dabrowiak Jul 2012

Understanding How The Platinum Anticancer Drug Carboplatin Works: From The Bottle To The Cell, Anthony J. Di Pasqua, Jerry Goodisman, James C. Dabrowiak

Chemistry - All Scholarship

Carboplatin, a platinum anticancer drug used to treat many types of human cancer, contains a bidentate dicarboxylate chelate leaving ligand, a structural feature that makes it much less chemically reactive than the first-generation platinum anticancer drug cisplatin, which contains two monodentate chloride leaving ligands. In water, carboplatin exists in a monomer-dimer equilibrium with an association constant of K (M -1) ≈ 391, a property that accounts for the long-term stability of its ready-to-use infusion solution. When administered in the clinic, carboplatin is believed to exert its biological effects by interacting with genomic DNA and proteins. The slower substitution kinetics …


Understanding How The Platinum Anticancer Drug Carboplatin Works: From The Bottle To The Cell, Jerry Goodisman, James C. Dabrowiak, Anthony J. Di Pasqua Jul 2012

Understanding How The Platinum Anticancer Drug Carboplatin Works: From The Bottle To The Cell, Jerry Goodisman, James C. Dabrowiak, Anthony J. Di Pasqua

Chemistry - All Scholarship

Carboplatin, a platinum anticancer drug used to treat many types of human cancer, contains a bidentate dicarboxylate chelate leaving ligand, a structural feature that makes it much less chemically reactive than the first-generation platinum anticancer drug cisplatin, which contains two monodentate chloride leaving ligands. In water, carboplatin exists in a monomer–dimer equilibrium with an association constant of K (M−1) ≈ 391, a property that accounts for the long-term stability of its ready-to-use infusion solution. When administered in the clinic, carboplatin is believed to exert its biological effects by interacting with genomic DNA and proteins. The slower substitution kinetics …


Pt (Iv) Complexes As Prodrugs For Cisplatin, Yi Shi, Shu-An Liu, Deborah J. Kerwood, Jerry Goodisman, James C. Dabrowiak Feb 2012

Pt (Iv) Complexes As Prodrugs For Cisplatin, Yi Shi, Shu-An Liu, Deborah J. Kerwood, Jerry Goodisman, James C. Dabrowiak

Chemistry - All Scholarship

The antitumor effects of platinum(IV) complexes, considered prodrugs for cisplatin, are believed to be due to biological reduction of Pt(IV) to Pt(II), with the reduction products binding to DNA and other cellular targets. In this work we used pBR322 DNA to capture the products of reduction of oxoplatin, c,t,c-[PtCl 2(OH) 2(NH 3) 2], 3, and a carboxylate-modified analog, c,t,c-[PtCl 2(OH)(O 2CCH 2CH 2CO 2H)(NH 3) 2], 4, by ascorbic acid (AsA) or glutathione (GSH). Since carbonate plays a significant role in the speciation of platinum complexes in solution, we …


Stability Of Carboplatin And Oxaliplatin In Their Infusion Solutions Is Due To Self-Association, Anthony J. Di Pasqua, Deborah J. Kerwood, Yi Shi, Jerry Goodisman, James C. Dabrowiak Jan 2011

Stability Of Carboplatin And Oxaliplatin In Their Infusion Solutions Is Due To Self-Association, Anthony J. Di Pasqua, Deborah J. Kerwood, Yi Shi, Jerry Goodisman, James C. Dabrowiak

Chemistry - All Scholarship

Carboplatin and oxaliplatin are commonly used platinum anticancer agents that are sold as ready-to-use aqueous infusion solutions with shelf lives of 2 and 3 years, respectively. The observed rate constants for the hydrolysis of these drugs, however, are too large to account for their long shelf lives. We here use electrospray-trap mass spectrometry to show that carboplatin and oxaliplatin are self-associated at concentrations in their ready-to-use infusion solutions (∼27 mM and 13 mM, respectively) and, as expected, when the drug concentration is reduced to more physiologically relevant concentrations (100 μM and 5 μM, respectively) the association equilibrium is shifted in …


Isomer-Dependent Adsorption And Release Of Cis- And Trans-Platin Anticancer Drugs By Mesopomus Silica Nanoparticles, Zhimin Tao, Youwei Xie, Jerry Goodisman, Tewodros Asefa Dec 2010

Isomer-Dependent Adsorption And Release Of Cis- And Trans-Platin Anticancer Drugs By Mesopomus Silica Nanoparticles, Zhimin Tao, Youwei Xie, Jerry Goodisman, Tewodros Asefa

Chemistry - All Scholarship

We report on adsorption and release of the anticancer drugs cisplatin and transplatin from mesoporous silica nanomaterials, emphasizing the differences between cisplatin and its much less toxic isomer. Two types of particles, M.CM-41 and SBA-IS, were used, either as just synthesized or after calcination to remove the templates. The particles were characterized by TEM, nitrogen physisorption, and elemental analysis. The UV-vis spectra of cisplatin and transplatin were obtained and the intensities of several bands (205-210 nm, 210-220 nm, 220-235 nm, and 300-330 nm) were found proportional to drug concentrations, allowing their use for measuring drug concentration. To evaluate drug adsorption …


Noninvasive, In-Vivo, Tissue Modulated Near Infrared Spectroscopy Of Fingertips: Resonance Raman Spectrum Of Human Hemoglobin, Bin Deng, Jerry Goodisman, George Shaheen, Rebecca J. Bussjager, Joseph Chaiken Aug 2010

Noninvasive, In-Vivo, Tissue Modulated Near Infrared Spectroscopy Of Fingertips: Resonance Raman Spectrum Of Human Hemoglobin, Bin Deng, Jerry Goodisman, George Shaheen, Rebecca J. Bussjager, Joseph Chaiken

Chemistry - All Scholarship

Tissue modulation refers to using external stimuli such as mechanical pressure and temperature to produce various spatiotemporal distributions of blood and conceivably other fluids in tissues. Having the capacity to execute tissue modulation1 allows forms of difference spectroscopy to be used to isolate spectroscopic signals from specific components of the tissues noninvasively and in vivo. In the case of human fingertips we can think of the tissues present in the probed volume as being static tissue, plasma and red blood cells (RBCs). Static tissues deform under mechanical pressure based tissue modulation and the only possible fluid motions2 involve plasma …


On Probing Human Fingertips In Vivo Using Near-Infrared Light: Model Calculations, Jerry Goodisman, Joseph Chaiken May 2010

On Probing Human Fingertips In Vivo Using Near-Infrared Light: Model Calculations, Jerry Goodisman, Joseph Chaiken

Chemistry - All Scholarship

We probe volar-side fingertip capillary beds with nearinfrared laser light and collect Raman, Rayleigh, and Mie scattered light and fluorescence. The results are interpreted using radiation transfer theory in the single-scattering approximation. The surface topography of the skin is modeled using the Fresnel equations. The skin is treated as a three-layer material, with a mean-field treatment of tissue composition and related optical properties. The model, with a reasonable choice of tissue parameters, gives a remarkably accurate account of the features of actual measurements. It predicts the optimal values for the incident angle of the laser beam and the distance between …


Cytotoxicity Of Cu(Ii) And Zn(Ii) 2,2′-Bipyridyl Complexes: Dependence Of Ic 50 On Recovery Time, Yi Shi, Bonnie B. Toms, Namrata Dixit, Jerry Goodisman, James C. Dabrowiak Apr 2010

Cytotoxicity Of Cu(Ii) And Zn(Ii) 2,2′-Bipyridyl Complexes: Dependence Of Ic 50 On Recovery Time, Yi Shi, Bonnie B. Toms, Namrata Dixit, Jerry Goodisman, James C. Dabrowiak

Chemistry - All Scholarship

We measure the cytotoxicity of three metal complexes containing the 2,2′-bypyridine ligand, Cu(bpy)(NCS) 2, 1, [Cu(bpy) 2(H 2O)](PF 6) 2, 2, and Zn(bpy) 2(NCS) 2, 3, toward neuroblastoma cells (SK-N-SH) and ovarian cancer cells (OVCAR-3) using two different cell assays. The cells were exposed to various concentrations of the compounds for 1 h and the percent inhibition of cell growth, I, measured for various times after exposure, i.e., as a function of the recovery time t. After developing the theory showing the relationship between I and t, the cytotoxicity data were analyzed to …


Cytotoxicity Of Cu(Ii) And Zn(Ii) 2,2′-Bipyridyl Complexes: Dependence Of Ic_50 On Recovery Time, Yi Shi, Bonnie B. Toms, Namrata Dixit, Jerry Goodisman, James C. Dabrowiak Apr 2010

Cytotoxicity Of Cu(Ii) And Zn(Ii) 2,2′-Bipyridyl Complexes: Dependence Of Ic_50 On Recovery Time, Yi Shi, Bonnie B. Toms, Namrata Dixit, Jerry Goodisman, James C. Dabrowiak

Chemistry - All Scholarship

We measure the cytotoxicity of three metal complexes containing the 2,2′-bypyridine ligand, Cu(bpy)(NCS)2, 1, [Cu(bpy)2(H2O)](PF6)2, 2, and Zn(bpy)2(NCS)2, 3, toward neuroblastoma cells (SKN- SH) and ovarian cancer cells (OVCAR-3) using two different cell assays. The cells were exposed to various concentrations of the compounds for 1 h and the percent inhibition of cell growth, I, measured for various times after exposure, i.e., as a function of the recovery time t. After developing the theory showing the relationship between I and t, the cytotoxicity data were analyzed to reveal that the two copper complexes, 1 and 2, cause the cells to …


Mesoporous Silica Microparticles Enhance The Cytotoxicity Of Anticancer Platinum Drugs, Zhimin Tao, Bonnie Toms, Jerry Goodisman, Tewodros Asefa Feb 2010

Mesoporous Silica Microparticles Enhance The Cytotoxicity Of Anticancer Platinum Drugs, Zhimin Tao, Bonnie Toms, Jerry Goodisman, Tewodros Asefa

Chemistry - All Scholarship

We report on the endocytosis and the time-dependent enhanced cytotoxicity of anticancer platinum drugs when the drugs are combined with (or loaded into) one of the two most common types of mesoporous silica materials, MCM-41 or SBA-15. The anticancer drug cisplatin and its isomer transplatin, when loaded on MCM-41 and SBA-15 microparticles, were less cytotoxic to leukemia cells than the drugs alone after 12 h exposure. However, the drug-loaded microparticles exhibited unprecedented enhanced cytotoxicity to the cancerous cells after 24 h of exposure. This cytotoxicity of the drug-loaded microparticles was even higher than of the pure drugs in solutions, suggesting …


Mesoporosity And Functional Group Dependent Endocytosis And Cytotoxicity Of Silica Nanomaterials, Zhimin Tao, Bonnie B. Toms, Jerry Goodisman, Tewodros Asefa Aug 2009

Mesoporosity And Functional Group Dependent Endocytosis And Cytotoxicity Of Silica Nanomaterials, Zhimin Tao, Bonnie B. Toms, Jerry Goodisman, Tewodros Asefa

Chemistry - All Scholarship

We report different mesoporosity-dependent and functional group-dependent cytotoxicity and endocytosis of various silica nanomaterials on suspended and adherent cells. This dependency further varied with incubation time and particle dosage, and appeared to be associated with the particles' endocytotic efficiency and their chemical and physical properties. We studied two common mesoporous nanomaterials (MSNs), MCM-41 and SBA-15, and one type of solid-cored silica microsphere, paralleled by their quaternary amine functionalized counterparts. Compared to SBA-15, MCM-41 has a larger surface area but smaller pore size, whereas SMS exhibits low surface area and poor porosity. In Jurkat cells, SBA-15 and MCM-41 exhibited different cytotoxicity …


Mesoporosity And Functional Group Dependent Endocytosis And Cytotoxicity Of Silica Nanomaterials, Zhimin Tao, Jerry Goodisman, Tewodros Asefa, Bonnie B. Toms Aug 2009

Mesoporosity And Functional Group Dependent Endocytosis And Cytotoxicity Of Silica Nanomaterials, Zhimin Tao, Jerry Goodisman, Tewodros Asefa, Bonnie B. Toms

Chemistry - All Scholarship

We report different mesoporosity-dependent and functional group-dependent cytotoxicity and endocytosis of various silica nanomaterials on suspended and adherent cells. This dependency further varied with incubation time and particle dosage, and appeared to be associated with the particles’ endocytotic efficiency and their chemical and physical properties. We studied two common mesoporous nanomaterials (MSNs), MCM-41 and SBA-15, and one type of solid-cored silica microsphere, paralleled by their quaternary amine functionalized counterparts. Compared to SBA-15, MCM-41 has a larger surface area but smaller pore size, whereas SMS exhibits low surface area and poor porosity. In Jurkat cells, SBA-15 and MCM- 41 exhibited different …


Simultaneous, Noninvasive Observation Of Elastic Scattering, Fluorescence And Inelastic Scattering As A Monitor Of Blood Flow And Hematocrit In Human Fingertip Capillary Beds, Joseph Chaiken, Jerry Goodisman, Bin Deng, Rebecca J. Bussjager, George Shaheen Jul 2009

Simultaneous, Noninvasive Observation Of Elastic Scattering, Fluorescence And Inelastic Scattering As A Monitor Of Blood Flow And Hematocrit In Human Fingertip Capillary Beds, Joseph Chaiken, Jerry Goodisman, Bin Deng, Rebecca J. Bussjager, George Shaheen

Chemistry - All Scholarship

We report simultaneous observation of elastic scattering, fluorescence, and inelastic scattering from in vivo near-infrared probing of human skin. Careful control of the mechanical force needed to obtain reliable registration of in vivo tissue with an appropriate optical system allows reproducible observation of blood flow in capillary beds of human volar side fingertips. The time dependence of the elastically scattered light is highly correlated with that of the combined fluorescence and Raman scattered light. We interpret this in terms of turbidity (the impeding effect of red blood cells on optical propagation to and from the scattering centers) and the changes …


Accelerated Oxidation Of Epinephrine By Silica Nanoparticles, Zhimin Tao, Gang Wang, Jerry Goodisman, Tewodros Asefa Apr 2009

Accelerated Oxidation Of Epinephrine By Silica Nanoparticles, Zhimin Tao, Gang Wang, Jerry Goodisman, Tewodros Asefa

Chemistry - All Scholarship

We have measured the influence of mesoporous silica (MCM-41 and SBA-15) nanoparticles and dense silica nanoparticles on epinephrine oxidation, a pH-dependent reaction, whose rate is small in acidic or neutral solutions but much greater at higher pH. The reaction was measured by monitoring adrenochrome at 480 nm, the product of epinephrine oxidation. In distilled water (dH 2O) with no particles present, the oxidation of epinephrine occurs slowly but more rapidly at higher pH. The presence of MCM-41 or silica spheres does not accelerate the oxidation, but SBA-15 does, showing that the difference in the structures of nanomaterials leads to …


Kinetic Studies On Enzyme-Catalyzed Reactions: Oxidation Of Glucose, Decomposition Of Hydrogen Peroxide And Their Combination, Zhimin Tao, Ryan A. Raffel, Abdul-Kader Souid, Jerry Goodisman Apr 2009

Kinetic Studies On Enzyme-Catalyzed Reactions: Oxidation Of Glucose, Decomposition Of Hydrogen Peroxide And Their Combination, Zhimin Tao, Ryan A. Raffel, Abdul-Kader Souid, Jerry Goodisman

Chemistry - All Scholarship

The kinetics of the glucose oxidase-catalyzed reaction of glucose with O2, which produces gluconic acid and hydrogen peroxide, and the catalase-assisted breakdown of hydrogen peroxide to generate oxygen, have been measured via the rate of O2 depletion or production. The O2 concentrations in air-saturated phosphate-buffered salt solutions were monitored by measuring the decay of phosphorescence from a Pd phosphor in solution; the decay rate was obtained by fitting the tail of the phosphorescence intensity profile to an exponential. For glucose oxidation in the presence of glucose oxidase, the rate constant determined for the rate-limiting step was k = (3.0 ± …


Quantitative Measure Of Cytotoxicity Of Anticancer Drugs And Other Agents., Zhimin Tao, Eyone Jones, Jerry Goodisman, Abdul-Kader Souid Jun 2008

Quantitative Measure Of Cytotoxicity Of Anticancer Drugs And Other Agents., Zhimin Tao, Eyone Jones, Jerry Goodisman, Abdul-Kader Souid

Chemistry - All Scholarship

Many anticancer drugs act on cancer cells to promote apoptosis, which includes impairment of cellular respiration (mitochondrial O(2) consumption). Other agents also inhibit cellular respiration, sometimes irreversibly. To investigate the sensitivity of cancer cells to cytotoxins, including anticancer drugs, we compare the profiles of cellular O(2) consumption in the absence and presence of these agents. Oxygen measurements are made at 37 degrees C, using glucose as a substrate, with [O(2)] obtained from the phosphorescence decay rate of a palladium phosphor. The rate of respiration k is defined as -d[O(2)]/dt in a sealed container. Different toxins produce different profiles of impaired …


Quantitative Measure Of Cytotoxicity Of Anticancer Drugs And Other Agents, Zhimin Tao, Eyone Jones, Jerry Goodisman, Abdul-Kader Souid Apr 2008

Quantitative Measure Of Cytotoxicity Of Anticancer Drugs And Other Agents, Zhimin Tao, Eyone Jones, Jerry Goodisman, Abdul-Kader Souid

Chemistry - All Scholarship

Many anticancer drugs act on cancer cells to promote apoptosis, which includes impairment of cellular respiration (mitochondrial O 2 consumption). Other agents also inhibit cellular respiration, sometimes irreversibly. To investigate the sensitivity of cancer cells to cytotoxins, including anticancer drugs, we compare the profiles of cellular O 2 consumption in the absence and presence of these agents. Oxygen measurements are made at 37 °C, using glucose as a substrate, with [O 2] obtained from the phosphorescence decay rate of a palladium phosphor. The rate of respiration k is defined as -d[O 2]/dt in a sealed container. Different toxins …


Mesoporous Silica Nanoparticles Inhibit Cellular Respiration, Zhimin Tao, Tewodros Asefa, Cole Duncan, Abhishek Anan, Jerry Goodisman Mar 2008

Mesoporous Silica Nanoparticles Inhibit Cellular Respiration, Zhimin Tao, Tewodros Asefa, Cole Duncan, Abhishek Anan, Jerry Goodisman

Chemistry - All Scholarship

We studied the effect of two types of mesoporous silica nanoparticles, MCM-41 and SBA-15, on mitochondrial O 2 consumption (respiration) in HL-60 (myeloid) cells, Jurkat (lymphoid) cells, and isolated mitochondria. SBA-15 inhibited cellular respiration at 25-500/ μg/mL; the inhibition was concentration-dependent and time-dependent. The cellular ATP profile paralleled that of respiration. MCM-41 had no noticeable effect on respiration rate. In cells depleted of metabolic fuels, 50 μg/mL SBA-15 delayed the onset of glucose-supported respiration by 12 min and 200 μg/mL SBA-15 by 34 min; MCM-41 also delayed the onset of glucose-supported respiration. Neither SBA-15 nor MCM-41 affected cellular glutathione. Both …


New Extracellular Resistance Mechanism For Cisplatin, Corey R. Centerwall, Deborah J. Kerwood, Jerry Goodisman, Bonnie B. Toms, James C. Dabrowiak Jan 2008

New Extracellular Resistance Mechanism For Cisplatin, Corey R. Centerwall, Deborah J. Kerwood, Jerry Goodisman, Bonnie B. Toms, James C. Dabrowiak

Chemistry - All Scholarship

The HSQC NMR spectrum of 15N-cisplatin in cell growth media shows resonances corresponding to the monocarbonato complex, cis-[Pt(NH3)2(CO3)Cl]-, 4, and the dicarbonato complex, cis-[Pt(NH3)2(CO3)2]-2, 5, in addition to cisplatin itself, cis-[Pt(NH3)2Cl2], 1. The presence of Jurkat cells reduces the amount of detectable carbonato species by (2.8 ± 0.7) fmol per cell and has little effect on species 1. Jurkat cells made resistant to cisplatin reduce the amount of detectable carbonato species by (7.9 ± 5.6) …


Modification Of Carboplatin By Jurkat Cells, Anthony J. Di Pasqua, Jerry Goodisman, Deborah J. Kerwood, James C. Dabrowiak, Bonnie B. Toms Oct 2007

Modification Of Carboplatin By Jurkat Cells, Anthony J. Di Pasqua, Jerry Goodisman, Deborah J. Kerwood, James C. Dabrowiak, Bonnie B. Toms

Chemistry - All Scholarship

Using [1H,15N] heteronuclear single quantum coherance (HSQC) NMR and 15N-labeled carboplatin, 1, we show that Jurkat cells affect the rate of disappearance of the HSQC NMR peak in culture medium for this Pt2+ anticancer drug. The decay or disappearance rate constant for 1 in culture medium containing cells is k1=kc[CO32-]+km+kuN, where kc is the rate constant for reaction of 1 with carbonate in the medium, km is the rate constant for reaction of 1 with all other components of the medium, and ku is the rate constant for reaction of …


Oxygen Measurement Via Phosphorescence: Reaction Of Sodium Dithionite With Dissolved Oxygen, Zhimin Tao, Jerry Goodisman, Abdul-Kader Souid Sep 2007

Oxygen Measurement Via Phosphorescence: Reaction Of Sodium Dithionite With Dissolved Oxygen, Zhimin Tao, Jerry Goodisman, Abdul-Kader Souid

Chemistry - All Scholarship

A homemade instrument for the measurement of oxygen concentration in aqueous solutions measures the decay rate of the phosphorescence of a Pd-porphyrin complex (phosphor) dissolved in the solution, which is flashed every 0.1 s with 630 nm light. The concentration of O 2 is a linear function of the decay rate. The instrument is used to study the reaction of dithionite (S 2O 4 2-) with O 2 at 25°C and 37°C. It is found that the ratio of dithionite to oxygen consumed in the reaction is 1.2 ± 0.2 at 25°C and 1.7 ± 0.1 at 37°C, …


Hard/Soft-Acid/Base Principle And The Reaction Ahbs+Asbh → Ahbh+Asbs, Jerry Goodisman Aug 2007

Hard/Soft-Acid/Base Principle And The Reaction Ahbs+Asbh → Ahbh+Asbs, Jerry Goodisman

Chemistry - All Scholarship

A demonstration of the hard/soft-acid/base principle involves showing that the energy change for Ah Bs + As Bh → Ah Bh + As Bs is always negative. We point out problems with assumptions made about hardness and strength of the components, but emphasize that problems with the way in which energies are calculated are even more important.


Modification Of Carboplatin By Jurkat Cells, Anthony J. Di Pasqua, Jerry Goodisman, Deborah J. Kerwood, Bonnie B. Toms, James C. Dabrowiak Jun 2007

Modification Of Carboplatin By Jurkat Cells, Anthony J. Di Pasqua, Jerry Goodisman, Deborah J. Kerwood, Bonnie B. Toms, James C. Dabrowiak

Chemistry - All Scholarship

Using [1H,15N] heteronuclear single quantum coherance (HSQC) NMR and 15N-labeled carboplatin, 1, we show that Jurkat cells affect the rate of disappearance of the HSQC NMR peak in culture medium for this Pt2+ anticancer drug. The decay or disappearance rate constant for 1 in culture medium containing cells is k1 = kc [CO32 -] + km + ku N, where kc is the rate constant for reaction of 1 with carbonate in the medium, km is the rate constant for reaction of 1 with all …


Role Of Carbonate In The Cytotoxicity Of Carboplatin, Anthony J. Di Pasqua, Jerry Goodisman, Deborah J. Kerwood, Bonnie B. Toms, Ronald L. Dubowy Feb 2007

Role Of Carbonate In The Cytotoxicity Of Carboplatin, Anthony J. Di Pasqua, Jerry Goodisman, Deborah J. Kerwood, Bonnie B. Toms, Ronald L. Dubowy

Chemistry - All Scholarship

Carboplatin, [Pt(NH3)2(CBDCA-O,O')], 1, where CBDCA is cyclobutane-1,1-dicarboxylate, is used against ovarian, lung, and other types of cancer. We recently showed (Di Pasqua et al. (2006) Chem. Res. Toxicol. 19, 139-149) that carboplatin reacts with carbonate under conditions that simulate therapy to produce carbonato carboplatin, cis-[Pt(NH3)2(O-CBDCA)(CO3)]2-, 2. We use 13C and 1H NMR and UV-visible absorption spectroscopy to show that solutions containing carboplatin that have been aged in carbonate buffer under various conditions contain 1, 2, and other compounds. We then show that aging carboplatin in carbonate produces compounds that are more toxic to human neuroblastoma (SK-N-SH), proximal renal tubule (HK-2) …


Scaling And The Smoluchowski Equations, Jerry Goodisman, J. Chaiken Aug 2006

Scaling And The Smoluchowski Equations, Jerry Goodisman, J. Chaiken

Chemistry - All Scholarship

The Smoluchowski equations, which describe coalescence growth, take into account combination reactions between a j-mer and a k-mer to form a (j+k)-mer, but not breakup of larger clusters to smaller ones. All combination reactions are assumed to be second order, with rate constants K jk. The K jk are said to scale if K λj,γkμγ μK jk for j ≤ k. It can then be shown that, for large k, the number density or population of k-mers is given by Ak ae -bk, where A is a normalization constant (a function of a, …


Application Of Scaling And Kinetic Equations To Helium Cluster Size Distributions: Homogeneous Nucleation Of A Nearly Ideal Gas, J. Chaiken, Jerry Goodisman, Oleg Komilov, J. Peter Toennies Aug 2006

Application Of Scaling And Kinetic Equations To Helium Cluster Size Distributions: Homogeneous Nucleation Of A Nearly Ideal Gas, J. Chaiken, Jerry Goodisman, Oleg Komilov, J. Peter Toennies

Chemistry - All Scholarship

A previously published model of homogeneous nucleation [Villarica et al., J. Chem. Phys. 98, 4610 (1993)] based on the Smoluchowski [Phys. Z. 17, 557 (1916)] equations is used to simulate the experimentally measured size distributions of 4He clusters produced in free jet expansions. The model includes only binary collisions and does not consider evaporative effects, so that binary reactive collisions are rate limiting for formation of all cluster sizes despite the need for stabilization of nascent clusters. The model represents these data very well, accounting in some cases for nearly four orders of magnitude in variation in abundance over …


Formation Of Monofunctional Cisplatin-Dna Adducts In Carbonate Buffer, Alexandra Binter, Jerry Goodisman, James C. Dabrowiak Jul 2006

Formation Of Monofunctional Cisplatin-Dna Adducts In Carbonate Buffer, Alexandra Binter, Jerry Goodisman, James C. Dabrowiak

Chemistry - All Scholarship

Carbonate in its various forms is an important component in blood and the cytosol. Since, under conditions that simulate therapy, carbonate reacts with cisplatin to form carbonato complexes, one of which is taken up and/or modified by the cell [C.R. Centerwall, J. Goodisman, D.J. Kerwood, J. Am. Chem. Soc., 127 (2005) 12768–12769], cisplatin-carbonato complexes may be important in the mechanism of action of cisplatin. In this report we study the binding of cisplatin to pBR322 DNA in two different buffers, using gel electrophoresis. In 23.8 mM HEPES, N-(2-hydroxyethyl)-piperazine-N′-2-ethanesulfonic acid, 5 mM NaCl, pH 7.4 buffer, cisplatin produces …


Dactinomycin Impairs Cellular Respiration And Reduces Accompanying Atp Formation, Zhimin Tao, Syed S. Ahmad, Harvey S. Penefsky, Jerry Goodisman, Abdul Kader Souid Apr 2006

Dactinomycin Impairs Cellular Respiration And Reduces Accompanying Atp Formation, Zhimin Tao, Syed S. Ahmad, Harvey S. Penefsky, Jerry Goodisman, Abdul Kader Souid

Chemistry - All Scholarship

The effect of dactinomycin on cellular respiration and accompanying ATP formation was investigated in Jurkat and HL-60 cells. Cellular mitochondrial oxygen consumption (measured by a homemade phosphorescence analyzer) and ATP content (measured by the luciferin-luciferase bioluminescence system) were determined as functions of time t during continuous exposure to the drug. The rate of respiration, k, was the negative of the slope of [O2] versus t. Oxygen consumption and ATP content were diminished by cyanide, confirming that both processes involved oxidations in the mitochondrial respiratory chain. In the presence of dactinomycin, k decreased gradually with t, the decrease being more pronounced …


Constancy In Integrated Cisplatin Plasma Concentrations Among Pediatric Patients, Jerry Goodisman, Abdul-Kader Souid Mar 2006

Constancy In Integrated Cisplatin Plasma Concentrations Among Pediatric Patients, Jerry Goodisman, Abdul-Kader Souid

Chemistry - All Scholarship

The authors report on the variability in the integrated quantity of free (unbound) plasma cisplatin (area under curve of plasma concentration versus time, AUC). The AUC was measured in 19 patients receiving cisplatin doses proportional to body surface areas (BSA), 30mg/m2 over 1 hour. The relative standard deviation (RSD, population standard deviation divided by mean value) for the maximum free plasma cisplatin concentration (Cmax, μM) was 0.338; for the half-life (t½, minute), 0.210; and for the AUC (μM minute), 0.320. Thus, BSA-based dosing gave significant variability in the AUC. We attempted to use (weight)a(height)b, seeking values of a and b …