cssi/SciSciGPT-SciSciNet huggingface dataset:
A Simplified Predictive Index for Renal Replacement Therapy After Cardiac Surgery

JAMA Derivation and Validation of a Simplified Predictive Index for Renal Replacement Therapy After Cardiac Surgery Duminda N. Wijeysundera, MD; Keyvan Karkouti, MD, MSc; Jean-Yves Dupuis, MD; Vivek Rao, MD, PhD; Christopher T. Chan, MD; John T. Granton, MD; W. Scott Beattie, MD, PhD Context: A predictive index for renal replacement therapy (RRT; hemodialysis or continuous venovenous hemodiafiltration) after cardiac surgery may improve clinical decision making and research design. Objective: To develop a predictive index for RRT using preoperative information. Design, Setting, and Patients: Retrospective cohort of 20 131 cardiac surgery patients at 2 hospitals in Ontario, Canada. The derivation cohort consisted of 10 751 patients at Toronto General Hospital (1999-2004). The validation cohorts consisted of 2566 patients at Toronto General Hospital (2004-2005) and 6814 patients at Ottawa Heart Institute (1999-2003). Main Outcome Measure: Postoperative RRT. Results: RRT rates in the derivation, Toronto validation, and Ottawa validation cohorts were 1.3%, 1.8%, and 2.2%, respectively. Multivariable predictors of RRT were preoperative estimated glomerular filtration rate, diabetes mellitus requiring medication, left ventricular ejection fraction, previous cardiac surgery, procedure, urgency of surgery, and preoperative intra-aortic balloon pump. The predictive index was scored from 0 to 8 points. An estimated glomerular filtration rate less than or equal to 30 mL/min was assigned 2 points; other components were assigned 1 point each: estimated glomerular filtration rate 31 to 60 mL/min, diabetes mellitus, ejection fraction less than or equal to 40%, previous cardiac surgery, procedure other than coronary artery bypass grafting, intra-aortic balloon pump, and nonelective case. Among the 53% of patients with low risk scores (≤1), the risk of RRT was 0.4%; by comparison, this risk was 10% among the 6% of patients with high-risk scores (≥4). The predictive index had areas under the receiver operating characteristic curve in the derivation, Toronto validation, and Ottawa validation cohorts of 0.81, 0.78, and 0.78, respectively. When these cohorts were stratified based on index scores, likelihood ratios for RRT were more concordant than observed RRT rates. Conclusion: RRT after cardiac surgery is predicted by readily available preoperative information. A simple predictive index based on this information discriminated well between low- and high-risk patients in derivation and validation cohorts. The index had improved generalizability when used to predict likelihood ratios for RRT. jama. 2007;297(16):1801-1809.
Two conformations in the human kinesin power stroke defined by X-ray crystallography and EPR spectroscopy

Crystal structures of the molecular motor kinesin show conformational variability in a structural element called the neck linker. Conformational change in the neck linker, initiated by ATP exchange, is thought to drive the movement of kinesin along the microtubule track. We use site-specific EPR measurements to show that when microtubules are absent, the neck linker exists in equilibrium between two structural states (disordered and 'docked'). The active site nucleotide does not control the position taken by the neck linker. However, we find that sulfate can specifically bind near the nucleotide site and stabilize the docked neck linker conformation, which we confirmed by solving a new crystal structure. Comparing the crystal structures of our construct with the docked or undocked neck linker reveals how microtubule binding may activate the nucleotide-sensing mechanism of kinesin, allowing neck linker transitions to power motility.
Trough serum vancomycin levels predict the relapse of gram-positive peritonitis in peritoneal dialysis patients

We reviewed 31 episodes of gram-positive peritonitis that occurred in our peritoneal dialysis population between 1990 and 1993 in an attempt to identify the risk factor(s) for peritonitis relapse. All patients were treated with 4 weekly doses of intravenous vancomycin. Vancomycin doses no. 1 and 2 were based on body weight (15 mg/kg with a 1-g minimum); vancomycin doses no. 3 and 4 were adjusted in an attempt to maintain the trough serum vancomycin level at greater than 12 mg/L. Nine peritonitis episodes complicated by a relapse were identified. Peritonitis episodes preceding a relapse were similar to relapse-free episodes with respect to patient age, diabetes, peritoneal dialysis modality, duration of peritoneal dialysis treatment, residual urea clearance, peritoneal fluid cell count, causative organism, and weekly vancomycin dose. However, cumulative 4-week mean trough vancomycin levels were consistently lower during peritonitis episodes preceding a relapse (7.8 +/- 0.6 mg/L during relapse-prone episodes v 13.7 +/- 0.9 mg/L during relapse-free episodes; P = 0.0004). Furthermore, relapses developed during nine of 14 peritonitis episodes demonstrating a 4-week mean trough vancomycin level less than 12 mg/L compared with zero of 17 episodes with a 4-week trough level greater than 12 mg/L (P < 0.05). The detection of a low initial 7-day trough vancomycin level also was a useful marker for subsequent peritonitis relapse. In 13 peritonitis episodes associated with an initial trough level less than 9 mg/L, nine were complicated by a relapse.(ABSTRACT TRUNCATED AT 250 WORDS)
Methadone, Buprenorphine, and Street Drug Interactions with Antiretroviral Medications

While street drugs appear unlikely to alter the metabolism of antiretroviral (ARV) medications, several ARVs may induce or inhibit metabolism of various street drugs. However, research on these interactions is limited. Case reports have documented life-threatening overdoses of ecstasy and gamma-hydroxybutyrate after starting ritonavir, an ARV that inhibits several metabolic enzymes. For opioid addiction, methadone or buprenorphine are the treatments of choice. Because a number of ARVs decrease or increase methadone levels, patients should be monitored for methadone withdrawal or toxicity when they start or stop ARVs. Most ARVs do not cause buprenorphine withdrawal or toxicity, even if they alter buprenorphine levels, with rare exceptions to date including atazanavir/ritonavir associated with significant increases in buprenorphine and adverse events related to sedation and mental status changes in some cases. There are newer medications yet to be studied with methadone or buprenorphine. Further, there are many frequently used medications in treatment of complications of HIV disease that have not been studied. There is need for continuing research to define these drug interactions and their clinical significance.
Preparation and characterization of sol-gel derived copper-strontium-oxide thin films

Abstract P-type transparent conductive oxides have potential applications in photovoltaics, transparent electronics, and organic optoelectronics. In this paper, results are presented on the synthesis of Cu 2 SrO 2 thin films, a p-type transparent conducting oxide by a sol–gel route. Cu(II)methoxide and Sr-metal dissolved in anhydrous isopropanol were used as precursor for the sol preparation. For potassium (K) doping, K-acetate dissolved in anhydrous isopropanol was used as the precursor. Films were spin-coated onto substrates and partially pyrolysed in air at 225°C. After partial pyrolization, a two stage annealing sequence was used to achieve the final film microstructure and composition. Although combinations of oxygen pressure, annealing time, and annealing temperature were used to obtain phase pure Cu 2 SrO 2 thin films, X-ray diffraction consistently showed the presence of Cu 2 O as a second phase with Cu 2 SrO 2 −the desired phase. Microstructural studies showed similar phase separation in the films and confirmed the microcrystalline nature. The best conductivities obtained for the undoped and 1% K-doped films were 2 × 10 − 3 and 1.2 × 10 − 2 S/cm, respectively. Both films showed a broad optical absorption edge in the visible range.
Optimizing Ultrafiltration Parameters for the Development of a Lowfat Cheddar Cheese

Abstract Ultrafiltration was used to produce a high quality, lowfat Cheddar cheese. Acidification and diafiltration were performed during UF to optimize manufacturing conditions. Treatments consisted of concentration by UF with and without acidification and diafiltration steps. Samples of concentrate and permeate were taken in Whirl Pak bags at 20-min intervals during UF. These samples were immediately refrigerated and analyzed the following day for fat, protein, moisture, pH, and curd strength. Sensory evaluation of the lowfat cheese for flavor and body and texture was performed on 0 d and after 1, 2, 3, 4, 6, and 12 mo of storage at 8°C. Analyses showed significant reductions in lactose and calcium content of the retentate. Sensory evaluation of the lowfat Cheddar cheese manufactured from acidified and diafiltered UF lowfat milk revealed a significant improvement in the flavor and body and texture of the cheese upon extended storage (12 mo) at 8°C when compared with that of UF low-fat Cheddar cheese made without these two steps.
Michael Psellos on the rhetoric of hagiography and the Life of St Auxentius

AbstractHagiography and rhetoric appear incompatible according to modern conceptions of how each functioned in Byzantine society. Rhetoric, a vehicle of upward mobility, depended upon an elaborate theoretical literature and promised to skilled practitioners enviable professional reputations in remunerative public pursuits among influential people. Hagiography, in contrast, appealed to a socially diverse Christian audience and recorded the deeds of those who chose to seek spiritual rather than worldly rewards. Rhetoric and hagiography, however, intertwined inevitably in the Byzantine world, as did rhetoric and most literary genres. The basic intention of the hagiographer was, after all, to persuade, impress, and edify his audience, and the tenets of rhetoric assisted him in that goal. Since education in Byzantium included at all levels both the theory and practice of rhetoric, the educated portion of a hagiographer's audience would expect him to use the familiar devices of rhetoric and would scorn poorly c...
Patient tumor EGFR and PDGFRA gene amplifications retained in an invasive intracranial xenograft model of glioblastoma multiforme.

We have previously described a panel of serially transplantable glioblastoma multiforme xenograft lines established by direct subcutaneous injection of patient tumor tissue in the flanks of nude mice. Here we report the characterization of four of these lines with respect to their histopathologic, genetic, and growth properties following heterotopic-to-orthotopic (flank-to-intracranial) transfer. Cells from short-term cultures, established from excised flank xenografts, were harvested and injected into the brains of nude mice (106 cells per injection). The intracranial tumors generated from these injections were all highly mitotic as well as highly invasive, but they lacked necrotic features in most instances and failed to show endothelial cell proliferation in all instances. For mice receiving injections from a common explant culture, tumor intracranial growth rate was consistent, as indicated by relatively narrow ranges in survival time. In contrast to the loss of epidermal growth factor receptor gene (EGFR) amplification in cell culture, high-level amplification and overexpression of EGFR were retained in intracranial tumors established from two EGFR-amplified flank tumors. A third intracranial tumor retained patient tumor amplification and high-level expression of platelet-derived growth factor receptor alpha gene. Because the heterotopic-to-orthotopic transfer and propagation of glioblastoma multiforme preserves the receptor tyrosine kinase (RTK) gene amplification of patient tumors, this approach should facilitate investigations for determining the extent to which RTK amplification status influences tumor response to RTK-directed therapies. The fact that such studies were carried out by using an invasive tumor model in an anatomically appropriate context should ensure a rigorous preclinical assessment of agent efficacy.
Comment on “Long-Lived Giant Number Fluctuations in a Swarming Granular Nematic”

Narayan et al. (Reports, 6 July 2007, p. 105) reported giant number fluctuations attributed to curvature-driven active currents specific for nonequilibrium nematic systems. We present data demonstrating that similar results can be found in systems of spherical particles due either to inelastic clustering or persistent density inhomogeneity, suggesting two alternative explanations for their results.
The ‘ability’ scale in item characteristic curve theory

For the six available sets of empirical data, the discrimination (slope) parameter of the logistic item characteristic curve was found to have a significant positive correlation over items with the difficulty (location) parameter. This unpleasant situation can be eliminated by a suitably chosen transformation of the ability scale. An example of the transformation is given and some empirical results of using the transformed scale are shown.
The effect of stimulation and blocking of histamine H2 receptors on the turnover of the serotonin in different parts of the alimentary tract and the brain of the rat.

In the experiments performed on Wistar rats it was found that histamine (0.05 and 0.5 mg/kg i.p.) caused an acceleration of the turnover of serotonin (5-HT) in the stomach. After the lowest dose of ranitidine (3 mg/kg i.p.) a decrease in the rate of 5-HT turnover in the stomach was observed, whereas the higher doses (15.0 and 30 mg/kg i.p.) accelerated the turnover of this amine. In the duodenum, both doses of histamine accelerated the turnover of 5-HT, however, ranitidine in all doses induced a reduction in the rate of 5-HT turnover in this part of the alimentary tract. In the intestine, both doses of histamine enhanced the turnover of 5-HT but after all doses of ranitidine a decrease of the turnover was observed. The blockade of histamine H2 receptors with ranitidine did not completely abolish the effects of histamine on the 5-HT system, in the parts of the rat digestive system studied which suggests also an indirect activity of other receptors in presented observations. In the rat brain, an acceleration of the turnover of 5-HT after both doses of histamine was found. However, ranitidine only reduced the rate of 5-HT turnover at the lowest dose. In animals treated with ranitidine (15 mg/kg i.p.) for three days, histamine did not produce any change in the turnover of 5-HT in rat brain. These experiments show, that in the alimentary tract a relationship exists between histaminergic and serotoninergic systems.
Resistance of mice suppressed for IgM production to Babesia microti infection.

The immunological mechanisms responsible for overcoming infections with Babesia, an intra-erythrocytic protozoan, are not fully understood. Although high titres of specific anti-babesial antibodies have been observed in several species of animals1, and protection has been obtained by transfer of large volumes of recovery serum2, the role of antibody in the immune response to an infection is uncertain. The present study investigates the nature of B-cell participation during Babesia microti infections by observing the course of the disease in mice in which IgM production has been suppressed from birth and which contain no B cells. The results show that, in contrast to control mice, which develop and subsequently clear circulating parasitaemias, suppressed mice show an unexpected resistance to infection as reflected by a virtual absence of parasites in the peripheral circulation.
A closed-form, hierarchical, multi-interphase model for composites—Derivation, verification and application to nanocomposites

A closed form Hierarchical Multi-interphase Model (HMM) based on the classical elasticity theory is proposed to study the influence of the interphase around inclusions on the enhancement mechanism of composites in the elastic regime. The HMM is verified by three-dimensional Finite Element simulations and highly consistent results are obtained for the cases with relatively low stiffness ratios (SR) between the inclusions and the matrix (SR<100). For cases with large SRs (up to 10,000), the HMM with the assumption of ellipsoidal inclusions provides a lower bound for the stiffnesses of composites enhanced by non-ellipsoidal particles with the same aspect ratio of inclusions. The Modified Hierarchical Multi-interphase Model (MHMM) is developed by introducing morphology parameters to the HMM, to capture the high morphology sensitivity of composites at high SRs with the non-uniform stress–strain fields. In addition, one important feature of the HMM and the MHMM is the particle-size dependency. As an application of this model to predict size effects and shape effects, the enhancement efficiencies of three typical inclusions – sphere, fiber-like particle and platelet – at different scales, are studied and compared, producing useful information about the morphology optimization at the nano-scale.
Does spelling matter in instant messaging?: answers from measuring error correction frequency

Although Instant Messaging (IM) is widely perceived as a communication mode with relaxed spelling and grammar rules, three measures show that people still perceive errors and often correct them. In two usability studies with different tasks, participants on average corrected 89 and 95 percent of their typographical and grammatical errors that they identified. However, their self-correction rates were substantially lower and more variable when compared to all errors found by independent proofreaders. The results from the second measurement showed that participants were aware of their own errors. They judged their own error rate to be significantly higher than the other person's even when that was not true. Using the third measure, correction rates in IM were found to be lower than "normal" typing. The self-sensitivity to errors prompts further investigation of techniques for error detection and correction appropriate for IM's rapid pace and relaxed linguistic register.
The metal-binding properties of DREAM: evidence for calcium-mediated changes in DREAM structure.

DREAM, an EF-hand protein, associates with and modulates the activity of presenilins and Kv4 potassium channels in neural and cardiac tissues and represses prodynorphin and c-fos gene expression by binding to DNA response elements in these genes. Information concerning the metal-binding properties of DREAM and the consequences of metal binding on protein structure are important in understanding how this protein functions in cells. We now show that DREAM binds 1 mol of calcium/mol of protein with relatively high affinity and another 3 mol of calcium with lower affinity. DREAM binds 1 mol of magnesium/mol of protein. DREAM, pre-loaded with 1 mol of calcium, binds 1 mol of magnesium, thus demonstrating that the magnesium-binding site is distinct from the high affinity calcium-binding site. Analysis of metal binding to mutant DREAM protein constructs localizes the high affinity calcium-binding site and the magnesium-binding site to EF-hands 3 or 4. Binding of calcium but not magnesium changes the conformation, stability, and α-helical content of DREAM. Calcium, but not magnesium, reduces the affinity of apo-DREAM for specific DNA response elements in the prodynorphin and c-fos genes. We conclude that DREAM binds calcium and magnesium and that calcium, but not magnesium, modulates DREAM structure and function.
Cultural Therapeutic Awareness and Sickle Cell Anemia

Sickle cell anemia is a hereditary blood disorder in which abnormal red blood cells damage the cerebrovascular system as well as organs such as the liver and spleen. Children with sickle cell anemia manifest high mortality rates, depres- sion, pain, strokes, and social maladjustment. Interventions often challenge the family's beliefs and attitudes. A cognitive behavioral approach, the Health Belief Model, was offered as a strategic option in working with African American cli- ents diagnosed with sickle cell anemia. Two descriptive case studies were pre- sented. Whereas one case illustrated a lack of a coordinated system of care, the other demonstrated the effectiveness of a multidisciplinary system of services. The purpose of this article is to present a brief description of the medical, neu - rological, and psychoeducational problems caused by sickle cell anemia and to suggest that services be provided by culturally competent, systems-oriented professionals.
A discussion of the paper “The distributions of bound sulfates and chlorides in concrete subjected to mixed NaCl, MgSO4, Na2SO4 attack” by P.W. Brown and Steven Badger ☆

Abstract The use of scanning electron microscopy (SEM) for investigating sulfate attack to concrete is fraught with pitfalls, including analyses of volumes only about one-trillionth of a cubic inch, extrapolation of elemental identifications to compounds, interpretation of results without a “zero-time” basis, and failure to consider optical petrography conclusions.
Maternal Psychopathology and Perception of Child Behavior in Psychiatrically Referred and Child Maltreatment Families

Thirty-five mothers of abused and neglected children and 35 demographically matched mothers of children referred to a general child psychiatry clinic were compared on the basis of maternal psychopathology and index child behaviors. Standardized assessment instruments (the BSI and Achenbach CBC) were employed. While comparable levels of child maladjustment were reported, maternal psychopathology was greater for the maltreatment group who, in addition, demonstrated IQs in the Dull Normal Range. Nonabused siblings were seen as relatively well-adjusted. Perceived child behavior was strongly associated with self-reported maternal psychopathology.
A Prospective Study of the Effect of IV Pentamidine Therapy on Ventricular Arrhythmias and QTc Prolongation in HIV-infected Patients

Study objectives IV pentamidine therapy in HIV-infected patients has been associated in case reports and one uncontrolled prospective series with frequent prolongation of the rate-corrected QT interval (QTc) and a high risk for potentially lethal ventricular arrhythmias, especially torsade de pointes. The aim of this study was to prospectively examine in a controlled manner the effect of IV pentamidine therapy on the QT interval and the incidence of ventricular arrhythmias. Design Open, nonrandomized, prospective evaluation of ventricular arrhythmia incidence in HIV-infected patients receiving pentamidine or trimethoprim-sulfamethoxazole (TMP-SMX) utilizing Holter monitoring prior to and during therapy with these agents. Setting Staten Island University Hospital, Staten Island, NY. Patients Twenty-seven HIV-infected patients, of whom 16 received IV pentamidine and 11 received IV TMP-SMX. Measurements and results Study patients underwent Holter monitoring prior to therapy and during the first 3 days and last 2 days of therapy with pentamidine or TMP-SMX, 12-lead ECG prior to and every 24 to 48 h, serum electrolytes prior to and on days 3, 6, 9, and 12 of therapy, and baseline transthoracic two-dimensional and Doppler echocardiography. In the pentamidine group, the results for each monitoring period were as follows (means are presented ± SEM): pretherapy, 1.66±1.03 (median=0) premature ventricular complexes (PVCs) per hour, zero nonsustained ventricular tachycardia (NSVT), zero sustained ventricular tachycardia (VT); early therapy, 1.55 ±0.91 (median=0.04) PVCs per hour, two NSVT (both ≤5 complexes), zero sustained VT; late therapy, 1.69±1.17 (median=0.08) PVCs per hour, zero NSVT, zero sustained VT (p value not significant for early or late therapy as compared to pretherapy for PVCs per hour, NSVT, or sustained VT). In the TMP-SMX group, the Holter monitoring results were as follows: pretherapy, 1.36 ±1.27 (median=0) PVCs per hour, zero NSVT, zero sustained VT; early therapy, 0.71±0.53 (median=0.03) PVCs per hour, two NSVT, zero sustained VT; late therapy, 0.56±0.51 (median=0) PVCs per hour, zero NSVT, zero sustained VT (p value not significant for pretherapy, early therapy, or late therapy with TMP-SMX as compared to pentamidine for PVCs per hour, NSVT, or VT). The QTc also did not significantly differ during therapy with pentamidine as compared to TMP-SMX. The mean QTc in the pentamidine group decreased during therapy as compared to pretherapy with the difference approaching significance for days 2, 4, and 6 with pentamidine (p Conclusions QTc prolongation during therapy with pentamidine in HIV-infected patients is not as frequent an occurrence as has been reported previously. In the absence of QTc prolongation, pentamidine therapy was not associated with a significant increase in PVCs, NSVT, or sustained VT as compared to pretherapy recordings or as compared to therapy with TMP-SMX.
Urban Managers and Public Policy Do Institutional Arrangements Influence Decisions to Initiate Policy

Here the authors examine the policy behavior of urban administrators in the area of reinventing government. They argue that managers in places with institutions that tend to produce conflict will b...
Effect of DMSO concentration, cell density and needle gauge on the viability of cryopreserved cells in three dimensional hyaluronan hydrogel

For cells seeded in scaffolds, transplanted cell survival rate plays an important role for cell transplantation efficiency, and is essential for successful cell transplantation. Fibroblast viability in HyStem-C was examined by a double staining Live/Dead Viability/Cytotoxicity assay, and cell images were analyzed using MetaMorph software for calculating live cell percentage for fresh and cryopreserved cells at different incubation time points, delivery methods, differing DMSO and cell concentrations. The results of this research demonstrated that in HyStem-C, the viability of cryopreserved cells (85%) was significantly lower than fresh collected cells (96.7%). In addition, the physical force from a 27 gauge needle significantly decreased frozen cell survival rates to 83-85% compared to pipette delivered cells. Higher DMSO concentration (1.0%) and higher cell density (2 × 107 per milliliter) also significantly decreased cell survival to 73%. Cryopreserved cell viability in three dimensional scaffolding can be maintained over 80% with cell density of 1 × 107 per milliliter, total DMSO concentration of 0.5%, and passed through a 27-gauge needle. These results demonstrate the viability of cells seeded in hyaluronan hydrogel with commonly used storage and delivery methods can bring rather satisfactory cell transplantation efficiency.
Gas chromatographic determination of the anomers of blood glucose in normal and diabetic rats.

Abstract A precise and reproducible gas chromatographic procedure for the determination of anomeric composition of glucose in biological fluids is described. When applied to blood, peaks of the silylated glucose anomers were well resolved and were the only two major peaks found in blood. Blood glucose of normal and alloxan-diabetic Sprague-Dawley rats fed or fasted, was found statistically to have an anomeric composition slightly favoring the β-anomer over the thermodynamic equilibrium composition in water (39.15 ± 0.6 α- and 60.9% ± 0.6 β-). The anomeric composition of glucose in plasma as well as in whole blood remained close to equilibrium after the administration of insulin to normal or diabetic rats. However, there was a statistically noticeable decrease in the percentage of blood β-glucose as a result of insulin treatment of normal animals. The metabolic basis of this effect remains to be investigated.
The uses of theory

(1991). The uses of theory. Text and Performance Quarterly: Vol. 11, Criticsm since the 1970s, pp. 267-277.
Synthesis and characterization of zirconium pentafluorophenyl complexes: X-ray crystal structures of [ZrCl2(C6F5)42-] and [ZrF2(C6F5)53-]

Abstract Treatment of ZrCl4 with LiC6F5, followed by addition of 1,4,7,10-tetraoxacyclododecane (12-crown-4) or N,N,N′,N′-tetramethylethylenediamine (tmed), leads to the isolation of two pentafluorophenylzirconate complexes: [Li(12-crown-4)2]2[ZrCl2(C6F5)4] (1) and [Li(tmed)2][Li(tmed)]2[ZrF2(C6F5)5] (2). The presence of Zr–F groups in the latter compound shows that C–F bond activation has occurred. The anion in the former complex adopts an octahedral structure owing to the π-donor character of the chloride ligands, whereas the anion in the latter adopts a regular pentagonal bipyramidal structure. The lithium atoms in 1 are not interacting with the anion, whereas two of the lithium atoms in 2 are involved in Li⋯F interactions with fluorine atoms in the anion. Selected bond distances and angles for 1: Zr–C=2.478(5)–2.510(5), Zr–Cl=2.409(5), 2.435(5) A, C–Zr–C(cis)=77.9–106.9(2), C–Zr–C(trans)=161.1, 169.1(2), Cl–Zr–Cl=166.7(2)°. Selected bond distances and angles for 2: Zr–C=2.432–2.449(8), Zr–F=1.986(4), Li⋯F=1.73(2)–2.50(2) A, C–Zr–C(cis)=69.6–73.3, F–Zr–F=178.8(2)°. Crystal data for 1: monoclinic, space group P21/n, a=15.2288(14), b=17.328(2), c=24.013(2) A, β=91.936(3)°, V=6333(1) A3, Z=4, wR2=0.2985 for 7801 reflections and 722 parameters. Crystal data for 2: monoclinic, space group P21/n, a=11.6143(5), b=29.6561(9), c=20.4427(8) A, β=103.266(1)°, V=6853.3(4) A3, Z=4, wR2=0.1822 for 8762 reflections and 759 parameters.
Transrectal ultrasound of the prostate bed after collagen injection

Transurethral injection of collagen (TCI) may be used to treat urinary incontinence following radical prostatectomy for prostate cancer. The transrectal ultrasound (TRUS) findings after TCI are described in this report. TRUS exams of four postprostatectomy patients who had undergone TCI were reviewed. Findings were correlated with pathologic specimens obtained at TRUS-guided core biopsy. These histologic specimens were compared with others from postprostatectomy patients who had not undergone TCI. Well defined bladder apex masses of uniform echogenicity, hypoechoic to adjacent fat and muscle, were identified sonographically in all TCI patients. Masses from which positive biopsies were obtained were similar in appearance to those with no malignant. Hypocellular fibrous tissue and foci of acellular loose connective tissue were identified in the biopsies of those patients who had undergone TCI No acellular areas were identified in specimens from patients who had not had TCI. Sequelae of to should be included in the differential diagnosis of perianastomotic masses in postprostatectomy patients. However, the need for biopsy is not obviated as residual or recurrent prostate carcinoma may coexist. 14 refs., 4 figs.
Synchronization of the climate system to eccentricity forcing and the 100,000-year problem

The 100,000-year problem refers to an apparent mismatch between the strength of solar forcing associated with the 100,000-year cycle of eccentricity in the Earth’s orbit and the amplitude of glacial–interglacial cycles. Numerical analyses suggest that recent glacial–interglacial cycles can instead be explained by a phase locking between internal climate oscillations and the 413,000-year eccentricity cycle.
Near equilibrium distributions for beams with space charge in linear and nonlinear periodic focusing systems

A procedure to obtain a near equilibrium phase space distribution function has been derived for beams with space charge effects in a generalized periodic focusing transport channel. The method utilizes the Lie transform perturbation theory to canonically transform to slowly oscillating phase space coordinates. The procedure results in transforming the periodic focusing system to a constant focusing one, where equilibrium distributions can be found. Transforming back to the original phase space coordinates yields an equilibrium distribution function corresponding to a constant focusing system along with perturbations resulting from the periodicity in the focusing. Examples used here include linear and nonlinear alternating gradient focusing systems. It is shown that the nonlinear focusing components can be chosen such that the system is close to integrability. The equilibrium distribution functions are numerically calculated, and their properties associated with the corresponding focusing system are discussed.
Preliminary results of human scleral ablation in vitro with Ho:YAG laser

This study evaluated the effect of the Ho:YAG laser operating at a wavelength of 2.1 micrometers and a repetition rate of 2 Hz on a human scleral tissue. The effects were assessed in terms of the ablation rate (micrometers /pulse) and the thermal damage (micrometers ) induced. The results were compared to those found from porcine scleral ablation. Data indicate that for the pulsed Ho:YAG laser, the ablation rate of scleral tissue increases linearly with laser fluence. The ablation rates are about 40% lower for the human scleral tissue than for the porcine scleral tissue at the same fluences. Data indicate that the mean Ho:YAG laser induced thermal damage is not significantly affected by varying the fluence.
“Inverse” organic-inorganic composite materials: high glass content non-shrinking sol-gel composites

Abstract We, as well as others, have been interested in the sol-gel process for the synthesis inorganic-organic composite materials. Since our first report on the application of tetraalkoxysilanes possessing polymerizable alkoxides for the production of non-shrinking sol-gel composites, we have extended our efforts towards increasing the glass content in these composite materials. The stoichiometry in the tetraalkoxysilanes limits the maximum glass content in the original non-shrinking composites to 10%–18%. In order to increase the glass content to greater than 50%, we focused our efforts on the use of silicic acid oligomers. Molecular weights of the poly(silicic acid) materials were varied from M n = 5000 to M n = 2 000 000 by controlling reaction conditions. In addition, branching ratios ( i.e. linear vs. spherical particles) can be controlled by changing the catalysts used. The properties of the resulting composite can range from a transparent flexible material to a transparent hard material simply by changing the organic polymer in the composite.
Molecular Basis of Hereditary Colorectal Cancer

Advances in molecular biology have defined the molecular basis for colorectal cancer (CRC). Although only a fraction of CRC has been determined to have a hereditary component, the discovery of genetic alterations in these clinical syndromes has permitted definition of similar discoveries in sporadic CRC. Here we delineate the molecular basis for the most common of these defined syndromes, including familial adenomatous polyposis, hereditary nonpolyposis colon cancer, MUTYH -associated polyposis, juvenile polyposis, Peutz–Jeghers syndrome, and Cowden's syndrome. The newest paradigm with implications for the pathogenesis of sporadic CRC is called the cancer stem cell hypothesis. As this paradigm also implicates aberrations in molecular pathways, a brief discussion of this hypothesis is included.
Effects of the Oxygenation level on Formation of Different Reactive Oxygen Species During Photodynamic Therapy

We examined the effect of the oxygenation level on efficacy of two photosensitizing agents, both of which target lysosomes for photodamage, but via different photochemical pathways. Upon irradiation, the chlorin termed NPe6 forms singlet oxygen in high yield while the bacteriopheophorbide WST11 forms only oxygen radicals (in an aqueous environment). Photokilling efficacy by WST11 in cell culture was impaired when the atmospheric oxygen concentration was reduced from 20% to 1%, while photokilling by NPe6 was unaffected. Studies in a cell-free system revealed that the rates of photobleaching of these agents, as a function of the oxygenation level, were correlated with results described above. Moreover, the rate of formation of oxygen radicals by either agent was more sensitive to the level of oxygenation than was singlet oxygen formation by NPe6. These data indicate that the photochemical process that leads to oxygen radical formation is more dependent on the oxygenation level than is the pathway leading to formation of singlet oxygen.
Fabrication of nanopillars by nanosphere lithography

A low cost nanosphere lithography method for patterning and generation of semiconductor nanostructures provides a potential alternative to the conventional top-down fabrication techniques. Forests of silicon pillars of sub-500 nm diameter and with an aspect ratio up to 10 were fabricated using a combination of the nanosphere lithography and deep reactive ion etching techniques. The nanosphere etch mask coated silicon substrates were etched using oxygen plasma and a time-multiplexed 'Bosch' process to produce nanopillars of different length, diameter and separation. Scanning electron microscopy data indicate that the silicon etch rates with the nanoscale etch masks decrease linearly with increasing aspect ratio of the resulting etch structures.
Phosphorus biogeochemistry across a precipitation gradient in grasslands of central North America.

Soil P transformations and distribution studies under water limited conditions that characterize many grasslands may provide further insight into the importance of abiotic and biotic P controls within grassdominated ecosystems. We assessed transformations between P pools across four sites spanning the shortgrass steppe, mixed grass prairie, and tallgrass prairie along a 400-mm precipitation gradient across the central Great Plains. Pedon total elemental and constituent mass balance analyses reflected a pattern of increased chemical weathering from the more arid shortgrass steppe to the more mesic tallgrass prairie. Soil surface A horizon P accumulation was likely related to increased biocycling and biological mining. Soluble P, a small fraction of total P in surface A horizons, was greatest at the mixed grass sites. The distribution of secondary soil P fractions across the gradient suggested decreasing Ca-bound P and increasing amounts of occluded P with increasing precipitation. Surface A horizons contained evidence of Ca-bound P in the absence of CaCO3 , while in subsurface horizons the Ca-bound P was associated with increasing CaCO3 content. Calcium-bound P, which dominates in water-limited systems, forms under different sets of soil chemical conditions in different climatic regimes, demonstrating the importance of carbonate regulation of P in semi-arid ecosystems. Published by Elsevier Ltd.
Existence and geometric structure of metrics on surfaces which extremize eigenvalues

This is an exposition of the research area around our lecture at the 60th anniversary conference of IMPA which was held in October of 2012. It is a survey of results which have been obtained over many years concerning sharp upper bounds on the first eigenvalue of a surface, either with or without boundary, in terms or area or boundary length and the surface topology. It is mostly expository, but contains a new coarse upper bound for non-orientable surfaces with boundary. It also contains a classical reformulation of recent results in [10].
Marginal iron deficiency without anemia impairs aerobic adaptation among previously untrained women

Iron deficiency without anemia has been shown to reduce both muscle-tissue oxidative capacity and endurance in animals. However the consequences of iron deficiency in humans remain unclear. We investigated the effects of iron supplementation on adaptation to aerobic training among marginally iron-depleted women. We hypothesized that iron supplementation for 6 wk would significantly improve iron status and maximal oxygen uptake (VO/2max) after 4 wk of concurrent aerobic training. Forty-one untrained iron-depleted nonanemic women were randomly assigned to receive either 50 mg FeSO4 or a placebo twice daily for 6 wk in a double-blind trial. All subjects trained on cycle ergometers 5 d/wk for 4 wk beginning on week 3 of the study. Six weeks of iron supplementation significantly improved serum ferritin and serum transferrin receptor (sTfR) concentrations and transferrin saturation without affecting hemoglobin concentrations or hematocrit. Average VO/2max and maximal respiratory exchange ratio improved in both the placebo and iron groups after training; however the iron group experienced significantly greater improvements in VO/2max. Both iron-status and fitness outcomes were analyzed after stratifying by baseline sTfR concentration (> and = 8.0 mg/L) which showed that the previously observed treatment effects were due to iron-status and fitness improvements among subjects with poor baseline iron status. Our findings strongly suggest that iron deficiency without anemia but with elevated sTfR status impairs aerobic adaptation among previously untrained women and that this can be corrected with iron supplementation. (authors)
Gallogermanate Glasses As Near IR Optical Waveguides

Alkaline earth gallogermanate glasses are a possible low-loss oxide optical material which would be able to operate in the 1.6–2 μm wavelength range. Processing techniques investigated to date and pertinent optical property data are presented.
Convexity-based algorithms for design centering

A new technique for design centering and polytope approximation of the feasible region for a design are presented. In the first phase, the feasible region is approximated by a convex polytope, using a method based on a theorem on convex sets. As a natural consequence of this approach, a good approximation to the design center is obtained. In the next phase, the exact design center is estimated using one of two techniques that we present in this paper. The first inscribes the largest Hessian ellipsoid, which is known to be a good approximation to the shape of the polytope, within the polytope. This represents an improvement over previous methods, such as simplicial approximation, where a hypersphere or a crudely estimated ellipsoid is inscribed within the approximating polytope. However, when the probability density functions of the design parameters are known, the design center does not necessarily correspond to the center of the largest inscribed ellipsoid. Hence, a second technique is developed that incorporates the probability distributions of the parameters, under the assumption that their variation is modeled by Gaussian probability distributions. The problem is formulated as a convex programming problem and an efficient algorithm is used to calculate the design center, using fast and efficient Monte Carlo methods to estimate the yield gradient. An example is provided to illustrate how ellipsoid-based methods fail to incorporate the probability density functions and is solved using the convex programming-based algorithm. >
Evidence for a common mechanism for spontaneous rhythmic contraction and myogenic contraction induced by quick stretch in detrusor smooth muscle

Detrusor smooth muscle exhibits myogenic contraction in response to a quick stretch (QS) as well as spontaneous rhythmic contraction (SRC); however, whether the same population of actomyosin crossbridges with a common regulatory mechanism is responsible for these two types of contraction has not been determined. Detrusor strips from New Zealand white rabbit bladders were allowed to develop SRC at a reference muscle length (Lref), or rhythmic contraction (RC) was induced with tetraethylammonium (TEA). Multiple 10-msec stretches of 15% Lref were then imposed at Lref randomly during the rhythm cycle, and the nadir-to-peak (NTP) tension amplitude of the resulting myogenic contraction was measured. The amplitude and period of the rhythm cycle were measured prior to each QS. NTP was larger when a QS was imposed during a portion the cycle when tension was smaller (n = 3 each SRC and TEA-induced RC). These data suggest that when the rhythmic mechanism was mostly inactive and tension was near a minimum, a larger portion of a shared population of crossbridges was available to produce a myogenic response to a QS. Rho kinase, cyclooxygenase-1, and cyclooxygenase-2 inhibitors (H-1152, SC-560, and NS-398) affected SRC amplitude and NTP amplitude following a QS to the same degree (n = 3 each drug), providing additional evidence to support the hypothesis that a common mechanism is responsible for SRC and myogenic contraction due to QS. If a common mechanism exists, then QS is a potential mechanical probe to study SRC regulation and its alteration in overactive bladder.
Elevated Levels of the Plasmodium yoelii Homologue of Macrophage Migration Inhibitory Factor Attenuate Blood-Stage Malaria

The excessive production of proinflammatory cytokines plays a significant role in the pathogenesis of severe malaria. Mammalian macrophage migration inhibitory factor (MIF) (mMIF) is an immune mediator that promotes a sustained proinflammatory response by inhibiting the glucocorticoid-mediated downregulation of inflammation. In addition, Plasmodium parasites also encode a homologue of mammalian MIF that is expressed in asexual-stage parasites. We used the Plasmodium yoelii murine model to study the potential role of parasite-encoded MIF in the pathogenesis of malaria. Antibodies raised against purified, non-epitope-tagged P. yoelii MIF (PyMIF) were used to localize expression in trophozoite- and schizont-stage parasites and demonstrate extracellular release. In vitro, recombinant PyMIF was shown to actively induce the chemotaxis of macrophages but did not induce or enhance tumor necrosis factor alpha (TNF-α) production from peritoneal macrophages. To examine the role of parasite-derived PyMIF in vivo, two transgenic parasite lines that constitutively overexpress PyMIF were generated, one in a nonlethal P. yoelii 17X background [Py17X-MIF(+)] and the other in a lethal P. yoelii 17XL background [Py17XL-MIF(+)]. Challenge studies with transgenic parasites in mice showed that the increased expression of PyMIF resulted in a reduction in disease severity. Mice infected with Py17X-MIF(+) developed lower peak parasitemia levels than controls, while malaria-associated anemia was unaltered. Infection with Py17XL-MIF(+) resulted in a prolonged course of infection and a reduction in the overall mortality rate. Combined, the data indicate that parasite-derived MIF does not contribute significantly to immunopathology but, through its chemotactic ability toward macrophages, may attenuate disease and prolong infection of highly virulent parasite isolates.
Perinatal Cytomegalovirus Infections: Epidemiology, Prevention, and Treatment

Mother-to-child transmission of cytomegalovirus (CMV) can lead to severe birth defects and neurologic impairment of infants. Congenital CMV is the most common congenital infection and the leading infectious cause of infant hearing loss and neurologic deficits, complicating up to 2% of all pregnancies globally. Although antiviral treatment of congenitally CMV-infected infants can ameliorate CMV-associated hearing loss and developmental delay, interventions that can effectively prevent congenital CMV infection and the associated neurologic impairments are still being evaluated. Moreover, an effective CMV vaccine to protect mothers against CMV acquisition during pregnancy is urgently needed to reduce the sizeable health and economic burden of this disease. Active and passive maternal and infant immunization strategies to prevent symptomatic perinatal CMV infection are a critical need in pediatric health.