cssi/SciSciGPT-SciSciNet huggingface dataset:
Differences in the protein binding of several drugs and bilirubin in serum and heparinized plasma of rats.

Abstract The purpose of this investigation was to compare the protein binding of salicylic acid, phenytoin, warfarin and bilirubin in serum and heparinized plasma of rats. Protein binding was determined by equilibrium dialysis (drugs) or by a reaction rate method (bilirubin), using serum and plasma obtained from the same animals. The three drugs were significantly less protein bound in heparinized plasma than in serum; this difference was particularly pronounced in the case of warfarin. Addition of heparin to serum also resulted in a decrease in the protein binding of the drugs but to a lesser extent than in plasma. The protein binding of bilirubin was more extensive in plasma than in serum, irrespective of the anticoagulant used (heparin, sodium citrate, or disodium ethylenediamine-tetraacetate). It may be desirable to perform all binding studies with serum rather than plasma.
Defensive maneuver cyber platform modeling with Stochastic Petri Nets

Distributed and parallel applications are critical information technology systems in multiple industries, including academia, military, government, financial, medical, and transportation. These applications present target rich environments for malicious attackers seeking to disrupt the confidentiality, integrity and availability of these systems. Applying the military concept of defense cyber maneuver to these systems can provide protection and defense mechanisms that allow survivability and operational continuity. Understanding the tradeoffs between information systems security and operational performance when applying maneuver principles is of interest to administrators, users, and researchers. To this end, we present a model of a defensive maneuver cyber platform using Stochastic Petri Nets. This model enables the understanding and evaluation of the costs and benefits of maneuverability in a distributed application environment, specifically focusing on moving target defense and deceptive defense strategies.
Counter-ion modulation of long-distance π-bonding of the open-shell p-benzoquinone anions

X-Ray crystallography of dichlorodicyano- or tetrachloro-p-benzoquinone salts with polyether-ligated alkali metals reveals discrete supramolecular complexes: [{M(L)A}2]. They show pairs of co-facial p-benzoquinone anions (A−) arranged at close interplanar separation: rπ≈ 2.9 A characteristic of ion-radical π-dimers. Moreover, these π-bonded anions are tethered by couples of alkali–metal cations (M+) nested in the crown-ether (L) cavities. The structures of such assemblies are compared to the non-tethered π-dimers (with 1 ∶ 1 cation/anion coordination), as well as to the separated dianionic [A2]2− and monoanionic [A2]−˙π-dyads. Such a comparison reveals that, contrary to electrostatic implications, counter-ion coordination (or monomer charge decrease) is accompanied by increase of the interplanar separations (rπ) between π-bonded p-benzoquinones. In addition, counter-ion bridges switch the lateral monomer offset from longitudinal in the separated π-dimers to transversal in the tethered assemblies. In dichloromethane, equilibrium constants of π-dimers formation are higher for the ion-paired salts as compared to those of the separated analogues, but the enthalpies of π-dimerization (ΔHD) are essentially independent of counter-ions. Thus, structural (rπ) and thermodynamic (ΔHD) features of the anionic p-benzoquinone π-dimers suggest a superior compensation of coulombic interactions and relatively minor role of counter-ions in the long-distance ion-radicals π-bonding.
Characterization of systemic oxygen transport in end-stage chronic congestive heart failure.

Chronic congestive heart failure (CHF) is characterized by low cardiac index (CI) and low systemic oxygen delivery (DO2), which frequently are associated with lethal cardiogenic shock after acute myocardial infarction. Nevertheless, patients with severe CHF are able to survive with these low levels of systemic DO2 and CI. It was hypothesized that patients with CHF survive low CI and DO2 by downregulation of global metabolism and resting oxygen consumption (VO2) and a concomitant increase in systemic oxygen extraction ratio (O2ER). Therefore the objective of this study was to characterize the resting pattern of systemic oxygen transport (O2T) and utilization in patients with stable CHF. Seventeen patients with CHF (New York Heart Association functional class III or IV) for > or = 3 months and with left ventricular ejection fraction (EF) 60%. Subjects underwent right-heart catheterization for measurement and calculation of hemodynamic and O2T variables (VO2, DO2, and O2ER). There were no significant differences in mean age (67 +/- 6 vs 64 +/- 17 years) or gender ratio (male:female 14:3 vs 7:3) between CHF and control groups, respectively. The cause of CHF was ischemic in 13 and idiopathic in 4 patients. There were 9 patients in NYHA class III and 8 in class IV.(ABSTRACT TRUNCATED AT 250 WORDS)
Toxicity of trivalent chromium to early life stages of steelhead trout

Acute and early life stage toxicity tests were conducted with trivalent chromium and steelhead trout (Salmo gairdneri). A 96-h LC50 of 4,400 μg/L chromium was obtained with two-month-old juvenile fish. Early life stage exposure from newly fertilized eggs to 30-d post-swimup produced complete mortality at 495 μg/L, and significantly reduced survival to hatch and to the end of the test at 157 and 89 μg/L, respectively. An early life stage test started with eyed eggs produced similar results, with hatching survival significantly reduced at 271 μg/L. An acute test conducted with fish surviving the early life stage test showed that no acclimation resulted from previous chromium exposure.
Prediction of Positive Outcomes for Adolescent Psychiatric Inpatients

ABSTRACT Objective To identify individual, parent/family, and treatment follow-through predictors of outcome for adolescent psychiatric inpatients 6 months after hospital discharge. Method Eighty-nine adolescents participated in a comprehensive baseline evaluation during psychiatric hospitalization. Baseline measures included the Diagnostic Interview Schedule for Children, Social Adjustment Inventory for Children and Adolescents, Reynolds Adolescent Depression Scale (RADS), and Suicidal Ideation Questionnaire-Junior (SIQ-Jr). Structured telephone follow-up interviews assessed treatment follow-through, suicidal behaviors, rehospitalizations, living changes, and social adaptive functioning. The RADS and SIQ-Jr were also readministered. Results Baseline indices of adolescent functioning emerged as the strongest predictors of outcomes. Hierarchical multiple regression analyses indicated that baseline depression severity, a cluster of parent/family indices, and medication follow-through were significant predictors of outcome depression severity. Baseline social adaptive functioning, presence/absence of conduct disorder, and medication follow-through were significant predictors of outcome social adaptive functioning. Conclusions The nature and course of adolescent psychopathology was difficult to disrupt, with baseline characteristics as the strongest predictors of outcome. Nevertheless, the significance of medication follow-through as a predictor suggests that treatment-related gains are possible.
Sequence analysis of the non-structural protein 2 from epizootic hemorrhagic disease viruses

The non-structural protein 2 (NS2) of epizootic hemorrhagic disease virus serotype 1 (EHD-1) was cloned and sequenced. The NS2 gene was found to be 1185 bp containing a single open reading frame that encodes a 376 amino acid protein. A 97% nucleic acid identity was found between EHD-1 and a previously published NS2 sequence of EHD-2. Only a 60% nucleic acid identity was found between EHD and the bluetongue virus (BTV) serogroup. Comparison of the deduced amino acid sequences revealed 97% identity within the EHD serogroup, and less than or equal to 43% identity between serogroups.
Synovial cyst at the craniovertebral junction

A case of synovial cyst of the upper cervical spine that resulted in spastic quadriparesis and sensory loss is reported. Radiographic evaluation included a computed tomography scan after myelography and a magnetic resonance imaging scan. The synovial cyst was removed by a laminectomy at C-1 and C-2, combined with a foramen magnum craniectomy. The patient had a good recovery.
Ouabain blockade of inward slow current in cardiac muscle.

Myocardial cells rendered inexcitable by tetrodotoxin (TTX) or by partial depolarization with elevated K + (25 m m ) are a useful preparation on which to study the properties of slow channels. Utilizing this preparation, we previously demonstrated that certain positive inotropic agents, such as catecholamines, methylxanthines, histamine or F − ion, act to rapidly increase the number of available slow Ca 2+ −Na + channels, thus permitting the appearance of slowly-rising overshooting electrical responses which resemble the plateau component of the cardiac action potential. Hence, we examined the possibility that a cardiac glycoside might exert its positive inotropic action through a similar mechanism. Two preparations of 16-to 20-day-old embryonic chick myocardial cells were studied: (a) intact perfused hearts, and (b) spherical reaggregate cultures of trypsin-dispersed cells. Ouabain (10 −8 to 10 −4 m ) did not induce the slow response in either preparation. In contrast, high concentrations (10 −6 to 10 −4 m ) of ouabain depressed and blocked the isoproterenol- or caffeine-induced slow responses. These findings indicate that the positive inotropic effects of ouabain are not mediated by an increased electrogenic transmembrane Ca 2+ inward current during the cardiac action potential.
Separation and partial characterization of enzymes catalyzing δ-aminolevulinic acid formation in Synechocystis sp. PCC 6803

Formation of the universal tetrapyrrole precursor, delta-aminolevulinic acid (ALA), from glutamate via the five-carbon pathway requires three enzymes: glutamyl-tRNA synthetase, glutamyl-tRNA reductase, and glutamate-1-semialdehyde (GSA) aminotransferase. All three enzymes were separated from extracts of the unicellular cyanobacterium Synechocystis sp. PCC 6803, and two of them, glutamyl-tRNA synthetase and GSA aminotransferase, were partially characterized. After an initial high speed centrifugation and differentiatial ammonium sulfate fractionation of cell extract, the enzymes were separated by successive affinity chromatography on Reactive Blue 2-Sepharose and 2',5'-ADP-agarose. All three enzyme fractions were required to reconstitute ALA formation from glutamate. The apparent native molecular masses of glutamyl-tRNA synthetase and GSA aminotransferase were determined by gel filtration chromatography to be 63 and 98 kDa, respectively. Neither glutamyl-tRNA synthetase nor GSA aminotransferase activity was affected by hemin concentrations up to 10 and 30 microM, respectively, and neither activity was affected by protochlorophyllide concentrations up to 2 microM. GSA aminotransferase was inhibited 50% by 0.5 microM gabaculine. The gabaculine inhibition was reversible for up to 1 h after its addition, if the gabaculine was removed by gel filtration before the enzyme was incubated with substrate. However, irreversible inactivation was obtained by preincubating the enzyme at 30 degrees C either for several hours with gabaculine alone or for a few minutes with both gabaculine and GSA. Neither pyridoxal phosphate nor pyridoxamine phosphate significantly affected the activity of GSA aminotransferase at physiologically relevant concentrations, and neither of these compounds reactivated the gabaculine-inactivated enzyme. It was noted that the presence of pyridoxamine phosphate in the ALA assay mixture produced a false positive color reaction even in the absence of enzyme.
Complementary and Alternative Therapies for Cerebral Palsy.

The optimal practice of medicine includes integrating individual clinical expertise with the best available clinical evidence from systematic research. This article reviews nine treatment modalities used for children who have cerebral palsy (CP), including hyperbaric oxygen, the Adeli Suit, patterning, electrical stimulation, conductive education, equine-assisted therapy, craniosacral therapy, Feldenkrais therapy, and acupuncture. Unfortunately, these modalities have different degrees of published evidence to support or refute their effectiveness. Uncontrolled and controlled trials of hippotherapy have shown beneficial effects on body structures and functioning. Studies of acupuncture are promising, but more studies are required before specific recommendations can be made. Most studies of patterning have been negative and its use cannot be recommended. However, for the other interventions, such as hyperbaric oxygen, more evidence is required before recommendations can be made. The individual with CP and his or her family have a right to full disclosure of all possible treatment options and whatever knowledge currently is available regarding these therapies.
Nonreward anticipated: Effects on extinction runway performance in the rat

Following a 47-day extinction procedure, the reinstatement of the cue previously associated with reward produced an immediate improvement in performance. The cue was the opportunity to traverse the alley following an “anticipated” nonrewarded runway trial. Moreover, the animals trained in this matter exhibited daily increments in performance during the initial phase of extinction testing. The results were interpreted as consistent with the notion that the difference in extinction performance of one group as compared to another does not necessarily reflect the relative “strengths” of the instrumentally acquired habits. Instead, it probably indicates the degree of similarity of the extinction testing procedure to the acquisition training condition previously associated with reinforcement for the two individual groups.
Selective shunt in the management of variceal bleeding in the era of liver transplantation

This study reports the Emory experience with 147 distal splenorenal shunts (DSRS) and 110 orthotopic liver transplants (OLT) between January 1987 and December 1991. The purpose was to clarify which patients with variceal bleeding should be treated by DSRS versus OLT. Distal splenorenal shunts were selected for patients with adequate or good liver function. Orthotopic liver transplant was offered to patients with end-stage liver disease who fulfilled other selection criteria. The DSRS group comprised 71 Child's A, 70 Child's B, and 6 Child's C patients. The mean galactose elimination capacity for all DSRS patients was 330 +/- 98 mg/minute, which was significantly (p less than 0.01) above the galactose elimination capacity of 237 +/- 82 mg/minute in the OLT group. Survival analysis for the DSRS group showed 91% 1-year and 77% 3-year survival, which was better than the 74% 1-year and 60% 3-year survivals in the OLT group. Variceal bleeding as a major component of end-stage disease leading to OLT had significantly (p less than 0.05) poorer survival (50%) at 1 year compared with patients without variceal bleeding (80%). Hepatic function was maintained after DSRS, as measured by serum albumin and prothrombin time, but galactose elimination capacity decreased significantly (p less than 0.05) to 298 +/- 97 mg/minute. Quality of life, measured by a self-assessment questionnaire, was not significantly different in the DSRS and OLT groups. Hospital charges were significantly higher for OLT (median, $113,733) compared with DSRS ($32,674). These data support a role for selective shunt in the management of patients with variceal bleeding who require surgery and have good hepatic function. Transplantation should be reserved for patients with end-stage liver disease. A thorough evaluation, including tests of liver function, help in selection of the most appropriate therapeutic approach.
THE ACTIVITIES OF BUTYRYLCHOLINESTERASE AND CARBONIC ANHYDRASE, THE RATE OF ANAEROBIC GLYCOLYSTS, AND THE QUESTION OF A CONSTANT DENSITY OF GLIAL CELLS IN CEREBRAL CORTICES OF VARIOUS MAMMALIAN SPECIES FROM MOUSE TO WHALE

— The question of a constant density of glial cells in mammalian cerebral cortex regardless of species was examined by surveying the cortical activities of two enzymes primarily localized to dial cells. The cortical activity of butyrylcholinesterase (EC 3.1.1.8) was essentially constant at a rate of approx. 0.1 μmol of butyrylthiocholine hydrolysed min-1 g-1 over the range of species from rat (brain wt., 1.6 g) to fin whale and sperm whale (brain wt., 6800 and 7800 g, respectively). Over the same range the activity of cortical acetylcholinesterase, a neuronal enzyme, decreases by a factor of 7. Thus, butyrylcholinesterase ranged from < 2 per cent (in small rodent brains) to approximately 10 per cent (in whale brain) of the cortical acetylcholinesterase activity. The cortical activity of carbonic anhydrase (EC 4.2.1.1) was constant at a rate of 6.2 (± 0.25) μmol of CO2 evolved min-1 g-1 over the range of species from guinea-pig (brain wt., 4.75 g) to fin whale (brain wt., 6800 g). These data obtained by assaying the dehydration reaction were confirmed by limited assays of the esterase activity of the enzyme (with p-nitrophenylacetate as substrate) and agreed with limited, previously reported data for the hydration reaction. Thus, the circumstantial evidence strongly favoured a relative constancy of cortical glial cell density regardless of species. The rates of anaerobic glycolysis in the cerebral cortex of various species were also investigated. For six species from mouse (brain wt., 0.4 g) to beef (brain wt., 380 g) cortical anaerobic glycolysis varied only slightly in the range of 50–62 μmol of CO2 evolved h-1 g-l, whereas cortical oxygen consumption for the same range of species decreased by a factor of 3. Previously frozen samples of beef cortex glycolysed at 35 per Cent of the rate of fresh (unfrozen) samples. Since identical rates were obtained for previously frozen samples of fin whale cerebral cortex, we concluded that the relative constancy of cortical anaerobic glycolysis could be extended to the range from mouse to whale and that this aspect of cortical metabolism is probably primarily glial in localization. Some implications of the latter conclusion for the proposed role of astrocytes as modulators of neuronal activity have been discussed.
The UW-PTMS: Systematic studies, measurement progress, and future improvements

Abstract The UW-Penning trap mass spectrometer (UW-PTMS) is now able to generate measurements with uncertainties near 10 ppt, making it necessary to address several major systematics, both experimentally and theoretically, in order to improve our present accuracy. These effects range from the image charge shift, originally investigated two decades ago, to the recently investigated limits due to residual magnetron energy. Using the knowledge gained from these studies, the atomic mass of O 16 has been completely reviewed and the results of this re-analysis are presented. There is also an adjustment given for the atomic mass of He 4 and we present a preliminary result for the atomic mass of H 2 . In addition, we present our plans for replacing the present spectrometer with a new one containing a cylindrical storage trap that will be loaded using an external ion source and two hyperbolic traps whose dimensions are identical to the Penning trap in our present spectrometer. Thus, it is expected that the new spectrometer will have essentially the same systematics as those described in this paper.
Staging of metastatic pancreatic cancer in orthotopic mouse models by fluorescence laparoscopy is improved by an LED light source

Introduction The aim of this study was to improve fluorescence laparoscopy with the use of an LED light source. In addition, the optimal fluorophore was determined to improve accurate identification and localization of tumor deposits without loss of background illumination. Methods Human pancreatic cancer models were established with fluorescent FG-RFP, MiaPaca2-GFP, BxPC-3-RFP, or BxPC-3 cancer cells implanted in 6-week-old female athymic mice. Two weeks post-implantation, diagnostic laparoscopy was performed with a Stryker L9000 LED light source or a Stryker X8000 xenon light source 24 hours after tail vein injection of CEA and/or CA19-9 antibodies conjugated with Alexa 488- or Alexa 555. Cancer lesions were detected and localized under each light mode. Intravital images were obtained with the Maestro CRI Small Animal Imaging System, serving as a positive control. Tumors were collected for histologic review. Results Fluorescence laparoscopy with a 495-nm emission filter and an LED light source enabled real-time visualization of the fluorescence-labeled tumor in the peritoneal cavity. Improved detection of more and smaller lesions compared to standard xenon bright field laparoscopy was achieved. With adjustments to the LED light source, we could simultaneously detect tumor lesions of different fluorescent colors as well as surrounding structures with minimal autofluorescence. Conclusions In conclusion, we have demonstrated that by using an LED light source with adjustments to the red, blue and green wavelengths, we can simultaneously identify tumor metastases expressing fluorescent proteins of different wavelengths without compromising background illumination. Further development of this technology for clinical use can improve the staging and treatment of pancreatic cancer.
Human dorsal anterior cingulate cortex neurons mediate ongoing behavioural adaptation

Functional imaging, single-cell recording and targeted surgical lesions were used in human patients undergoing cingulotomy to show that the dorsal anterior cingulate cortex provides a continuously updated prediction of expected cognitive demand. The dorsal anterior cingulate cortex (dACC) plays an important part in regulating cognitive control in both humans and non-human primates, but its precise function remains a matter of debate. Various hypotheses have been proposed, including reward-based decision making, monitoring for conflict between competing responses, and predicting task difficulty. This paper combines functional imaging, single-cell recording and targeted surgical lesions in human patients preparing for cingulotomy, and shows that the dACC provides a continuously updated prediction of expected cognitive demand. The authors propose that it helps to optimize future behavioural responses by hastening or delaying responses as appropriate to the upcoming cognitive load. The ability to optimize behavioural performance when confronted with continuously evolving environmental demands is a key element of human cognition. The dorsal anterior cingulate cortex (dACC), which lies on the medial surface of the frontal lobes, is important in regulating cognitive control. Hypotheses about its function include guiding reward-based decision making1, monitoring for conflict between competing responses2 and predicting task difficulty3. Precise mechanisms of dACC function remain unknown, however, because of the limited number of human neurophysiological studies. Here we use functional imaging and human single-neuron recordings to show that the firing of individual dACC neurons encodes current and recent cognitive load. We demonstrate that the modulation of current dACC activity by previous activity produces a behavioural adaptation that accelerates reactions to cues of similar difficulty to previous ones, and retards reactions to cues of different difficulty. Furthermore, this conflict adaptation, or Gratton effect2,4, is abolished after surgically targeted ablation of the dACC. Our results demonstrate that the dACC provides a continuously updated prediction of expected cognitive demand to optimize future behavioural responses. In situations with stable cognitive demands, this signal promotes efficiency by hastening responses, but in situations with changing demands it engenders accuracy by delaying responses.
Discharge of Thermal Storage Tanks via Immersed Baffled Heat Exchangers: Numerical Model of Flow and Temperature Fields

A model of a thermal storage tank in which stored energy is extracted via an immersed heat exchanger is presented and used to predict transient temperature and velocity fields in tanks with and without baffles. The heat exchanger is modeled as a porous medium within the storage fluid. A simple cylindrical baffle that creates an annular space in which a coiled tube heat exchanger is positioned provides a modest increase in the rate of energy extraction compared to a tank with no baffle. The improved discharge rate is attributed to an increase in the flow speed across the heat exchanger. A baffle with greater hydraulic resistance slows the flow and reduces performance.Copyright © 2007 by ASME
55 Ice age kelp forests: climate-driven changes in kelp forest distribution since the last glacial maximum

Kelp forest distributions are constrained by the availability of rocky substrate within the depth range tolerable for growth and reproduction, which can vary over relatively short geological timescales (millennia) due to interactions between coastal bathymetry and climate-driven changes in eustatic sea level. Using GIS, a digital bathymetric map, sea level curves, and published kelp depth tolerances, I reconstructed changes in the size and distribution of giant kelp (Macrocystis pyrifera) forests in the Southern California Bight since the last glacial maximum. Reconstructions predicted that the total area of available kelp forest habitat for the California Channel Islands during the last glacial maximum (18.5 kyr BP; 628 square km) was greater than at present (382 square km) but less than at 16.5 kyr BP (1130 square km). Available kelp forest habitat along the southern California mainland also increased rapidly from 18.5 to 16.5 kyr BP but continued to increase with sea level rise. Differences in the effects of sea level rise on coastal geomorphology between the islands and mainland further constrained the extent of rocky substrate available to kelps. Given biomass and productivity estimates from present-day kelp forests, these reconstructions suggest more productive and spatially extensive island kelp forests near the last glacial maximum than at present, but the opposite pattern for the mainland. These climate-driven changes in kelp forest distribution and productivity likely had important historical impacts on the ecology and evolution of the present-day kelp ecosystem including kelp forest exploitation by early human inhabitants of southern California.
Genomic Epidemiology of Complex Disease: The Need for an Electronic Evidence-based Approach to Research Synthesis

Modern microarray genotyping now permits simultaneous analysis of tens of thousands of polymorphisms, and this technology is being widely used to associate the role of genes with the etiology of complex disease. Genome-wide hypothesis-free mapping will also increasingly generate candidate genes that require further testing in association studies. At the same time, genetic effects are increasingly observed to be buffered by a wide array of biologic mechanisms that evolved to protect the genome from environmental insult and that serve to obscure observation of direct effects of polymorphisms on a disease phenotype. These two forces combine to make replication of genomic epidemiology extraordinarily difficult. Traditional research synthesis of emerging bodies of genomic epidemiology is problematic and often quickly outdated. The author proposes that electronic evidence-based methodology, perhaps modeled after that used by the Cochrane Collaboration in clinical medicine, would facilitate the systematic preparation and frequent updating of systematic reviews, which is essential for identifying valid and replicable gene-disease associations.
Creating functional autogenous vascular access in older patients.

Objective Arteriovenous fistulas (AVFs) are the preferred choice for hemodialysis vascular access (AV access); however, there is debate over the utility of AVFs in older patients, particularly concerning access maturation and functionality. We reviewed our AV access experience in patients ≥65 years of age. Methods We analyzed consecutive AV access patients ≥65 years old with access operations between March 2003 and December 2009. All patients had ultrasound vessel mapping. In addition to overall outcomes review, the data for patients ≥65 years old were stratified into three 10-year increments by age for further analysis. We compared functional patency data for our older patients with those of our non-elderly patients aged 21 to 64 years treated during the same time period. Results Four hundred sixty-one consecutive AV access patients new to our practice were included in this study. Ages were 65 to 94 years (mean, 73 years). Two hundred thirty-six (51.2%) were female, 276 (59.9%) patients were diabetic, and 103 (22.3%) were obese. One hundred seven (23.2%) patients had previous access operations. Radiocephalic AVFs were constructed in 29 (6.3%) patients, 99 (21.5%) patients had brachial artery inflow AVFs, 330 (71.6%) had proximal radial artery AVFs, and three were based on the femoral artery. Transposition AVFs were used in 124 (26.9%) patients. No grafts were used for AV access in any patient during the study period. Time to AVF use was 0.5 to 6 months (mean, 1.5 months). Primary, primary assisted, and cumulative patency for patients aged 65 to 94 years were 59.9%, 93.7%, and 96.9% at 12 months and 45.3%, 90.1%, and 94.6% at 24 months, respectively. Follow-up was 1.5 to 77 months (mean, 17.0 months). Subgroup age stratification (65-74 [n = 268], 75-84 [n = 167], 85-94 [n = 26] years) found no statistical difference in functional access outcomes. Primary, primary assisted, and cumulative patency rates were not statistically different in the elderly and non-elderly populations ( P = .29, .27, and .37, respectively). One hundred fifty-six patients died during the study period, 1.3 to 61 months (mean, 20 months) after access creation. No deaths were related to access operations. Conclusions AVFs are feasible and offer functional and timely AV access in older patients. There was no difference in functional access outcomes for older patients with subgroup age stratification. AVF patency rates were not statistically different in the elderly and non-elderly populations. Cumulative AVF patency for patients ≥65 years of age was 96.9% at 12 months and 94.6% at 24 months.
The effect of frequency on the magnitude of cyclic variation of backscatter in dogs and implications for prompt detection of acute myocardial ischemia

The magnitude of cyclic variation of integrated backscatter was measured for 3-4, 4-5, 5-6, 6-7, and 7-8 MHz. In ten normal dogs, the magnitude of cyclic variation (M) was found to increase with ultrasonic frequency in an approximately linear fashion. The least squares linear fit to the data yielded M=2.5 dB+0.24f dB/MHz where f is the ultrasonic frequency (MHz). The potential frequency dependence of detection of the immediate consequences of myocardial ischemia was investigated. Acute ischemic injury was induced in each of seven dogs by ligation of a coronary artery. The magnitude of cyclic variation of integrated backscatter was measured in regions of myocardium supplied by this artery before and after ligation. Ischemic myocardium was clearly differentiable from normal myocardium in all five frequency bands. The magnitude of cyclic variation of integrated backscatter demonstrated substantial recovery upon reperfusion. The results offer promise for the detection of ischemia in humans using clinical imaging systems. >
Ascorbic Acid Enhances Differentiation of Embryonic Stem Cells Into Cardiac Myocytes

Background— Embryonic stem (ES) cells are capable of self-renewal and differentiation into cellular derivatives of all 3 germ layers. In appropriate culture conditions, ES cells can differentiate into specialized cells, including cardiac myocytes, but the efficiency is typically low and the process is incompletely understood. Methods and Results— We evaluated a chemical library for its potential to induce cardiac differentiation of ES cells in the absence of embryoid body formation. Using ES cells stably transfected with cardiac-specific α-cardiac myosin heavy chain (MHC) promoter-driven enhanced green fluorescent protein (EGFP), 880 compounds approved for human use were screened for their ability to induce cardiac differentiation. Treatment with ascorbic acid, also known as vitamin C, markedly increased the number of EGFP-positive cells, which displayed spontaneous and rhythmic contractile activity and stained positively for sarcomeric myosin and α-actinin. Furthermore, ascorbic acid induced the expressi...
Entrepreneurship as a solution: The allure of self-employment for women and minorities

Abstract In this paper, we discuss the experiences that women and minorities encounter in organizational settings that result in frustration and discontent with corporate life and their opportunities for advancement. We suggest that such experiences push many of these individuals out of organizations, attracting them to entrepreneurship as an alternate route to both personal and professional success. Our discussion includes an examination of the issues that give rise to these experiences and a consideration of how entrepreneurship appears to provide a solution to them. It also identifies some of the potential pitfalls of entrepreneurship for women and minorities. In our concluding comments, we urge organizations to recognize the unique problems women and minorities face and the necessity of addressing these problems if they are to retain these potentially valuable members of the workforce.
Dimensions of the World Food and Climate Problem

Understanding and dealing with the problem of climate’s impact on food production and distribution is a crucial endeavor if world food needs are to be met by the year 2000 and beyond.
Making Consumers Comfortable: The Early Decades of Air Conditioning in the United States

During the air conditioner industry's first four decades, most installations were “commercial comfort” air conditioning systems, purchased by retailers to increase demand for their products. Air conditioning spread unevenly through the commercial sector and across the country. Using data from a variety of sources, I offer a quantitative account of this diffusion, viewed through an interpretive framework that emphasizes differences across geographic markets and industries in the costs and benefits to retailers of installing air conditioning. Correlates of early adoption of commercial air conditioning include electricity rates and consumer income and education levels.
Architectural Optimization of Decomposition Algorithms for Wireless Communication Systems

Matrix decomposition is required in various algorithms used in wireless communication applications. FPGAs strike a balance between ASICs and DSPs, as they have the programmability of software with performance capacity approaching that of a custom hardware implementation. However, FPGA architectures require designers to make a countless number of system, architectural and logic design decisions. By performing design space exploration, a designer can find the optimal device for a specific application, however very few tools exist which can accomplish this task. This paper presents automatic generation and optimization of decomposition methods using a core generator tool, GUSTO, that we developed to enable easy design space exploration with different parameterization options such as resource allocation, bit widths of the data, number of functional units and organization of controllers and interconnects. We present a detailed study of area and throughput tradeoffs of matrix decomposition architectures using different parameterizations.
Melatonin receptor (MT1) knockout mice display depression-like behaviors and deficits in sensorimotor gating

Although critical for transducing seasonal information, melatonin has also been implicated in several physiological systems, as well as the regulation of behavioral and cognitive processes. Therefore, we investigated the neurobehavioral effects of mice missing the type 1 melatonin receptor (MT1). Male and female MT1 knockout (MT1-/-) and wild-type (WT) mice were tested in the acoustic startle/prepulse inhibition (PPI), open field and Porsolt forced swim tests. Male and female MT1-/- mice displayed dramatically impaired prepulse inhibition in the acoustic startle response. Female WT mice were more active in the open field than WT males. However, male and female MT1-/- mice did not differ in total locomotor activity. WT animals spent significantly more time in the center of the arena (a behavioral outcome associated with reduced anxiety-like behavior) than MT1-/- mice. Also, the sex difference between male and female WT mice in the amount of time spent in the center versus periphery was not observed among MT1-/- mice. Both male and female MT1-/- mice significantly increased the time spent immobile in the forced swim test, an indication of depressed-like behavior. The lifetime lack of MT1 signaling contributes to behavioral abnormalities including impairments in sensorimotor gating and increases in depressive-like behaviors. Taken together, MT1 receptor signaling may be important for normal brain and behavioral function.
DNA molecules descending a nanofluidic staircase by entropophoresis

A complex entropy gradient for confined DNA molecules was engineered for the first time. Following the second law of thermodynamics, this enabled the directed self-transport and self-concentration of DNA molecules. This new nanofluidic method is termed entropophoresis. As implemented in experiments, long DNA molecules were dyed with cyanine dimers, dispersed in a high ionic strength buffer, and confined by a nanofluidic channel with a depth profile approximated by a staircase function. The staircase step depths spanned the transition from strong to moderate confinement. The diffusion of DNA molecules across slitlike steps was ratcheted by entropic forces applied at step edges, so that DNA molecules descended and collected at the bottom of the staircase, as observed by fluorescence microscopy. Different DNA morphologies, lengths, and stoichiometric base pair to dye molecule ratios were tested and determined to influence the rate of transport by entropophoresis. A model of ratcheted diffusion was used to interpret a shifting balance of forces applied to linear DNA molecules of standard length in a complex free energy landscape. Related metrics for the overall and optimum performance of entropophoresis were developed. The device and method reported here transcend current limitations in nanofluidics and present new possibilities in polymer physics, biophysics, separation science, and lab-on-a-chip technology.
Structures, mechanical properties, equations of state, and electronic properties of β-HMX under hydrostatic pressures: a DFT-D2 study.

We report the hydrostatic compression studies of the β-polymorph of a cyclotetramethylene tetranitramine (HMX) energetic molecular crystal using DFT-D2, a first-principles calculation based on density functional theory (DFT) with van der Waals (vdW) corrections. The molecular structure, mechanical properties, electronic properties, and equations of state of β-HMX are investigated. For the first time, we predict the elastic constants of β-HMX using DFT-D2 studies. The equations of state under hydrostatic compression are studied for pressures up to 100 GPa. We found that the N–N bonds along the minor axis are responsible for the sensitivity of β-HMX. The analysis of the charge distribution shows that the electronic charge is transferred from hydrogen atoms to nitro groups with the amount of 0.131 and 0.064e for the nitro groups along the minor axis and major axis, respectively, when pressure changes from 0 GPa to 100 GPa. The electronic energy band gap changes from direct at a pressure of 0 GPa to indirect at a pressure of 50 GPa and higher. The band gap decreases with respect to an increase in pressure, implying that the impact sensitivity increases with compression. Our study suggests that the van der Waals interactions are critically important in modeling the mechanical properties of this molecular crystal.
Demonstration of the Innate Electrophilicity of 4-(3-(Benzyloxy)phenyl)-2-(ethylsulfinyl)-6-(trifluoromethyl)pyrimidine (BETP), a Small-Molecule Positive Allosteric Modulator of the Glucagon-Like Peptide-1 Receptor

4-(3-(Benzyloxy)phenyl)-2-(ethylsulfinyl)-6-(trifluoromethyl)pyrimidine (BETP) represents a novel small-molecule activator of the glucagon-like peptide-1 receptor (GLP-1R), and exhibits glucose-dependent insulin secretion in rats following i.v. (but not oral) administration. To explore the quantitative pharmacology associated with GLP-1R agonism in preclinical species, the in vivo pharmacokinetics of BETP were examined in rats after i.v. and oral dosing. Failure to detect BETP in circulation after oral administration of a 10-mg/kg dose in rats was consistent with the lack of an insulinotropic effect of orally administered BETP in this species. Likewise, systemic concentrations of BETP in the rat upon i.v. administration (1 mg/kg) were minimal (and sporadic). In vitro incubations in bovine serum albumin, plasma, and liver microsomes from rodents and humans indicated a facile degradation of BETP. Failure to detect metabolites in plasma and liver microsomal incubations in the absence of NADP was suggestive of a covalent interaction between BETP and a protein amino acid residue(s) in these matrices. Incubations of BETP with glutathione (GSH) in buffer revealed a rapid nucleophilic displacement of the ethylsulfoxide functionality by GSH to yield adduct M1, which indicated that BETP was intrinsically electrophilic. The structure of M1 was unambiguously identified by comparison of its chromatographic and mass spectral properties with an authentic standard. The GSH conjugate of BETP was also characterized in NADPH- and GSH-supplemented liver microsomes and in plasma samples from the pharmacokinetic studies. Unlike BETP, M1 was inactive as an allosteric modulator of the GLP-1R.
Follow the water: Connecting a CO2 reservoir and bleached sandstone to iron-rich concretions in the Navajo Sandstone of south-central Utah, USA: COMMENT

Concretions comprise an important diagenetic record of fluid flow in the Jurassic Navajo Sandstone (Utah, United States). Mobilization and transport of chemically reduced Fe+2 in solution likely occurs via groundwater with CH4 or other hydrocarbons as reducing agents ([Beitler et al., 2003][1]; [
Brain Angiotensin II and Synaptic Transmission

The renin-angiotensin system is an enzymatic cascade by which angiotensinogen is cleaved by renin and then by angiotensin-converting enzyme to produce angiotensin II (Ang II) and subsequently other angiotensins. Biochemical and neurophysiological studies have documented the presence of the reninangiotensin system and specific Ang II receptors in the brain. Also, circulating Ang II can exert some of its actions, such as blood pressure control and body fluid homeostasis, through stimulation of Ang II receptors in the circumventricular organs that lack a normal blood-brain barrier. In addition to some of the post-synaptic effects of Ang II, recent studies have revealed that Ang II regulates synaptic transmission in several brain regions, especially the nucleus of the solitary tract, hypothalamic paraventricular nucleus, and hippocampus. This review summarizes emerging new evidence on the effect of brain Ang II on glutamatergic and GABAergic synaptic transmission. This previously unrecognized presynaptic action of Ang II is important for the control of neuronal excitability and many physiological functions including autonomic control, hormone secretion, and memory. Future research on the role of brain-derived Ang II and its receptors in synaptic transmission will further enhance our understanding of the cellular mechanisms of Ang II and the relationship between the renin-angiotensin system and brain functions.
Curing “Incurable” Cancer

Cancer cells are preferentially killed by anticancer agents because key signals for growth and cell division are "always on" as opposed to the alternative "on" and "off" signaling of normal cells. Too much of today's anticancer drug discovery effort may go toward reversing genetically promoted "always on" signals. More effective anticancer drug targets may be found through use of RNAi technologies that pinpoint the key gene regulatory and metabolic weakness of the "always on" cancer cells.
Potential role of active vitamin D in retarding the progression of chronic kidney disease

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EXTRARENAL WILMS' TUMOR : AN ULTRASTRUCTURAL AND IMMUNOELECTRON MICROSCOPIC CASE REPORT

Wilms’ tumor is the most common malignancy of the genitourinary tract in children but the occurrence of extrarenal Wilms’ tumor is extremely rare. Extrarenal Wilms’ tumor, which by definition excludes a primary tumor in the kidney, has been reported less than fifty times. The ultrastructural appearance of renal Wilms’ tumor has been well documented, but the present report is believed to be the first description of the ultrastructural appearance of extrarenal Wilms’ tumor. The authors report, for the first time, localization of intermediate filament proteins (vimentin and cytokeratin) and epithelial membrane antigen (EMA) by immunoelectron microscopy in this neoplasm. Demonstration of the coexpression of vimentin and cytokeratin within the same blastemal cell, as well as the identification of desmosomes in a cell with vimentin intermediate filaments, suggests a relationship between stroma, blastema, and epithelia similar to that proposed in renal Wilms’ tumor.