cssi/SciSciGPT-SciSciNet huggingface dataset:
Collagen types I, III, and V in human embryonic and fetal skin

The dermis of human skin develops embryonically from lateral plate mesoderm and is established in an adult-like pattern by the end of the first trimester of gestation. In this study the structure, biochemistry, and immunocytochemistry of collagenous matrix in embryonic and fetal dermis during the period of 5 to 26 weeks of gestation was investigated. The dermis at five weeks contains fine, individual collagen fibrils draped over the surfaces of mesenchymal cells. With increasing age, collagen matrix increases in abundance in the extracellular space. The size of fibril diameters increases, and greater numbers of fibrils associate into fiber bundles. By 15 weeks, papillary and reticular regions are recognized. Larger-diameter fibrils, larger fibers, denser accumulations of collagen, and fewer cells distinguish the deeper reticular region from the finer, more cellular papillary region located beneath the epidermis. The distribution of collagen types I, III, and V were studied at the light microscope level by immunoperoxidase staining and at the ultrastructural level by transmission (TEM) and scanning electron microscopy (SEM) with immunogold labeling. By immunoperoxidase, types I and III were found to be evenly distributed, regardless of fetal age, throughout the dermal and subdermal connective tissue with an intensification of staining at the dermal-epidermal junction (DEJ). Staining for types III and V collagen was concentrated around blood vessels. Type V collagen was also localized in basal and periderm cells of the epidermis. By immuno-SEM, types I and III were found associated with collagen fibrils, and type V was localized to dermal cell surfaces and to a more limited extent with fibrils. The results of biochemical analyses for relative amounts of types I, III, and V collagen in fetal skin extracts were consistent with immunoperoxidase data. Type I collagen was 70-75%, type III collagen was 18-21%, and type V was 6-8% of the total of these collagens at all gestational ages tested, compared to 85-90% type I, 8-11% type III, and 2-4% type V in adult skin. The enrichment of both types III and V collagen in fetal skin may reflect in part the proportion of vessel- and nerve-associated collagen versus dermal fibrillar collagen. The accumulation of dermal fibrillar collagen with increasing age would enhance the estimated proportion of type I collagen, even though the ratios of type III to I in dermal collagen fibrils may be similar at all ages.
Progress and prospects: immune responses to viral vectors

Viral vectors are potent gene delivery platforms used for the treatment of genetic and acquired diseases. However, just as viruses have evolved to infect cells efficiently, the immune system has evolved to fight off what it perceives as invading pathogens. Therefore, innate immunity and antigen-specific adaptive immune responses against vector-derived antigens reduce the efficacy and stability of in vivo gene transfer. In addition, a number of vectors are derived from parent viruses that humans encounter through natural infection, resulting in preexisting antibodies and possibly in memory responses against vector antigens. Similarly, antibody and T-cell responses may be directed against therapeutic gene products that often differ from the endogenous nonfunctional or absent protein that is being replaced. As details and mechanisms of such immune reactions are uncovered, novel strategies are being developed, and vectors are being specifically engineered to avoid, suppress or manipulate the response, ideally resulting in sustained expression and immune tolerance to the transgene product. This review provides a summary of our current knowledge of the interactions between the immune system adeno-associated virus, adenoviral and lentiviral vectors, and their transgene products.
Particle—particle interactions in concentrated dispersions as probed by the capillary force balance with application to batch sedimentation

A novel capillary force balance technique in conjunction with differential interferometry was used to measure quantitatively the dynamic stability of micro- and macrostructures due to the interaction between coarse and fine particles in concentrated dispersions. Using this technique, the values of threshold capillary pressures or yield stress for both fine and coarse particles are reported for the first time. The measured values of the threshold capillary pressures were then used to predict the batch sedimentation rates of particles in a concentrated suspension.
Spitzer Warm Mission Transition and Operations

Following the successful dynamic planning and implementation of IRAC Warm Instrument Characterization activities, transition to Spitzer Warm Mission operations has gone smoothly. Operation teams procedures and processes required minimal adaptation and the overall composition of the Mission Operation System retained the same functionality it had during the Cryogenic Mission. While the warm mission scheduling has been simplified because all observations are now being made with a single instrument, several other differences have increased the complexity. The bulk of the observations executed to date have been from ten large Exploration Science programs that, combined, have more complex constraints, more observing requests, and more exo-planet observations with durations of up to 145 hours. Communication with the observatory is also becoming more challenging as the Spitzer DSN antenna allocations have been reduced from two tracking passes per day to a single pass impacting both uplink and downlink activities. While IRAC is now operating with only two channels, the data collection rate is roughly 60% of the four-channel rate leaving a somewhat higher average volume collected between the less frequent passes. Also, the maximum downlink data rate is decreasing as the distance to Spitzer increases requiring longer passes. Nevertheless, with well over 90% of the time spent on science observations, efficiency has equaled or exceeded that achieved during the cryogenic mission.
Nonlinear constitutive models and the finite element absolute nodal coordinate formulation

In this investigation, the use of three different nonlinear constitutive models based on the hyper-elasticity theory with the absolute nodal coordinate formulation is considered. These three nonlinear constitutive models are based on the Neo-Hookean constitutive law for compressible materials, the Neo-Hookean constitutive law for incompressible materials, and the Mooney-Rivlin constitutive law in which the material is assumed to be incompressible. These models, which allow capturing Poisson modes, are suitable for many materials and applications, including rubber-like materials and biological tissues which are governed by nonlinear elastic behavior and are considered incompressible or nearly incompressible. Numerical examples that demonstrate the implementation of these nonlinear constitutive models in the absolute nodal coordinate formulation are presented. The results obtained using the nonlinear and linear constitutive models are compared in this study. The results show that when linear constitutive models are used in the large deformation analysis, singular configurations are encountered and basic formulas such as Nanson’s formula are no longer valid. These singular deformation configurations are not encountered when the nonlinear constitutive models are used.Copyright © 2007 by ASME
Nutrition: US recommendations fail to correct vitamin D deficiency.

Vitamin D deficiency is widespread among women with breast cancer. Guidelines currently recommend daily supplementation with 400 IU vitamin D3; however, attainment of a circulating level of 25-hydroxyvitamin D defined as sufficient (that is, ≥75 nmol/l) might not be possible with this level of supplementation, according to data published in the Journal of Clinical Oncology.
Characterization of porcine malate dehydrogenase I. An active center peptide

Abstract Iodoacetamide has been found to be a highly useful reagent for the selective chemical modification of active center residues of porcine heart mitochondrial malate dehydrogenase ( l -malate:NAD + oxidoreductase, EC 1.1.1.37). The addition of the coenzyme, NADH, fully protects the enzyme from alkylation thus suggesting that chemical modification is occurring at or near the NADH binding site. Alkylation by this reagent leads to a totally inactive enzyme. The identification of histidine as the site of chemical modification confirms work recently reported by B.H. Anderton ( Eur. J. Biochem. , 15 (1970) 562). However, in addition to the alkylated histidine, we have isolated a small active center peptide containing 2 residues of glycine in addition to carboxymethyl histidine. The composition and structure of this peptide was identified after difficulties arose in attempts to identify the active center residues derived from proteolytic digestion of the iodoacetamide modiffied enzyme.
Corrected TIMI frame count does not predict 30-day adverse outcomes after reperfusion therapy for acute myocardial infarction.

Abstract Background Thrombolysis in Myocardial Infarction (TIMI) flow grading is limited by subjectivity and imprecision. The corrected TIMI frame count (cTFC) has been proposed to obviate these problems. We sought to validate the utility of the cTFC in predicting adverse clinical outcomes after reperfusion therapy. Methods and Results We used angiographic core laboratory data from the Intravenous nPA for Treating Infarcting Myocardium Early Study (lanoteplase versus alteplase) to assess the predictive capacity of both final TIMI flow and cTFC on 30 day-composite adverse outcome (death, reinfarction, and new or worsening congestive heart failure). Only 390 angiograms of 586 were analyzable for cTFC; 33.4% of angiograms could not be analyzed for cTFC because filling of distal landmarks was not visualized for technical reasons such as inadequate panning. The interobserver correlation for determination of the cTFC was 0.99 and the intraobserver correlation was 0.97. The cTFC in the group with adverse outcomes was 49 ± 34; in the group without adverse outcomes, it was 44 ± 31 ( P = .27). Of note, the TIMI flow correlated with adverse outcome in the overall group of patients ( P = .018, area under the receiver-operator characteristic curve [c] = 0.590) as well as in the group of patients with cines analyzable for cTFC ( P = .025, c=0.600). The independent correlates of adverse outcomes were age ( P P = .001), TIMI flow grade ( P = .027), and infarct location ( P = .038) but not cTFC. Conclusions The cTFC did not predict adverse outcomes in this population of patients but did show excellent reproducibility within our core laboratory. (Am Heart J 1999;138:785-90.)
Increased oxidative metabolism by leukocytes of patients with osteogenesis imperfecta and of their relatives

Leukocyte oxidative metabolism was investigated in 14 patients with osteogenesis imperfecta, 8 of whom complained of increased sweating and heat intolerance. Leukocyte respiration, measured in a Warburg apparatus, was significantly increased above control values. Hexose monophosphate shunt activity, determined by the amount of 1- 14 CO 2 produced by leukocytes from 1- 14 C-glucose, was also significantly elevated. A significant increase in nitroblue tetrazolium reduction was observed histochemically in neutrophils of patients, thus confirming the enhanced activity of the hexose monophosphate shunt-associated oxidative pathway in these leukocytes. In approximately 50 per cent of asymptomatic relatives of patients with osteogenesis imperfecta, nitroblue tetrazolium reduction by neutrophils was abnormally elevated. These data confirm previous findings that osteogenesis imperfecta is a generalized metabolic disease, of which an important component is an increase in cellular oxidative metabolism. Measurement of the hexose monophosphate shunt-linked respiration in leukocytes of relatives may help in delineating the genetic aspect of osteogenesis imperfecta.
Prostatic adenocarcinoma of ductal origin

Clinical and histopathologic features of prostatic ductal adenocarcinomas have been incompletely described. A review of 4,286 cases of prostatic adenocarcinoma (1950 through 1970) at the Mayo Clinic showed 55 cases in which lesions were of a distinctive ductal type. Eight of the 55 lesions originated from periurethral primary prostatic ducts and had exuberant papillary folds. Cystoscopic examination revealed a polypoid and villous or an infiltrative urethral component. The 5-year survival rate (42.8%) was similar to that for the usual acinic adenocarcinomas. Carcinomas originating from secondary ducts had a multi-centric origin and papillary, comedo-like, and cribriform-papillary histopathologic features. The overall 5-year survival rate was 24.2%. Palliative hormone therapy appeared to be less effective in prolonging life in these patients as compared to patients with acinic carcinomas. Bone metastases were osteoblastic, and serum acid phosphatase activities were elevated if metastases were present.
Synthrusting deposition of the Pennsylvanian and Permian Strathearn Formation, Northern Carlin Trend, Nevada

Abstract The middle Upper Pennsylvanian and middle Lower Permian Strathearn Formation belongs to the overlap assemblage of the Antler orogen in Nevada. At Beaver Peak, near the Carlin Trend of gold deposits, it contains synorogenic conglomerate deposits associated with emplacement of a regionally extensive, 1-km-thick tectonic wedge that is floored by the Coyote thrust. Normal marine conodont biofacies throughout the Strathearn Formation suggest middle shelf or deeper, depositional environments. The allochthon floored by the Coyote thrust has been thrust above a middle Upper Pennsylvanian, lower conglomerate unit of the Strathearn Formation. A middle Lower Permian upper conglomerate unit, the highest unit recognized in the Strathearn Formation, as well as similarly aged dolomitic siltstone, onlap directly onto Ordovician quartzarenite of the Vinini Formation that makes up most of the Coyote allochthon. Quartz grains and quartzarenite fragments of variable roundness and shape in the conglomerate units were derived from the presently adjoining tectonic lobe of mostly quartzarenite that advanced southeast (present geographic coordinates) during the late Paleozoic into the developing Strathearn basin. Chert fragments in the conglomerates probably were derived mostly from Devonian Slaven Chert, including a widespread thick melange unit of the Slaven Chert in the footwall of the Coyote thrust. Lithologic and shape ratio data from approximately 4200 clasts at 17 sites of the two major conglomerate units in the Strathearn Formation at Beaver Peak are roughly similar in that they contain only chert and quartzarenite clasts, and chert clasts predominate in both units. They differ in the relative proportion of the two lithologies whereby quartzarenite clasts increase sixfold in the upper unit (middle Lower Permian) versus its content in the lower conglomerate unit. Relations at the unconformity between the upper conglomerate unit and its underlying quartzarenite shows quartzarenite fragments actually breaking away from an immediately subjacent source. Ordovocian quartzarenite, which forms a tectonically uplifted wedge with the Coyote thrust at its base, became a source region for much of the quartzarenite detritus deposited preferentially in the upper parts of the Strathearn Formation. The conglomerate units of the Strathearn Formation temporally bracket emplacement of the Coyote thrust. Thrusting related to contractional reactivation of the Robert Mountains thrust system largely was completed by middle Early Permian.
Primary prevention of stroke: impact of healthy lifestyle.

After heart disease, stroke is the second leading cause of death worldwide in persons ≥15 years of age.1 Stroke was responsible for an estimated 5.7 millions deaths in 2005, with ≈87% of the deaths occurring in low- and middle-income countries. It is the fourth leading cause of disease burden as determined by disability-adjusted life-years. In the United States, stroke caused an estimated 1 in 16 deaths in 2004; ≈780 000 new or recurrent strokes occurred; and 15% to 30% of stroke survivors were permanently disabled.2 In the United States in 2008, the direct and indirect cost of stroke is estimated to be $65.5 billion. Globally, stroke death is anticipated to rise to 6.5 million in 2015 and 7.8 million in 2030.1 Although stroke poses a major public health challenge, it is preventable.3 Observational epidemiological studies and clinical trials have laid the groundwork for well-developed evidence-based stroke prevention guidelines. Article p 947 The INTERHEART study helped to clarify the role of traditional cardiovascular risk factors in coronary heart disease among 15 152 cases of acute myocardial infarction and 14 820 controls in 52 countries on every inhabited continent.4 This important observational epidemiological study showed that for men and women, old and young, and in all areas of the world, 9 potentially modifiable factors accounted for >90% of the proportion of the risk of initial acute myocardial infarction. The factors were abnormal lipids; smoking; hypertension; diabetes; abdominal obesity; psychosocial factors; consumption of fruits, vegetables, and alcohol; and regular physical activity. Because coronary heart disease and stroke share common risk factors,5 a combination of healthy lifestyle factors also might influence stroke risk. There has been a relatively paucity of information, however, in this area of study. In this issue of Circulation , Chiuve et al6 report …
Differential equations without solutions

Dopo aver esposto alcuni risultati recenti sulla risolubilita locale di sistemi di equazioni differenziali, si definisce il complesso di Cauchy-Riemann indotto su una sottovareta generica di Cn e si danno criteri per la non trivialita dei suoi gruppi di coomologia locale.
G proteins, effectors and GAPs: structure and mechanism.

Abstract G proteins form a diverse family of regulatory GTPases which, in the GTP-bound state, bind to and activate downstream effectors. Structure of Ras homologs bound to effector domains have revealed mechanisms by which G proteins couple GTP binding to effector activation and achieve specificity. Complexes between structurally unrelated GTPase-activating proteins with complementary G proteins suggest common mechanisms by which GTP hydrolysis is stimulated via direct interactions with conformationally labile switch regions of the G protein.
NASA 3-Meter Infrared Telescope Facility at Mauna Kea

The demonstrated pointing, tracking and offsetting characteristics of the NASA 3-meter infrared telescope are reviewed. Other special features of the telescope such as low thermal background and versatile chopping secondary are also discussed. Experience is presented as to why these design features are important when making infrared observations of astronomical objects.
Allograft replacement of distal radius for giant cell tumor

Abstract Three cases of resection of the distal radius with allograft replacement for giant cell tumor of bone were reviewed. In one patient the tumor had penetrated the distal articular cortex; in another it had broken through the anterior cortex; in the third there had been recurrence of the tumor within a year of currettage and autogenous bone graft. In each case the allograft was glycerinized to help to preserve the viability of the articular cartilage and then it was frozen at -70° C to decrease bone antigenicity. In all three patients rapid healing at the recipient-graft juncture took place, and none showed signs of rejection or of recurrence of the tumor. All three have a useful and relatively painless range of wrist motion. Distal radial resection and allograft replacement is recommended for giant cell tumor of bone if there has been spontaneous cortical or articular breakthrough, recurrence, or evidence of a rapidly enlarging lesion or a frankly malignant histologic appearance.
Pulmonary surfactant: a surface chemistry viewpoint.

In this paper, we attempt to review and evaluate pulmonary surfactant research from what is essentially a surface chemistry viewpoint. The physiological importance of the system underlies the discussion, but this is coupled with the surface chemical consideration of pulmonary surfactant as a complex multicomponent system of soluble and insoluble surfactants at a liquid-air interface. The systemin vivo is at a constant temperature (37°C) and an essentially constant bulk pressure, but is subject to large variations in surface cycling frequency and in maximum and minimum surface area. In this context, then, the present level of knowledge of the system is discussed, and areas of uncertainty or conflict which require further study are isolated. In addition, experimental or analytical approaches useful for future surface studies are given wherever possible.
Stability of the scapolite meionite (3CaAl2Si2O2 · CaCO3) at high pressures and storage of CO2 in the deep crust

The stability field of the end-member scapolite meionite was determined in piston-cylinder apparatus. Meionite has very high thermal stability at high pressures, exceeding 1500° C at 20 kbar. Below 6 kbar and 1270 ° C scapolite breakdown is subsolidus, to an-orthite + gehlenite + wollastonite + CO2, with a slope of 20 bars/degree. An extrapolation of existing thermodynamic data for CO2 permits calculation of ΔGFo=-2384.5 kcal/mol for meionite at 1270 ° C, very close to the value for 3 anorthite + calcite. Above 1270 ° C, scapolite begins to melt to An+Geh+Liq+CO2, and as pressure increases the melting curve steepens, the Geh and An being progressively replaced by Liq+corundum with Al in 6-coordination. At pressures >25kbar dp/dt becomes negative, corundum is the only crystalline product, and CO2 bubbles disappear from the quenched glass, indicating a solubility of CO2 under these conditions of about 5 wt. percent in the liquid.
Diverse roles of integrins in human T lymphocyte biology.

T lymphocytes are the primary cells responsible for maintaining the immune system. There are many intricate mechanisms involved in the regulation of T cells and the integrin family of adhesive surface proteins plays a pivitol role in the control of T lymphocyte activation and functions. Integrins are heterodimeric transmembrane proteins that are not merely adhesion molecules but also function in T cell coactivation by providing a scaffold for signaling and cytoskeletal proteins that are adept at transmitting signals from the inside of the cell to the outside (“inside-out signaling”) or from the outside of the cell to the inside (“outside-in signaling”). The signaling property of integrins allows for rapid responses to changes T cell needs to adhere or detach, integrins can quickly accommodate either state of the cell. Once cells are guided to sites of infection, inflammation, or antigen presentation, integrins can also participate in the initiation, maintenance, or termination of the response. This review will focus on the aspects of integrin-mediated T cell coactivation, affinity and avidity control of integrins, signaling molecules involved with integrins, association of integrins in lipid microdomains, and negative regulation of integrins.
Gradient estimates for degenerate diffusion equations II

We establish upper and lower bounds for various norms of solutions and their gradients for the equation ut = div (|∇u|m−1 ∇u) in ℝN in terms of the norms of the initial data. Based on the L∞ estimate of ∇u, we conclude that u(x, t) is Lipschitz continuous in space-time, for all t>0, whenever u(x,0) is in L1(ℝN).
Low-Frequency Phenomena in a Frictionally Excited Beam

A cantilevered beam was excited by a periodically reciprocating friction contact surface. Frequency sweeps revealed frequency regions of dynamic responses in the flexural direction of the beam. Chaotic and quasiperiodic responses were observed when the input frequency was fixed. The quasiperiodic responses sometimes were accompanied by beam oscillations normal to the friction surface. Extremely low frequencies were observed (up to over 100 times lower than the driver). Two-frequency quasiperiodicity was observed, and underlying circle maps were extracted. Winding numbers were matched to frequencies quantified in FFTs. Impending torus folding and intermittency were revealed. Three-frequency quasiperiodicity was also evident. A torus doubling bifurcation was documented.Copyright © 2004 by ASME
APC and colon cancer: two hits for one

Two studies suggest how mutations in the APC tumor suppressor gene can contribute to chromosomal aberrations in precancerous cells.
Laminated Electrodes for Biopotential Studies

Electrodes designed for in vitro peripheral nerve studies were fabricated by laminating Plexiglas®sheets and silver or platinum foil. Many tissue-electrode interface geometries and electrode separations were obtained. A nerve chamber was developed to support the laminated electrodes at selected positions in precise planar alignment.
Surgical treatment of trigeminal neuralgia: results of percutaneous treatment versus microsurgical decompression

A patient with trigeminal neuralgia may need different forms of treatment during his or her lifetime. Physicians should be aware of the different available surgical treatments, and know their effectiveness, side effects and complications. Microvascular decompression is considered by many to be the most effective treatment. The goal of the procedure is to remove the cause of pain, obtained by decompressing the nerve at its entry point into the pons. Percutaneous procedures are more easily performed but the recurrence rate of pain is higher. It is difficult to compare the results of surgical procedures reported by different authors. Therefore, we compare the efficacy of 155 microvascular decompressions with 113 radiofrequency thermocoagulations and 215 percutaneous microcompressions performed by the same surgical team. Our study confirms microvascular decompression as the most effective surgical treatment, although percutaneous procedures play an important role in the treatment protocol and have to be offered to patients as a therapeutic option.
Kinetics of ordering and disordering for a two-dimensional binary lattice gas

Abstract We study the coverage and stoichiometry dependence of the kinetics of ordering and disordering for a twodimensional binary lattice gas with repulsive interactions using a time-dependent quasichemical approximation. The system is characterized by three long-range order (LRO) parameters and three short-range order (SRO) parameters. The time evolutions of all six quantities are obtained by numerical solution of appropriate coupled non-linear equations of motion. For the case of ordering, the SRO typically reaches a quasi-equilibrium state very rapidly, followed by exponential growth of LRO and final relaxation of both SRO and LRO to equilibrium. For the case of disordering, the SRO typically achieves its equilibrium value quickly while the LRO decreases very rapidly at short times followed by an exponential decay to the final state. In all cases, the exponential time constant is obtained analytically from a linearized version of the theory and qualitative arguments are advanced to explain its variations as a function of coverage and stoichiometry at T = 1 2 tc.
Response of a recurrent choroid plexus tumor to combination chemotherapy.

Choroid Plexus tumors are rare. Surgery and biopsy is diagnostic, and radiotherapy has been used as the treatment of choice for choroid plexus carcinoma (CPC) and recurrent choroid plexus papilloma (CPP). We report the first case of CPP responding to combination chemotherapy consisting of cisplatin, bleomycin and vinblastine (CBV). This chemotherapy regimen should be considered for future trials in patients with choroid plexus tumors and recurrence after surgery and/ or radiotherapy.
Laboratory-Based Microgrid Setup for Validating Frequency and Voltage Control in Islanded and Grid-Connected Modes

Small sized synchronous generator based distributed generators (DG) often have low start-up times, and therefore serve as valuable dispatchable generators in a microgrid environment. The advantage is that it allows the power network to operate in a true smart grid environment. The disadvantage is that such DGs typically tend to have low inertia and the prime movers driving these resources need to be controlled in real time for them to operate effectively in islanded, grid-connected modes and during transition. When multiple DGs are present in the microgrid, the overall control can become complicated because of the need for sharing the resources. A smart grid environment is then necessary to control all dispersed generation sources in the microgrid. The most common control strategy adopted for multiple DGs connected to a network is droop control. Droop control ensures that the load needed to be served is shared by all the generators in the network in proportion to their generating capability. Preliminary test results performed on a laboratory microgrid test bench is presented to demonstrate the ability to serve the load at nominal voltage and frequency irrespective of the support received from the main grid.
Needle biopsy for suspicious lesions of the head of the pancreas: pitfalls and implications for therapy

Controversy continues to exist concerning the optimal diagnostic approach to a pancreatic head lesion suspected of being a neoplasm. The objective of this study was to evaluate the impact of needle biopsy in suspicious pancreatic head neoplasia and its effect on therapy and outcome. Seventy-three patients with symptoms or signs of periampullary neoplasia and a pancreatic head lesion identified on CT scan were reviewed retrospectively. Forty patients with potentially resectable lesions underwent intraoperative transduodenal core needle biopsy of the head of the pancreas. Thirty-three patients underwent CT-guided percutaneous fine-needle aspiration. The sensitivity and specificity of core needle biopsy were 76% and 100%, respectively. One death was directly related to the procedure and therapy was adversely affected in one patient with a false negative result. The sensitivity and specificity of percutaneous fine-needle aspiration were 85% and 92%, respectively, and were not significantly different from the core needle biopsy results (P>0.3). Three false negative fine-needle aspiration biopsies occurred in patients with potentially resectable lesions and a low clinical suspicion for malignancy. In patients with a mass in the head of the pancreas on CT scan, fine-needle aspiration biopsy offers results similar to those of intraoperative transduodenal core needle biopsy. In patients estimated to have resectable disease, a pancreaticoduodenectomy should be performed without a biopsy. For patients with unresectable disease, cytologic examination of fine-needle aspirate should be performed. If this examination is positive, it offers the advantage of facilitating the construction of a rational plan for palliation.
The clinical use of deproteinized bovine bone mineral on bone regeneration in conjunction with immediate implant installation.

Twenty-one c.p. titanium screw-shaped implants were immediately installed after extraction and thorough curettage of the alveoli in 15 patients. Granules of deproteinized bovine bone of 0.25-1.0 mm diameter were used to fill the remaining defect when the distance of the defect wall to the implant surface was > 3 mm. Dimensional measurements of the defect height and width were made with a pocket probe. Fourteen sites in the upper jaw and 7 sites in the lower jaw were thus treated. The mean defect depth varied between 7 mm vestibularly and 10 mm mesially. The mucoperiosteal flaps were hermetically closed. At re-entry, the particles were packed and firmly attached but still distinguishable from the surrounding bone. Of the 21 sites treated, 5 sites had an exposure of the implant cover screw during the healing period. An exposure of the granular material occurred in 4 sites, but loss of granules in only 3. Even in these sites no signs of infection or inflammation of the soft tissues were observed. At re-entry after 6 months, 10 sites were completely and 9 partially filled. For the partial fills, the mean remaining defect height was 1.6 mm (range: 0.6-3.0 mm). Two sites showed an increased defect of respectively 2.4 and 4.8 mm. No fixtures were lost. The present results indicate that deproteinized bovine bone is a safe filling material to fill remaining defects around implants installed in fresh extraction sockets.
Combining molecular dynamics and an electrodiffusion model to calculate ion channel conductance

Establishing the relation between the structures and functions of protein ion channels, which are protein assemblies that facilitate transmembrane ion transport through water-filled pores, is at the forefront of biological and medical sciences. A reliable way to determine whether our understanding of this relation is satisfactory is to reproduce the measured ionic conductance over a broad range of applied voltages. This can be done in molecular dynamics simulations by way of applying an external electric field to the system and counting the number of ions that traverse the channel per unit time. Since this approach is computationally very expensive we develop a markedly more efficient alternative in which molecular dynamics is combined with an electrodiffusion equation. This alternative approach applies if steady-state ion transport through channels can be described with sufficient accuracy by the one-dimensional diffusion equation in the potential given by the free energy profile and applied voltage. The theory refers only to line densities of ions in the channel and, therefore, avoids ambiguities related to determining the surface area of the channel near its endpoints or other procedures connecting the line and bulk ion densities. We apply the theory to a simple, model system based on the trichotoxin channel. We test the assumptions of the electrodiffusion equation, and determine the precision and consistency of the calculated conductance. We demonstrate that it is possible to calculate current/voltage dependence and accurately reconstruct the underlying (equilibrium) free energy profile, all from molecular dynamics simulations at a single voltage. The approach developed here applies to other channels that satisfy the conditions of the electrodiffusion equation.
Phospholipid and neutral lipid separation by one-dimensional thin-layer chromatography.

Abstract A simple and rapid method for separation of six major phospholipids and four major neutral lipids from cell extracts by one-dimensional preadsorbant thin-layer chromatography was developed. Due to the inert characteristics of the preadsorbent layer (Celite) no separation occurs until the sample reaches the preadsorbent (Celite)—silica gel junction. The compounds were applied to the preadsorbent (Celite) area (625 mm2) in 10-μl aliquots (total volume of 0.15 ml). By this method, samples can be applied rapidly in large volumes without respotting any area of the preadsorbent layer. The time required to apply one sample was reduced considerably (2 min) compared to conventional methods (10 min). Since all the compounds move with the solvent front as a sharp, narrow band to the preadsorbent (Celite)—silica gel boundary, excellent separation was achieved when up to 650 μg of lipid material was applied on each lane (25 mm wide). Thus, this method is suitable for the separation of relatively large amounts of radiolabeled and non-radiolabeled lipids and free fatty acids from extracts of biological fluids, tissues, or cells maintained in monolayer culture.
IMPLEMENTATION OF VIRTUAL REALITY IN ROUTINE BRIDGE INSPECTION

The innovative use of QuickTime Virtual Reality (QTVR) and panoramic image-creation utilities for recording field observations and measurements during routine bridge inspections is reported. A virtual reality approach provides the ability to document a bridge's physical condition by using different media types at a significantly higher level of detail than is possible in a written bridge inspection report. Digitally recorded data can be stored on compact disc for easy access before, during, or after an inspection. The development of a QTVR bridge record consists of four major steps: selection of the camera stations, acquisition of the digital images, creation of cylindrical or cubic panoramas, and rendering of the QTVR file. Specific details related to these steps are provided, as applied to various bridge inspection projects. The potential impact of QTVR on bridge management---in which routine inspection data are a factor in making decisions regarding the future maintenance, rehabilitation, or replacemen...
Eclipsing Z-scan measurement of λ/10 4 wave-front distortion

We introduce a simple modification to the Z-scan technique that results in a sensitivity enhancement that permits measurement of nonlinearly induced wave-front distortion of ≃λ/104. This sensitivity was achieved with 10-Hz repetition-rate pulsed laser sources. Sensitivity to nonlinear absorption is also enhanced by a factor of ≃3. This method permits characterization of nonlinear thin films without the need for waveguiding.
Action of steroids on H+ and NH+4 excretion in the toad urinary bladder.

This study was done to determine if steroid compounds will stimulate the urinary bladder of the toad to increase its capacity to acidify the urine and excrete NH 4 + , Aldosterone, 17β-estradiol, dexamethasone, pregnenolone, and cholesterol were tested on the bladder. All compounds tested were found to stimulate the rate of acidification by the bladder, above that of a paired control hemibladder. In contrast, only the steroids aldosterone and 17β-estradiol were found to stimulate NH 4 + excretion in the bladder. Cycloheximide was found to block the action of aldosterone on the NH 4 + excretion, but did not have a significant effect on the stimulation of acidification by aldosterone. We conclude that steroids stimulate H+ and NH 4 + excretion in the toad urinary bladder. In addition, the NH 4 + excretory system seems to be more specific to this effect than is the H+ excretory system.
Transmission electron microscopy study of dislocations and interfaces in CdTe solar cells

Abstract We report on our transmission electron microscopy study of dislocations and interfaces in CdTe solar cells. The atomic structure of dislocations formed inside CdTe grains have been determined by atomic-resolution transmission electron microscopy. We discuss the electronic properties of the dislocations and explore the effects of oxygen on the interdiffusion at CdS/CdTe interface. We find that the presence of oxygen in either CdS or CdTe suppresses the interdiffusion at the CdS/CdTe interface. We have further investigated interdiffusion at the CdS/Zn2SnO4 interface. We find that Zn diffuses into CdS from Zn2SnO4 and Cd diffuses into Zn2SnO4 from CdS. The possible effects of the interdiffusion are discussed. Finally, we have examined the distribution of intentionally introduced Cu at the CdTe/CdS junction, and we find that Cu is distributed uniformly in the CdS layer.
Entering the ninth decade is not a contraindication for carotid endarterectomy

The role of carotid endarterectomy (CEA) in stroke prevention is now better defined. However, its role in patients older than 79 years of age is controversial. This group of patients has been excluded in most clinical trials. In this study the authors reviewed their experience with CEA patients >79 years old. The records of all patients older than 79 years of age who underwent a CEA in a recent time period from January 1988 to December 1996 were retrospectively reviewed. Forty-one patients (31 men, 10 women) were identified by computer search. The indication for operation included transient ischemic attack in 12 (29.3%), amaurosis fugax in nine (22%), stroke in two (4.9%), and nonhemispheric symptoms in three (7.3%). Fifteen patients (36.6%) were asymptomatic. Medical risk factors included coronary artery disease in 26 (63.4%), hypertension in 22 (53.7%), and smoking in 12 (29.3%). The procedure was performed under EEG monitoring in all patients. General anesthesia was administered in 37 (90%) and regional anesthesia in four (10%). Shunts were used in four (10%) patients. The internal carotid artery was patched in 16 patients (39%). One patient (2.4%) developed a perioperative stroke and only one patient developed perioperative myocardial infarction (MI). None of the patients died within 30 days of surgery. In addition to the one MI case, five patients developed minor complications. The average length of time for stay after CEA was 3.4 days. Patients were followed up for an average of 20.7 months. Six patients died during follow-up. Four of those died from an MI and two from a stroke. The authors conclude that with proper selection of patients, CEA is safe in the octogenarian. Age alone should not be a contraindication for CEA.
The Extragenic Spacer Length Between the 5′ and 3′ Ends of the Transgene Expression Cassette Affects Transgene Silencing From Plasmid-based Vectors

In quiescent tissues, minicircle DNA vectors provide at least 10 times higher sustained levels of transgene expression compared to that achieved with a canonical plasmid containing the same expression cassette. It is not known if there is a specific DNA sequence or structure that is needed for DNA silencing. To directly address this question, we substituted the bacterial plasmid DNA with various lengths of extragenic spacer DNAs between the 5′ and 3′ ends of the transgene expression cassette and determined the expression profiles using two different reporter expression cassettes. Both the human alphoid repeat (AR) and randomly generated DNA sequences of ≥1 kb in length resulted in transgene silencing while shorter spacers, ≤500 bp exhibited similar transgene expression patterns to conventional minicircle DNA vectors. In contrast, when the ≥1 kb random DNA (RD) sequences were expressed as part of the 3′-untranslated region (UTR) transgene silencing was not observed. These data suggest that the length and not the sequence or origin of the extragenic DNA flanking the expression cassette is responsible for plasmid-mediated transgene silencing. This has implications for the design of nonviral vectors for gene transfer applications as well as providing insights into how genes are regulated.
Compositional changes in natural gas bubble plumes: observations from the Coal Oil Point marine hydrocarbon seep field

Detailed measurements of bubble composition, dissolved gas concentrations, and plume dynamics were conducted during a 9-month period at a very intense, shallow (22-m water depth) marine hydrocarbon seep in the Santa Barbara Channel, California. Methane, car- bon dioxide, and heavier hydrocarbons were lost from rising seep bubbles, while nitrogen and oxygen were gained. Within the rising seawater bubble plume, dis- solved methane concentrations were more than 4 orders of magnitude greater than atmospheric equilibrium concentrations. Strong upwelling flows were observed and bubble-rise times were � 40 s, demonstrating the rapid exchange of gases within the bubble plume.
Insecticidal activity of some reducing sugars against the sweet potato whitefly, Bemisia tabaci, Biotype B.

The effects of 16 sugars (arabinose, cellobiose, fructose, galactose, gentiobiose, glucose, inositol, lactose, maltose, mannitol (a sugar alcohol), mannose, melibiose, ribose, sorbitol, trehalose, and xylose) on sweet potato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) survival were determined using in vitro bioassays. Of these sugars, arabinose, mannose, ribose, and xylose were strongly inhibitory to both nymphal and adult survival. When 10% mannose was added to the nymphal diet, 10.5%, 1.0%, and 0% developed to the 2nd, 3rd, and 4th instars, respectively. When 10% arabinose was added, 10.8% and 0% of the nymphs molted to the 2nd and 3rd instars, respectively. Addition of 10% xylose or ribose completely terminated B. tabaci development, preventing the molt to the 2nd instar. With decreasing sugar concentrations the inhibitory effect was significantly reduced. In tests using adults, arabinose, galactose, inositol, lactose, maltose, mannitol, mannose, melibiose, ribose, sorbitol, trehalose, and xylose significantly reduced mean day survival. Mortality rates were highest when arabinose, mannitol, mannose, ribose, or xylose was added to the diet. Mean day survival was less than 2 days when adults were fed on diet containing 10% of any one of these five sugars. When lower concentrations of sugars were used there was a decrease in mortality. Mode of action studies revealed that toxicity was not due to the inhibition of alpha glucosidase (converts sucrose to glucose and fructose) and/or trehalulose synthase (converts sucrose to trehalulose) activity. The result of agarose gel electrophoresis of RT-PCR products of bacterial endosymbionts amplified from RNA isolated from whiteflies fed with 10% arabinose, mannose, or xylose indicated that the concentration of endosymbionts in mycetomes was not affected by the toxic sugars. Experiments in which B. tabaci were fed on diets that contained radio-labeled sucrose, methionine or inulin and one or none (control) of the highly toxic sugars showed that radioactivity (expressed in DPM) in the body, in excreted honeydew and/or carbon dioxide, was significantly reduced as compared to controls. Thus, it appears that the ability of insecticidal sugars to act as antifeedants is responsible for their toxicity to B. tabaci.
An RF Receiver Detection Technique for Cognitive Radio Coexistence

A receiver detection technique is proposed by measuring the low-level leakage signal from a nearby receiver local oscillator. The probabilities of false alarm and missed detection are derived to quantify the detection performance. The technique provides higher sensitivity than a radiometer and is robust to estimation error even if the power spectral density of the ambient noise is unknown.
Hypertriglyceridemia: impact and treatment.

The treatment of elevated levels of low-density lipoprotein cholesterol is standard medical practice supported by conclusive outcome data. Less definitive information exists for hypertriglyceridemia. Only in the setting of severe hyperchylomicronemia is the benefit of triglyceride lowering clear: it is a means to reduce the risk of pancreatitis. The relationship of triglycerides and cardiovascular disease is still unclear. Moreover, the cardiovascular benefits of reducing triglycerides and of using triglyceride-lowering medications remain unproved. Nonetheless it has become almost standard to reduce the levels of triglyceride-rich lipoproteins that are a major component of plasma non–high-density lipoprotein cholesterol.
The effect of insulin and insulin-like growth factors on luteal progesterone secretion in the rabbit.

Objective:The purpose of this study was to determine if insulin or insulin-like growth factors (IGF) either alone or in combination with estradiol (E2) could maintain progesterone secretion by rabbit luteal cells in culture.Methods:Progesterone secretion was measured in media of luteal cell cultures incubated in serum-free media alone or containing E2 with or without added insulin, IGF-I or IGF-II.Results:Progesterone production by rabbit luteal cells in culture fell precipitously in serum-free media containing E2, IGF-I, IGF-II, or insulin alone. However, when E2 was combined with insulin, IGF-I, or IGF-II, serum progesterone production was stimulatewd two- to fivefold above control levels.Conclusion:There is an important synergism between insulin/IGF and E2 in regulating luteal steroidogenesis.
A 500MHz Low Phase-Noise A1N-on-Silicon Reference Oscillator

This paper presents a 496 MHz low phase-noise reference oscillator using a high-Q lateral-mode AlN-on-Si micromechanical resonator that does not require DC voltage for operation. The sustaining amplifier consists of an inductorless high-gain CMOS transimpedance amplifier (TIA) that is optimized for low phase-noise. The resonator is designed to have a high quality factor in air (Q-3800) with low motional impedance. The measured phase-noise at 1 kHz offset is -92 dBc/Hz with phase-noise floor below -147 dBc/Hz (exceeding GSM phase-noise requirement by 2 dB and 28 dB, respectively).