cssi/SciSciGPT-SciSciNet huggingface dataset:
Structures and phase transformations of odd-numbered asymmetric main-chain liquid crystalline polyesters

Abstract Two new asymmetric odd-numbered main-chain liquid crystalline (LC) polyesters (BPE-Cn) were synthesized through the condensation polymerization of A–B type asymmetric α,ω-carboxylic acid–hydroxyl terminated monomers with odd-numbers of methylene units in the spacers (BPCA-Cn-PmOH, where n=7 and 9). The phase behaviors and structures of these odd-numbered BPE-Cn samples were characterized using the combined techniques of differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), selected area electron diffraction (SAED) and polarized light microscopy (PLM). One-dimensional (1D) powder WAXD results at different temperatures combined with DSC results revealed that during cooling these two polyesters enter a low-ordered LC phase before developing a crystalline phase at lower temperatures. Based on 2D WAXD of oriented fiber patterns, the low ordered LC phase of odd-numbered BPE-Cn was identified to be a smectic A (SmA) phase, which was constructed by each chemical repeating unit along the fiber drawn direction. The crystalline structures were determined to be monoclinic unit cells (KM). However, BPE-C7 possessed a γ=87°, while BPE-C9 had a β=100°. These crystalline structure identifications were also confirmed by SAED from single crystals. Two-chain packing models of the KM phases with four chemical repeating units were proposed on the basis of the experimental diffraction patterns. The different structures were attributed to the interplay between the mesogenic group ordering propensity and the chain constraints dictated by the methylene spacer and the meta-linkage at the end of mesogen. In the ordered phases of these two odd-numbered BPE-Cn polyesters, aromatic mesogenic groups are more or less parallel to each other along the chain with small angles of deviation from the c-axis of the crystal lattice, different from those large zigzag conformation structures in even-numbered BPE-Cn crystals. Crystallographic calculations of these two unit cell structures indicated that the neighboring chains in the crystals are translated along the c-axis (in the case of BPE-C9) or twisted away from the b-axis (in the case of BPE-C7) in order to incorporate both of the bend attributed to the odd-numbered methylene spacers and of the configurational meta-linkage at the end of mesogens. The simulated diffractions based on these calculations qualitatively agreed with the experimental observations. The phase identifications were also supported by the observed texture changes in PLM.
Endoscopic Management of Complications After Gastrointestinal Weight Loss Surgery

As more patients undergo bariatric surgery, gastroenterologists will increasingly encounter variant postsurgical anatomies and postoperative complications. We discuss the diagnosis and management of bleeding, ulcers, foreign bodies, stenoses, leaks, fistulas, pancreaticobiliary diseases, weight regain, and dilated outlets.
Bacterial removal of mercury from sewage

Mercury-resistant bacteria, which are able to reduce mercuric ion (Hg(2+)) to metallic mercury (Hg(0)), were examined for their ability to remove mercury from waste-water aerobically. Growth studies in artificial medium indicated that mercury increases the lag phase, but does not effect the growth rate of these bacteria. Further studies demonstrated that growth was minimal during a phase of rapid mercury removal, after which growth resumed. Small but significant amounts of carbohydrates are required for the mercuric ion reduction. Prolonged periods of bacterial growth under nonsterile conditions was accomplished without the loss of the mercuric reducing ability of the culture. A continuous culture of the resistant organism was maintained on raw sewage for two weeks, during which time relatively high concentrations of mercury (70 mg/L) were removed from the sewage at a rate of 2.5 mg/L h and at efficiencies exceeding 98%.
Change in the order of a martensitic phase transformation by an external field

Abstract It is shown on the basis of the Labbe-Friedel model for A3B compounds that the martensitic phase transformation in Nb3Sn can be changed from a first to a second order transition by an external stress. The Hamiltonian operator describing the phase transition in an external stress field has been mapped to a spin 1 2 Ising model with infinite range interactions showing a second order phase transition. Estimates of the transition temperature and the maximum order parameter are given suggesting new experiments.
Diurnal and acute patterns of postprandial apolipoprotein B-48 in VLDL, IDL, and LDL from normolipidemic humans.

Abstract Smaller size particles of intestinal origin may be more relevant to atherosclerosis than larger particles because of easier transendothelial transport. We examined the diurnal pattern in response to low-fat high-carbohydrate meals and the effect of a single high-fat milkshake on apoB-48 in very light S f °>400, light S f ° 60–400, and dense S f ° 20–60 VLDL, IDL, and LDL in 24 subjects (12 in each study). After the high-fat meal, apoB-48 concentrations peaked at 3h for very light VLDL, 4h for light VLDL, and 5h for dense VLDL and IDL, suggesting a delipidation cascade. The diurnal pattern was characterized by a sharp increase in light and dense VLDL apoB-48 after breakfast, reaching the highest concentration 4–8h after breakfast. Less response was observed after lunch, dinner or snack, despite 75% of energy supplied by these meals. The proportion of apoB-48 in LDL in the fasting state ranged between 48 and 54%. LDL apoB-48 concentration decreased by 35% after the high-fat meal, and slowly recovered to near fasting concentrations after 10–12h. In contrast, in the diurnal study, LDL apoB-48 concentration steady increased peaking 13h after breakfast, followed by a sharp decrease. In sum, most intestinally synthesized apoB lipoproteins circulate in LDL, and are likely formed in the late postprandial period from larger VLDL-size particles. Although small apoB-48 lipoproteins may be atherogenic remnant particles, their very low concentration may diminish their clinical significance.
Materials Science The Biocompatibility of Dental Implant Materials Measured in an Animal Model

The biocompatibility of two implant materials, vitallium and poly-methyl methacrylate (PMMA), was evaluated in an animal model in which bone formation and resorption are independent of each other. Neither material accelerated resorption, but formation was inhibited 12% by vitallium and 38% by PMMA. When three PMMA preparations varying in monomer content were tested, the data exhibited a dose-response relation, suggesting that inhibition of bone formation was due to the presence of residual monomer.
Un dispositivo per lo studio della produzione dei mesoni nella stratosfera

Si descrive un apparato costruito negli anni 1947–48 e 1948–49 presso l'Universita di Chicago, atto ad investigare il processo di creazione dei mesoni nella stratosfera. Si fa vedere come il dispositivo, portato a grande altezza, permetta di riconoscere se i mesoni prodotti (localmente) sono del tipo pesante (mesoni π) o del tipo ordinario (mesoni μ) e, inoltre, se essi sono generati da una radiazione ionizzante o meno. Si discutono altre possibili informazioni ottenibili attraverso misure effettuate alle quote accessibili con i palloni.
Attending to feelings and cognitive performance

Abstract The effect on cognitive performance of attending to internally generated stimuli was examined. Specifically, the effect of examining feelings and sensations upon performance in the Stroop test and upon the performance of mental addition was measured. In two initial experiments subjects more quickly named, in the Stroop test, the color of the ink (“red”) in which a color word (“green”) was printed following instructions to attend to their feelings. It was found that this facilitation was due in part to the slowing of the automatic, interfering habit of reading for word meanings. In a third experiment, the effect of attending to physical sensations on the back of the hand was found to have a similar facilitating effect and was seen as resulting from the allocation of attention to internally generated stimuli. In a final experiment, attending to feelings and to the physical sensations on the back of the hand was found to increase speed of mental addition. This effect was attributed to increased attention to internally generated stimuli (here knowledge about the arithmetic performance at the moment).
α-Thrombin-mediated Phosphatidylinositol 3-Kinase Activation through Release of Gβγ Dimers from Gαq and Gαi2

Chinese hamster embryonic fibroblasts (IIC9 cells) express the Galpha subunits Galphas, Galphai2, Galphai3, Galphao, Galpha(q/11), and Galpha13. Consistent with reports in other cell types, alpha-thrombin stimulates a subset of the expressed G proteins in IIC9 cells, namely Gi2, G13, and Gq as measured by an in vitro membrane [35S]guanosine 5'-O-(3-thio)triphosphate binding assay. Using specific Galpha peptides, which block coupling of G-protein receptors to selective G proteins, as well as dominant negative xanthine nucleotide-binding Galpha mutants, we show that activation of the phosphatidylinositol 3-kinase/Akt pathway is dependent on Gq and Gi2. To examine the role of the two G proteins, we examined the events upstream of PI 3-kinase. The activation of the PI 3-kinase/Akt pathway by alpha-thrombin in IIC9 cells is blocked by the expression of dominant negative Ras and beta-arrestin1 (Phillips-Mason, P. J., Raben, D. M., and Baldassare, J. J. (2000) J. Biol. Chem. 275, 18046-18053, and Goel, R., Phillips-Mason, P. J., Raben, D. M., and Baldassare, J. J. (2002) J. Biol. Chem. 277, 18640-18648), indicating a role for Ras and beta-arrestin1. Interestingly, inhibition of Gi2 and Gq activation blocks Ras activation and beta-arrestin1 membrane translocation, respectively. Furthermore, expression of the Gbetagamma sequestrant, alpha-transducin, inhibits both Ras activation and membrane translocation of beta-arrestin1, suggesting that Gbetagamma dimers from Galphai2 and Galphaq activate different effectors to coordinately regulate the PI 3-kinase/Akt pathway.
Superradiant stability in specially shaped small samples

Abstract The instability of the superradiant state due to self-induced frequency shifts is analysed for samples much smaller than λ. The superradiant state is relatively stable in a spherical sample, but even there it will be destroyed (dephased) before it can radiate through the equator of the Bloch sphere.
Reaction-dependent heteroatom modification of acid–base catalytic cooperativity in aminosilica materials

Abstract The effects of heteroatom substitution on the cooperative catalytic activity of a series of bifunctional acid–base aminosilica catalysts are probed in aldol and nitroaldol condensations. Three M3+ (B, Al, and Ga) and three M4+ (Ti, Zr, and Ce) heteroatoms are incorporated into different samples of SBA-15 silica and then grafted with aminosilanes to produce bifunctional acid–base catalysts. The catalytic activity of each material is measured in the aldol condensation of 4-nitrobenzaldehyde with acetone at 50 °C and the nitroaldol condensation of 4-nitrobenzaldehyde with nitromethane at 40 °C and compared to the catalytic activity of a heteroatom-free aminosilica catalyst. The heteroatom substitutions produce catalysts with larger amounts of strong Lewis acid sites compared to the heteroatom-free aminosilica catalyst. We rationalize these results in the context of the physical (e.g. surface area, pore diameter, particle size) and chemical properties (e.g. total number and strength of acid sites) of each material and the proposed catalytic mechanisms of the two reactions. The increase in the number of strong Lewis acid sites of each heteroatom material decreased its activity in the aldol condensation, though four heteroatom substitutions (B, Al, Ga, and Ti) increased the catalytic activity of the aminosilica catalyst in the nitroaldol condensation. The results suggest that inclusion of a small amount of Lewis acid sites in aminosilica materials can increase the cooperative catalytic activity of the materials in the nitroaldol condensation. The results also suggest that inclusion of Lewis acid sites in aminosilica materials decreases the cooperative catalytic activity of the materials in the aldol condensation.
Humanitarian Crisis as Everyday Life

Contemporary scholarship understates the resilience of everyday life in humanitarian crisis. Disaster may seem like a fleeting moment—colloquially, we say “the world stood still” or “everything changed in a blink”—but in the Buduburam Refugee Camp, a predominately Liberian refugee camp in Ghana, people experienced calamitous tragedy accumulated over years of daily activities. Though they remained politically and economically “out of place,” residents constructed buildings and other ordinary material objects to forge a new lived environment. As residents engaged with this new lived environment—from building homes to managing rainwater—they regularly participated in moral boundary work that helped establish how “good” people ought to act in inhumane circumstances. Moral boundary work did not obviate inequality or conflict, but it did help mediate between immediate bodily needs and the wider social order. More broadly, the study documents the crucial role that seemingly mundane material objects play in moral boundary work. Material objects like signs, garbage cans, and homes can operate like sociospatial props in the stories that people tell about their daily lives. These stories reinforce the moral boundaries that divide “good” and “bad” people and ultimately help make a shared moral order possible.
Fertility status and symptoms in childbearing couples

The symptoms of 58 pregnant couples–37 with a history of infertility and 21 without a history of infertility–were compared. The Symptomatology Inventory, a checklist of 42 common physical and psychological symptoms of pregnancy, was completed by each spouse from months 4 to 9 of pregnancy. For purposes of analysis, the individual symptoms were grouped into three categories: physical symptoms, negative affective symptoms, and positive affective symptoms. Although the infertile pregnant couples did not experience more symptoms than fertile couples, their pattern of reporting pregnancy-related symptoms was quite different. In terms of both number and type of symptoms, infertile spouses' symptoms tended to be positively related. Compared to fertile couples, the infertile couples experienced symptoms globally and were more consistent in the number of symptoms reported by each spouse. Additional research is needed to confirm these findings and to determine the implications of these differences for childbearing and the marital relationship. ©1995 John Wiley & Sons, Inc.
Strongly regular graphs with non-trivial automorphisms

The possible existence of 16 parameter sets for strongly regular graphs with 100 or less vertices is still unknown. In this paper, we outline a method to search for strongly regular graphs by assuming a non-trivial automorphism of prime order. Among these unknown parameter sets, we eliminated many possible automorphisms, but some small prime orders still remain. We also found 6 new strongly regular graphs with parameters (49,18,7,6).
Measurement of the oxidation‐reduction potentials of amicyanin and c‐type cytochromes from Paracoccus denitrificans

The oxidation-reduction potentials of four periplasmic electron carrier proteins from Paracoccus denitrificans have been determined. Their midpoint potentials are: amicyanin, 294±6 mV; cytochrome c-550, 253±5 mV; cytochrome c-551i, 190±4 mV, and cytochrome c-553i, 148±5 mV. Although rapid amicyanin-mediated transfer of electrons from methylamine dehydrogenase to cytochrome c-551i was observed, reduced amicyanin did not reduce oxidized cytochrome c-551i in the absence of methylamine dehydrogenase.
Acute Hemorrhage and Necrosis of the Intestines Associated with Digitalization

Eleven cases with acute hemorrhage and necrosis of the bowel are described. In all cases there was high dosage of digitalis and definite toxicity in seven. Digitalis was considered as the main associated factor, especially since there was no mesenteric arterial involvement and, in four cases, there was no congestive failure at autopsy. Hepatic vein or sinusoidal sphincter constriction with resulting portal splanchnic venous congestion was considered as possible mechanisms by which digitalization produced this syndrome.
Hypertension in diphtheria

Summary Two cases of postdiphtheritic paralysis accompanied by hypertension are reported. The blood pressure increased as the paralysis progressed and gradually decreased as the paralysis cleared. Several comparable cases were cited from the literature. Review of the literature reveals that the occurrence of hypertension in children is not uncommon. Various etiological possibilities were mentioned. It seems most likely that late hypertension coming on at the time of paralysis is of neurologic origin, attributed either to damage to a center in the medulla or mediated by irritation of nerve fibers similar to the carotid sinus reflex.
Musicians' and Nonmusicians' Aural Perception of Orchestral Instrument Families

The purpose of this study was to examine aural perception in a selective listening task using a Continuous Response Digital Interface (CRDI). Undergraduate college students (60 musicians, 60 nonmusicians) listened to an excerpt from Billy the Kid by Aaron Copland. Subjects indicated focus on instrumental family by manipulating the indicator of the CRDI. “Sound intervals” were determined by changes in predominant instrument family in the orchestral texture. Families were divided into five categories: (a) brass, (b) percussion, (c) woodwinds, (d) strings, and (e) all The “all” category indicated focus on three or more families simultaneously (e.g., tutti). Results were based on examination of subjects' category selections in terms of percentages of time focused on each category within each interval Analyses of cumulative seconds across all intervals indicated that nonmusicians focused on brass and percussion longer than did musicians. Musicians focused on strings longer and selected strings mare frequently ...
Vibration control with state-switched piezoelectric materials

In this paper, a semi-active control law is used to switch the electrical shunt circuit of a piezoelectric actuator for energy dissipation in a simple mechanical system. Switching is carried out between open-circuit (high stiffness) and short- or resistive-circuit (low stiffness) states. The actuator is held in its high stiffness state when the system is moving such that energy can be stored in the actuator. When the system’s motion would cause it to receive energy back from the actuator, the actuator is switched to a low stiffness state, dissipating the energy. In this paper, the concept is developed starting with the governing piezoelectric equations. Numerical simulation results are presented which show that the technique provides energy dissipation that is comparable to other piezoelectric shunt mechanisms, using optimal shunt resistance in each case. Finally, a brief analysis is presented in which the piezoelectric element is used in a flexible beam element to illustrate the effects of a parallel str...
Connoisseur's Choice: Enargite, Longfellow Mine, Red Mountain District, San Juan County, Colorado

Are all things beautiful? Are all types equally beautiful when we abstract from our practical prejudices? If the reader gives his assent … we must declare that no object is essentially ugly. —Georg...
Irritable bowel syndrome: Streamlining the diagnosis

IBS is one of the most common of the gastrointestinal disease, but it can be a diagnostic challenge because of the many symptoms that overlap with other such diseases. Most common among the symptoms are abdominal pain, a feeling of intestinal distention or bloating, and either diarrhea or constipation. Patients may be found to have an exacerbation of symptoms with stress, and they may have an increased sensitivity to bowel distention. History and physical examination findings often can be relied on to make the diagnosis, avoiding overuse of laboratory testing. Treatment consists of patient education and support, lifestyle and dietary changes, and use of several pharmacologic agents for symptom relief. Antidepressants are being investigated as a possible additional form of treatment.
KINEMATICS OF GENERAL SCATTERING PROCESSES AND THE MANDELSTAM REPRESENTATION

The kinematics of an arbitrary process involving two incoming and two outgoing particles is studied in terms of the invariants used in Mandelstam's representation, treating the three processes described by the same Green's function simultaneously. It is shown that the physical regions for these processes are bounded by a cubic curve in the plane of the two independent invariants. The unitarity conditions are discussed in the approximation of neglecting intermediate states of more than two particles. The formula for the spectral functions of the double dispersion relation is obtained explicitly in terms of the invariants chosen.
The Cystic Fibrosis Transmembrane Conductance Regulator Impedes Proteolytic Stimulation of the Epithelial Na+ Channel

Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) that prevent its proper folding and trafficking to the apical membrane of epithelial cells. Absence of cAMP-mediated Cl− secretion in CF airways causes poorly hydrated airway surfaces in CF patients, and this condition is exacerbated by excessive Na+ absorption. The mechanistic link between missing CFTR and increased Na+ absorption in airway epithelia has remained elusive, although substantial evidence implicates hyperactivity of the epithelial Na+ channel (ENaC). ENaC is known to be activated by selective endoproteolysis of the extracellular domains of its α- and γ-subunits, and it was recently reported that ENaC and CFTR physically associate in mammalian cells. We confirmed this interaction in oocytes by co-immunoprecipitation and found that ENaC associated with wild-type CFTR was protected from proteolytic cleavage and stimulation of open probability. In contrast, ΔF508 CFTR, the most common mutant protein in CF patients, failed to protect ENaC from proteolytic cleavage and stimulation. In normal airway epithelial cells, ENaC was contained in the anti-CFTR immunoprecipitate. In CF airway epithelial cultures, the proportion of full-length to total α-ENaC protein signal was consistently reduced compared with normal cultures. Our results identify limiting proteolytic cleavage of ENaC as a mechanism by which CFTR down-regulates Na+ absorption.
Reduce IC power consumption by >10x with a green transistor?

Growing IC power use poses challenges for thermal management and electricity conservation. A low voltage green transistor could be the key to allowing more growth of microelectronics [1].
Obstructive sleep apnea syndrome: natural history, diagnosis, and emerging treatment options

Sleep apnea is an entity characterized by repetitive upper airway obstruction resulting in nocturnal hypoxia and sleep fragmentation. It is estimated that 2%-4% of the middle-aged population has sleep apnea with a predilection in men relative to women. Risk factors of sleep apnea include obesity, gender, age, menopause, familial factors, craniofacial abnormalities, and alcohol. Sleep apnea has been increasingly recognized as a major health burden associated with hypertension and increased risk of cardiovascular disease and death. Increased airway collapsibility and derangement in ventilatory control responses are the major pathological features of this disorder. Polysomnography (PSG) is the gold-standard method for diagnosis of sleep apnea and assessment of sleep apnea severity; however, portable sleep monitoring has a diagnostic role in the setting of high pretest probability sleep apnea in the absence of significant comorbidity. Positive pressure therapy is the mainstay therapy of sleep apnea. Other treatment modalities, such as upper airway surgery or oral appliances, may be used for the treatment of sleep apnea in select cases. In this review, we focus on describing the sleep apnea definition, risk factor profile, underlying pathophysiologic mechanisms, associated adverse consequences, diagnostic modalities, and treatment strategies.
Biplanar oncoplastic surgery: a novel approach to breast conservation for small and medium sized breasts.

UNLABELLED Biplanar oncoplastic surgery represents a novel technique with which to address partial breast reconstruction defects in small to medium sized breasts. Traditional oncoplastic volume displacement techniques may correct contour irregularities but do not address volumetric asymmetries. Volume replacement techniques classically rely on autologous tissue flaps. A biplanar approach, with a combination of glandular rearrangement techniques and volume enhancement with submuscular implants, can result in an alternative approach in select patients to achieve symmetry. CLINICAL QUESTION/LEVEL OF EVIDENCE Therapeutic, V.
Gain-current relation for GaAs lasers with n-type and undoped active layers

Results for the optical gain coefficient as a function of the nominal current density are given for GaAs lasers with compensated n-type active layers and with undoped active layers. The results suggest that n-type layers may give lower threshold currents near room temperature than do comparable p-type layers.
Determination of minimum number of sensors and their locations for an automated facility : an algorithmic approach

Abstract We present an algorithmic approach to determine the minimum number of sensors and their placements required to monitor the workplace. For a 2-D workspace this involves finding the minimal sensor placement to ‘see’ the edges of all the objects (polygons) in the workspace and the boundary of the workspace. The problem belongs to a class of geometric optimization problems called the art gallery problems and is a variant of the minimum guard cover problem (MGCP). Utilizing the concepts of visibility of a point, we characterize the problem of strong visibility of an edge in a polygon with holes. An efficient algorithm is presented which runs in time linear to the number of edges present to obtain the strong visibility polygon for an edge. The visibility polygons of all edges give us a set of points which is sufficient to include the optimal placement of sensors. A set covering problem is then solved on this set of points to extract a minimal set of points that provides visibility of all the desired edges. The set covering problem is NP-complete and makes the overall approach NP-complete (the MGCP is also known to be NP-complete). However, the finite set of sufficient location points and efficient heuristics for the set covering problem make this method a viable one.
Solvent-washable polymer templated synthesis of mesoporous materials and solid-acid nanocatalysts in one-pot

We report a new and simple one-pot synthetic method to produce mesoporous silica and nanoporous solid acid catalyst capable of catalyzing pinacole-pinacolone rearrangement and esterification reactions, by preparing a solvent washable phosphonated triblock copolymer template and self-assembling it in the presence of alkoxysilane.
Evolutionary approach for crowdsourcing quality control

Crowdsourcing is widely used for solving simple tasks (e.g. tagging images) and recently, some researchers (Kittur et al., 2011 9 and Kulkarni et al., 2012 10) propose new crowdsourcing models to handle complex tasks (e.g. article writing). In both type of crowdsourcing models (for simple and complex tasks), voting is a technique that is widely used for quality control 9. For example, 5 workers are asked to write 5 outlines for an article, and another 5 workers are asked to vote for the best outline among the 5 outlines. However, we argue that voting is actually a technique that selects a high quality answer from a set of answers. It does not directly enhance answer quality. In this paper, we propose a new quality control approach for crowdsourcing that can incrementally improve answer quality. The new approach is based upon two principles - evolutionary computing and slow intelligence, which help the crowdsourcing system to propagate knowledge among workers and incrementally improve the answer quality. We perform explicitly 2 experimental case studies to show the effectiveness of the new approach. The case study results show that the new approach can incrementally improve answer quality and produce high quality answers.
Facilitated communication with children diagnosed as autistic in public school settings

In spite of claims that facilitated communication is a unique and effective communication option for individuals with autism, validity of this method has not been established. The present study focused on evaluating the effectiveness of facilitated communication with elementary-age children with autism. Ten public school children and their teachers, who served as facilitators, were involved in this 15-week facilitated communication validation study. Several subjects revealed ability to complete simple responses to requests and questions to which the facilitators knew the answers. However, little success was shown by subjects in answering questions to which the facilitators lacked answers, or in communicating via an augmentative communication device. Results of the study are discussed, along with implications for future use of facilitated communication with children with autism.
Recent advances in the organometallic vapor phase epitaxial growth of HgCdTe by the direct alloy growth process

In the last few years, emphasis in the organometallic vapor phase epitaxy (OMVPE) of HgCdTe has been in the study of its suitability for device applications. This paper will review recent results in the growth of HgCdTe by the direct alloy growth (DAG) process and some of the latest device results. For a layer with a cutoff wavelength of 5.5 μm, the p-n junction R0A products as high as 1 × 106 Ω cm2 and metal-insulator-semiconductor (MIS) charge storage times as high as 250 ms were obtained. The issue of uniformity and reproducibility of the layers will also be addressed.
Rare non-mosaic trisomies in chorionic villus tissue not confirmed at amniocentesis

This paper reports eight cases of non-mosaic, rare, and typically lethal trisomies diagnosed in chorionic villi and not confirmed by amniocentesis. Four cases were 47,XX, + 16; two cases were 47,XX, +2; one was 47,XX, + 12; and one was 47,XY, +7. There have been no known complications in any of these gestations. These eight cases were found in a series of approximately 12 000 samples processed in our laboratory (0.07 per cent). We conclude that (1) rare non-mosaic trisomy not reflecting the fetal condition is an occasional source of diagnostic ambiguity in chorionic villus sampling; and (2) when encountered, a follow-up amniocentesis should be recommended to the patient to confirm or rule out the abnormality. We propose the term ‘confined placental abnormality’ to describe non-mosaic trisomies and other related abnormalities found only in chorionic tissue.
Neutron stars and the dense matter equation of state

Neutron stars provide a unique laboratory with which to study cold, dense matter. The observational quantities of primary astrophysics interest are the maximum mass and the typical radius of a neutron star. These quantities are related to the relative stiffness of neutron-rich matter at supernuclear densities and the density dependence of the nuclear symmetry energy near the nuclear saturation density. The measurements of these nuclear properties via nuclear systematics and structure, heavy-ion collisions and parity-violating electron scattering from neutron-rich nuclei, are discussed. Several new observations, including mass measurements of binary pulsars and a confirmed distance determination for a nearby cooling neutron star, will be summarized. Additionally addressed will be observations of thermal emissions from cooling neutron stars in globular clusters and thermonuclear explosions from accreting stars. It will be demonstrated how this astrophysical data is shedding light on the pressure-density relation of extremely dense matter.
Stem Cell Therapy for Female Urinary Incontinence

Both stress and urge urinary incontinence affect a significant proportion of women, yet the treatment options currently available may lack long-term effectiveness or may be associated with significant adverse events limiting their use. Thus, novel treatment options are needed. Stem cells, with the ability to transform into multiple cell types or to self-renew, have been proposed as a potential treatment option for both stress and urge incontinence. The majority of research has been performed in animal models and has shown that urethral or intradetrusor injection of various types of stem cells improves surrogate markers of incontinence. Although many of these studies have shown promising effects, significant research is still needed before translating these findings into clinical practice.
New National Academy of Sciences Guidelines for Nutrition During Pregnancy

In June 1990, the Institute of Medicine of the National Academy of Sciences (NAS) released a report, Nutrition During Pregnancy , that recommends individualized assessment-based nutritional management for pregnant women. This is the first publication by the NAS on maternal nutrition since the Food and Nutrition Board9s landmark report Maternal Nutrition and the Course of Pregnancy was published in 1970. The newer report is divided into two parts; the first part is on weight gain, and the second part deals with nutrient supplementation during pregnancy. Dr. Roy Pitkin, Chair of the Department of Obstetrics and Gyne-cology, School of Medicine, University of California, Los Angeles, chaired the Committee on Nutritional Status During Pregnancy and Lactation, which authored the 1990 report.
Ligand-Dependent Conformational Cycle of the Na+/Hydantoin Transporter Mhp1

The LeuT Fold is characterized by a five transmembrane helix, inverted repeat structure that has been observed in an increasing number of physiologically important transporter families. The recurrence of this structural scaffold among the LeuT Fold transporters has stimulated conjectures of a unified mechanism of alternating access despite significant diversity in sequence, function, and ion coupling stoichiometries. Mhp1, a Na+-coupled symporter of the Nucleobase:Cation Symporter 1 (NCS1) family, was the first LeuT Fold member to be structurally characterized by a full complement of canonical states including outward-facing, inward-facing, and occluded conformations, which implied a rocking bundle mechanism. Here we report an investigation of Mhp1 dynamics by electron paramagnetic resonance (EPR) spectroscopy. In this analysis, double electron-electron resonance (DEER) distance distributions between pairs of spin labels monitored conformational changes in response to ligand-binding. These experimental distance distributions were directly compared with the Mhp1 crystal structures by applying MD simulations of spin label rotamers at the double mutant sites and simulating distance histograms. The results of this investigation support the assertion that the crystallographically-captured conformations of Mhp1 are reflected in solution as major conformations and that Mhp1 operates primarily through a rocking bundle-like mechanism. However, unlike LeuT, Na+ binding does not induce transitions between inward- and outward-facing conformations, rather it appears that Na+ powers transport exclusively through modulation of substrate binding affinity. The model of Mhp1 transport proposed here depends critically on the description of conformational equilibria, as the Mhp1 transport cycle progresses through states using low probability transitions. A comparative analysis of the LeuT and Mhp1 mechanisms highlight significant mechanistic divergence that we speculate may in part be explained by the differential mechanisms of coupling to the Na+ gradient.
Development of high power ch3f laser systems for plasma diagnostics

Abstract The operating characteristics of high power pulsed 496 μm CH3F laser systems have been studied. A theoretical model which describes both the optical pumping and submillimeter wave emission has been developed. This model is used to account for measurements of saturated absorption of 9.55 μm CO2 laser radiation in CH3F gas. A 9 kW CH3F oscillator has been built. This oscillator is characterized by a power conversion efficiency of ∼ 0.15% and dominant single longitudinal mode operation. The linewidth of this mode was ∼ 28 MHz. An oscillator amplifier system has been constructed and tested. Measurements of the frequency distribution of the radiation from this system indicate that the lineshape of the oscillator signal is preserved. Narrow linewidth CH3F radiation in the 200 kW-1 MW range should be attainable by appropriate scaling of the present oscillator amplifier system.
Shell effects on the determination of neutron densities from hadron scattering

The influence of spin-unsaturated subshells on the coupling between hadronic probes and the target nucleons is studied for the case of elastic scattering. Particular attention is focused on the case of pion scattering from nuclei where the sigma-arrow-rightxn term in the pion-nucleon t matrix gives rise to a surface correction term to the ..pi..-nucleus optical potential. A closed form expression for this term is given and its effects on a few cases of ..pi..-nucleus scattering are estimated. Similar estimates are made for proton-nucleus scattering at 800 MeV bombarding energy.
A Redetermination of the crystal structure of 2-aminophenol

The crystal structure of 2-aminophenol has been redetermined from automatic diffractometer data in order to locate the hydroxyl and amino hydrogens and confirm the nature of the intermolecular hydrogen bonding. Crystals are orthorhombic, space groupPbca, witha =19.751(6),b = 7.250(3), andc = 7.852(5) A, and eight molecules per cell. The structure was solved by Multan and refined to a conventionalR value of 0.030. The molecular geometry compares well with previously reported structures of related species. The molecules are hydrogen bonded from OH to N to form chains parallel to theb axis, with these chains linked together to form sheets by NH to O hydrogen bonds essentially parallel toc. The NH - O hydrogen bonds are 0.33 A longer than the OH - N ones, and an explanation for this is provided which incorporates newly computed values for atomic electronegativities. Pairs of molecules are mutually hydrogen bonded across inversion centers. There are large cavities between the sheets which could conceivably result in easy intercalation of small foreign molecules, much as in the clathrates formed by urea and β-quinol.
Genetic signature of histiocytic sarcoma revealed by a sleeping beauty transposon genetic screen in mice

Histiocytic sarcoma is a rare, aggressive neoplasm that responds poorly to therapy. Histiocytic sarcoma is thought to arise from macrophage precursor cells via genetic changes that are largely undefined. To improve our understanding of the etiology of histiocytic sarcoma we conducted a forward genetic screen in mice using the Sleeping Beauty transposon as a mutagen to identify genetic drivers of histiocytic sarcoma. Sleeping Beauty mutagenesis was targeted to myeloid lineage cells using the Lysozyme2 promoter. Mice with activated Sleeping Beauty mutagenesis had significantly shortened lifespan and the majority of these mice developed tumors resembling human histiocytic sarcoma. Analysis of transposon insertions identified 27 common insertion sites containing 28 candidate cancer genes. Several of these genes are known drivers of hematological neoplasms, like Raf1, Fli1, and Mitf, while others are well-known cancer genes, including Nf1, Myc, Jak2, and Pten. Importantly, several new potential drivers of histiocytic sarcoma were identified and could serve as targets for therapy for histiocytic sarcoma patients.
REGIONAL DISTRIBUTION OF BLOOD FLOW WITH HYPOVOLEMIC HYPOTENSION IN THE NEONATAL LAMB

We studied the blood flow (BF) to and vascular resistance (VR) of vital tissues in 7 anesthetized newborn lambs in response to hypovolemic hypotension. BF was measured with radioactive microspheres injected into the left ventricle; blood pressure (BP) and arterial blood samples were taken from axillary arteries. BP was reduced by phlebotomy in three steps in each lamb. Calculated VR decreased in the heart, brain and adrenals and increased in the kidney and spleen. However, VR in the small intestine was not changed with hypotension. These data indicate that in the neonatal lamb the vascular response of the intestine to hypotension may be different than that of other abdominal visceral organs. Supported by USUHS grants C08631 and C08626.
Predicting future years of healthy life for older adults

Cost-effectiveness studies often need to compare the cost of a program to the lifetime benefits of the program, but estimates of lifetime benefits are not routinely available, especially for older adults. We used data from two large longitudinal studies of older adults (ages 65-100) to estimate transition probabilities from one health state to another, and used those probabilities to estimate the mean additional years of healthy life that an older adult of specified age, sex, and health status would experience. We found, for example, that 65-year-old women in excellent health can expect 16.8 years of healthy life in the future, compared to only 8.5 years for women in poor health. We also provide estimates of discounted years of healthy life and future life expectancy. These estimates may be used to extend the effective length of the study period in cost-effectiveness studies, to examine the impact of chronic diseases or risk factors on years of healthy life, or to investigate the relationship of years of life to years of healthy life. Several applications are described.
Effects of pressure and precursor loading in the flame synthesis of titania nanoparticles

Abstract The synthesis of TiO 2 nanoparticles is investigated experimentally and computationally in low-pressure H 2 /O 2 /N 2 burner-stabilized flat stagnation flames, using titanium tetra-iso-propoxide as precursor. The flow field is modeled with detailed chemical kinetics and transport, and is compared with measurements using laser-induced fluorescence to map gas-phase temperature and OH-radical species concentration. A sectional model, coupled with the simulated flow field and flame structure, is employed to model particle growth dynamics, computing aggregate particle size distribution, geometric standard deviation, and average primary particle size. The computations are compared with the experiments, for which in situ characterization of the nanoparticles in the flow field is accomplished by a low-pressure aerosol sampling system connected to a nano-scanning mobility particle sizer. Effects of operating pressure and precursor-loading rate on particle growth are examined experimentally and are compared with computational modeling. Different from other works, temperature profiles, rather than mass flow rate, are fixed using strategic dilution to base the comparisons. Higher pressures produce larger aggregate particles, but also smaller primary particles, due to longer residence times, as seen in both the experiments and computations. For higher precursor-loading rates, aggregate particle size is larger (for both experiments and computations), while primary particle size remains constant for the experiments and decreases slightly for the computations in the corresponding range.
DNA Motif Databases and Their Uses

Transcription factors (TFs) recognize and bind to specific DNA sequences. The specificity of a TF is usually represented as a position weight matrix (PWM). Several databases of DNA motifs exist and are used in biological research to address important biological questions. This overview describes PWMs and some of the most commonly used motif databases, as well as a few of their common applications.
Distribution of Natural Isotopes of Carbon in Linsley Pond and Other New England LAKES1

One product of lake metabolism, the CO/sub 2/ that is produced anaerobically, is naturally labeled by its high C/sup 13/ content, but in the presence of carbonates, even the modest amounts found in medium-hard Linsley Pond, such enrichment is not distinctive. Groundwater near the lake is highly charged (175 ml/liter) with CO/sub 2/; because its source includes ancient carbonate, it is naturally labeled as C/sup 14/-poor. Combining these data with estimates of surface inflow, outflow, and other gains and losses of water and carbon, we can account for the C/sup 14/ deficiency observed in hypolimnetic water by a groundwater contribution of the order of 1 liter/(m/sup 2/ x day), perhaps less than 1% of the flow expected if the lake were not well insulated by a clay basin seal. Under ice, during the winter of 1961--62, C/sup 14/ depletion of the deep water developed so rapidly as to suggest direct injection of groundwater and its accumulation by gravitational flow,; however, groundwater carbon is ordinarily cycled metabolically, as shown by the fact that organic surface mud has an apparent age of 1,000 years. Inadequate knowledge of the hydrology of Linsley Pond interferes with rigorous description of the carbon balance, as doesmore » recent strong but irregular contamination of air by artificial (hydrogenbomb) C/sup 14/. By 1960, submerged pondweeds and surface waters of several lakes were enriched in artificial C/sup 14/ by less than 5%, while water- lily leaves, which use atmospheric rather than aquatic sources of carbon, were enriched by 22%. Using the enrichment of Linsley Pond, 1.9% per year, as a tracer, we find the invasion of atmospheric CO/sub 2/ to be slow, 1.2 moles/(m/ sup 2/ x yr) 11.4 mg/(cm/sup 2/ x yr)!. Contributions from groundwater and from air being small, and metabolism being an internal cycle that is nearly closed, the carbon balance of a small lake is seen as part of the hydrologic cycle and as dominated by bicarbonate in surface runoff. (auth)« less
The role of communication in group decision-making efficacy: A task-contingency perspective.

This article advances the general argument that the importance of communicationfor group decision-making performance and its impact on such performance are a function of three task characteristics:...