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Objectives Talaromycosis is an invasive mycosis endemic to Southeast Asia. This study aimed to investigate the epidemiology, clinical features and prognostic factors of HIV-associated talaromycosis in Guangdong, China. Methods We retrospectively evaluated HIV patients hospitalized with histopathology- or culture-confirmed talaromycosis between 2011 and 2017. Factors associated with poor prognosis were identified using logistic regression. Results Overall, 1079 patients with HIV-associated talaromycosis were evaluated. Both the number and prevalence of talaromycosis among HIV admissions increased from 125 and 15.7% in 2011 to 253 and 18.8% in 2017, respectively, reflecting the increase in HIV admissions. Annual admissions peaked during the rainy season between March and August. Common clinical manifestations included fever (85.6%), peripheral lymphadenopathy (72.3%), respiratory symptoms (60.8%), weight loss (49.8%), skin lesions (44.5%) and gastrointestinal symptoms (44.3%). Common laboratory abnormalities were hypoalbuminaemia (98.6%), anaemia (95.6%), elevated aspartate aminotransferase level (AST) (76.9%), elevated alkaline phosphatase level (55.8%) and thrombocytopenia (53.7%). The median CD4 count was 9 cells/μL. Talaromyces marneffei was isolated from blood and bone marrow cultures of 66.6% and 74.5% of patients, respectively. The rate increased to 86.6% when both cultures were performed concurrently. At discharge, 14% of patients showed worsening conditions or died. Leucocytosis, thrombocytopenia, elevated AST, total bilirubin, creatinine and azole monotherapy independently predicted poor prognosis. Conclusions The incidence of HIV-associated talaromycosis has increased in Guangdong with the high HIV burden in China. Skin lesions were seen in less than half of patients. Induction therapy with azole alone is associated with higher mortality. Findings from this study should help to improve treatment of the disease.

The effects of vibrational non-equilibrium and vibration–chemistry coupling on hydrogen–air detonation are numerically investigated by solving reactive Euler equations coupled with a multiple vibrational temperature-based model. Detailed hydrogen–air reaction kinetic is utilized, Landau–Teller model is adopted to solve the vibrational relaxation process, and the coupled vibration–chemistry vibration model is used to evaluate the vibration–chemistry coupling. It is shown that the relaxation process and vibration–chemistry coupling considerably influence the hydrogen–air detonation structure, highlighting the importance of correct treatment of vibrational non-equilibrium in detonation simulations.

A technique to study nanowire growth processes on locally heated microcantilevers in situ in a transmission electron microscope has been developed. The in situ observations allow the characterization of the nucleation process of silicon wires, as well as the measurement of growth rates of individual nanowires and the ability to observe the formation of nanowire bridges between separate cantilevers to form a complete nanowire device. How well the nanowires can be nucleated controllably on typical cantilever sidewalls is examined, and the measurements of nanowire growth rates are used to calibrate the cantilever-heater parameters used in finite-element models of cantilever heating profiles, useful for optimization of the design of devices requiring local growth.

We discuss the benefits of using metals other than Au to catalyze the growth of Si and Ge nanowires, emphasizing the opportunities that these non-conventional materials provide for tailoring electronic and structural nanowire properties. However, since these metals are more reactive than Au, their use creates constraints on wire growth conditions as well as difficulties in post-growth characterization. These issues are illustrated for Si and Si/Ge nanowires grown from Al, Cu and AuAl starting materials. The vacuum requirements for the deposition of the reactive metals are discussed as well as the effect of atmospheric exposure on the structure of wires observed post-growth with electron microscopy.

Novel lightweight micro- and nanostructured materials are being used as constituents in hierarchically structured composites for providing high stiffness, high strength, and energy absorbing capability at low weight. Three dimensional SU-8 periodic microframe materials with submicrometer elements exhibit unusual large plastic deformations. Here, the plastic dissipation and mechanical response of polymeric microframe structures is investigated using micromechanical modeling of large deformations. Finite element analysis shows that multiple deformation domains initiate, stabilize, and then spread plasticity through the structure; simulated deformation mechanisms and deformation progression are found to be in excellent agreement with experimental observation. Furthermore, the geometry can be used to tailor aspects of 3D behavior such as effective lateral contraction ratios (elastic and plastic) during tensile loading as well as negative normal stress during simple shear deformation. The effects of structural geometry on mechanical response are also studied to tailor and optimize mechanical performance at a given density. These quantitative investigations enable simulation-based design of optimal lightweight material microstructures for dissipating energy.

The transformations between the η and η′ phases of Cu3Si were studied by in situ transmission electron microscope (TEM) diffraction analysis and by differential scanning calorimetry (DSC). The space groups of η and η′ are and , respectively. The lattice parameters of η are a = 4.06 A and c = 7.33 A. The η′ phase results from faulted stacking of the η unit cell, and has lattice parameters: a = 35.16 A and c = 21.99 A. A long-period anti-phase domain structure appears in these two phases and is part of a sequence of phase transformations from η′ to η upon heating. The Cu silicide precipitates that form in voids in silicon are the η′ phase, oriented in the silicon matrix according to: (0001)η'∥(110)Si; [001]Si.

Methylamine (CH3NH2) was employed with SiH4 to deposit amorphous silicon carbon nitride films due to its easy dissociation as well as containing both carbon and nitrogen elements. The effect of dilution gas, such as H2 ,N 2, Ar and He on the film growth was studied in electron cyclotron resonance plasma chemical vapor deposition (CVD) reactor. At a microwave power of 250 W and a substrate temperature of 700 ◦ C, ternary silicon carbon nitride film has been successfully deposited using He as dilution gas. However, only binary silicon nitride films were formed using dilution gases of Ar, N 2 and H2 but otherwise similar conditions. Characterization of the films using FTIR, XPS and optical emission study of the plasma were employed to study the growth process. Possible explanations and discussion for the growth behaviors of the dilution gases are presented. © 2001 Elsevier Science B.V. All rights reserved.

The hardness and effective modulus of hydrogen-containing and hydrogen-free amorphous SiC x N y films were studied by nano-indentation. Amorphous SiC x N y films with and without hydrogen were deposited by electron cyclotron resonance plasma chemical vapor deposition (ECR-CVD) using a SiH 4 –CH 3 NH 2 –N 2 –H 2 gas mixture and hydrogen-free ion-beam sputtering deposition (IBSD), respectively. Fourier-transform infrared spectroscopy (FTIR) studies were used to investigate the bonding states of the SiC x N y materials. SiH, CH and NH bonds were detected by FTIR in ECR-CVD, but not in IBSD, films. The incorporation of hydrogen led to a reduction in both the hardness and modulus of the amorphous SiC x N y films. From nano-indentation measurements, the hardness and effective modulus of the IBSD coated, hydrogen-free amorphous SiC x N y films were 27–30 and 211–258 GPa, respectively. The corresponding values for the ECR-CVD coated, hydrogen-containing amorphous SiC x N y were 22–26 and 115–144 GPa, respectively.

The effect of carbon source on SiCN film growth was studied in an electron cyclotron resonance plasma chemical vapor deposition reactor. The growth characteristics of CH4, C2H2 and CH3NH2 were examined with and without H2 addition during growth. The results indicated that SiCN films were deposited successfully using CH4 with H2 addition as well as using CH3NH2 both with and without H2 addition. (Si; C) and N composition ratios of the films thus deposited were around 0.75. Carbon was hardly incorporated into the films when deposited using C2H2 as the source gas regardless of H2 addition during growth. Among the three source gas studied, CH3NH2 was the most effective for the SiCN films growth. Spectroscopic study of the gas phase species during growth and discussion on the growth phenomena are presented in this paper.

Comparative studies on field emission properties of various carbon-related materials including diamond, amorphous carbon, SiCN films, SiCN nanorods, and carbon nanotubes are presented. While diamond is well known for its potential use in cold cathodes, the emission current of a hydrogen-treated diamond film is relatively small compared to that of amorphous carbon or diamond-like-carbon film. Meanwhile, carbon nanotubes have demonstrated large emission currents at much lower threshold voltages, showing their potential for applications. However, the emission from carbon nanotubes is subjected to significant decay under long-term operation. The emission current and long-term stability can be improved using a new SiCN compound with nanorod morphology. The effective barrier height and the field enhancement factor derived from the Fowler–Nordheim equation are discussed in this paper.

Three screening methods were used to isolate GL-7-ACA acylase-producing strains. Three positive isolates were identified with Pseudomonas nitroreducens CCRC 11041 possessing the highest activity, against GL-7-ACA and GL-7-ADCA. No activity was detected when Ceph C or succinyl-7-ACA was used as substrate; glutaric acid was found to be inhibitory. CCRC 11041 could produce maximal GL-7-ACA acylase activity when cultivated on meat extract medium II. The enzyme had a pH optimum of 5.0 and a temperature optimum of 42°C.

We use real-time observations of the growth of copper-catalyzed silicon nanowires to determine the nanowire growth mechanism directly and to quantify the growth kinetics of individual wires. Nanowires were grown in a transmission electron microscope using chemical vapor deposition on a copper-coated Si substrate. We show that the initial reaction is the formation of a silicide, eta'-Cu(3)Si, and that this solid silicide remains on the wire tips during growth so that growth is by the vapor-solid-solid mechanism. Individual wire directions and growth rates are related to the details of orientation relation and catalyst shape, leading to a rich morphology compared to vapor-liquid-solid grown nanowires. Furthermore, growth occurs by ledge propagation at the silicide/silicon interface, and the ledge propagation kinetics suggest that the solubility of precursor atoms in the catalyst is small, which is relevant to the fabrication of abrupt heterojunctions in nanowires.

Sharp Nanowires The potential for using nanowires in devices can be limited by the ability to synthesize them from two or more materials while maintaining compositional purity at the interfaces. Instead of using liquid droplets at the eutectic point when the melting point is at a minimum, Wen et al. (p. 1247 ) show that generating the wires at solid alloy catalysts allows fabrication of silicon germanium wires with atomically sharp interfaces. The system works well because an AlAu alloy composition was chosen in which Si and Ge have a low solubility but which have a high enough eutectic temperature so that nanowire growth is not limited by the reactivity of the Si and Ge precursors.

The phase diagram of a nanoscale system can be substantially different than in the bulk, but quantitative measurements have proven elusive. Here we use in situ microscopy to observe a phase transition in a nanoscale system, together with a simple quantitative model to extract the size effects from these measurements. We expose a Au particle to disilane gas, and observe the transition from a two-phase Au + AuSi system to single-phase AuSi. Size effects are evident in the nonlinear disappearance of the solid Au. Our analysis shows a substantial shift in the liquidus line, and a discontinuous change in the liquid composition at the transition. It also lets us estimate the liquid-solid interfacial free energy.

This study reports the reactivities of acetylcholinesterase (AChE) and choline acetyltransferase (ChAT) in some of the nonneuronal elements in the external cuneate nucleus (ECN) of gerbils. AChE reaction products were localized in some oligodendrocytes in their cisternae of rough endoplasmic reticulum, nuclear envelope and Golgi saccules. The basal lamina lining the capillary endothelia also displayed AChE reactivity. In ChAT immunocytochemistry, the reaction products were found to be associated with the vascular basal lamina as well as the endothelial plasma membrane facing the lumen. The most remarkable finding was the localization of ChAT immunoreactivity in some oligodendrocytes and occasional glioblasts (small glial precursor cells containing a thin rim of cytoplasm surrounding an irregular nucleus with homogeneous chromatin materials). The ChAT-positive oligodendrocytes consisted of two types, medium-dense and dark cells, either associated with blood vessels or ChAT-stained neuronal elements. It is suggested from these new findings that at least some of the oligodendrocytes and glioblasts in the ECN of gerbils may be involved in the synthesis, storage, release and degradation of acetylcholine.

The present study examined the existence of catecholamine-, corticotropin-releasing factor (CRF)- and neurotensin (NT)-containing neurons in the external cuneate nucleus (ECN) of the gerbil using single label pre-embedding immunocytochemistry in an attempt to shed light on the increasing evidence for autonomic involvement of the ECN. Peroxidase immunoreactivity of phenylethanolamine-N-methyl-transferase (PNMT), CRF or NT was identified in the heterogeneous population of the ECN neurons characterized by a deeply infolded nucleus. The label was localized in their somata, dendrites, myelinated axons and axon terminals. The immunolabelled dendrites were contacted by spherical (S) and flattened (F) types of presynaptic boutons containing spherical and flattened synaptic vesicles, respectively. The PNMT-labelled dendrites, however, were postsynaptic to an additional type of axon terminals containing pleomorphic (P) synaptic vesicles. Among the immunoreactive axon terminals, the PNMT-labelled boutons consisted of two types: S and F; in the CRF- and NT-labelled axon terminals, only the S type was observed. The catecholamine-containing ECN neurons differed from the CRF- and NT-immunoreactive neurons in their synaptic organization. The latter two were considered to be of the same cell population because of their similarities in ultrastructural features and synaptic relations. In view of a high frequency (48% for PNMT, 50% for CRF and 46% for NT) of the F-typed boutons associated with the three categories of immunolabelled neurons in the ECN, it is possible that they are under considerable inhibitory control. The presence of catecholamine, CRF and NT in the ECN suggests that the nucleus may be involved in the integration of proprioception-, exercise- or stress-evoked autonomic responses.

Using acetylcholinesterase histochemical and choline acetyltransferase immunocytochemical localization methods, this study has provided conclusive evidence for the existence of cholinergic neurons in the external cuneate nucleus of gerbils. By light microscopy, both acetylcholinesterase and choline acetyltransferase labelling was confined to the rostral portion of the external cuneate nucleus. Ultrastructurally, acetylcholinesterase reaction products were found in the nuclear envelope, cisternae of rough endoplasmic reticulum and Golgi saccules of some somata and large dendrites as well as in the membranes of small dendrites, myelinated axons and axon terminals. These neuronal elements were also stained for choline acetyltransferase; immunoreactivity was associated with nuclear pores, nuclear envelope, perikaryal membrane and all the membranous structures within the cytoplasm. Of the total choline acetyltransferase-labelled neuronal profiles analysed, 79% were myelinated axons, 15% dendrites, 4% somata and 2% axon terminals. The immunostained axon terminals consisted of two types containing either round (Rd type; 62.5%) or pleomorphic (Pd type; 37.5%) vesicles. Both were associated directly with choline acetyltransferase-positive dendrites. In contrast to the paucity of choline acetyltransferase-labelled axon terminals, numerous choline acetyltransferase-positive myelinated axons were present. It may thus be hypothesized that most, if not all, of the external cuneate nucleus cholinergic neurons are projection cells; such cells may give rise to axonal collaterals which synapse onto their own dendrites for possible feedback control. Choline acetyltransferase-positive dendrites were contacted by numerous unlabelled presynaptic boutons, 60% of which contained round or spherical synaptic vesicles (Rd boutons) and 40% flattened vesicles (Fd boutons), suggesting that these neurons are under strong inhibitory control. The preferential concentration of cholinergic components in the rostral external cuneate nucleus may be significant in the light of the highly organized somatotopy in the external cuneate nucleus and its extensive efferent projections to medullary autonomic-related nuclei. Our results suggest that the cholinergic neurons may be involved in somatoautonomic integration.

The present study revealed the efferent projections from the external cuneate nucleus (ECN) to various medullary nuclei in the gerbl as demonstrated in fresh living brainstem slices by using in vitro anterogradely tracing with the dextran-tetramethyl-rhodamine-biotin. The tracer-labelled ECN axon terminals were observed (1) in most of the vital autonomic-related nuclei: the nucleus solitary tractus, nucleus ambiguus, rostroventrolateral reticular nucleus and C 2 adrenergic area, (2) in the reticular formation: the medullary, parvocellular, intermediate, gigantocellular, dorsal paragigantocellular and lateral paragigantocellular reticular nuclei and medullary linear nucleus, and (3) in sensory nuclei: the cuneate nucleus, spinal trigeminal nuclei caudalis and interpolaris, paratrigeminal nucleus, medial and spinal vestibular nuclei, inferior olive and prepositus hypoglossal nucleus. These new findings are discussed in relation to possible roles of the ECN in cardiovascular, respiratory and sensorimotor controls.

A comprehensive model for the simulation of fluidized bed coal combustors (FBC) is developed, capable of predicting the combustion efficiency, char and limestone elutriation and the corresponding particle size distribution in the bed and in the entrained materials, solids withdrawal rate from the bed, bed temperature profile, sulfur dioxide retention, sulfur dioxide and NOx emissions, concentrations of oxygen, carbon monoxide, carbon dioxide, volatiles, sulfur dioxide and NOx along the combustor height. The model can also simulate combustors with varying cross section along the bed height. The performance of the model is compared with the data obtained from four different combustors. Agreement between the computed results and the data is good. The salient features in the model which need further investigation are pointed out.

A one-parameter volume reaction model is developed by a simplified analytical approach to describe reaction of a gas and a consumble solid in a porous particle. In this model, a modified Thiele modulus M is introduced to take into account the effect of solid reactant depletion during the reaction. Experimental results of an isothermal carbon-carbon dioxide reaction in the temperature range from 1 130° to 1 365°K under atmospheric pressure were analyzed by the working diagrams derived from this model. A satisfactory agreement between the experimental results and those predicted by the model indicated the applicability of this model.

A method for estimating entropies of both solid and liquid fuels is proposed. An example showing calculation of availability of coal is presented. Entropy and availability of coal calculated are compared with those obtained by other methods. Deviations among different methods examined are discussed. On propose une methode pour evaluer les entropies de combustibles solides et liquides. On montre un exemple de calcul de l'accessibilite au charbon. On compare l'entropie et l'accessibilite du charbon obtenues par calcul avec celles obtenues en employant d'autres methodes. On discute les ecarts qu'on trouve entre les resultats des differentes methodes examinees.

Presynaptic dendrites (PSDs) are described in the cuneate nucleus of the monkey. These PSDs establish dendro-dendritic synapses with dendrites of variable size. They contain small numbers of pleomorphic synaptic vesicles which are clustered together near the presynaptic membrane. Such PSDs have also been observed to be postsynaptic to medium-sized or large axon terminals containing round vesicles.

A comprehensive model incorporating elutriation, entrainment and reaction is presented to describe the chemical reaction and hydrodynamics occurring in the freeboard of a fluidized bed. A comparison of experimental data on the amount of particles elutriated and the concentration profiles of SO2 and NOx obtained from the freeboard of fluidized bed coal combustion (FBC) by the Babcock & Wilcox Company with the calculation based on the proposed model to include the effect of interaction among the entrained particles is desirable. More experimental data with chemical reactions in the freeboard are needed to validate the model for applications to fluidized bed catalytic reactors.

Solid-fluid reactions often involve two or more simultaneous reactions because either the feed contains multiple fluid reactants or the fluid products are reactive with the solid. Three types of simultaneous reactions, independent, parallel, and consecutive, are examined in terms of the selectivity and the effectiveness factor based on the unreacted core shrinking model under isothermal conditions. Criteria for high selectivities are derived, and effects of diffusion and chemical reaction are discussed.

The coal char hydrogasification reaction may be regarded as two simultaneous reactions differing considerably in their rates. The rate of coal hydrogasification, particularly that for the initial rapid reaction, was studied. The initial reaction rates in semiflow tests were analyzed and found to be proportional to the amount of unreacted carbon remaining in the particles as well as the effective partial pressure of hydrogen. The rate constant for small conversion of carbon was found to be 2.0 (atm.-hr.)/sup -1/. The reaction model used for semiflow test analysis was satisfactorily applied to continuous free-fall reactor tests.

Kinetic and diffusion models for gas-solid reactions in spherical particle, comparing core shrinking mechanism and activation energies

A new fluid-solid contacting technique known as Semifluidization has been studied. Mass transfer data were obtained for a benzoic acid–water system, and correlations in terms of mass transfer factors and over-all void fractions (for both packed and fluidized sections) are presented. Previous mass transfer correlations for fixed and fluidized beds are critically evaluated with respect to the limitation and applicability and are discussed in relation to semifluidized-bed mass transfer correlations.

The kinetics of simultaneous, noncatalytic solid-gas reaction systems has been analyzed in terms of the selectivity and effectiveness factor, based on the unreacted core shrinking model. The reaction systems discussed include the first-order independent, parallel, and consecutive reactions with the simultaneous influences of heat and mass transfer. The effects of various chemical and transport properties on the stability, selectivity, and effectiveness factor of the system are discussed. The pseudosteady state approximation is employed to reduce the mathematical difficulties.

The nonisothermal unreacted-core-shrinking model with unsteady state heat transfer analysis has been experimentally evaluated. The system studied is the combustion of a single agglomerated carbon-fire clay sphere in a thermobalance. By comparing the experimental results with those predicted by the model it is concluded that the model adequately describes the reaction system under the experimental conditions such that the ash layer diffusion is rate controlling. (40 refs.)

The axial dispersion correlations in liquid-solid fluidized beds presented by Chung and Wen(1) and Krishnaswamy and Shemilt(8) are compared and the applicability of the correlations are discussed. On compare les correlations sur les dispersions axiales dans des lits fluidises formes de liquides et de solides qu'ont presentees Chung et Wen(1) et Krishnaswamy et Shemilt(8), on discute aussi l'applicabilite desdites correlations.

It is well known that the identification of flow regimes is important in scale-ups and designs of multiphase reactors. Therefore, it is natural that the selections of parameter prediction methods for the reactor models should be based on flow regimes. Very few correlations, theories and models are capable of covering the whole spectrum of flow regimes. Often, accuracy is sacrificed for generality. By concentrating on each individual flow regime and its characteristics, the correlations and models selected can be expected to give better results. The evaluation of correlations for phase holdups and liquid dispersion coefficients has been evaluated for both the slurry reactors and the three-phase fluidized bed reactors.