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Increased ventilator use during the COVID-19 pandemic resurrected persistent questions regarding mechanical ventilation including the difference between physiological and artificial breathing induced by ventilators (i.e., positive- versus negative-pressure ventilation, PPV vs NPV). To address this controversy, we compare murine specimens subjected to PPV and NPV in ex vivo quasi-static loading and quantify pulmonary mechanics via measures of quasi-static and dynamic compliances, transpulmonary pressure, and energetics when varying inflation frequency and volume. Each investigated mechanical parameter yields instance(s) of significant variability between ventilation modes. Most notably, inflation compliance, percent relaxation, and peak pressure are found to be consistently dependent on the ventilation mode. Maximum inflation volume and frequency note varied dependencies contingent on the ventilation mode. Contradictory to limited previous clinical investigations of oxygenation and end-inspiratory measures, the mechanics-focused comprehensive findings presented here indicate lung properties are dependent on loading mode, and importantly, these dependencies differ between smaller versus larger mammalian species despite identical custom-designed PPV/NPV ventilator usage. Results indicate that past contradictory findings regarding ventilation mode comparisons in the field may be linked to the chosen animal model. Understanding the differing fundamental mechanics between PPV and NPV may provide insights for improving ventilation strategies and design to prevent associated lung injuries. [ABSTRACT FROM AUTHOR]

The Ufm1 conjugation system is a novel ubiquitin-like modification system, consisting of Ufm1, Uba5 (E1), Ufc1 (E2) and poorly characterized E3 ligase(s). RCAD/Ufl1 (also known as KIAA0776, NLBP and Maxer) was reported to function as a Ufm1 E3 ligase in ufmylation (Ufm1-mediated conjugation) of DDRGK1 and ASC1 proteins. It has also been implicated in estrogen receptor signaling, unfolded protein response (UPR) and neurodegeneration, yet its physiological function remains completely unknown. In this study, we report that RCAD/Ufl1 is essential for embryonic development, hematopoietic stem cell (HSC) survival and erythroid differentiation. Both germ-line and somatic deletion of RCAD/Ufl1 impaired hematopoietic development, resulting in severe anemia, cytopenia and ultimately animal death. Depletion of RCAD/Ufl1 caused elevated endoplasmic reticulum stress and evoked UPR in bone marrow cells. In addition, loss of RCAD/Ufl1 blocked autophagic degradation, increased mitochondrial mass and reactive oxygen species, and led to DNA damage response, p53 activation and enhanced cell death of HSCs. Collectively, our study provides the first genetic evidence for the indispensable role of RCAD/Ufl1 in murine hematopoiesis and development. The finding of RCAD/Ufl1 as a key regulator of cellular stress response sheds a light into the role of a novel protein network including RCAD/Ufl1 and its associated proteins in regulating cellular homeostasis. [ABSTRACT FROM AUTHOR]

Upregulated expression of nucleolar GTPase nucleostemin (NS) has been associated with increased cellular proliferation potential and tumor malignancy during cancer development. Recent reports attribute the growth regulatory effects of NS protein to its role in facilitating ribosome production. However, the oncogenic potential of NS remains unclear, as imbalanced levels of NS have been reported to exert growth inhibitory effect by modulating p53 tumor-suppressor activity. It also remains in questions if aberrant NS levels might have a p53-independent role in regulation of cell proliferation and growth. In this study, we performed affinity purification and mass spectrometry analysis to explore protein-protein interactions influencing NS growth regulatory properties independently of p53 tumor suppressor. We identified the alternative reading frame (ARF) protein as a key protein associating with NS and further verified the interaction through in vitro and in vivo assays. We demonstrated that NS is able to regulate cell cycle progression by regulating the stability of the ARF tumor suppressor. Furthermore, overexpression of NS suppressed ARF polyubiquitination by its E3 ligase Ubiquitin Ligase for ARF and elongated its half-life, whereas knockdown of NS led to the decrease of ARF levels. Also, we found that NS can enhance NPM stabilization of ARF. Thus, we propose that in the absence of p53, ARF can be stabilized by NS and nucleophosmin to serve as an alternative tumor-suppressor surveillance, preventing potential cellular transformation resulting from the growth-inducing effects of NS overexpression. [ABSTRACT FROM AUTHOR]

In this study, we combined the advantages of bitmaps and remote sensing data to reconstruct three-dimensional (3D) harbor models and establish a new simulation navigation system. The models employ triangular elements to reconstruct the topology relationships between the seabed and the harbor area contour map segmentation, thereby producing the grids and polygons of harbor models and the irregular triangular surfaces of land models. Subsequently, sonar data can be inputted repeatedly to detail the extrapolation operators of seabed geography and construct a complete 3D harbor model. The elements and characteristics of simulated environment technologies were included in this study. They enable 3D graphics to be applied in numerous fields and greatly increase the quality of project planning and design by reducing costs and risks, accelerating project implementation, and strengthening the awareness, understanding, and management of integration at various stages, thereby bringing substantial economic benefits to harbor areas. [ABSTRACT FROM AUTHOR]

Generally, the difficulty with multivariable system control is how to overcome the coupling effects for each degree of freedom. The computational burden and dynamic uncertainty of multivariable systems makes the model-based decoupling approach hard to implement in a real-time control system. In this study, an intelligent adaptive controller is proposed to handle these behaviors. The structure of these model-free new controllers is based on fuzzy systems for which the initial parameter vector values are found based on the genetic algorithm. One modified adaptive law is derived based on Lyapunov stability theory to control the system for tracking a user-defined reference model. The requirement of the Kalman-Yacubovich lemma is fulfilled. In addition, a non-square multivariable system can be decoupled into several isolated reduced-order square multivariable subsystems by using the singular perturbation scheme for different time-scale stability analysis. The adjustable parameters for the intelligent system can be initialized using a genetic algorithm. Novel online parameter tuning algorithms are developed based on the Lyapunov stability theory. A boundary-layer function is introduced into these updating laws to cover parameter and modeling errors and to guarantee that the state errors converge into a specified error bound. Finally, a numerical simulation is carried out to demonstrate the control methodology that can rapidly and efficiently control nonlinear multivariable systems. [ABSTRACT FROM AUTHOR]

Background/Objectives: To examine the daily intake of bone health-related nutrients and to explore the association between diet composition and estimated net endogenous acid production (estimated NEAP) in Hong Kong Chinese adolescents.Subject/Methods: In total, 171 boys and 180 girls aged 10–12 years of Chinese origin from nine primary schools from the Hong Kong Adolescent Bone Health Cohort Study. The study design used food frequency questionnaire. Mean daily intakes of foods and selected nutrients were estimated. Mean percentage of nutrient intake contributed by different food groups was presented. Frassetto's method was used to calculate the estimated NEAP from the diet's protein to potassium ratio.Results: There was no significant difference in the energy-adjusted intakes of most nutrients between boys and girls, except for intakes of vitamins C and D. Mean protein, sodium and potassium intakes were higher than the Chinese dietary reference intake (DRI), whereas mean intakes of magnesium, calcium and vitamin D were lower than the DRI. Boys had significantly higher estimated NEAP than girls (P=0.0051). Estimated NEAP was significantly positively correlated with meat intake and negatively associated with the consumption of fruits, vegetables, legumes, beverages and dairy products.Conclusions: The results highlight the importance of considering whole diet quality when interpreting the effects of single nutrient or diet's net acid load on bone. The effect on high protein intake and low fruit and vegetable intake on the long-term bone health of Hong Kong Chinese adolescents warrants attention.European Journal of Clinical Nutrition (2009) 63, 505–512; doi:10.1038/ejcn.2008.3; published online 30 January 2008 [ABSTRACT FROM AUTHOR]

Inaccurate coronal plane and inadvertent sagittal plane realignment is a common problem after high tibial osteotomies (HTO). While the effects of an HTO on the coronal have been studied extensively, the influence on axial rotation has not been described in detail. The current study examines the effect of HTO on tibial rotation in the axial plane as determined by computed tomography. We hypothesized that high tibial osteotomies have an effect on tibial rotation in the axial plane and that depending on the predefined osteosynthetic implant used, a corresponding change in the tibial slope would occur. HTOs with a tapered 12.5 mm Puddu plate were performed on 13 limbs under computer-navigated control. All limbs were CT scanned before and after the HTO. Using specific software, the CT data was converted into 3D computer models and the following parameters compared: (a) varus-valgus leg alignment; (b) tibial axial rotation; (c) tibial slope (including determination of lateral and medial tibial slope, (d) leg length including determination of the tibial length. Results revealed: (a) a varus-valgus alignment increase of 11 ± 4.7° ( P < 0.005); (b) an axial tibial rotation of 2.7 ± 6.3° ( P < 0.075) occurred with external rotation in 10 out of 13 limbs (12° max external; 9.5° max internal); (c) tibial slope revealed differences of 4.2 ± 5.9° ( P < 0.025); (d) the tibial length increased after HTO by 7.1 ± 3.7 mm ( P < 0.005), while there was no significant change in overall leg length. In summary, tibial rotation does occur in high tibial osteotomies with though the degree of external rotation in this study tended not to be statiscally significant. Tapered implants do not guarantee maintenance of a steady tibial slope, while tibial length changes significantly when HTOs are performed. The combined use of CT and 3D software measurement techniques is reproducible and can be used without any further invasive fixation devices. [ABSTRACT FROM AUTHOR]

This study evaluated the magnitude of the correlations among grip strength, bone mineral density (BMD) and bone mineral content (BMC), after controlling for weight, height, pubertal development, weight-bearing activities and calcium intake. The results lead to the conclusion that grip strength is an independent predictor of bone mass in both sexes. The relationship between muscle strength and bone mass is systemic. Previous studies had shown a site-specific relationship between muscle strength and bone in pubertal children. This study evaluated the magnitude of the correlations among grip strength, bone mineral density (BMD) and bone mineral content (BMC) at distant bone. Cross-sectional data of 169 11- to 12-year-old boys and 173 10- to 11-year-old girls came from the baseline result of a cohort study. Grip strength, BMD, BMC, weight, height, pubertal development, weight-bearing activities and calcium intake were measured. Pearson correlations and multiple regressions were used to calculate univariate and adjusted associations among grip strength and bone mass at distant bone. Significant correlations were shown between grip strength and bone mass at hip, spine and whole body (boys: BMC:0.72–0.74, BMD:0.38–0.60; girls: BMC:0.71–0.72, BMD:0.44–0.63; p<0.0001). Multiple regressions with all covariates showed that about 70% and 50%, respectively, of the variations in BMC and BMD could be explained but not for whole body BMD. Grip strength was an independent predictor of bone mass, except hip BMD in boys and whole body BMD in girls. Stepwise regression showed that grip strength was a robust predictor in both sexes. Prediction models by grip strength and weight explained about 60% and 40% of the variations in BMC of different sites and in BMD of hip and spine, respectively. We found that grip strength is an independent predictor of bone mass in both sexes. The relationship between muscle strength and bone mass is systemic. [ABSTRACT FROM AUTHOR]

The advent of mesh devices allowed for tension-free inguinal hernia repairs and a subsequent reduction in the rate of recurrences. In 1993, Rutkow and Robbins introduced the plug-and-patch repair method whereby the hernia defect is filled with a mesh plug. This new procedure led to new technique-specific complications. Here, we report the case of a man who presented with obstructive symptoms and pain at the site of his inguinal hernia repair performed with the Prolene Hernia System® 18 months prior. At laparotomy, he was found to have a small bowel obstruction and perforation due to mesh contact with the small bowel and colon. The literature is reviewed for cases of bowel complications due to mesh plugs. Based on reported complications, three recommendations can be made to avoid or reduce the risk of this complication. First, the pre-peritoneal dissection should be performed carefully with particular attention to identify and repair any tears of the peritoneum. Secondly, the mesh plug should not be placed too deep within the defect. Finally, the plug should be secured to reduce the possibility of mesh migration. [ABSTRACT FROM AUTHOR]

The optical and electrical characteristics of pulsed discharges in pure Ar at pressures of up to 7 atm, at which the discharge becomes unstable, are studied in a simple experimental device with automatic preionization. The gas temperature in the discharge is estimated from the width of the recorded emission spectrum. An analytical model of the vibrational relaxation of Ar*2(v) is used to better determine the constants of the vibrational–translational relaxation of Ar*2(v) molecules in their collisions with Ar atoms. The zero-dimensional numerical model of a pulsed discharge in Ar is modified. The experimental and calculated results are compared in detail. Good agreement is achieved between the measured and calculated time dependences of the electrode voltage and the intensity of spontaneous emission in the pressure range of 1–6 atm, as well as between the measured and calculated values of the gas temperature at pressures of 3–6 atm. Preliminary results from numerical studies of the possibility of achieving generation are discussed. © 2004 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]

We hereby report the endovascular management of a posttraumatic caroticocavernous fistula combined with an occlusive ipisilateral carotid dissection; this was successfully managed by a contra-lateral arterial approach via the anterior communicating artery. [ABSTRACT FROM AUTHOR]

Distributed feedback lasing characteristics of oxazine dye in zirconia waveguides and in solutions were investigated. Oxazine-dye-doped waveguides were characterized by ellipsometry. Intensity modulation and polarization modulation were used to generate laser action. Tunable narrow line width laser action was achieved for the first, second, third and fourth Bragg orders. It was observed that the threshold pump energy decreased with the decrease of the Bragg order. The degree of polarization of the laser output also changed from 0.8 at the third Bragg order to 0.1 at the first Bragg order. Wide-band tuning of the distributed feedback laser output from 700 nm to 870 nm was achieved for the first-order action during intensity modulation. [ABSTRACT FROM AUTHOR]

Using an automated PCR-based genomics approach, TOtal Gene expression Analysis (TOGA®), we have examined gene expression profiles of mouse striatum and frontal cortex in response to clozapine and haloperidol drug treatment. Of 17?315 mRNAs observed, TOGA® identified several groups of related molecules that were regulated by drug treatment. The expression of some genes encoding proteins involved in neurotransmission, signal transduction, oxidative stress, cell adhesion, apoptosis and proteolysis were altered in the brains of both clozapine- and haloperidol-treated mice as recognized by TOGA®. Most notable was the differential expression of those genes whose products are associated with lipid metabolism. These include apolipoprotein D (apoD), the mouse homolog of oxysterol-binding protein-like protein 8 (OSBPL8), a diacylglycerol receptor (n-chimerin), and lysophosphatidic acid (LPA) acyltransferase. Real-time PCR analysis confirmed increases in the RNA expression of apoD (1.6-2.2-fold) and OSBPL8 (1.7-2.6-fold), and decreases in the RNA expression of n-chimerin (1.5-2.2-fold) and LPA acyltransferase (1.5-fold) in response to haloperidol and/or clozapine treatment. Additional molecules related to calcium homeostasis and signal transduction, as well as four sequences of previously unidentified mRNAs, were also confirmed by real-time PCR to be regulated by drug treatment. While antipsychotic drugs may affect several metabolic pathways, lipid metabolism/signaling pathways may be of particular importance in the mechanisms of antipsychotic drug action and in the pathophysiology of psychiatric disorders.Molecular Psychiatry (2003) 8, 983-993. doi:10.1038/sj.mp.4001425 [ABSTRACT FROM AUTHOR]

Laser action was generated in dye-doped sol-gel glass waveguides and in liquid solutions by crossing two beams from a frequency-doubled neodymium:YAG laser. The angle between the polarization directions of the two beams was varied continuously from 0-90°. The case of 0° corresponded to pure intensity modulation. As the angle increased, the degree of intensity modulation decreased, resulting in the decline and finally the demise of the laser output. At 90°, corresponding to pure polarization modulation, distributed feedback laser action with narrow line-width output was again observed when the pump energy was increased three-fold. The laser output also showed different polarization characteristics when the feedback mechanism was changed from intensity modulation to polarization modulation. [ABSTRACT FROM AUTHOR]

We have studied the luminescence and spectroscopic properties of erythrosin B-doped sol-gel silica in aqueous solutions. Stern-Volmer plot was obtained for the phosphorescence intensity as a function of the dissolved oxygen content. Leaching of the dye molecules from the sol-gel matrix was examined by absorption spectroscopy. That acid-catalysed sol-gel materials leach slowly and based-catalysed sol-gel materials leach rapidly was revealed. Absorption data of the sol-gel materials indicated the existence of two leaching rate constants. Finally we demonstrated that the sol-gel oxygen sensor had a response time faster than 30 ms. [ABSTRACT FROM AUTHOR]

ABSTRACT Optical and electrical properties of a high-pressure discharge of pure xenon and xenon-helium and xenon-neon mixtures are studied experimentally. Uniform discharge at total gas pressure as high as 10 atm is achieved in xenon-lean mixtures. Vacuum ultraviolet emissions due to the first and second continua of Xe[sup *, sub 2] are examined spectroscopically. The vibrational relaxation rate constant k[sub He] of Xe[sup *, sub 2] by helium is determined to be of the order of 10[sup -11] cm³ s[sup -1] from spectroscopic data. Laser oscillation for the 172-nm band was attempted without success. Discharge instability at high gas pressures is considered to the cause of the unsuccessful laser experiments. Some issues related to discharge instability in a high-pressure rare-gas discharge are discussed. [ABSTRACT FROM AUTHOR]

The spontaneous emission efficiency of an Ar[sup *][sub 2] excimer and its amplification properties at a wavelength of 126 nm are studied using a numerical model of the weakly ionized plasma of a pulsed discharge in Ar at elevated pressures. It is shown that, under real experimental conditions, it is possible to achieve a net gain coefficient of the active medium equal to approx. 0.065cm[sup –1] by increasing the gas density up to 4.0×10[sup 20]cm[sup –3] at an initial gas temperature of 170 K. The internal conversion efficiency of discharge energy into spontaneous emission depends weakly on the gas temperature and attains 75% for a gas density of 2.7×10[sup 20]cm[sup –3], but with excitation powers much lower than for the maximum gain. The applicability of the model at low excitation powers is tested by comparison with the experimental data. © 2001 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]

Abstract. Doped and undoped silica samples were fabricated using the sol--gel method. Extended UV transmission down to 200 nm was observed for the undoped sol--gel silica. Three UV dyes (PTP, Exalite 351, and PBD) were used to dope sol--gel silica by diffusion. Lasing and fluorescence properties of these UV laser dyes in the silica matrices were studied. Laser emissions for PTP-, Exalite 351-, and PBD-doped silica samples peaked at 342 nm, 352 nm, and 364 nm. The laser output at 342 nm was the shortest wavelength yet achieved in solid-state dye lasers. The slope efficiency of the PTP-doped sol-gel silica laser was up to 17%. The output energy of the laser emission decreased to 50% of its initial value after 700 shots with a pump repetition rate of 5 Hz. [ABSTRACT FROM AUTHOR]

A comprehensive kinetic model for XeCl lasers excited by microwave discharge is formulated. In the model, the rate equations of reaction kinetics are solved self-consistently with the Boltzmann equation for electrons and the radiation transfer equation. The effective electric field strength needed in the solution of the Boltzmann equation is determined, by the energy balance argument, in terms of the microwave energy dissipated in the XeCl laser plasmas. The accuracy of the model is checked by comparing calculations with the experimental results reported by Christensen et al. in Optics Letters, 12, 169 (1987). Reasonably good agreements in the peak output power and laser efficiency have been achieved. Model calculations also predict that an efficiency as high as 2.7% can be obtained once the conditions of the above-mentioned experiments have been optimized. From the consideration that the skin depth effectively limits the absorption length of the microwave pumping and hence the excitable volume, it is concluded that high input power densities (>2 MW/cm[sup 3] ) and higher gas pressures (between 3 and 10 atm) are the preferable conditions to achieve higher efficiency. Preliminary calculations on CCl[sub 4] containing XeCl gas mixtures show that improvement in laser efficiency by several folds may be achieved as a result of the higher intrinsic efficiency of excimer formation. [ABSTRACT FROM AUTHOR]

A theoretical model that accounts for fundamental plasma processes leading to the formation and decay of XeCs ionic excimers in high-pressure electron-beam-excited Ar/Xe/Cs mixtures was developed. Numerical calculations based on the model were performed. For atmospheric gas mixtures, the model predicts an intrinsic efficiency (energy stored in upper state/energy deposited) of 18%. Model calculations also indicate that while XeCs was predominantly formed via the rare-gas ion (Xe) channel over the entire e-beam duration, the rare-gas metastable (Xe*) channel assumes dominance in the afterglow period. [ABSTRACT FROM AUTHOR]

Lasing and fluorescence properties of ten dyes covering the spectral range from 400 nm to 800 nm were studied in a silica matrix prepared by the sol-gel technique. The dye-doped sol-gel silica samples fluoresced strongly under laser excitation. Many of the samples were also induced to superradiate. In comparison to dyes in alcohol solvents, significant red-shifting was observed in the sol-gel silica fluorescence spectra. Plausible causes of the red-shift are discussed. [ABSTRACT FROM AUTHOR]

Experimental results on striation instability in a self-sustained discharge-pumped XeCl laser are presented. The presence of HCl proves to be critical to the evolution of this particular mode of instability. The role of halogen donors in discharge instabilities of RGH lasers is discussed. That mixtures containing HCl will be susceptible to striation instability and those with F or NF will not is concluded. [ABSTRACT FROM AUTHOR]

Laser output of discharge excimer lasers is related to the avalanche completion time t. The important role of preionization electron number density n(0) in reducing t is then considered. A simple two-stage model is proposed to describe the electron avalanche process under marginal E/n conditions. The theoretical predictions according to the two stage model are in good agreement with the experiments. That vigorous preionization is critical to stable operation of large aperture, high pressure discharge devices is concluded. [ABSTRACT FROM AUTHOR]

Distributed feedback laser action of narrow line-width output was demonstrated in zirconia waveguides doped with trans-4-[p-(N-hydroxyethyl-N- methylamino) styryl]-N-methylpyridinium p-toluene sulfonate, a compound of strong two-photon up-converted emission near 620 nm. Single-beam pumping at 1.06 μm led to intense up-converted amplified spontaneous emission at 620 nm. Transient gratings for coherent scattering were generated in the waveguides by crossing two 1.06-μm beams. Narrow line-width distributed feedback laser emission was observed at 627 nm. [ABSTRACT FROM AUTHOR]

Abstract. Homogeneity of sol-gel-derived silica was improved by slowing down the drying and aging rate. Single longitudinal mode lasing was achieved in sol-gel silica doped with coumarin 460 dye. The laser linewidth was 1.58 GHz and the output wavelength was at 467 nm. [ABSTRACT FROM AUTHOR]

Broadband fluorescence emission ranging from 350–400 nm was observed from Exalite 377E (E377)-doped sol-gel silica in bulk form or in thin-film form. The fluorescence spectra of sol-gel samples of low dye concentrations (∼7×10[sup -5] M) show a two peak structure at 360 nm and 378 nm. Wideband tuning between 352 nm and 387 nm was obtained from a E377-doped sol-gel silica slab pumped by a short pulse (1 ns) N[sub 2] laser at 337 nm. The laser tuning curve also showed a two peak structure at 360 nm and 378 nm. [ABSTRACT FROM AUTHOR]

Fluorescence and lasing properties of coumarindoped silica samples prepared by sol-gel process were investigated. Superradiant emissions at peak power as high as 7MW were measured at around 535 nm when the silica samples were excited by a XeF laser. The energy of the superradiant pulse was 89 mJ, corresponding to a conversion efficiency of 36.6%. [ABSTRACT FROM AUTHOR]

Presents an image depicting how antipsychotic drug treatment alters the expression of mRNAs encoding lipid metabolism-related proteins.