Metabolism of the colonic mucosa in patients with inflammatory bowel diseases: an in vitro proton magnetic resonance spectroscopy study

Metabolism of the colonic mucosa of patients with ulcerative colitis (UC; n=31) and Crohn's disease (CD; n=26) and normal mucosa (control, n=26) was investigated using in vitro high-resolution proton magnetic resonance spectroscopy. Of the 31 UC patients, 20 were in the active phase and 11 were in the remission phase of the disease. Out of 26 CD patients, 20 were in the active phase, while 6 were in the remission phase of the disease. Twenty-nine metabolites were assigned unambiguously in the perchloric acid extract of colonic mucosa. In the active phase of UC and CD, significantly lower (P相似文献   

An 80 nm 4 Gb/s/pin 32 bit 512 Mb GDDR4 Graphics DRAM With Low Power and Low Noise Data Bus Inversion

4 Gb/s/pin 32 bit 512 Mb GDDR4 (Graphics Double Data Rate 4) SDRAM was implemented by using an 80 nm CMOS process. It employs a data bus inversion (DBI) coding to overcome the bottleneck of a parallel single-ended signaling, a power consumption of I/O, power supply noise, and crosstalk. Both DBI AC and DC modes are combined to a single circuit by eliminating the feedback path of a conventional DBI AC circuit while achieving high-speed operation. The proposed DBI circuit uses an analog majority voter insensitive to mismatch for small area and delay. R_onmiddot tuning further improves the voltage and time margin by adding a user-supplied offset to auto-calibrated R_onmiddot. In addition, a dual duty cycle corrector (DCC) is used to reduce duty error and jitter by averaging two outputs of two DCCs. Measured results show that DBI DC coding reduces the peak-to-peak jitter from 65.5 ps to 44.5 ps and the voltage fluctuation from 183 mV to 115 mV at the data rate of 4 Gb/s with the 2 V.     

Interaction of carbon monoxide with transition metal surfaces

XPS studies of the interaction of carbon monoxide with surfaces of Fe, Co and Ni indicate that at 300 K, the disproportionation reaction is prominent up to exposures of 10³ L giving rise to high surface concentrations of carbon. At higher exposures and higher temperatures, dissociation of carbon monoxide accompanied by the formation of surface oxide layers becomes more prominent. In the case of copper, disproportionation is prominent up to 10⁴ L even at 500 K followed by dissociation at higher exposures. These results are also supported by Auger spectroscopic studies.     

Therapeutic response of tumors by in-vitro proton nuclear magnetic resonance spectroscopy

Proton NMR spectra of perchloric acid extracts of methyl cholantherene induced tumors grown in rats have been analyzed and compared with the normal and the treated tumor tissue samples. Well-resolved resonances from numerous low-molecular weight compounds including various amino acids, nucleotides, choline, creatine, phosphocreatine etc. were observed and assigned using pH titration, 2D NMR and by comparison with the spectra of model compounds. Significant differences were noticed in the spectra of the tumor and the normal tissue samples. Ratios of metabolite levels were calculated for the normal, tumor and treated tumor tissues which are shown as good markers to assess the state of the tumor and their response to treatment.     

Adaptive predictive congestion control of high-speed ATM networks

This paper proposes an auto regressive moving average (ARMAX)-based adaptive control methodology to prevent congestion in high-speed asynchronous transfer mode (ATM) networks. An adaptive controller is developed to control traffic where sources adjust their transmission rates in response to the feedback information from the network switches. Specifically, the buffer dynamics at a given switch is modeled as a nonlinear discrete-time system and an ARMAX controller is designed so as to predict the explicit values of the transmission rates of the sources so as to prevent congestion. Tuning methods are provided for the unknown coefficients of the ARMAX model to estimate the unpredictable and statistically fluctuating network traffic. Mathematical analysis is given to demonstrate the stability of the closed-loop system so that a desired quality of service (QoS) can be guaranteed. The QoS is defined in terms of cell loss ratio (CLR), transmission delay and buffer utilization. We derive design rules mathematically for selecting the parameters of the ARMAX algorithm such that the desired performance is guaranteed during congestion and potential tradeoffs are shown. Simulation results are provided to justify the theoretical conclusions for multiple source/single switch scenarios using both ON/OFF and MPEG data. The performance of the proposed congestion control scheme is also evaluated in the presence of feedback delays for robustness considerations.     

The exponential map for representations ofU p,q (gl(2))

For the quantum groupGL _p,q (2) and the corresponding quantum algebraU _p,q (gl(2)) Fronsdal and Galindo [Lett. Math. Phys.27 (1993) 59] explicitly constructed the so-called universalT-matrix. In a previous paper [J. Phys. A28 (1995) 2819] we showed how this universalT-matrix can be used to exponentiate representations from the quantum algebra to get representations (left comodules) for the quantum group. Here, further properties of the universalT-matrix are illustrated. In particular, it is shown how to obtain comodules of the quantum algebra by exponentiating modules of the quantum group. Also the relation with the universalR-matrix is discussed.Presented at the 4th International Colloquium Quantum Groups and Integrable Systems, Prague, 22–24 June 1995.     

In vivo oral insulin delivery via covalent organic frameworks

With diabetes being the 7th leading cause of death worldwide, overcoming issues limiting the oral administration of insulin is of global significance. The development of imine-linked-covalent organic framework (nCOF) nanoparticles for oral insulin delivery to overcome these delivery barriers is herein reported. A gastro-resistant nCOF was prepared from layered nanosheets with insulin loaded between the nanosheet layers. The insulin-loaded nCOF exhibited insulin protection in digestive fluids in vitro as well as glucose-responsive release, and this hyperglycemia-induced release was confirmed in vivo in diabetic rats without noticeable toxic effects. This is strong evidence that nCOF-based oral insulin delivery systems could replace traditional subcutaneous injections easing insulin therapy.

We report the successful use of a gastro-resistant covalent organic framework for in vivo oral delivery of insulin.     

OPTICAL-MICROWAVE DOUBLE RESONANCE SPECTROSCOPY OF IN VIVO CHLOROPHYLL

At low temperatures, chloroplast and subchloroplast preparations exhibit complex fluorescence spectra. Emission bands can be attributed to photosystem (PS) particles and various antenna-chl proteins as well as solubilized chls. Initial results from a systematic study of the components of these fluorescence spectra via optical-microwave double resonance spectroscopy are presently reported. Conclusions regarding possible structural features are discussed. Experiments on triplet sublevel decay rates yielded data consistent with an interpretation of triplet energy transfer within antenna fragments.