PREDICTION OF MICROPORE GROWTH DURING GASIFICATION REACTIONS

The concept of changing pore geometry during the course of a reaction allows the microscopic solid-gas reaction models to have the potential to describe the porosity change during the reaction. However, only the bulk porous properties can be predicted due to the pore size range chosen for most of these models. The two population systems, micropore and macropore, chosen by the model of Zygourakls et al. [1] provides a method for predicting micropore property changes. However, this model over-predicts micropore property changes because it assumes that the average micropore radius is enlarged. By examining several sets of published carbon gasification data, it is shown that the average micropore radii are not enlarged by gasification. The commonly-used concept that reaction will enlarge all the pore radii is the major reason for the prediction error. A new concept is proposed in which the reaction will not enlarge the size of the micropores and will maintain a constant micropore length by reacting at both ends of micropores at equal rates. Based upon this concept, the model of Zygourakls et al. [1] has been modified. Both the original and the modified models can predict the gasification rate well by utilizing data from the carbon activation study of Yanai [2]. The model of Zygourakls et al. [1] gives a micropore surface area change close to the measured value, but the reaction enlarged micropores result in predicting high of values of micropore volume changes and average micropore sizes. The steady-state micropore concept used in the improved model predicts more realistic micropore property changes.     

Response map properties of units in the dorsal cochlear nucleus of barbiturate-anesthetized gerbil (Meriones unguiculatus)

The response map scheme introduced by Evans and Nelson (1973) and modified by others, including Davis et al. (1996) for use with gerbils, has been used primarily for classifying units recorded in the cochlear nucleus of unanesthetized decerebrate preparations. Units lacking spontaneous activity (SpAc) have been classified as either type I/III or type II units based on the relative strength of their responses to broad-band noise compared to their responses to best-frequency (BF) tones. The relative noise index (rho), a ratio of these responses after SpAc is subtracted out, provides a convenient measure of this relative strength. In this paper, responses of 320 units recorded in the dorsal cochlear nucleus (DCN) of barbiturate-anesthetized gerbils to short-duration BF tones and broad-band noise were recorded. Since 87.5% of these units lacked SpAc, their response maps resembled those of type II and type I/III units. Units were characterized by rho and the normalized slope (m) of a best line fit to the BF rate versus level plot starting from the sound level corresponding to the first inflection point of the rate curve (typically its maximum value or the start of its sloping saturation). The distributions of rho and m values do not form distinct clusters as they do for units in the decerebrate preparation. Thus, the criteria developed for classifying DCN units in the decerebrate preparation do not appear appropriate for units in the barbiturate-anesthetized preparation. Deposits of horseradish peroxidase were used to locate 52 units. Most of the low SpAc units, 56% with poor noise responses (5/9) and nearly 70% with strong noise responses (25/36), and nearly all of the high SpAc units (6/7), were located either within or below the fusiform cell layer.     

Preservation of global cardiac function in the rabbit following protracted ischemia/reperfusion using monophosphoryl lipid A (MLA)

Monophosphoryl lipid A (MLA), a derivative of the minimal substructure of lipopolysaccharide (lipid A) possesses immunomodulatory activity of the parent lipid A yet enjoys reduced toxicity. It has previously been reported that pretreatment with MLA reduces myocardial infarct size and stunning in dogs following ischemia and reperfusion. The aim of this study was to evaluate the ability of monophosphoryl lipid A (MLA) to preserve global cardiac function and peripheral hemodynamics in a rabbit model of prolonged regional ischemia (90 min), and reperfusion (6 h). An evaluation of potential mechanisms by which MLA may preserve cardiac function was also undertaken. Single dose pretreatment with MLA (35 micrograms/kg i.v.) 24 h prior to ischemia resulted in significant improvement in left ventricular developed pressure, dP/dt, rate-pressure product and mean arterial pressure during reperfusion (P < 0.05 v control). Although in this model of prolonged ischemia MLA pretreatment did not reduce infarct size (54.5 +/- 11.4% in control v 63.3 +/- 8.3% in MLA, P = N.S.), evaluation of myocardial adenylate and adenosine catabolite pools at the end of ischemia indicated a preservation of ATP and ADP and a decreased production of downstream adenosine catabolites including inosine, xanthine and uric acid. Adenosine kinase, but not 5'-nucleotidase (5'-NTase) or adenosine deaminase activity determined following reperfusion was 76% and 60% higher (P < 0.05) in non-risk and post-ischemic myocardium of MLA pretreated rabbits compared with controls. Although there was a trend toward lower tissue myeloperoxidase activity in post-ischemic myocardium from treated rabbits, the results were not significantly different from control animals. These results suggest that a 24-h pretreatment with MLA, without further treatment during ischemia or reperfusion was associated with: (1) preservation of global myocardial function during reperfusion; (2) preservation of myocardial high energy adenylates and reduced formation of adenosine catabolites during ischemia; (3) elevated myocardial adenosine kinase activity. Increased recycling of adenosine to phosphorylated nucleotides may result from MLA's affect on adenosine kinase, which could explain the drugs effect on adenylate and adenosine metabolite pools.     

Findings in gunshot wounds from tandem projectiles

Tandem projectiles are unusual events which can cause erroneous case interpretations if one is unfamiliar with them. This paper presents two such cases. The first case involved three .32 caliber bullets, two of which became lodged in a revolver barrel because of faulty ammunition. A third fired bullet subsequently pushed itself and the lodged bullets out of the barrel resulting in a single entrance wound with three bullets in the body. The second case involved a 20 gauge shotgun shell which apparently was inadvertently loaded into a 12 gauge shotgun. This resulted in an unusual entrance wound and unusual X-rays with fragments of the 20 gauge shotgun shell, as well as 12 gauge shotgun shell wadding, being removed from the same wound. The pertinent findings in such cases are discussed so that they may be correctly identified when they occur.     

A patient with Graves' disease, thrombocytopenia and chronic hepatitis B

A 22-year-old Chinese man, a HBsAg carrier, presented with relapse of thyrotoxic Graves' disease complicated by thrombocytopenia and hepatitis. Platelet count and liver enzymes gradually improved following successful treatment of the thyrotoxicosis with radioactive iodine. Possible pathogenetic links and therapeutic implications are discussed.     

Patterns of clinical metastasis in breast cancer: an analysis of 100 patients

Many patients diagnosed with breast cancer will develop metastases and these have diverse presentations. We have reviewed 100 consecutive patients who have died with metastatic breast cancer, to determine the frequency, sites and mode of presentation of recurrent disease. The commonest site of failure was loco-regional (n = 61), this usually presented with a mass, but a minority of patients also complained of pain. Bone metastases developed in 60 patients and produced bone pain, pathological fracture (n = 6) or cord compression (n = 5). Pulmonary metastases producing shortness of breath were diagnosed in 34 patients and were asymptomatic in a further 10. Intra-abdominal metastases were found at some time in 23 patients, most commonly in the liver (n = 20) and the majority complained of epigastric pain (n = 17). Brain metastases occurred in 23 patients and produced a wide range of symptoms including those of a space-occupying lesion (n = 10), cranial nerve palsy (n = 7), diabetes insipidus (n = 3), focal limb weakness (n = 2) and meningitis (n = 1). Three patients had choroid metastases producing reduced visual acuity. Recurrent breast carcinoma can present in a variety of ways, therefore any new symptom or sign should be considered to represent recurrence until proved otherwise.     

EFFECT OF GLASS COLOR ON SETTING RATES IN MANUFACTURE OF GLASS BOTTLES *

It has been observed in the manufacture of bottles of the same size and shape from various colored glasses, such as emerald green and amber and the so-called flint bottle glass, that higher machine speeds are usually obtained in the case of the colored glasses. A laboratory test has been devised to measure the cooling rates of several colored and colorless glasses throughout their respective working ranges, which gives results paralleling the speeds obtained in actual bottle manufacture.     

Is apoptosis involved in mechanisms to eliminate Onchocerca ochengi during Simulium damnosum s.l. immune response?

Co-injection of the parasite Onchocerca ochengi and the caspase inhibitors z-VAD.fmk and boc-D.fmk into the natural vector Simulium damnosum s.l. led to significantly increased survival of the parasites. Subsequent in situ apoptosis detection assays demonstrated that in the case of boc-D.fmk the enhanced survival was due to a diminished apoptosis level of the microfilariae in vivo. Additional assays using O. ochengi microfilariae which were coinjected with serine protease inhibitors into S. damnosum s.l. revealed that certain serine protease inhibitors can reduce the level of apoptosis.