Role of Frothers in Bubble Generation and Coalescence in a Mechanical Flotation Cell

Two frothers covering a very broad range from weak and selective (DF‐200) to powerful (DF‐1012) flotation performance were chosen to test the effect of frothers on bubble generation and bubble coalescence in a laboratory scale flotation cell. In two‐phase, gas‐liquid systems, the experiments showed that the frothers affect both the bubble breaking process and the coalescence of bubbles. While the DF‐200 frother, characterized by much larger critical coalescence concentration (CCC) values than DF‐1012, has the ability to produce finer bubbles at concentrations exceeding the CCC value, the bubbles generated in the DF‐1012 solutions at concentrations exceeding CCC are much larger.     

Thymic carcinoid. Report of a case with diagnosis by fine needle aspiration biopsy

BACKGROUND: Fine needle aspiration biopsy (FNAB) affords a less expensive, less morbid approach to masses within the complex anatomy of the mediastinum as opposed to surgical biopsy. Given the current state of computed tomography guidance and the available cell block preparations and ancillary studies, definitive diagnosis of mediastinal tumors is possible. CASE: A 19-year-old male presented with weight loss and muscle weakness. Computed tomography revealed an anterior superior mediastinal mass with attachment to the posterior sternum and anterior aorta. FNAB yielded hyperchromatic cells with densely clumped chromatin and prominent nucleoli. These were present as single cells and clusters. Cell block preparations were studied with immunoperoxidase methods and were strongly positive for chromogranin and glucagon, supporting the diagnosis of carcinoid tumor. Surgical excision yielded a 7-cm, unencapsulated, red-brown tumor with medium-sized cells with oval to round nuclei, scant and granular cytoplasm and coarse "salt and pepper" chromatin with prominent nucleoli. The cells were arranged in islands and bands and were associated with prominent capillaries and dense, collagenous septae. Immunoperoxidase and electron microscopy demonstrated numerous intracytoplasmic, nonspecific neurosecretory granules and positivity for somatostatin, synaptophysin, cytokeratin and chromogranin. CONCLUSION: FNAB affords an accurate and timely diagnosis of an anterior mediastinal tumor without the necessity for open biopsy and also offers accurate surgical planning and decreased morbidity.     

Total body heliotherapy

Sunlight has long been known to be beneficial for a variety of skin diseases. Patients with psoriasis and eczema frequently employ ambient heliotherapy to control their conditions. However, social norms do not permit a person to expose the entire body in public, thus placing severe restrictions on the utility of this modality for the treatment of generalized psoriasis, for example. Tan-Thru bathing suits, designed to attract those who wish to tan without an accentuated "tan line", are reported to absorb ultraviolet (UV) rays up to a maximum equivalent of a sun protection factor (SPF) 10 sunblock, thus offering approximately 89% protection while in use, according to their manufacturer. If so, this bathing suit may allow patients with UV-responsive skin dermatoses to achieve full body exposure in a socially acceptable manner. The objective of this study was to verify the SPF and to determine the actual transmittance to skin covered by a Tan-Thru bathing suit. Ten healthy adult subjects were recruited for this investigation. UVB minimal erythema dose (MED) was determined on unaffected gluteal or lower back skin, once with and once without the swimsuit on. Our results showed that the mean SPF afforded by the bathing suit was in fact 4.9 (range 4.5-5.6). In conclusion, theoretically, the Tan-Thru bathing suits could allow enough UVB penetration under ambient conditions to be beneficial for patients with UVB responsive conditions.     

Married couples' experiences at a human reproduction center

The present study was intended to understand the feeling demonstrated by married couples seeking a Human Reproduction Center for infertility evaluation. Intending to understand the way Assisted Reproduction is experienced from the couple's perspective, a phenomenological approach was adopted and the directing question was: "How do you feel using the Assisted Reproduction as a treatment?"     

Integrated-optical Mach-Zehnder add-drop filter fabricated by a single UV-induced grating exposure

A four-port bandpass filter is demonstrated with good performance by use of UV-induced Bragg gratings in P-doped channel waveguides without UV trimming. The simple, single-step fabrication procedure is experimentally and theoretically analyzed, and tolerances are calculated for achieving practical wavelength-division-multiplexed communication system performance.     

Multivariate analysis of single unit cells in electron crystallography

High-resolution electron cryomicroscopy of two-dimensional protein crystals is associated with extremely noisy raw data in which even the crystal lattice often cannot be discerned. Correlation averaging procedures, aimed at calculating the total average of all unit cells of crystals in order to reduce noise, are now used routinely in electron crystallography. Multivariate statistical analysis (MSA) may be used for finding not only the average structure but also for quantifying the systematic departures from that average within the population of individual unit cells. We show that the MSA approach is applicable to single unit-cell images in the low-dose (< 10 electrons/A2), high-resolution (< 5 A) realm using 400 keV electron spot-scan images of ice-embedded gp32*I protein crystals. Our feasibility study opens a pathway toward exploiting these naturally occurring variations on the unit-cell theme in order to achieve higher-resolution three-dimensional reconstruction results, or to better understand the dynamic behaviour of molecules within two-dimensional crystals. We explain how single unit-cell images can be processed and classified into homogeneous groups, and we review how the results of such discriminate averaging may subsequently be exploited within the context of conventional "h, k"-space electron crystallographic approaches. Variations among the individual unit cells may thus be one of the most significant resolution-limiting factors currently experienced in electron crystallography. The quantitative assessment and exploitation of such variations may lead to an increased performance of electron crystallographic procedures.     

Coronary atherosclerosis or diabetic cardiomyopathy? Pathoanatomic changes of blood vessels, nerves and myocardium in patients with diabetes mellitus

In patients with diabetes mellitus, heart disease is more common that in the background populations and has a more serious prognosis. The reasons are only partially understood. Whether patients with diabetes mellitus have a more diffuse and pronounced coronary atherosclerosis has been the subject of many investigations with diverging results. However, the larger studies suggest that coronary atherosclerosis is more pronounced and diffuse in diabetics compared with non-diabetic patients. The pathoanatomic picture of the atherosclerotic process seems to be identical in patients with and without diabetes mellitus. A number of structural abnormalities in the intramural vessels and interstitial tissue of the heart have been demonstrated in diabetics. However, similar abnormalities have also been reported in non-diabetic patients. With respect to where "diabetic cardiomyopathy" is a specific entity, the existing data are not confirmative. Whether diabetes mellitus per se induces functional changes in the coronary vascular system leading to myocardial ischaemia and dysfunction is a subject for future investigations.     

Discriminative stimulus effects of a cocaine/heroin "speedball" combination in rhesus monkeys

Cocaine and heroin often are abused together in a combination known as a "speedball," but relatively little is known about ways in which cocaine and heroin may interact to modify each other's abuse-related effects. The present study evaluated the discriminative stimulus effects of a speedball combination of cocaine and heroin. Three rhesus monkeys were trained to discriminate vehicle from a 10:1 ratio of cocaine (0.4 mg/kg) in combination with heroin (0.04 mg/kg). Both cocaine alone and heroin alone substituted completely for the cocaine/heroin combination, although cocaine and heroin were more potent when administered together than when administered alone. Combined pretreatment with the dopamine antagonist flupenthixol and the opioid antagonist quadazocine dose-dependently antagonized the discriminative stimulus effects of the cocaine/heroin combination, but pretreatment with either antagonist alone was less effective. These findings suggest that either cocaine or heroin alone was sufficient to substitute for the cocaine/heroin training combination. To characterize the discriminative stimulus properties of this speedball more fully, a series of cocaine-like and heroin-like agonists were studied in substitution tests. The indirect dopamine agonists CFT, amphetamine and bupropion and the mu opioid agonists alfentanil, fentanyl and morphine produced high levels of speedball-appropriate responding. However, the indirect dopamine agonist GBR12909, the D1 dopamine agonist SKF82958, the D2 dopamine agonist quinpirole and the partial mu opioid agonist nalbuphine did not substitute for the cocaine/heroin combination. Because these compounds produce discriminative stimulus effects similar to either cocaine or mu opioid agonists alone, these findings suggest that the discriminative stimulus effects of the cocaine/heroin combination do not overlap completely with the effects of cocaine and heroin alone. Finally, a series of compounds that produce partial or no substitution for cocaine or mu agonists alone also did not substitute for the cocaine/heroin combination, which indicates that the discriminative stimulus effects of the combination were pharmacologically selective. Taken together, these findings suggest that a combination of cocaine and heroin produces a pharmacologically selective discriminative stimulus complex that includes aspects of both component drugs.