Power-law distribution of pressure fluctuations in multiphase flow.

Bubbling fluidized beds are granular systems, in which a deep layer of particles is set in motion by a vertical gas stream, with the excess gas rising as bubbles through the bed. We show that pressure fluctuations in such a system have non-Gaussian statistics. The probability density function has a power-law drop-off and is very well represented by a Tsallis distribution. Its shape is explained through the folding of the Gaussian distribution of pressure fluctuations produced by a monodisperse set of bubbles, onto the actual distribution of bubble sizes in the bed, assuming that bubbles coalesce via a Smoluchowski-type aggregation process. Therefore, the Tsallis statistics arise as a result of bubble polydispersity, rather than system nonextensivity.

Nonstandard roughness of terraced surfaces

We present a class of surfaces which are simultaneously flat and rough over the same range of lengths. They are self-affine, have well-defined roughness exponents, and consist of terraces of all sizes. The coexistence of flat and rough makes them respond to different external interactions with variable roughness. We demonstrate this for optical scattering (including x rays), two wetting situations, diffusion currents, and catalysis. A terraced Cu surface is a "self-assembled" experimental example, and designs for nano- and micromachined examples are presented.

Religious activity improves life satisfaction for some physicians and older patients.

OBJECTIVE: To assess religious perceptions and activities of physicians and older patients and to determine whether religious activities are associated with life satisfaction. DESIGN AND SETTING: A cross-sectional survey of practicing Virginia internists and psychiatrists and hospitalized or institutionalized (nursing home) older adults. PARTICIPANTS: One hundred randomly sampled practicing physicians and 55 hospitalized or institutionalized older patients. METHODS: A mailed survey was used for the physicians and a structured interview for the patients. All subjects provided information pertaining to demographics and life satisfaction using the Life Satisfaction Index (LSI-B). For physicians or patients who engaged in any religious activity, the Intrinsic/Extrinsic Religiosity (I/E-R) scale was used. RESULTS: Of the 100 physicians (49 internists and 51 psychiatrists) who answered the survey (50% response rate), 75% used religious activity as a coping resource (39% somewhat, 36% definitely). There was a positive correlation between intrinsic religious activity (e.g., prayer, Bible reading) and life satisfaction (r = .293, P = .042). Of the 55 patients interviewed, 47 (86%) used religion as a coping resource, and intrinsic religious activity was positively associated with life satisfaction (r = .843, P < .001). Even after controlling for age, gender, health, and marital status, intrinsic religious activity remained a predictor of higher life satisfaction. CONCLUSIONS: Intrinsic religious activity is associated positively with life satisfaction in physicians and ill older adults.

Older males secrete luteinizing hormone and testosterone more irregularly, and jointly more asynchronously, than younger males.

New statistical perspectives on the secretory patterns of both luteinizing hormone (LH) and testosterone (T) may prove useful in further understanding the aging process, and possibly ultimately in improving the diagnosis and treatment of spermatogenetic failure and loss of sexual interest. We examined serum concentration time-series for LH and T in 14 young (21-34 years of age) and 11 aged (62-74 years of age) healthy men. For each subject, blood samples were obtained at 2.5-min intervals during a sleep period, with an average sampling duration of 7 hr. For each of LH and T, we used the model-independent statistic approximate entropy (ApEn) to quantify the irregularity of the serum concentration time-series; to quantify joint LH-T secretory asynchrony, we employed the recently introduced cross-ApEn. Although mean (and SD) LH and T concentrations were indistinguishable in the two age groups (P > 0.25), for LH, aged subjects had greater ApEn values (1.525 +/- 0.221) than younger individuals (1.207 +/- 0.252), P < 0.003, indicating more irregular secretion in the older cohort. For T, aged subjects also had greater ApEn values (1.622 +/- 0.120) than younger counterparts (1.384 +/- 0.228), P < 0.004. In young, but not older men, ApEn(T) significantly exceeded ApEn(LH), P < 0.02. Aged subjects had greater cross-ApEn values (1.961 +/- 0.121) than younger subjects (1.574 +/- 0.249), P < 10(-4), with nearly 100% sensitivity and specificity, indicating greater LH-T asynchrony in the older group. In conjunction with previous findings of greater irregularity of growth hormone release with increasing age, we propose that increased secretory irregularity with advancing age may be a widespread hormonal phenomenon. Finally, theoretically, we clarify the need for quantifications such as ApEn and cross-ApEn via a study of a "variable lag" pulsatile process, and empirically note the potential wide applicability of cross-ApEn to quantify asynchrony in interconnected (hormonal) networks.

Quality of life in patients using self-administered intracavernous injections of prostaglandin E1 for erectile dysfunction.

PURPOSE: We assessed changes in quality of life after 6 months of self-injections of prostaglandin E1 for the treatment of erectile dysfunction. MATERIALS AND METHODS: A prospective study was done at a university affiliated Veterans Affairs medical center of patients using prostaglandin E1 at home. Quality of life was assessed with the Case Western Reserve University sexual functioning questionnaire and the Duke health profile. These questionnaires were administered before initiation and after 6 months of prostaglandin E1 therapy. RESULTS: Of 16 subjects injecting prostaglandin E1 at home 15 completed 6 months of therapy, and 13 of them completed both questionnaires. While using prostaglandin E1 we found an increase in the frequency of sexual activity from 2.9 to 5.5 times during the prior month (p = 0.01), rigidity of erection scores from 3.8 to 7.6 (p = 0.002, score 0-no erection to 8-full erection) and sexual satisfaction scores from 2.5 to 4.1 (p = 0.03, score 0-extremely unsatisfied to 5-extremely satisfied). We also found improvements in mental health scores from 80.0 to 92.3 (p = 0.007), social health scores from 61.5 to 80.8 (p = 0.004) and self-esteem scores from 72.3 to 86.9 (p = 0.01) on a scale of 0 to 100, where a higher score indicates better health. CONCLUSIONS: Self-injection of prostaglandin E1 improves sexual satisfaction and quality of life in men with erectile dysfunction.

Slow injection of prostaglandin E1 decreases associated penile pain.

OBJECTIVES: A randomized, double-blind study to determine whether speed of intracavernous injection of prostaglandin E1 (PGE1) is associated with pain. METHODS: On two separate occasions, using two different speeds of injection (5 versus 60 seconds), 11 subjects received the same dose of PGE1 that they used at home. The presence, duration, and intensity of pain were recorded. RESULTS: We found that fast penile injection of PGE1 was associated with a greater intensity of pain (P = 0.04). CONCLUSIONS: Slow injection of PGE1 is less often associated with penile pain, the most common adverse effect of this treatment.

Amplified nocturnal luteinizing hormone (LH) secretory burst frequency with selective attenuation of pulsatile (but not basal) testosterone secretion in healthy aged men: possible Leydig cell desensitization to endogenous LH signaling--a clinical research center study.

The specific mechanisms underlying the relative hypogonadism of aging remain to be elucidated fully. We used frequent venous sampling (every 2.5 min), sensitive and specific LH and testosterone assays, and deconvolution analysis of the endocrine time series to delineate the differences between healthy young (n = 10, age 21-34 yr) and aged (n = 8, age 62-74 yr) men in the nocturnal secretion of LH and testosterone and their half-lives. We found that elderly men vs. young men had more frequent bursts of LH secretion (1.4 vs. 0.9/h, P = 0.003), less testosterone secreted per testosterone secretory burst (9.2 vs. 17.0 nmol/L, P = 0.021), and less testosterone secreted per hour (10.7 vs. 25.0 nmol/L.h, P = 0.05). As the frequency of nocturnal LH secretory bursts increased, the frequency of testosterone bursts decreased (r = -0.746, P = 0.034). We conclude that healthy aging is associated with diminished nocturnal testosterone production attributable to 1) a decrement in the mass of testosterone released per burst and 2) an inadequate response by the pituitary gland to enhance testosterone production via an accelerated LH secretory pulse frequency. We speculate that this may reflect a partial desensitization of Leydig cells to LH.

[The malignant degeneration of colorectal polyps]. / Malignizarea polipilor rectocolici.

The authors make a retrospective analysis of problems related to diagnosis and therapy raised by malignization of adenomatous rectocolic polyps representing 38.7% of the total number of adenomatous polyps (98 cases), and 5% of cancers of the large bowel (759 cases in all). It is stressed that the rate of malignization increases in direct proportion with the number of polyps, and it is higher in segmentary or diffuse polyposis, predominantly in the sigmoidorectal segment. The clinical, endoscopic and radiologic signs have an orientational value in the diagnosis of malignant polyps, but they are truly important for the detection of the polyps (the site, the number, the extent, and the morphology), and for certain indices of malignancy (density, bleeding, ulceration), which are not constantly found, and which occur at the later stage of the disease. The diagnosis is made by polypectomy and histologic examination of multiple sections, the major diagnostic condition being the identification of the malignancy in the initial stage. Directed partial endobiopsies is frequently followed by diagnostic errors (in 32.2% of the cases), and should be reserved for those cases where polypectomy is technically unfeasible. With regard to therapeutic problems the necessity for oncologic interventions is stressed, characterized by wide exeresis with ablation of all polyps, the type and the extension of the resections depending on the site of the malignancy, and the extent of the polyps. It is stressed that polypectomy, as a definitive therapeutic procedure, does not represent a radical type of surgery, and has exceptional indications for patients with major operatory risks and incipient malignancies. Detection and treatment of polyps in the benign stage is one of the preventive methods that can be applied in rectocolic cancers.

[Emergency operations in colorectal cancer]. / Operatii de urgenta în cancerul recto-colonic.

In a group of 161 patients subjected to emergency surgery of rectocolonic cancers with occlusive (111 cases), hemorrhagic (39 cases) or perforating (11 cases) complications, the authors analyze the immediate therapeutic results, as a function of the complication form and the surgical method used in emergency (primary colectomy, serial surgeries, palliative surgeries). Emergency colectomy (55 cases) performed deliberately in strictly selected cases or as the unique possible choice, was followed by immediate good results (the lowest rate of surgical morbidity and mortality) in comparison with the serial surgeries (cumulative morbidity and mortality). The paper discusses the indications of the proximal colectomy and of Hartman's surgery in primary emergency colectomies. Serial surgeries (secondary colectomy--30 cases) are mainly indicated in the complicated cancers of the left colon, in the patients with resectable tumours, but with critical biological state or with insufficiently prepared colon. Palliative surgeries (colostomies, internal derivations) used in patients with nonresectable tumours were followed by the highest surgical mortality, a consequence of the biological substrate weakened by disease and complications. The data reported show the necessity of a selective tactical behaviour in the emergency surgery of rectocolonic cancer and plead for the primary urgent colectomy in the patients meeting certain general and local conditions. Likewise, they point to the importance of discovering rectocolonic cancer in an early stage, before the appearance of complications requiring the emergency surgery.

[Considerations on the results of initial chemotherapy in pulmonary tuberculosis]. / Consideratii privind rezultatele chimioterapiei initiale în tuberculoza pulmonara.

The results of initial chemotherapy applied in 501 patients with secondary pulmonary tuberculosis hospitalized and treated between 1973 and 1978 are analized. At the end of the treatment the following results have been noted: 94.8% bacteriological negativation, and 5.2% of cases which had not been influenced by chemotherapy and had constantly presented Koch bacilli in their sputum. From the clinical and radiological viewpoints a persistence of cavitary lesions was noted in 12.1% of all patients, or in 22.4% of those who presented initially with cavities. In the surveillance period 7.5% of the patients again became positive, and another course of therapy solved the new positivity in 84.2% of those involved. A percentage of 95.2% global favourable results have been noted in the final stage of the therapy, and 4.8% failures. Relapses, and bacteriological failures were noted with a higher frequency in males, and are in direct proportion with the extension of the lesions and the severity of the clinical forms. Eighteen of the patients (3.6%) had a course which led to chronicization of the disease. The favourable results and the reduction to a minimum of the therapeutic failures could be obtained by a correct application of chemotherapy and dispensarization of the patients under control.