Risks, time trends, and mortality of colonoscopy-induced perforation in hospitalized patients.

BACKGROUND AND AIM: Colonic perforation is a rare complication of colonoscopy and ranges from 0% to 1% in all patients undergoing colonoscopy. The aim of this study was to assess the time trends, risk factors, and mortality associated with colonoscopy-induced perforation (CIP) in hospitalized patients as the data are limited. METHODS: Data are obtained from the Nationwide Inpatient Sample database to identify hospitalized patients between 2005 and 2014 that had CIP. Various factors like age and gender were assessed for association with CIP, followed by univariate and multivariate regression analyses. RESULTS: A total of 2 651 109 patients underwent inpatient colonoscopy between 2005 and 2014, and 4567 (0.2%) of the patients had CIP. Overall, incidence of CIP has increased from 2005 to 2014 (0.1% to 0.3%) (P < 0.001). On multivariate analysis, the adjusted odds ratio (OR) for CIP was highest in Caucasian race (OR: 1.49 [1.09, 2.06]), followed by after polypectomy, history of inflammatory bowel disease, end-stage renal disease, and age > 65 years (OR [95% CI] of 1.35 [1.23, 1.47], 1.34 [1.17, 1.53], 1.28 [1.02, 1.62], and 1.21 [1.11, 1.33], respectively) (all P < 0.05). CIP group had 33% less obesity (OR [95% CI]: 0.77 [0.65-0.9], P = 0.002) and 13-fold higher mortality (0.5% vs 8.1%) (P < 0.001) as compared to patients without CIP. The CIP-associated mortality ranged from 2% to 8% and remained stable throughout the study period. CONCLUSIONS: Our study suggests that the risk of CIP was highest in elderly patients, Caucasians, those with inflammatory bowel disease, end-stage renal disease, and after polypectomy. Recognizing the factors associated with CIP may lead to informed discussion about risks and benefits of inpatient colonoscopy.

Intercomparison of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples.

Boron determination in blood and tissue samples is a crucial task especially for treatment planning, preclinical research, and clinical application of boron neutron capture therapy (BNCT). Comparison of clinical findings remains difficult due to a variety of analytical methods, protocols, and standard reference materials in use. This paper addresses the comparability of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples. It was possible to demonstrate that three different methods relying on three different principles of sample preparation and boron detection can be validated against each other and yield consistent results for both blood and tissue samples. The samples were obtained during a clinical study for the application of BNCT for liver malignancies and therefore represent a realistic situation for boron analysis.

Activation analysis and evaluation of the radionuclide inventories, decay heat for European DEMO divertor components.

This work presents neutron flux calculation results and specific decay heat and activity for the European DEMO reactor divertor structure. Two DEMO 2017 models were used in calculations; one with a homogenised WCLL breeder blanket and the other with a homogenised HCPB breeder blanket. The neutron flux calculations were performed using MCNP6 code with JEFF 3.2 nuclear data. Activation and decay heat calculations were performed using the FISPACT-II code with TENDL - 2017 nuclear data library.

Numerical simulation for bioconvectional flow of burger nanofluid with effects of activation energy and exponential heat source/sink over an inclined wall under the swimming microorganisms.

Nanofluids has broad applications such as emulsions, nuclear fuel slurries, molten plastics, extrusion of polymeric fluids, food stuffs, personal care products, shampoos, pharmaceutical industries, soaps, condensed milk, molten plastics. A nanofluid is a combination of a normal liquid component and tiny-solid particles, in which the nanomaterials are immersed in the liquid. The dispersion of solid particles into yet another host fluid will extremely increase the heat capacity of the nanoliquid, and an increase of heat efficiency can play a significant role in boosting the rate of heat transfer of the host liquid. The current article discloses the impact of Arrhenius activation energy in the bioconvective flow of Burger nanofluid by an inclined wall. The heat transfer mechanism of Burger nanofluid is analyzed through the nonlinear thermal radiation effect. The Brownian dispersion and thermophoresis diffusions effects are also scrutinized. A system of partial differential equations are converted into ordinary differential equation ODEs by using similarity transformation. The multi order ordinary differential equations are reduced to first order differential equations by applying well known shooting algorithm then numerical results of ordinary equations are computed with the help of bvp4c built-in function Matlab. Trends with significant parameters via the flow of fluid, thermal, and solutal fields of species and the area of microorganisms are controlled. The numerical results for the current analysis are seen in the tables. The temperature distribution increases by rising the temperature ratio parameter while diminishes for a higher magnitude of Prandtl number. Furthermore temperature-dependent heat source parameter increases the temperature of fluid. Concentration of nanoparticles is an decreasing function of Lewis number. The microorganisms profile decay by an augmentation in the approximation of both parameter Peclet number and bioconvection Lewis number.

Microbial profile of symptomatic pericoronitis lesions: a cross-sectional study.

OBJECTIVE: The microbial composition of pericoronitis (Pc) is still controversial; it is not yet clear if the microbial profile of these lesions is similar to the profile observed in periodontitis (Pd). Therefore, the aim of the present study was to describe the microbial profile of Pc lesions and compare it directly with that of subjects with Pd. METHODOLOGY: Subjects with Pc and Pd were selected, and subgingival biofilm samples were collected from (i) third molars with symptomatic Pc (Pc-T), (ii) contralateral third molars without Pc (Pc-C) and (iii) teeth with a probing depth >3 mm from subjects with Pd. Counts and proportions of 40 bacterial species were evaluated using a checkerboard DNA-DNA hybridization technique. RESULTS: Twenty-six patients with Pc and 18 with Pd were included in the study. In general, higher levels of microorganisms were observed in Pd. Only Actinomyces oris and Eubacterium nodatum were present in higher mean counts in the Pc-T group in comparison with the Pc-C and Pd-C groups (p<0.05). The microbiota associated with Pc-T was similar to that found in Pc-C. Sites with Pc lesions had lower proportions of red complex in comparison with the Pd sites. CONCLUSION: The microbiota of Pc is very diverse, but these lesions harbour lower levels of periodontal pathogens than Pd.

Long-lived chemiluminescence in cigarette smoke.

Cigarette smooke contains high concentrations of unstable moleculles that react with oxygen to produce chemiluminescence. The chemiluminescent activity is concentrated in the aerosol phase that can be absorbed on glass-fiber filters and extracted into organic solvents. Cigarette smnoke in N, N-dimethylformamide produces a long-lasting luminescence visible to the dark-adapted eye. We have demonstrated the oxygen dependence and have measured the kinetics, activation energies, emission spectra, and absolute photon intensities of this chemiluminescence. The total light emission from a single puff (35 cubic centimeters) of cigarette smoke is greater than 10(12) photons. There was a significant correlation between smoke chemiluminescence anSd tar content. It is suggested that the chemical production of electronically excited states of aromatic hydrocarbons is equivalent to photoexcitation in the promotion of the carcinogenicity of these agents.

Mercury concentrations in museum specimens of tuna and swordfish.

The mercury levels of museum specimens of seven tuna caught 62 to 93 years ago and a swordfish caught 25 years ago have been determined by instrumental neutron activation analysis. These levels are in the same range as those found in specimens caught recently.

Methylmercury as percentage of total mercury in flesh and viscera of salmon and sea trout of various ages.

The proportion of methylmercury to total mercury in the flesh of salmon (Salmo salar) 1 to 7 years old and sea trout (Salmo ocla) 1 and 2 years old was found to average 93 percent with a range of 81 to 98 percent, and to be independent of the age of the fish. In salmon and sea trout 1 and 2 years old, methylmercury constituted 26 to 67 percent of the total visceral mercury, without age dependence.

The elongation-termination decision in transcription.

At any template position, the decision to extend the transcript by one residue or to release the nascent RNA represents a kinetic competition between elongation and termination pathways. This competition is discussed in terms of alternative Eyring transition state barriers; changes in termination efficiency correspond to small changes in the relative heights of these barriers. Elongation complexes are stable at nonterminator positions; a model is presented to explain the destabilization of these complexes at intrinsic termination sites. Functionally analogous effects can operate at rho-dependent terminators. Mechanisms for modulation of termination efficiency by regulatory proteins are described.

Elimination of sodium-24 and potassium-42 interferences in activation analysis of biological samples.

We have developed a simple novel column technique for the removal of sodium-24 and potassium-42 based on a heterogeneous isotopic exchange reaction between an organic eluting solution (acetone-hydrochloric acid) and fine crystals of sodium chloride or potassium chloride or their analogs. The technique is fast, efficient, and highly selective; it has been successfully applied to irradiated human tissues prior to gamma-ray spectrometry with lithium-drifted germanium detectors.

Activation analysis of ungulate hair.

Hair samples from the horse, elk, deer, moose, and antelope; subcutaneous tissue from the moose and antelope; and cast and living skin of the rattlesnake were activated by exposure to a neutron flux. The resulting products were studied by pulse-height analysis. Differences in type and proportion of trace elements appear to be consistent within the species studied.

Activation analysis of soluble and fixed sodium in mammalian hair.

Antelope hair was soaked in sodium-22 to simulate external contamination and then systematically washed to remove all traces of the sodium; progress of the wash was followed by gamma-ray spectrometry. Hair was then activated by neutron bombardment which showed sodium still present as sodium-24. It is concluded that a fraction of sodium in hair can be readily washed away with water and that a second fraction is held in the hair in such a manner that extended washing does not remove it. This suggests that sodium in two states may be associated with hair, one as an external contaminant and the other as a more nearly integral part of the hair.

An isomorphous heavy-atom derivative of crystaline formylmethionine transfer RNA.

An isomorphous osmium derivative of crystalline yeast initiator transfer RNA has been prepared and interpreted to 6-angstrom resolution. The coordinates of the heavy atoms have been determined by Patterson and "direct" methods applied to the difference coefficients of the centric projections, followed by least-squares refinement. There is one dominant site per asymmetric unit, consistent with the finding by neutron-activation analysis that there is approximately one osmium atom per molecule of transfer RNA. The osmium derivative appears to be a normal substrate for enzymatic aminoacylation.

Mercury content of common foods determined by neutron activation analysis.

The mercury contents in samples of flour, sugar, nonfat dry milk, potatoes, hamburger, chicken breast, shrimp, liver, eggs, and whole milk were determined by neutron activation analysis. The mercury was separated by anion exchange chromatography and precipitated as the sulfide. The mercury concentrations for all these foods were below 50 parts per billion.

Organic mercury identified as the cause of poisoning in humans and hogs.

Atomic absorption spectrophotometry and neutron activation analysis showed the presence of mercury in organic extracts of seed grain and in tissues of hogs fed the contaminated grain. Mercury was also found in the urine, serum, and cerebrospinal fluid of humans who ate the contaminated pork. Mass spectral analysis confirmed the presence of organic mercury. This paper reports the first documented episode of indirect mercury poisoning in humans in the United States caused by the ingestion of contaminated meat from animals that had consumed mercury in their food supply.

Effects of spectral smearing and temporal fine structure degradation on speech masking release.

This study assessed the effects of spectral smearing and temporal fine structure (TFS) degradation on masking release (MR) (the improvement in speech identification in amplitude-modulated compared to steady noise observed for normal-hearing listeners). Syllables and noise stimuli were processed using either a spectral-smearing algorithm or a tone-excited vocoder. The two processing schemes simulated broadening of the auditory filters by factors of 2 and 4. Simulations of the early stages of auditory processing showed that the two schemes produced comparable excitation patterns; however, fundamental frequency (F0) information conveyed by TFS was degraded more severely by the vocoder than by the spectral-smearing algorithm. Both schemes reduced MR but, for each amount of spectral smearing, the vocoder produced a greater reduction in MR than the spectral-smearing algorithm, consistent with the effects of each scheme on F0 representation. Moreover, the effects of spectral smearing on MR produced by the two schemes were different for manner and voicing. Finally, MR data for listeners with moderate hearing loss were well matched by MR data obtained for normal-hearing listeners with vocoded stimuli, suggesting that impaired frequency selectivity alone may not be sufficient to account for the reduced MR observed for hearing-impaired listeners.

Inhibition of Hageman factor activation.

A method for studying inhibitors of the contact stages of blood coagulation is described. A number of positively charged substances were shown to inhibit the contact stages. The inhibitory substances include spermine, cytochrome c, ribonuclease, and lysozyme. The inhibitory effect of these substances was neutralized by the addition of an activated plasma thromboplastin antecedent, factor XI, (PTA) fraction. Other positively charged substances including protamine, hexadimethrine, polylysine, polyornithine, methylene blue, and ortho-toluidine blue also inhibited the contact stages of coagulation, but the inhibitory effect on coagulation was not neutralized by the activated PTA fraction. Negatively charged substances such as heparin and insulin did not inhibit the contact stages of coagulation. Cytochrome c inhibited Celite adsorption of a partially purified Hageman factor fraction, and cytochrome, ribonuclease, spermine, and lysozome inhibited the adsorption of Hageman factor from PTA-deficient plasma. Very much smaller quantities of Celite completely adsorbed Hageman factor from the fraction rather than from whole plasma, which suggested the possibility that plasma contains an inhibitor or inhibitors of Hageman factor adsorption. Furthermore cytochrome c, spermine, ribonuclease, and lysozyme inhibited the coagulant activity of the following activators of the Hageman and PTA factors: Celite, kaolin, sodium stearate, ellagic acid, and skin. It is suggested that negatively charged sites on these activators are critical for adsorption and activation and that inhibition results from neutralization of the negatively charged sites by the adsorbed inhibtor. Tests with polylysine polymers indicate that inhibitory activity is directly related to molecular size over the molecular weight range of 4000 to 100,000.

Direct measurement of osteolysis in man.

Precise, direct measurement of bone calcium release (v(o-)) has been accomplished using a continuous tracer administration (CTA) technique. Dietary calcium (96.97% (40)Ca) is replaced by (40)Ca (99.991% (40)Ca) and blood levels of the naturally occuring isotope (48)Ca are monitored by neutron activation analysis as a function of time. (48)Ca abundance falls as this isotope is excreted and only partially replaced by release from bone. After a suitable period, an asymptotic abundance of (48)Ca in serum, E, is approached which is the fraction of the turnover rate of the rapidly exchangeable calcium pools coming from the skeleton (E = v(o-)/v(t)). E is determined with a standard error of 2%, providing a precise, sensitive index of v(o-). 13 studies in three normal men and one postmenopausal woman receiving maintenance estrogen show large intersubject variations in parameters of calcium metabolism using both CTA and pulse tracer administration (PTA) plus balance techniques. Induced hypercalcemia results in a prolonged decrease in v(o-). Glucocorticoid therapy initially and consistently induces a marked hypercalciuria while effects on most other parameters of calcium kinetics are variable. In two men E fell when testosterone was added to glucocorticoid treatment, consistent with the known antiosteolytic effect of androgens, despite the short period of study.

Changes in bone sodium and carbonate in metabolic acidosis and alkalosis in the dog.

Metabolic acidosis and alkalosis were produced in adult dogs over 5- to 10-day periods. Midtibial cortical bone was analyzed for calcium, sodium, phosphorus, and carbonate. In acidosis bone CO(3)/Ca decreased 9.5% and bone Na/Ca decreased 6.3%. In alkalosis bone CO(3)/Ca increased 3.1% and bone Na/Ca increased 3.0%. Previous attempts to account for changes in net acid balance by summation of extra- and intracellular acid-base changes have uniformly resulted in about 40-60% of acid gained or lost being "unaccounted for." If it is assumed that changes in tibial cortex reflect changes in the entire skeletal system, changes in bone CO(3) (=) are sufficiently large to account for the "unaccounted for" acid change without postulating changes in cellular metabolic acid production.

From tau to toxicity: emerging roles of NMDA receptor in Alzheimer's disease.

Glutamate toxicity through NMDA receptor channels has long been central to the understanding of acute neuronal injury. Recent studies implicate similar events in chronic neurodegenerative diseases. Here, we analyze some of the most intriguing evidence for NMDA receptor-mediated cellular dysfunction and propose a mechanism by which hyperactive NMDA receptors might lead to neurofibrillary degeneration in Alzheimer's disease.