Stable isotope signatures of hydration water in secondary mineralization on UO2.

Hydrated secondary mineralization readily forms on the surface of UO2 particles exposed to humidity in an oxidizing environment. The oxygen stable isotope composition of the secondary uranium oxide may reflect that of the water vapor, as well as the hydrogen and oxygen stable isotopic composition of the mineral hydration water. The geospatial organization of δ2H and δ18O values of atmospheric humidity and precipitation is increasingly well understood, which suggests that the hydrogen and oxygen stable isotopes in secondary mineral hydration water may yield information on the environment in which the mineralization formed. UO2 powders were exposed to air with constant 30%, 61%, and 91% relative humidity, and constant H and O stable isotope composition. Aliquots were sampled from the UO2 materials at intervals of 1-10 days through the total humidity exposure duration of 180 days. Scanning electron microscopy, transmission electron microscopy, and x-ray diffraction analysis of the humidity-exposed UO2 indicates that schoepite/metaschoepite [(UO3)•2H2O] secondary phases had formed on the underlying UO2. The δ2H and δ18O values of mineral hydration waters were determined by thermogravimetry-enabled isotope ratio infrared spectroscopy (TGA-IRIS). Results indicate that hydrogen in the surface sorbed and mineral hydration waters is exchangeable and thus their δ2H values are difficult to interpret. However, oxygen in these waters is less exchangeable, and thus the oxygen stable isotope composition of the schoepite/metaschoepite hydration water is likely to be related to that of the exposure water vapor. After formation of schoepite/metaschoepite, the δ18O values of the hydration water in schoepite/metaschoepite does not change in response to changes in exposure vapor δ18O values, which suggests that the δ18O values of the hydration water is relatively durable. These findings suggest that information about the origin and storage history of a UO2 sample may be discernable from δ18O values of schoepite/metaschoepite hydration water.

Is donating blood for the faint of heart? a systematic review of predictors of syncope in whole blood donors.

BACKGROUND: Adverse events during donation negatively impact the likelihood of subsequent donation. Syncope is a possible complication of blood donation in healthy individuals. This systematic review aims to identify risk factors for syncope in healthy blood donors. STUDY DESIGN AND METHODS: Medline, Embase, Cochrane, CINAHL, Web of Science, Transfusion Evidence Library, and PubMed libraries up to November 2016 were searched. Inclusion criteria were observational and interventional trials, case series including more than 10 participants, randomized controlled trials, and clinical trials. Papers required data pertaining to syncopal events separate from presyncope for inclusion. Incomplete text or non-English language versions were excluded. Papers were evaluated using the CHARMS 2014 checklist. RESULTS: From 3316 papers, 1297 unique citations were identified, and 11 were selected for data extraction. Sex, estimated blood volume, age, donor status, blood pressure, heart rate, weight, previous reaction, caffeine, sleep, and donation site were identified as risk factors for syncope during blood donation. CONCLUSION: Possible risk factors for syncope in healthy blood donors have been identified that could allow for improved screening prior to donation and potential reduction in donor attrition due to negative experiences.

The Association Between Organizational Culture and the Ability to Benefit From "Just Culture" Training.

OBJECTIVE: This study aimed to determine whether there was an association between the organizational culture and the hospital's readiness to benefit from "Just Culture" training. METHODS: The "Just Culture" Assessment Tool and the Competing Values Framework surveys were administered before and 6 weeks after a structured "Just Culture" training session to 172 care providers and administrators on similar units at two community for-profit hospitals of compatible size and offering comparable services in suburban communities. Data were analyzed for significance using IBM SPSS software. RESULTS: At baseline, there was a significantly higher percentage of problematic responses (PPRs) for hospital 1 as compared with hospital 2. Administrators and managers reported significantly fewer PPRs than frontline staff. In addition, the archetypal organizational culture for hospital 1 was found to be more hierarchical, whereas the culture for hospital 2 was found to be more group oriented. Six weeks after the completion of "Just Culture" training, there was a 0.02% overall reduction in PPRs at hospital 1 as compared with a 62.01% overall reduction in PPRs at hospital 2. There was also a significant increase in the Group Culture Score, a significant decrease in both the Hierarchical Culture and Rational Culture scores for hospital 2 as compared with hospital 1. CONCLUSIONS: There was a significantly greater reduction in PPR on the "Just Culture" Assessment Tool in the hospital with the more group-oriented organizational culture. Given the cost and effort required to conduct "Just Culture" training in an organization, it seems to be important to address the organizational culture before the implementation of this type of training.

The Long Road to the Left Main: A Multidisciplinary Approach to the Revascularization of Complex Left Main Coronary Artery Disease.

Severe aortic stenosis (AS) is considered a contraindication to the use of mechanical circulatory support (MCS) devices, including the Impella heart pump (Abiomed, Aachen, Germany). We describe a case in which a 72-year-old female with severe AS and peripheral vascular disease (PVD) presented with retractable ischemia in the setting of a non-ST elevation myocardial infarction (NSTEMI). Using a coordinated multidisciplinary approach, our case is the first to combine iliac angioplasty, balloon aortic valvuloplasty (BAV), and the insertion of an Impella CP device in the setting of severe AS to facilitate successful coronary artery revascularization in a non-surgical patient.

Ventriculography to Identify Ventricular Free-Wall Rupture in Acute Coronary Syndrome.

A 76-year-old previously well female with late-presentation acute coronary syndrome underwent left ventriculography, which demonstrated contrast leak into the pericardium consistent with left ventricular free-wall rupture. Confirmatory imaging, including echocardiography, was performed. Our case highlights the persistent utility of ventriculography as an imaging modality to identify free-wall rupture in acute coronary syndromes.

Cytotoxicity of three South African medicinal plants using the Chang liver cell line.

BACKGROUND: Arctotis arctotoides, Gasteria bicolor and Pittosporum viridiflorum are commonly used in the Eastern Cape, South Africa by traditional healers for the treatment of opportunistic fungal infections in HIV/AIDS patients. Unfortunately, there is a dearth of published data regarding the toxicity of the selected plants, despite the fact that experimental screening of toxicity is crucial to guarantee the safety of the users. MATERIALS AND METHODS: Therefore, it was decided to evaluate the cytotoxicity of the hexane and acetone extracts of the medicinal plants against the Chang Liver cell line using the in vitro MTT assay. Different concentrations of the extracts were added into 24-hour cultured cells and incubated for 72 hours under specific condition (37 °C, 5% CO2). Cell survival was evaluated using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. RESULTS: Depending on the dosage and duration of treatment, the cytotoxic effects of Gasteria bicolor and Pittosporum viridiflorum were considered relatively weak (but not entirely absent) and less of a toxicity risk. Arctotis arctotoides extracts were the most toxic both in terms of IC50 values as well as the steeper slope of the dose response curve. The IC50 values for the acetone and hexane extracts of this plant were 17.4 and 12.4 µg/ml respectively. CONCLUSION: These relatively low values raise concern for potential hepatotoxic effects and deserve further investigation or at least a warning to potential users.

Foliar micro-morphology of Gasteria bicolor haw. (Asphodelaceae) from South Africa.

BACKGROUND: The succulent genus, Gasteria, which comprises 16 species, is endemic to South Africa and has its main centre of distribution in the Savanna Region of the Eastern Cape. Whereas G. bicolor has been investigated phyto-chemically and pharmacologically, not much data concerning the anatomical and micro-morphological features can be found in literature. MATERIALS AND METHODS: This study was undertaken, using light and scanning electron microscopy to obtain information on the micro-morphological features of this important medicinal plant to facilitate its identification and authentication. The elemental composition of the leaf was determined by energy dispersive X-ray spectroscopy (EDXS). RESULTS: The epidermal cells are either hexagonal or pentagonal in form, and are compactly arranged with undulate anti-clinal cell walls. The epidermal cell width was approximately 50 µm. Stomata apertures are elliptical and the upper epidermis of the leaf has paracytic stomata which are slightly raised above the epidermal surface with 4 to 5 subsidiary cells surrounding each stoma. Based on the EDXS microanalysis, the mineral crystals present at the level of the mesophyll of G. bicolor were probably mixtures of calcium oxalate, calcium sulphate and silica. CONCLUSION: The co-occurrence of aluminum suggests the potential role of the crystals in detoxification of aluminum and heavy metals, as reported previously.

Obesity and pain.

Recent reports suggest that almost half of the UK population is expected to be obese by 2030. A number of associations between obesity and chronic pain have been displayed in previous studies, and therefore it can be expected that the presentation of obese patients with chronic pain will rise in accordance with the prevalence of obesity. No single causative relationship between the two can be suggested, so the link between them is believed to be multifactorial. Despite this, little work has been done to draw together the many associations between obesity and pain. A better understanding of their connection, then, is required to appropriately manage this patient group that is increasing in numbers. This article aims to draw together existing evidence on the associations between obesity and pain to create a model of their multifactorial relationship. The article will systematically address each of the current theories in order to gradually build a diagrammatic representation of the relationship, which shall conclude the article.

Phytochemical studies and antioxidant activity of two South African medicinal plants traditionally used for the management of opportunistic fungal infections in HIV/AIDS patients.

BACKGROUND: It has been observed that perturbations in the antioxidant defense systems, and consequently redox imbalance, are present in many tissues of HIV-infected patients. Hence, the exogenous supply of antioxidants, as natural compounds that scavenge free radicals, might represent an important additional strategy for the treatment of HIV infection. The aim of this study was therefore to analyse the phytochemical constituents and antioxidant potential of Gasteria bicolor Haw and Pittosporum viridiflorum Sims., two South African plants traditionally used for the management of opportunistic fungal infections (OFIs) in AIDS patients. METHODS: The in vitro antioxidant properties of the two plants were screened through DPPH (1,1-diphenyl-2-picrylhydrazyl), NO (nitric oxide), H2O2 (hydrogen peroxide) radical scavenging effects and reducing power assays. Phytochemical studies were done by spectrophotometric techniques. RESULTS: There were no significant differences in the flavonoid and proanthocyanidins contents between the leaves and bark extracts of Gasteria bicolor and Pittosporum viridiflorum respectively, while the total phenolic content of the bark extract of P. viridiflorum was significantly higher than that of G. bicolor leaf. The acetone extracts of both plants indicated strong antioxidant activities. CONCLUSION: The results from this study indicate that the leaves and stem extracts of Gasteria bicolor and Pittosporum viridiflorum respectively possess antioxidant properties and could serve as free radical inhibitors, acting possibly as primary antioxidants. Since reactive oxygen species are thought to be associated with the pathogenesis of AIDS, and HIV-infected individuals often have impaired antioxidant defenses, the inhibitory effect of the extracts on free radicals may partially justify the traditional use of these plants in the management of OFIs in HIV patients in South Africa.

Uterine serous carcinoma: increased familial risk for lynch-associated malignancies.

Serous uterine cancer is not a feature of any known hereditary cancer syndrome. This study evaluated familial risk of cancers for patients with serous uterine carcinoma, focusing on Lynch syndrome malignancies. Fifty serous or mixed serous endometrial carcinoma cases were prospectively enrolled. Pedigrees were developed for 29 probands and tumors were assessed for DNA mismatch repair (MMR) abnormalities. Standardized incidence ratios for cancers in relatives were estimated. A second-stage analysis was undertaken using data from Gynecologic Oncology Group (GOG)-210. Incidence data for cancers reported in relatives of 348 patients with serous and mixed epithelial and 624 patients with endometrioid carcinoma were compared. Nineteen of 29 (65.5%) patients in the single-institution series reported a Lynch-related cancer in relatives. Endometrial and ovarian cancers were significantly overrepresented and a high number of probands (6 of 29, 20.7%) reported pancreatic cancers. None of the probands' tumors had DNA MMR abnormalities. There was no difference in endometrial or ovarian cancer incidence in relatives of serous and endometrioid cancer probands in the case-control study. Pancreatic cancers were, however, significantly more common in relatives of patients with serous cancer [OR, 2.39; 95% confidence interval (CI), 1.06-5.38]. We identified an excess of endometrial, ovarian, and pancreatic cancers in relatives of patients with serous cancer in a single-institution study. Follow-up studies suggest that only pancreatic cancers are overrepresented in relatives. DNA MMR defects in familial clustering of pancreatic and other Lynch-associated malignancies are unlikely. The excess of pancreatic cancers in relatives may reflect an as yet unidentified hereditary syndrome that includes uterine serous cancers.

Dynamically biased RRKM model of activated gas-surface reactivity: vibrational efficacy and rotation as a spectator in the dissociative chemisorption of CH4 on Pt(111).

The reactivity of CH(4) impinging on a Pt(111) surface was examined using a precursor-mediated microcanonical trapping model of dissociative chemisorption wherein the effects of rotational and vibrational energy could be explored. Dissociative sticking coefficients for a diverse range of non-equilibrium effusive beam, supersonic beam, and eigenstate-resolved experiments were simulated and an average relative discrepancy between theory and experiment of better than 50% was achieved by treating molecular rotations and translation parallel to the surface as spectator degrees of freedom, and introducing a dynamically-biased vibrational efficacy. The model parameters are {E(0) = 57.9 kJ mol(-1), s = 2, η(v) = 0.40} where E(0) is the apparent threshold energy for reaction, s is the number of surface oscillators participating in energy exchange within each gas-surface collision complex formed, and η(v) is the mean vibrational efficacy for reaction relative to normal translational energy which figures in the assembly of the active exchangeable energy which is available to surmount the activation barrier to dissociative chemisorption. GGA-DFT electronic structure calculations provided vibrational frequencies for the transition state for dissociative chemisorption. The asymmetry of the rotational state populations in supersonic and effusive molecular beam experiments allowed kinetic analysis to establish that taking rotation as a spectator degree of freedom is a good approximation. Surface phonons, rather than the incident molecules, are calculated to play the dominant role in supplying the energy required to overcome the activation barrier for dissociative chemisorption under the thermal equilibrium conditions relevant to high pressure catalysis. Over the temperature range 300 K ≤T≤ 1000 K, the thermal dissociative sticking coefficient is predicted to be well described by S(T) = S(0) exp(-E(a)/RT) where S(0) = 0.62 and E(a) = 62.6 kJ mol(-1).