The decomposition of dimethyl methyl phosphonate (DMMP), a simulant for the nerve agent sarin, was investigated on Cu₄/TiO₂(110) and K/Cu₄/TiO₂(110) surfaces using a combination of near-ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) and density functional theory calculations (DFT). Mass-selected Cu₄ clusters and potassium (K) atoms were deposited onto TiO₂(110) as a metal catalyst and alkali promoter to improve the reactivity and recyclability of the TiO₂ surface after exposure to DMMP. Surface reaction products resulting from decomposition of DMMP were probed by NAP-XPS measurements of phosphorus (P) 2p and carbon 1s core-level spectra. The Cu₄/TiO₂(110) surface is found to be very active for DMMP decomposition with highly reduced P-species observed even at room temperature (RT). The codeposition of K atoms and Cu₄ clusters further improves the reactivity with no intact DMMP detectable. Temperature-dependent measurements show that the presence of K atoms promotes the removal of residual P-species at temperatures > 600 K. Detailed DFT calculations were performed to determine the surface structures and energetically accessible pathways for DMMP decomposition on Cu₄/TiO₂(110) and K/Cu₄/TiO₂(110) surfaces. The calculations show that DMMP and P-containing reaction products preferentially bind to the TiO₂ surface, while the molecular fragments, i.e., methoxy and methyl, bind to both the Cu₄ clusters and TiO₂. The Cu₄ clusters make the P-O, O-C, and P-C bond cleavages of DMMP markedly more exothermic. The Cu₄ clusters are highly fluxional with atomic structures that depend on the configuration of fragments bound to them. Finally, the manifold of P 2p chemical shifts calculated for a large number of energetically favorable configurations of decomposition products is in good agreement with the observed XPS spectra and provides an alternative way of interpreting incompletely resolved core-level spectra using an ensemble of observed structures.

Surgeons encounter neutropenic patients through elective or emergency consultation with increasing regularity. As medical management continues to extend the lives of patients with benign hematologic diseases, hematologic malignancies, solid malignancies, or iatrogenic neutropenia, more patients are presenting with infectious complications caused and/or complicated by their neutropenia. This leaves surgeons in the difficult position of managing medically fragile patients with unusual presentations of common disease processes. These patients often fall outside of classical guidelines and treatment pathways. Many studies addressing these issues are retrospective and non-randomized. Here, we review common emergency gastrointestinal surgery scenarios and their management in the setting of a neutropenic patient. While biliary disease, appendicitis, anorectal disease, and perforations will be covered in detail, an extensive appreciation of a patient's medical or oncologic disease course and appropriate utilization of consultants such as interventional radiology, gastroenterology, and hematology is often necessary.

The morphology and reactivity of mass-selected titania clusters, Ti3O6 and Ti3O5, deposited onto Au(111) were studied by scanning tunneling microscopy and temperature programmed desorption. Despite differing by only one oxygen atom, the stoichiometric Ti3O6 and the sub-stoichiometric ("reduced") Ti3O5 clusters exhibit very different structures and preferred binding sites. The Ti3O6 clusters bind at step edges and form small assemblies (2-4 clusters) on Au terraces, while the "reduced" Ti3O5 clusters form much larger fractal-like assemblies that can extend across step boundaries. Annealing the Ti3O5,6/Au(111) systems to higher temperatures causes changes in the size-distributions of cluster assemblies, but does not lead to the formation of TiOx nanoislands for temperatures ≤700 K. Reactivity studies show that the reduced Ti3O5 cluster has higher activity than Ti3O6 for 2-propanol dehydration, although both clusters exhibit substantial activity for dehydrogenation to acetone. Calculations using DFT+U suggest that the differences in aggregate morphology and reactivity are associated with the number of undercoordinated Ti3c sites in the supported clusters.

Background

Few studies have focused on prognostic factors among adolescents and young adults (AYAs) 15 to 39 years of age when diagnosed with differentiated thyroid cancer (DTC). Our study expands upon prior work by including an evaluation of survival among AYA men and by neighborhood socioeconomic status, health insurance, and clinical factors to identify subgroups of young DTC patients at higher risk of mortality.

Methods

Data for 16,827 AYA DTC patients diagnosed between 1988 and 2010 were obtained from the California Cancer Registry. Survival, through 2010, by sociodemographic and clinical factors was analyzed using Cox proportional hazards regression.

Results

Of the 2.1% of AYAs who died, 16.7% died from thyroid cancer and 21.4% died from a subsequent cancer. In multivariate analyses, older AYAs 35 to 39 year of age (versus 15- to 29-year-olds), men (hazard ratio [HR] 2.77, 95% confidence interval [CI] 1.62-4.72), and AYAs of African American or Hispanic race/ethnicity (versus non-Hispanic whites) had worse thyroid cancer specific survival. In addition, residing in low socioeconomic status neighborhoods (HR 3.11 [CI 1.28-7.56]) and nonmetropolitan areas (HR 5.53 [CI 2.07-14.78]) was associated with worse thyroid cancer-specific survival among AYA men, but not AYA women.

Conclusions

Despite the generally good prognosis among AYAs with DTC, we identified subgroups of AYA patients at risk for poor outcomes. Further study of the factors underlying these associations, including possible barriers to receiving high-quality treatment and follow-up care, as well as lifestyle factors, are critical to reducing these disparities.

Background

The reported rate of incidental parathyroidectomy (IP) during thyroid surgery is between 5.2 and 21.6 %. Current literature reports wide discrepancy in incidence, risk factors, and outcomes. Thus study was designed to address definitively the topic of IP and identify associated risk factors and clinical outcomes with this multi-institutional study.

Methods

This retrospective cohort study included 1767 total thyroidectomies that occurred between 1995 and 2014 at two academic centers. Pathologic reports were reviewed for the presence of unintentionally removed parathyroid glands. Demographics, potential risk factors, and postoperative calcium levels were compared with matched control group. Logistic regression, t tests, and Chi squared tests were used when appropriate.

Results

IP occurred in 286 (16.2 %) of thyroidectomies. Risk factors for IP were: malignancy, neck dissection, and lymph node metastases (p = 0.005, <0.001, and <0.001). Fifty-three (19.2 %) of IPs were intrathyroidal. Those with IP were more likely to have postoperative biochemical (65.6 vs. 42.0 %; p < 0.001) and symptomatic (13.4 vs. 8.1 %; p = 0.044) hypocalcemia than controls. The number of parathyroids identified intraoperatively was inversely correlated with the number of parathyroid glands in the specimen (p < 0.001).

Conclusions

Our findings indicate that malignancy, lymph node dissection, and metastatic nodal disease are risk factors for IP. Patients with IP were more likely to have postoperative biochemical and symptomatic hypocalcemia than controls, showing that there is a physiologic consequence to IP. Additionally, intraoperative surgeon identification of parathyroid glands results in a lower incidence of IP, highlighting the importance of awareness of parathyroid anatomy during thyroid surgery.