Search

The room-temperature photoabsorption spectra of a number of linear alkynes with internal triple bonds (e.g., 2-butyne, 2-pentyne, and 2- and 3-hexyne) show similar resonances just above the lowest ionization threshold of the neutral molecules. These features result in a substantial enhancement of the photoabsorption cross sections relative to the cross sections of alkynes with terminal triple bonds (e.g., propyne, 1-butyne, 1-pentyne, ...). Based on earlier work on 2-butyne [ Xu et al., J. Chem. Phys. 2012, 136, 154303 ], these features are assigned to excitation from the neutral highest occupied molecular orbital (HOMO) to a shape resonance with g (l = 4) character and approximate π symmetry. This generic behavior results from the similarity of the HOMOs in all internal alkynes, as well as the similarity of the corresponding gπ virtual orbital in the continuum. Theoretical calculations of the absorption spectrum above the ionization threshold for the 2- and 3-alkynes show the presence of a shape resonance when the coupling between the two degenerate or nearly degenerate π channels is included, with a dominant contribution from l = 4. These calculations thus confirm the qualitative arguments for the importance of the l = 4 continuum near threshold for internal alkynes, which should also apply to other linear internal alkynes and alkynyl radicals. The 1-alkynes do not have such high partial waves present in the shape resonance. The lower l partial waves in these systems are consistent with the broader features observed in the corresponding spectra.

Gestational diabetes mellitus (GDM) is a subtype of diabetes mellitus defined as the development, or first recognition, of glucose intolerance during pregnancy. The risk of developing type 2 diabetes mellitus (T2DM) is greater in mothers with GDM compared to the general population. Preventing the development of GDM could help lower the prevalence of T2DM and long-term morbidity in children of affected mothers. The purpose of this study was to investigate the awareness of GDM and its risk factors among pregnant women in Samoa, exploring where participants obtained information, and understanding their attitudes towards diet and physical activity. A quantitative cross-sectional study of 141 women attending Tupua Tamasese Meaole (TTM) hospital in Apia, Samoa in May 2015 was performed. Fifty-eight percent women were aware diabetes can occur for the first time during pregnancy. The greatest information source was from doctors (37%, n=44) followed by family members (22%, n=28), based on 118 respondents. Only one woman correctly identified all four risk factors for GDM. Most women recognized eating a healthy diet (79%) and regular physical activity (78%) to be appropriate lifestyle changes to help prevent GDM. These findings suggest awareness of GDM among pregnant women in Samoa is mixed, with a very small proportion having good knowledge (based on the number of risk factors identified). We conclude that increased education about GDM is necessary, both in hospital clinics and within the community. By increasing awareness of GDM, it may be possible to decrease the prevalence of T2DM in Samoa.

A decline in breastfeeding rates in Samoa has been reported over the last century. To assess the length of time women breastfeed, their knowledge of both the advantages of and recommendations for breastfeeding, and the factors that influence their decisions to continue or discontinue breastfeeding, a questionnaire was distributed at Tupua Tamasese Meaole Hospital. One hundred and twenty-one eligible participants were included aged 18-50 years (mean age 28.2). Ninety percent of participants initiated breastfeeding, and the majority (78%) of babies were exclusively breastfed for at least the recommended 6 months. Many mothers introduced complementary (solid) foods later than World Health Organization (WHO) and United Nation's International Children's Fund (UNICEF) recommendations of 6 months. Awareness of the advantages of breastfeeding was mixed. The most widely known advantage was "the development of an emotional bond between mother and baby" (67%). Other advantages were less widely known. Only a small minority were aware that breastfeeding reduces risk of maternal diabetes and aids weight loss post partum. Doctors and healthcare workers were listed as the top factors encouraging breastfeeding. Participants' comments revealed a generally positive attitude towards breastfeeding, a very encouraging finding. Participants identified that the number of breastfeeding breaks available at work and the length of their maternity leave were factors discouraging breastfeeding. Future studies are necessary to determine if problems identified in this study are applicable on a national level. These could be important to determine measures to improve breastfeeding practices in Samoa.

The absolute photoabsorption cross sections of 1- and 2-butyne have been recorded at high resolution by using the vacuum-ultraviolet Fourier-Transform spectrometer at the SOLEIL Synchrotron. Both spectra show more resolved structure than previously observed, especially in the case of 2-butyne. In this work, we assess the potential importance of Rydberg states with higher values of orbital angular momentum, l, than are typically observed in photoabsorption experiments from ground state molecules. We show how the character of the highest occupied molecular orbitals in 1- and 2-butyne suggests the potential importance of transitions to such high-l (l = 3 and 4) Rydberg states. Furthermore, we use theoretical calculations of the partial wave composition of the absorption cross section just above the ionization threshold and the principle of continuity of oscillator strength through an ionization threshold to support this conclusion. The new absolute photoabsorption cross sections are discussed in light of these arguments, and the results are consistent with the expectations. This type of argument should be valuable for assessing the potential importance of different Rydberg series when sufficiently accurate direct quantum chemical calculations are difficult, for example, in the n ≥ 5 manifolds of excited states of larger molecules.

The recently introduced synchrotron radiation-based Fourier transform spectroscopy has been employed to study the excited electronic states of thiophene. A highly resolved photoabsorption spectrum has been measured between ∼5 and 12.5 eV, providing a wealth of new data. High-level ab initio computations have been performed using the second-order algebraic-diagrammatic construction (ADC(2)) polarization propagator approach, and the equation-of-motion coupled-cluster (EOM-CC) method at the CCSD and CC3 levels, to guide the assignment of the spectrum. The adiabatic energy corrections have been evaluated, thereby extending the theoretical study beyond the vertical excitation picture and leading to a significantly improved understanding of the spectrum. The low-lying π→π* and π→σ* transitions result in prominent broad absorption bands. Two strong Rydberg series converging onto the X(~)(2)A2 state limit have been assigned to the 1a2→npb1(1)B2 and the 1a2→nda2(1)A1 transitions. A second, and much weaker, d-type series has been assigned to the 1a2→ndb1(1)B2 transitions. Excitation into some of the Rydberg states belonging to the two strong series gives rise to vibrational structure, most of which has been interpreted in terms of excitations of the totally symmetric ν4 and ν8 modes. One Rydberg series, assigned to the 3b1→nsa1(1)B1 transitions, has been identified converging onto the Ã(2)B1 state limit, and at higher energies Rydberg states converging onto the B(~)(2)A1 state limit could be identified. The present spectra reveal highly irregular vibrational structure in certain low energy absorption bands, and thus provide a new source of information for the rapidly developing studies of excited state non-adiabatic dynamics and photochemistry.

The absolute photoabsorption cross section of propyne was recorded between 62,000 and 88,000 cm(-1) by using the vacuum-ultraviolet, Fourier-transform spectrometer at the Synchrotron Soleil. This cross section spans the region including the lowest Rydberg bands and extends above the Franck-Condon envelope for ionization to the ground electronic state of the propyne cation, X̃(+). Room-temperature spectra were recorded in a flowing cell at 0.9 cm(-1) resolution, and jet-cooled spectra were recorded at 1.8 cm(-1) resolution and a rotational temperature of ~100 K. The reduced widths of the rotational band envelopes in the latter spectra reveal new structure and simplify a number of assignments. Although nf Rydberg series have not been assigned previously in the photoabsorption spectrum of propyne, arguments are presented for their potential importance, and the assignment of one nf series is proposed. As expected from previous photoelectron spectra, Rydberg series are also observed above the adiabatic ionization threshold that converge to the v3(+) = 1 and 2 levels of the C≡C stretching vibration.

Background: Cyclophosphamide-methotrexate-5-fluorouracil (CMF) is often selected as adjuvant chemotherapy for older patients with early-stage breast cancer due to perceived superior tolerability. We sought to measure persistence with CMF, adherence to oral cyclophosphamide, and the association of these with toxic effects., Patients and Methods: CALGB 49907 was a randomized trial comparing standard chemotherapy (CMF or AC, provider/patient choice) with capecitabine in patients aged ≥65 with stage I-IIIB breast cancer. Those randomized to standard therapy and choosing CMF were prescribed oral cyclophosphamide 100 mg/m(2) for 14 consecutive days in six 28-day cycles. Persistence was defined as being prescribed six cycles of at least one of the three CMF drugs. Adherence was the number of cyclophosphamide doses that women reported they had taken divided by the number prescribed. Persistence and adherence were based on case report forms and medication calendars., Results: Of 317 randomized to standard chemotherapy, 133 received CMF. Median age was 73 (range 65-88). Seventy-one percent submitted at least one medication calendar; 65% persisted with CMF. Non-persistence was associated with node negativity (P = 0.019), febrile neutropenia (P = 0.002), and fatigue (P = 0.044). Average adherence was 97% during prescribed cycles., Conclusions: Self-reported adherence to cyclophosphamide was high, but persistence was lower, which may be attributable to toxic effects.

Background: Patients with end-stage renal disease (ESRD) requiring chronic haemodialysis who undergo coronary artery bypass graft surgery (CABG) are at significant risk for perioperative mortality. However, the impact of changes in ESRD patient volume and characteristics over time on operative outcomes is unclear., Methods: Using the Nationwide Inpatient Sample database (1988-03), we evaluated rates of CABG surgery with and without concurrent valve surgery among ESRD patients and outcomes including in-hospital mortality, and length of hospital stay. Multivariate regression models were used to account for patient characteristics and potential cofounders., Results: From 1988 to 2003, annual rates of CABG among ESRD patients doubled from 2.5 to 5 per 1000 patient-years. Concomitantly, patient case-mix changed to include patients with greater co-morbidities such as diabetes, hypertension and obesity (all P < 0.001). Nonetheless, among ESRD patients, in-hospital mortality rates declined nearly 6-fold from over 31% to 5.4% (versus 4.7% to 1.8% among non-ESRD), and the median length of in-hospital stay dropped in half from 25 to 13 days (versus 14 to 10 days among non-ESRD)., Conclusions: Since 1988, an increasing number of patients with ESRD have been receiving CABG in the USA. Despite increasing co-morbidities, operative mortality rates and length of in-hospital stay have declined substantially. Nonetheless, mortality rates remain almost 3-fold higher compared to non-ESRD patients indicating a need for ongoing improvement.

We studied the feasibility and efficacy of a two-step approach to Auto-SCT for patients with AML in second remission. Step 1 consisted of consolidation chemotherapy using cytarabine 2000 mg/m(2) i.v. every 12 h for 4 days plus etoposide 40 mg/kg total dose by continuous i.v. infusion over the same 4 days. PBSC were collected after G-CSF stimulation during recovery from this chemotherapy. Step 2, auto-SCT, used a preparative regimen of oral BU 16 mg/kg over 4 days followed by etoposide 60 mg/kg i.v. Of the 50 patients entered on Step 1, two died from treatment complications, and seven failed to proceed to transplantation. A median CD34+ cell dose of 5.9 x 10(6)/kg was collected in a median of three collections. With a median follow-up of 8.2 years, 5-year disease-free survival (DFS) is 28%. The most important prognostic factor was cytogenetics, with acute promyelocytic leukemia (APL) patients having a 5-year DFS of 67% compared with 16% for others. We conclude that this two-step approach to autologous transplantation produces good CD34+ mobilization and that this approach has cured some patients. Results in patients with APL are especially promising.

Background: Despite declining lengths of stay, postdischarge healthcare resource utilization may be increasing because of shifts to nonacute care settings. Although changes in hospital stay after coronary artery bypass graft (CABG) surgery have been described, patterns of discharge remain unclear. Our objective was to determine patterns of discharge disposition after CABG surgery in the United States., Methods and Results: We examined discharge disposition after CABG procedures from 1988 to 2005 using the Nationwide Inpatient Sample. Discharges with a "nonroutine" disposition defined patients discharged with continued healthcare needs. Multivariable regression models were constructed to assess trends and factors associated with nonroutine discharge. Median length of stay among 8,398,554 discharges decreased from 11 to 8 days between 1988 and 2005 (P<0.0001). There was a simultaneous increase in nonroutine discharges from 12% in 1988 to 45% in 2005 (P<0.0001), primarily comprising home healthcare and long-term facility use. Multivariable regression models showed age, female gender, comorbidities, concurrent valve surgery, and lower-volume hospitals more likely to be associated with nonroutine discharge., Conclusions: We found a significant increase in nonroutine discharges after CABG surgery across the United States from 1988 to 2005. The significant shortening of length of stay during CABG may be counterbalanced by the increased requirement for additional postoperative healthcare services. Nonacute care institutions are playing an increasingly significant role in providing CABG patients with postdischarge healthcare and should be considered in investigations of postoperative healthcare resource utilization. The impact of these changes on long-term outcomes and net resource utilization remain unknown.

Background: Random periareolar fine needle aspiration (RPFNA) is a research technique developed to assess short-term breast cancer risk in women at increased risk of breast cancer. Although there is increasing acceptance of RPFNA, neither the reproducibility nor the inter-institutional compatibility of RPFNA has been established. To address these key limitations, the Cancer and Leukemia Group B (CALGB) Prevention Group tested the reproducibility of RPFNA in a multi-institutional cross-sectional study., Methods: Sixty-three high-risk women from five CALGB institutions (Duke, Ohio State, Roswell Park, Dana Farber, and Vermont) underwent RPFNA from July 1, 2007 to June 30, 2008. Duplicate bilateral RPFNA was performed on each woman by a single investigator on a single day. Masood Cytology Index score was assessed by a single blinded cytopathologist., Results: There was a high degree of statistical agreement in the Masood Cytology Index scores of duplicate RPFNA samples from the same breast, with a Spearman correlation coefficient of 0.8312 (P < 0.0001). Importantly, although there was agreement in duplicate samples from the same breast, there was lack of agreement between duplicate samples from the opposite breast., Conclusions: This multi-institutional study shows that RPFNA is a highly reproducible measure of breast cytology in a cooperative group cross-sectional trial. RPFNA did not show a high degree of agreement between breasts, suggesting that breast cancer risk and progression may occur at different rates in individual breasts from a single woman. These studies provide proof-of-principle for future RPFNA-based cooperative group prevention studies.

Acute renal failure (ARF) is common after cardiac surgery and more frequent after complex cardiac surgery. While the incidence of ARF is increasing after coronary artery bypass graft (CABG) surgery, trends in other forms of cardiac surgery remain unclear. We investigated the trend of ARF in various cardiac procedures and compared patterns using CABG surgery as a reference group. The study population consisted of discharges from the Nationwide Inpatient Sample from 1988 to 2003, grouped according to surgery as: CABG, CABG with mitral valve, CABG with other valve, valve alone, and heart transplant. Standard diagnostic codes were used to identify ARF among discharges. Multivariable regression was used to determine trends in ARF among various procedures with CABG as a reference group. The incidence of ARF increased in all five groups (p < 0.001) over the 16-year period. The ARF incidence was highest in the heart transplant group (17%). Compared to the CABG population, patients following heart transplantation developed ARF at higher rates during the study period. In contrast, while ARF increased over time in other groups, the rates of rise were slower than in CABG patients. Among heart surgery procedures, ARF incidence is highest in heart transplantation. The incidence of ARF is also increasing at a faster rate in this group of patients in contrast to other procedure groups when compared to CABG surgery. The disproportionate increase in ARF burden after heart transplantation is a concern due to its strong association with chronic kidney disease and mortality.

A growing body of evidence suggests a role for cytokines in the mechanisms responsible for preterm parturition associated with intrauterine infection. Interleukin 6, a polyfunctional cytokine that is secreted by tissues in the feto-maternal interface in response to microbial products, has been implicated in the host response to intrauterine infection. The purpose of this study was to establish whether measurement of amniotic fluid concentrations of interleukin 6 could be of value in the diagnosis of microbial invasion of the amniotic cavity. Fluid was obtained by transabdominal amniocentesis from patients with preterm labour and intact chorioamniotic membranes and cultured for aerobic and anaerobic bacteria and mycoplasmas. Interleukin 6 concentrations were determined by an ELISA validated for human amniotic fluid. An interleukin 6 concentration above 11.2 ng/ml had a 93.7% sensitivity and a 92.3% specificity in the diagnosis of intra-amniotic infection. Moreover, patients with an amniotic fluid interleukin 6 level above 11.2 ng/ml and a negative amniotic fluid culture failed to respond to tocolysis, delivered a preterm infant and showed histological evidence of chorioamnionitis, and their neonates were at risk for congenital infections.