Measuring Adherence to Antibiotic Use Guidelines in Managing Mandible Fractures.

PURPOSE: Due to variability in practice patterns when managing patients with facial fractures, the Surgical Infection Society's Therapeutics and Guidelines Committee (SIS) released guidelines in June 2020 concerning antibiotic use in the treatment of patients with facial fractures. The purpose of this study was to measure adherence to SIS guidelines among patients treated for isolated mandibular fractures and to identify factors associated with deviation from SIS guidelines. MATERIALS AND METHODS: The authors designed and implemented a retrospective cohort study and enrolled a sample derived from the population of patients treated for isolated mandibular fractures at Harborview Medical Center (Seattle, WA) and University of Washington Medical Center-Montlake (Seattle, WA) from June 2020 through October 2021. The primary outcome variable was adherence to SIS antibiotic guidelines (yes or no). Covariates were grouped into the following categories: demographic (age, gender), treatment (operative treatment, primary service, transfer status), and risk factor (Charlson Comorbidity Index, tobacco use, alcohol use, drug use other than marijuana, mandibular injury severity score). Descriptive and bivariate statistics were computed to measure the association between adherence and the study variables. The level of statistical significance was set at a P-value ≤.05. RESULTS: The study sample was composed of 114 patients with a mean age of 41.8 ± 19.0 years and 72% were males. The frequency of adherence to SIS antibiotic protocol was 91.2%. Variables associated with deviation from SIS antibiotic protocol were operative treatment (P-value = .03 - relative risk (RR) not calculable), current drug use other than marijuana (RR = 4.1; 95% confidence interval, 1.3-12.8; P-value = .01), and transfer from an outside facility (RR = 4.1; 95% confidence interval, 1.3-12.8; P-value = .01). CONCLUSIONS: The findings of this study suggest that the SIS antibiotic guidelines in the management of isolated mandible fractures were translated well into practice at our institution as evidenced by the high level of compliance (>90%). To improve adherence, additional research is indicated to better understand how factors such as treatment choice, drug exposure, and transfer status adversely affect adherence to guidelines.

Workplace bullying, burnout and resilience amongst perioperative nurses in Australia: A descriptive correlational study.

AIM: This study aimed to investigate workplace bullying and explore correlations between bullying, burnout and resilience amongst perioperative nurses in Australia. BACKGROUND: Workplace bullying in perioperative nursing involves verbal, physical and psychological violence. However, no prior studies have measured Australian perioperative nurses' experiences of workplace bullying nor sought to understand if there is a relationship with burnout and resilience. METHODS: A descriptive correlational study was conducted utilizing an online survey incorporating four validated instruments. Descriptive statistics and regression models analysed workplace bullying, burnout and resilience. RESULTS: Over half of perioperative nurses (n = 158/257, 61%) were exposed to workplace bullying. Consequences included fatigue and exhaustion (n = 129/192, 67%), anxiety (n = 123/192, 64%) and sleeplessness (n = 121/192, 63%). Organisational processes (r = .458, p < .001), bullying acts (r = .289, p < .001) and avoidance and withdrawal at work (r = .440, p = .001) increased burnout. Psychosocial distress (r = -.216, p < .001) was associated with decreased resilience. CONCLUSIONS: Workplace bullying is a persistent issue with negative impacts upon burnout, resilience and well-being. IMPLICATIONS FOR NURSING MANAGEMENT: The psychological well-being of employees can be prioritized by establishing and maintaining an organisational climate of psychosocial safety, thereby inhibiting the potential of bullying to manifest and positively influencing employee well-being to help promote workplace engagement, productivity and reduced burnout.

Psychosocial situation, adherence, and utilization of video consultation in young adult long-term pediatric liver transplant recipients during COVID-19 pandemic.

BACKGROUND: Young adults who underwent liver transplantation in childhood (YALTs) are highly vulnerable to non-adherent behavior and psychosocial problems. During the COVID-19 pandemic, special efforts may be necessary to maintain contact with these patients and offer support. This can be achieved through the use of telemedicine. The study's objective was to assess adherence and the psychosocial situation of YALTs during the COVID-19 pandemic in Germany and to evaluate the utilization of video consultations. METHODS: In May 2020, a questionnaire was sent to YALTs treated at the Hamburg University Transplant Center, accompanied by the offer of video appointments with the attending physician. The questionnaire included the Generalized Anxiety Disorder Scale 7, the Patient Health Questionnaire 2, and questions compiled by the authors. RESULTS: Of 98 YALTs, 12% used the video consultation, while 65% had an in-person appointment. The 56 patients who completed the questionnaire did not report reduced medication adherence during the pandemic, but 40% missed follow-up visits with their primary care physician or check-up laboratory tests. About 70% of YALTs were afraid to visit their physician and the transplant center, and 34% were afraid of a SARS-CoV-2 infection. Mental health and well-being were unimpaired. CONCLUSIONS: During the COVID-19 pandemic, YALTs in our study did not show an increased need for psychosocial support, but a majority were afraid to attend medical appointments, and 40% reported lower appointment adherence. Acceptance of video consultations was lower than expected. The reasons for this need to be further investigated in order to optimize care.

What Is the Effect of COVID-19-Related Social Distancing on Oral and Maxillofacial Trauma?

PURPOSE: The purpose of this study was to understand the impact of social distancing policies enacted during the COVID-19 pandemic on the epidemiology of oral and maxillofacial fractures at an urban, Level I trauma center in the United States. MATERIALS AND METHODS: The investigators designed a retrospective cohort study and enrolled a sample of 883 subjects who presented for evaluation of oral and maxillofacial fractures (OMF) between March 1 and June 30 in the years 2018 through 2020. The primary predictor variable was the evaluation of OMF during a period with social distancing policies (2020 - experimental group) or without social distancing policies in place (2018 or 2019 - control group). The primary outcome variables were the facial fracture diagnosis, the abbreviated injury scale (AIS), injury severity score (ISS), and the mechanism of injury. Appropriate univariate and bivariate statistics were computed, and the level of significance was set at P < .05 for all tests. RESULTS: The number of subjects presenting with OMF was lower during the period of social distancing (n = 235 in 2020) than during the periods without (2018: n = 330; 2019: n = 318). During the period of social distancing, there were more individuals who presented secondary to assault, whereas fewer individuals presented secondary to falls (P = .05). On average, those who presented in 2020 had more severe oral and maxillofacial injuries (mean AIS = 3.2 ± 1.2 in 2020 vs 3.0 ± 1.1 in 2019 and 3.0 ± 1.1 in 2018. P = .03) and more overall injuries (mean ISS = 20.7 ± 13.1 in 2020 vs 19.2 ± 12.5 in 2019; 17.8 ± 12.8 in 2018. P = .03). CONCLUSIONS: The investigators found that during the period of social distancing through the COVID-19 pandemic, the number of OMF cases decreased but that the severity of oral and maxillofacial and overall injuries was higher.

Is Distance Between Home and Treatment Site a Risk Factor for Complications After Treating Mandibular Fractures?

PURPOSE: Our level I trauma center provides care over a large geographic area including Alaska, Washington, Idaho, Montana, and Wyoming, with many patients traveling hundreds of miles to receive care. Distance to a treatment site is documented to be an independent risk factor for complications after multisystem trauma, but it is unclear if it is a risk factor for isolated mandibular fractures. The study purpose was to measure the association between distance to treatment site and risk for postoperative complications after treatment of isolated mandibular fractures. MATERIALS AND METHODS: The investigators designed and implemented a retrospective cohort study and enrolled a sample derived from patients treated for isolated mandibular fractures at Harborview Medical Center by the oral and maxillofacial surgery service between June 2012 and December 2016. The primary predictor variable was distance (miles) between the patient's residence and site of treatment (Harborview Medical Center). The primary outcome variable was postoperative complication (yes or no), subcategorized as major and minor. Secondary outcome variables were time to treatment between injury and operative treatment (days) and length of hospital stay (LOS) (days). Descriptive, bivariate, and multiple logistic regression statistics were computed to measure the association between distance to treatment site and postoperative complications, time to treatment, and LOS. The level of statistical significance was set at P ≤ .05. RESULTS: The study sample was composed of 403 subjects with a mean age of 32.6 ± 14.3 years and 80% were men. The average distance from the patient's residence to treatment site was 44.8 ± 128.6 miles (range, 0 to 1,440 miles; median, 20.4 miles). Major complications occurred in 11.6% of patients. The average distance between patients with and without postoperative complications was not significantly different (42.3 ± 55.8 miles vs 45.5 ± 141.7 miles; P = .8). Increasing distance was significantly associated with longer LOS (r = 0.16; P < .001) but not time to treatment (r = .04; P = .4). CONCLUSIONS: In contrast to other studies regarding multisystem trauma, complications after treating isolated mandible fractures were not associated with increasing distance to treatment site. Increasing distance may be associated with longer LOS but not time to treatment.

[Severe secondary sclerosing cholangitis as manifestation of a very rare underlying disease]. / Schwere sekundär sklerosierende Cholangitis als Manifestation einer sehr seltenen Grunderkrankung.

Langerhans cell histiocytosis (LCH) is a very rare cause of secondary sclerosing cholangitis. We report the case of a 42-year-old male patient with sclerosing cholangitis and histological evidence of LCH from a bile duct biopsy. Due to rapid disease progression and exhaustion of conservative therapeutic approaches the patient received a liver transplantation. Nearly 2 years after transplantation the patient has a good graft function and no signs of recurrence of the underlying LCH.

Are Oral and Maxillofacial Surgeons Prescribing Fewer Opioids and More Non-Narcotic Analgesics for Postoperative Pain After Third Molar Removal?

PURPOSE: In response to the national opioid epidemic crisis, the purpose of this study was to measure changes in opioid and non-narcotic analgesia (NNA) prescribing practices over time after third molar (M3) removal. MATERIALS AND METHODS: A retrospective double cohort study was utilized enrolling 2 samples of patients who had M3s removed during 2 different 3-month intervals. The primary predictor variable was prescribing practice, divided into cohorts: 1) previous prescribing practice (PPP) occurring early during the evolving opioid epidemic (2014); and 2) current prescribing practice (CPP) (2018). The outcome measures were morphine milligram equivalents (MMEs), NNA prescriptions, and refill MMEs for inadequate pain control (IPC). Other variables were age, gender, payor, provider, anesthesia, procedure, and number of M3s removed. Descriptive, bivariate, and multiple linear and logistic regression models were computed. RESULTS: The sample included 330 subjects with a mean age of 23.1 ± 8.1 years; 42.4% were male. Of the 330 subjects, 147 were in the PPP cohort (44.5%) and 183 in CPP cohort (55.5%). Mean MMEs were 130.1 ± 42.4 and 68.5 ± 32.0 in the PPP and CPP cohorts, respectively (P ≤ .001). An adjusted linear regression model showed differences in MMEs prescribed persisted (P ≤ .001). The frequency of postoperative NNA prescriptions written increased from 2.7 to 71.6% (P ≤ .001). An adjusted logistic regression model also revealed that NNA prescriptions had significantly increased (odds ratio, 242.00; P ≤ .001). No difference was found in the frequency of refills for IPC (P = .13) or mean refill MME prescriptions between the cohorts (P = .48). CONCLUSIONS: Within our academic practice, fewer opioids and more NNAs are being prescribed for postoperative pain after M3 removal without an increase in IPC. Increased awareness through prescribing regulations, non-narcotic research findings, and organizational guidelines could have contributed to these changes.

Is the Mandible Injury Severity Score a Valid Measure of Mandibular Injury Severity?

PURPOSE: Developing a valid method for assessing mandibular injury severity could permit standardized comparisons of treatment-specific outcomes between and among various mandibular fracture studies. The study purpose was to assess the validity of the Mandible Injury Severity Score (MISS) developed by Shetty et al (J Oral Maxillofac Surg 65:663, 2007) by measuring the association between the MISS and postoperative complications, operative time, and length of hospital stay (LOS) after operative treatment of isolated mandibular fractures. MATERIALS AND METHODS: The authors designed and implemented a retrospective cohort study and enrolled a sample derived from patients treated for isolated mandibular fractures at Harborview Medical Center (Seattle, WA) by the oral and maxillofacial surgery service from June 2012 through December 2016. The primary predictor variable was the MISS. The primary outcome variable was postoperative complication (yes or no). Secondary outcome variables were operative time and LOS. Descriptive, bivariate, and multiple logistic regression statistics were computed to measure the association between the MISS and postoperative complications. The level of statistical significance was set at a P value less than or equal to .05. RESULTS: The study sample was composed of 415 patients with a mean age of 32.7 ± 14.3 years and 80% were men. The average MISS was 13.4 ± 3.5 (range, 6 to 25). The postoperative complication rate was 21%. The average MISS was significantly higher in patients with postoperative complications than in patients without complications (16.3 ± 3.3 vs 12.6 ± 3.1; P < .001). In the adjusted model, postoperative complications were significantly associated with an increasing MISS (odds ratio [OR] = 1.4; 95% confidence interval [CI], 1.3-1.6; P < .001) and open treatment (OR = 7.6; 95% CI, 1.6-35.6; P = .01). The MISS was positively correlated with operative time (r = 0.529; P < .001) and LOS (r = 0.114; P = .02). CONCLUSION: The results of this study suggest that the MISS may be a valid measurement of mandibular injury severity as evidenced by the positive correlation between the MISS and postoperative complications, duration of operation, and LOS.

Do Postoperative Antibiotics Decrease the Frequency of Inflammatory Complications Following Third Molar Removal?

PURPOSE: The purpose of this study was to answer the following clinical question: among patients who have their third molars (M3s) removed, do those who receive only postoperative antibiotics compared with those who receive no perioperative antibiotics have a lower frequency of postoperative inflammatory complications? MATERIALS AND METHODS: The authors designed and implemented a prospective cohort study and enrolled a sample of patients who had at least 1 M3 removed in an ambulatory private practice setting from June 2011 through May 2012 by oral and maxillofacial surgeons participating in a practice-based research collaborative. The predictor variable was postoperative antibiotic use categorized as postoperative antibiotics alone or no antibiotics. The primary outcome variable was the presence or absence of an inflammatory complication (ie, alveolar osteitis or surgical site infection) after M3 removal. Descriptive, bivariate, and multiple logistic regression statistics (adjusted for clustering within surgical practices) were computed to measure the association between postoperative antibiotic use alone and inflammatory complications after M3 removal, with statistical significance set at a P value less than or equal to .05. RESULTS: The study sample was composed of 1,877 patients having 5,631 M3s removed, of which 61% received postoperative antibiotics only. The overall inflammatory complication frequencies in the groups receiving postoperative antibiotic only and no antibiotic were 4.3 and 7.5%, respectively (P = .003). After adjusting for differences between the 2 study groups and clustering of patients within surgical practices, postoperative antibiotic use was associated with a 40% decreased risk of developing postoperative inflammatory complications (P = .04) with marginal statistical significance. CONCLUSIONS: The results of this study suggest that postoperative antibiotic therapy is associated with a statistically meaningful decreased risk of inflammatory complications after M3 removal compared with no antibiotic therapy.

Do Antibiotics Decrease the Risk of Inflammatory Complications After Third Molar Removal in Community Practices?

PURPOSE: The role of antibiotic use in third molar (M3) surgery is controversial. The purpose of this study was to measure the association between antibiotic use and postoperative inflammatory complications after M3 surgery in the community office-based ambulatory private practice setting. MATERIALS AND METHODS: The authors designed and implemented a prospective cohort study and enrolled a sample composed of patients who had at least one M3 removed in a private practice setting by oral and maxillofacial surgeons participating in a practice-based research collaborative from June 2011 through May 2012. The predictor variable was antibiotic use of any type, categorized as yes or no. The primary outcome variable was the presence or absence of an inflammatory complication, specifically surgical site infection (SSI) or alveolar osteitis (AO), after M3 removal. Descriptive, bivariate, and multiple logistic regression statistics were computed to measure the association between antibiotic use and inflammatory complications after M3 removal, with statistical significance set at a P value less than or equal to .05. RESULTS: The study sample was composed of 2,954 patients. Three fourths (75.2%) of the sample received antibiotics in some form. The overall inflammatory complication (AO or SSI) frequencies in the antibiotic and nonantibiotic groups were 5.0 and 7.5%, respectively (P = .012). After adjusting for differences between the two groups, statistical significance between the groups persisted. CONCLUSIONS: The results of this study suggest that antibiotic therapy, regardless of type, dose, frequency, or pattern of delivery, is associated with a decreased risk of inflammatory complications after M3 removal.

Threshold Photoelectron Spectra of Combustion Relevant C4H5 and C4H7 Isomers.

Threshold photoelectron spectra of combustion relevant C4H5 isomers, 2-butyn-1-yl and 1-butyn-3-yl, and C4H7 isomers, 1-methylallyl and 2-methylallyl, have been recorded using vacuum ultraviolet synchrotron radiation. Adiabatic ionization energies (IEad) have been determined by assigning spectroscopic transitions in mass-selected threshold photoelectron spectra aided by Franck-Condon simulations. The following values were obtained: (7.97 ± 0.02) eV (1-butyn-3-yl), (7.94 ± 0.02) eV (2-butyn-1-yl), (7.48 ± 0.01) eV (1-E-methylallyl), (7.59 ± 0.01) eV (1-Z-methylallyl), and (7.88 ± 0.01) eV (2-methylallyl). Good agreement with CBS-QB3 calculations and simulations could be achieved.

Threshold photoelectron spectroscopy of unstable N-containing compounds: Resolution of ΔK subbands in HNCO(+) and vibrational resolution in NCO(.).

The threshold photoelectron spectra (TPES) of two unstable nitrogen-containing species, HNCO and NCO, were recorded utilizing vacuum ultraviolet synchrotron radiation. Both are intermediates in combustion processes and play a role in the removal of nitrogen oxides from exhaust gases. The rovibronic structure of the first band in the TPES of HNCO(+) was analyzed within the framework of an orbital ionization model, and the resolved structure of the origin band was assigned to ΔK subbands. An ionization energy of 11.602 ± 0.005 eV was determined and the vibrational structure of the cationic ground state was analyzed by a Franck-Condon fit. Low lying electronically excited states of HNCO(+) were also observed. In a second series of experiments, the NCO radical was generated by flash pyrolysis from chlorine isocyanate. The ionization energy to the X(+) (3)Σ(-) ground state was determined to be 11.76 ± 0.02 eV, while for the a(+) (1)Δ state, a value of 12.93 ± 0.02 eV was obtained. Vibrational structure was observed for both states, and bands were assigned by Franck-Condon simulations.

Photoionization and pyrolysis of a 1,4-azaborinine: retro-hydroboration in the cation and identification of novel organoboron ring systems.

The photoionization and dissociative photoionization of 1,4-di-tert-butyl-1,4-azaborinine by means of synchrotron radiation and threshold photoelectron photoion coincidence spectroscopy is reported. The ionization energy of the compound was determined to be 7.89 eV. Several low-lying electronically excited states in the cation were identified. The various pathways for dissociative photoionization were modeled by statistical theory, and appearance energies AE0K were obtained. The loss of isobutene in a retro-hydroboration reaction is the dominant pathway, which proceeds with a reverse barrier. Pyrolysis of the parent compound in a chemical reactor leads to the generation of several yet unobserved boron compounds. The ionization energies of the C4 H6 BN isomers 1,2- and 1,4-dihydro-1,4-azaborinine and the C3 H6 BN isomer 1,2-dihydro-1,3-azaborole were determined from threshold photoelectron spectra.

Improved ionization energies for the two isomers of phenylpropargyl radical.

The ionization of two resonantly stabilized radicals, namely 1-phenylpropargyl (1PPR) and 3-phenylpropargyl (3PPR) are reinvestigated applying vacuum ultraviolet synchrotron radiation and threshold photoelectron spectroscopy. Ionization energies of 7.24±0.02 and 7.25±0.01 eV are obtained for 1 and 3PPR respectively, which compare well with ab initio calculations. The quality of the spectra are significantly improved mostly due to the application of a new high-photon-flux grating available at the VUV-beamline of Swiss Light Source. Resolved vibrational features are assigned according to a Franck-Condon approach.

Decomposition of diazomeldrum's acid: a threshold photoelectron spectroscopy study.

Derivatives of meldrum's acid are known precursors for a number of reactive intermediates. Therefore, we investigate diazomeldrum's acid (DMA) and its pyrolysis products by photoionization using vacuum ultraviolet (VUV) synchrotron radiation. The threshold photoelectron spectrum of DMA yields an ionization energy (IE) of 9.68 eV. Several channels for dissociative photoionization are observed. The first one is associated with loss of CH3, leading to a daughter ion with m/z = 155. Its appearance energy AE0K was determined to be 10.65 eV by fitting the experimental data using statistical theory. A second parallel channel leads to m/z = 69, corresponding to N2CHCO, with an AE0K of 10.72 eV. Several other channels open up at higher energy, among them the formation of acetone cation, a channel expected to be the result of a Wolff-rearrangement (WR) in the cation. When diazomeldrum's acid is heated in a pyrolysis reactor, three thermal decomposition pathways are observed. The major one is well-known and yields acetone, N2 and CO as consequence of the WR. However, two further channels were identified: The formation of 2-diazoethenone, NNCCO, together with acetone and CO2 as the second channel and E-formylketene (OCCHCHCO), propyne, N2 and O2 as a third one. 2-Diazoethenone and E-formylketene were identified based on their threshold photoelectron spectra and accurate ionization energies could be determined. Ionization energies for several isomers of both molecules were also computed. One of the key findings of this study is that acetone is observed upon decomposition of DMA in the neutral as well as in the ion and both point to a Wolff rearrangement to occur. However, the ion is subject to other decomposition channels favored at lower internal energies.

Electronic spectroscopy of 1-(phenylethynyl)naphthalene.

Recently 1-(phenylethynyl)naphthalene (1-PEN) was suggested to be the primary dimerization product of phenylpropargyl radicals and therefore an important polycyclic hydrocarbon in combustion processes. Here we describe a spectroscopic investigation of a genuine 1-PEN sample by several complementary techniques, infrared spectroscopy, multiphoton ionization (MPI), and threshold photoelectron spectroscopy. The infrared spectrum recorded in a gas cell confirms that 1-PEN is indeed the previously observed dimerization product of phenylpropargyl. The origin of the transition into the electronically excited S1 state lies at 30823 cm(-1), as found by MPI. Considerable vibrational activity is observed, and a number of low-wavenumber bands are assigned to a progression in the torsional motion. Values of 6 cm(-1) (S0) and 17 cm(-1) (S1) were derived for the fundamental of the torsion. In the investigated energy range the excited state lifetimes are in the nanosecond range. Spectra of the 1-PEN/Ar cluster exhibit a red shift of the electronic origin of 22 cm(-1), in good agreement with other aromatic molecules. A threshold photoelectron spectrum recorded using synchrotron radiation yields an ionization energy of 7.58 eV for 1-PEN. An excited electronic state of the cation is found at 7.76 eV, and dissociative photoionization does not set in below 15 eV.

The electronic structure of pyracene: a spectroscopic and computational study.

We report a synthetic, spectroscopic and computational study of the polycyclic aromatic molecule pyracene, which contains aliphatic five-membered rings annealed to a naphthalene chromophore. An improved route to synthesize the compound is described. Gas-phase IR and solid-state Raman spectra agree with a ground-state D2h structure. The electronically excited S1 A(1)B3u state has been studied by resonance-enhanced multiphoton ionisation. An adiabatic excitation energy T0 = 30,798 cm(-1) (3.818 eV) was determined. SCS-ADC(2) calculations found a D2h minimum energy structure of the S1 state and yielded an excitation energy of +3.98 eV, including correction for zero point vibrational energy. The spectrum shows a rich low-frequency vibrational structure that can be assigned to the overtones of out-of-plane deformation modes of the five-membered rings by comparison with computations. The appearance of these modes as well as the frequency reduction in the excited state indicate that the potential in the S1 state is very flat. At higher excess energies most bands can be assigned to fundamentals, overtones and combination bands of either totally symmetric ag modes or of b2g modes that appear due to vibronic coupling. Lifetimes between 43 ns and 76 ns were measured for a number of vibronic bands. For the S2 state an equilibrium geometry with a non-planar carbon framework was computed. In addition a signal from the pyracene dimer was present. The spectrum shows several broad and structureless transitions. The origin band has a maximum at around 329 nm (30,400 cm(-1)). Again lifetimes between 60 ns and 70 ns were found. The dimer ion signal rises within less than 10 ps. Computations show that a crossed geometry with the long axis of one unit aligned with the short axis of the second constitutes the most stable structure. The broadening of the bands is most likely caused by excimer formation.

Threshold photoionization of fluorenyl, benzhydryl, diphenylmethylene, and their dimers.

Two π-conjugated radicals, fluorenyl (C13H9) and benzhydryl (C13H11), as well as the carbene diphenylmethylene (C13H10) were studied by imaging photoelectron-photoion coincidence spectroscopy using VUV synchrotron radiation. The reactive intermediates were generated by flash pyrolysis from 9-bromofluorene and α-aminodiphenylmethane (adpm), respectively. Adiabatic ionization energies (IEad) for all three species were extracted. Values of 7.01 ± 0.02 eV for fluorenyl and 6.7 ± 0.1 eV for benzhydryl are reported. For the triplet diphenylmethylene, an IEad of 6.8 ± 0.1 eV is found. The dissociative photoionization of 9-bromofluorene, the precursor for fluorenyl, was also studied and modeled with an SSACM approach, yielding an appearance energy AE0K(C13H9(+)/C13H9Br) of 9.4 eV. All experimental values are in very good agreement with computations. For fluorenyl, the IEad agrees well with earlier values, while for the benzhydryl radical, we report a value that is more than 0.6 eV lower than the one previously reported. The geometry change upon ionization is small for all three species. Although individual vibrational bands cannot be resolved, some vibrational transitions in the threshold photoelectron spectrum of fluorenyl are tentatively assigned based on a Franck-Condon simulation. In addition, the dimerization products of fluorenyl and the benzhydryl radical were detected. Ionization energies of (7.69 ± 0.04) and (8.11 ± 0.04) eV were determined for C26H18 and C26H22, respectively. On the basis of the ionization energies, we identified both molecules to be the direct dimerization products, formed in the pyrolysis without further rearrangement. Both dimers might be expected to play a role in soot formation because the radical monomers do appear in flames.

H2CN+ and H2CNH+: new insight into the structure and dynamics from mass-selected threshold photoelectron spectra.

In this paper, we reinvestigate the photoionization of nitrogen containing reactive intermediates of the composition H2CN and H2CNH, molecules of importance in astrochemistry and biofuel combustion. In particular, H2CN is also of considerable interest to theory, because of its complicated potential energy surface. The species were generated by flash pyrolysis, ionized with vacuum ultraviolet synchrotron radiation, and studied by mass-selected threshold photoelectron (TPE) spectroscopy. In the mass-selected TPE-spectrum of m/z = 28, contributions of all four isomers of H2CN were identified. The excitation energy to the triplet cation of the methylene amidogen radical H2CN was determined to be 12.32 eV. Considerable activity in the C-N mode of the cation is visible. Furthermore, we derived values for excitation into the triplet cations of 11.72 eV for cis-HCNH, 12.65 eV for trans-HCNH, and 11.21 eV for H2NC. The latter values are probably accurate to within one vibrational quantum. The spectrum features an additional peak at 10.43 eV that corresponds to excitation into the C(2v)-symmetric H2CN(+). As this structure constitutes a saddle point, the peak is assigned to an activated complex on the singlet potential energy surface of the cation, corresponding to a hydrogen atom migration. For methanimine, H2CNH, the adiabatic ionization energy IE(ad) was determined to be 9.99 eV and the vibrational structure of the spectrum was analyzed in detail. The uncertainty of earlier values that simply assigned the signal onset to the IE(ad) is thus considerably reduced. The spectrum is dominated by the H-N-C bending mode ν1(+) and the rocking mode ν3(+). All experimental data were supported by calculations and Franck-Condon simulations.

Long-term Outcome of Pediatric Liver Transplant Recipients Who Have Reached Adulthood: A Single-center Experience.

BACKGROUND: As long-term survival of pediatric liver transplant recipients increases, the assessment of physical, psychological, and social well-being becomes more important. METHODS: In this retrospective analysis, 120 young adult patients (age ≥18 y) who underwent liver transplantation in childhood were studied. Patients with ideal outcome were defined as patients with perfect graft function, with no complications from the immunosuppressive medication, no late retransplantation, and no steroid treatment. Also, the patients' drug adherence and their psychosocial situation were assessed. RESULTS: After a median follow-up of 19 y, only 16.7% of the patients (mean age: 26.5 y) were considered patients with ideal outcome. The main reasons precluding ideal outcome were chronic kidney disease (38.3%), elevated liver enzymes (33.3%), and arterial hypertension (31.7%). Ideal outcome decreased over time from 54% to 42%, 26%, and 8% at 10-, 15-, 20-, and 25-y follow-up, respectively. Reduced drug adherence was noted in 24.8% of patients and associated with a significantly higher prevalence of donor-specific antibodies class II ( P = 0.015), elevated transaminases ( P = 0.010), and chronic rejection ( P < 0.001). Also, 15% of patients had a psychiatric disease, mainly depression. CONCLUSIONS: The morbidity of young adults who underwent liver transplantation as children was high and increased over time. The majority developed complications from immunosuppression or chronic graft dysfunction. More than 1 in 7 patients had a psychiatric disease and 1 in 4 was not perfectly drug adherent. Therefore, immunosuppressive treatment and psychological care should be optimized for these particularly vulnerable patients.