Dynamic strain evolution in an optically excited Pt thin film.

The structural evolution of a Pt thin film following photo-thermal excitation by 1 ps optical laser pulses was studied with a time resolution of 100 ps over a total time period of 1 ms. Laser pulse fluences below 50 mJ/cm2 were insufficient to relax the residual stress state of the as-prepared film even after 10 000 pulses. In this fluence regime, a rapid initial lattice expansion and a decrease in the lattice coherence length due to ultrafast photo-thermal heating were observed. The lattice expansion reached a maximum, and the coherence length reached a minimum, 100-200 ps after excitation before monotonically decaying back to their initial values in about 1 µs. Laser pulse fluences greater than 50 mJ/cm2 produced irreversible stress relaxation within the first 10 optical pulses. In this regime, the lattice expansion was qualitatively similar to that in the low fluence regime, except that the initial structural state was not recovered. The evolution in the coherence length, however, was more complex. Following an initial decrease similar to that observed at low fluence, the coherence length then increased to a broad maximum greater than the initial value, before recovery.

The rates of second lung cancers and the survival of surgically-resected second primary lung cancers in patients undergoing resection of an initial primary lung cancer.

BACKGROUND: The Lung Cancer Screening Trial demonstrated improved overall survival (OS) and lung cancer specific survival (LCSS), likely due to finding early-stage NSCLC. The purpose of our investigation is to evaluate whether long-term surveillance strategies (4+ years after surgical resection of the initial lung cancer(1LC)) would be beneficial in NSCLC patients by assessing the rates of second lung cancers(2LC) and the OS/LCSS in patients undergoing definitive surgery in 1LC as compared to 2LC (>48 months after 1LC) populations. METHODS: SEER13/18 database was reviewed for patients during 1998-2013. Log-rank tests were used to determine the OS/LCSS differences between the 1LC and 2LC in the entire surgical group(EG) and in those having an early-stage resectable tumors (ESR, tumors <4 cm, node negative). Joinpoint analysis was used to determine rates of second cancers 4-10 year after 1LC using SEER-9 during years 1985-2014. RESULTS: The rate of 2LCs was significantly less than all other second cancers until 2001 when the incidence of 2LCs increased sharply and became significantly greater than all other second cancers in females starting in year 2005 and in men starting in year 2010. OS/LCSS, adjusted for propensity score by using inverse probability weighting, demonstrated similar OS, but worse LCSS for 2LCs in the EG, but similar OS/LCSSs in the ESR group. CONCLUSION: Because the rate of 2LCs are increasing and because the OS/LCSS of the 1LC and 2LC are similar in early-stage lesions, we feel that continued surveillance of patients in order to find early-stage disease may be beneficial.

Pump-probe spectrometer for measuring x-ray induced strain.

A hard x-ray pump-probe spectrometer using a multi-crystal Bragg reflector is demonstrated at a third generation synchrotron source. This device derives both broadband pump and monochromatic probe pulses directly from a single intense, broadband x-ray pulse centered at 8.767 keV. We present a proof-of-concept experiment which directly measures x-ray induced crystalline lattice strain.

Transient crystalline superlattice generated by a photoacoustic transducer.

Designing an efficient and simple method for modulating the intensity of x-ray radiation on a picosecond time-scale has the potential to produce ultrafast pulses of hard x-rays. In this work, we generate a tunable transient superlattice, in an otherwise perfect crystal, by photoexciting a metal film on a crystalline substrate. The resulting transient strain has amplitudes approaching 1%, wavevectors greater than [Formula: see text], and lifetimes approaching 1 ns. This method has the potential to generate isolated picosecond x-ray bursts with scattering efficiencies in excess of 10%.

Social media: the way forward or a waste of time for physicians?

Social media is everywhere; its use has grown exponentially over recent years. The prevalence of these outlets for communication raises some interesting and potentially risky issues for physicians. On the one hand, some believe that physicians should have a strong social media presence and can benefit greatly from access to a global community of peers and leaders through blogs, online forums, Facebook, Twitter and other communication channels. Dr Anne Marie Cunningham provides a strong case for the advantages of developing networks and figuring out who and what to pay attention to online. On the other hand however, others believe that the use of social media places doctors at a professional and ethical risk and is essentially a waste of time for the already time-pressured physician. Professor DeCamp argues that the risks of social media outweigh their benefits. It makes it more difficult to maintain a distinction between private and professional personas, and as we have seen, one mistyped or inappropriate comment can have potentially negative consequences when taken out of context. With an already time-pressured day, the priority should be patients, not tweets. Whatever your thoughts on the benefits and risks of social media, it is here to stay. Specific guidelines and guidance are needed to ensure that physicians who decide to join an online community reap the benefits of global communication, rather than regret it.

Electron shell ionization of atoms with classical, relativistic scattering.

We investigate forward scattering of ionization from neon, argon, and xenon in ultrahigh intensities of 2 × 10(19) W/cm(2). Comparisons between the gases reveal the energy of the outgoing photoelectron determines its momentum, which can be scattered as far forward as 45° from the laser wave vector k(laser) for energies greater than 1 MeV. The shell structure in the atom manifests itself as modulations in the photoelectron yield and the width of the angular distributions. We arrive at an agreement with theory by using an independent electron model for the atom, a dipole approximation for the bound state interaction, and a relativistic, three-dimensional, classical radiation field including the laser magnetic field. The studies provide the atomic physics within plasmas, radiation, and particle acceleration in ultrastrong fields.

Confirmation of the role of diabetes in the local recurrence of surgically resected non-small cell lung cancer.

PURPOSE: We recently demonstrated that diabetes mellitus was an independent risk factor for local recurrence (LR) for patients undergoing resection of non-small cell lung cancer (NSCLC). This investigation was performed to confirm or refute this finding in a different patient cohort. MATERIALS AND METHODS: Patients were eligible if they did not have a second primary cancer within 5 years of the original diagnosis, had at least 3-month follow-up, and did not receive radiotherapy. There were 373 and 168 patients in the original (P1) and confirmatory (P2) cohorts, respectively, with 66 and 30 patients with diabetes. RESULTS: The median follow-up was 33 months (range, 3-98 months). Diabetes was an independent risk factor for LR in a Cox model in both the P2 (p=0.05, hazard ratio [HR] 2.15) and P1 (p=0.008, HR 1.90) cohorts, separately from BMI, glucose control, and the presence of the metabolic syndrome. The rates of LR in the patients with diabetes after combining the cohorts at 2, 3, and 5 years were 23%, 33%, and 56%, respectively; these rates were 15%, 19%, and 26% in non-diabetics. In multivariate Cox regression and competing risk analysis of the combined cohorts, the HRs for LR in patients with diabetes exceeded those of more established risk factors for LR including a 1-cm increase in tumor size and lymphovascular invasion. CONCLUSIONS: Diabetes was confirmed to be an independent predictor of the risk of LR following resection of NSCLC.

Coherent optical phonon generation in Bi3Ge4O12.

Time-domain spectroscopy of coherent optical phonons in bismuth germinate (Bi4Ge3O12) is presented. Utilizing both impulsive stimulated Raman scattering and time-domain terahertz spectroscopy, more than 12 unique vibrational states ranging in frequency from 2 to 11 THz are identified, each with coherent lifetimes ranging from 1 to 20 ps. These modes are highly sensitive to crystal orientation and demonstrate frequency shifts on picosecond timescales consistent with an anharmonic lattice potential.

Pregnancy outcomes in 188 French cases of prenatally diagnosed Klinefelter syndrome.

BACKGROUND: Klinefelter syndrome (KS), a common sex chromosome aneuploidy (47,XXY) is diagnosed prenatally with an incidence of 0.15%. The diagnosis is generally incidental, since there are no typical malformations on ultrasound (US). Once detected, genetic counseling is often difficult and the parents' decision to continue or terminate the pregnancy is greatly dependent on the amount and nature of the information provided. We sought to assess the pregnancy outcomes (i.e. continuation versus termination) and the influence of multidisciplinary centers for prenatal diagnosis on parental decisions in cases of KS. METHODS: From 1985 to 2009, 188 prenatal diagnoses of KS were made by 11 participating laboratories in mainland France. In each case, the karyotype indication, parental ages, year of prenatal testing, sampling procedure, karyotype, associated US findings and outcome were recorded. RESULTS AND CONCLUSIONS: The pregnancy termination rate declined markedly over time, from 46.9% before 1997 to 11.6% thereafter, in line with the introduction of new legislation on prenatal diagnosis for medical reasons and, more specifically, the creation of multidisciplinary prenatal diagnosis centers. However, an additional microdeletion in one KS infant who exhibited echogenic bowel on US was unfortunately diagnosed postnatally. This raises the question as to whether array comparative genomic hybridization should be prenatally advised when US abnormalities are detected, in line with advice for fetuses with a normal karyotype.

Subcarinal collection following mediastinoscopy: a normal post-procedural CT finding.

AIM: To determine the frequency with which a subcarinal collection is present at computed tomography (CT) following mediastinoscopy and to determine the CT features of the collection. MATERIALS AND METHODS: All patients who underwent uncomplicated mediastinoscopy during a 1-year period were retrospectively identified. This list was cross-referenced to determine those patients who also underwent CT within 15 days after the procedure. Each post-mediastinoscopy CT examination was assessed in consensus by three fellowship-trained thoracic radiologists for the presence of subcarinal abnormalities, which were also characterized in terms of their size and density. Additional CT findings were recorded, including tracheobronchial wall thickening, paratracheal collections, mediastinal fat stranding, and mediastinal air. RESULTS: The study cohort included 10 patients (seven men and three women) with mean age of 65 years (range 49-81 years). CT was performed a mean of 11 days following mediastinoscopy. The most common CT finding was an oval subcarinal collection in nine of 10 cases (size 1.1-3.2 cm). In all nine cases, the subcarinal collections were consistently lower in attenuation than the subcarinal lymph node in the same region on the pre-procedure CT examination. Other CT findings included anterior tracheobronchial wall thickening (n=7); paratracheal collection (n=6); mediastinal fat stranding (n=6); and mediastinal air in (n=4) cases. CONCLUSION: A subcarinal collection was identified in 90% of cases following mediastinoscopy. Its rapid development and characteristic appearance help to distinguish it from a lymph node.

Ionization of methane in strong and ultrastrong relativistic fields.

The photoionization of methane is reported for intensities up to 10(19) W/cm2 with linear and circular polarized light. While fragmental ions (e.g., CH3+, CH+, C+, C2+) created from 10(14) W/cm2 to 10(15) W/cm2 are formed by Coulomb explosion, ionization to form C3+ and C4+ involves Coulomb explosion and tunneling ionization. In ultrastrong fields, removal of a carbon K-shell electron from methane proceeds via tunneling and rescattering ionization, without the influence of molecular channels. Photoelectrons from methane at 10(19) W/cm2 extend up to kinetic energies of 0.6 MeV.

Amide I vibrational dynamics of N-methylacetamide in polar solvents: the role of electrostatic interactions.

The vibrational frequency of the amide I transition of peptides is known to be sensitive to the strength of its hydrogen bonding interactions. In an effort to account for interactions with hydrogen bonding solvents in terms of electrostatics, we study the vibrational dynamics of the amide I coordinate of N-methylacetamide in prototypical polar solvents: D2O, CDCl3, and DMSO-d6. These three solvents have varying hydrogen bonding strengths, and provide three distinct solvent environments for the amide group. The frequency-frequency correlation function, the orientational correlation function, and the vibrational relaxation rate of the amide I vibration in each solvent are retrieved by using three-pulse vibrational photon echoes, two-dimensional infrared spectroscopy, and pump-probe spectroscopy. Direct comparisons are made to molecular dynamics simulations. We find good quantitative agreement between the experimentally retrieved and simulated correlation functions over all time scales when the solute-solvent interactions are determined from the electrostatic potential between the solvent and the atomic sites of the amide group.

Incidence of primary neoplasms in explanted lungs: long-term follow-up from 214 lung transplant patients.

BACKGROUND: Undetected neoplasms in explanted lungs at transplantation are an unusual occurrence that may significantly complicate both the short- and long-term outcome of these patients. The incidence and survival of undetected primary neoplasms in explanted lungs with clinical and radiologic correlation have not been studied in a large cohort of patients. METHODS: We reviewed the files of 214 consecutive lung transplants from the Transplant Center at the Cleveland Clinic Foundation from 1991 to 2000. Data collected included age, gender, pathology of explanted lung, and survival. Retrospective review of all imaging studies was performed in those cases where a primary neoplasm was detected after transplant. RESULTS: One hundred thirteen males and 101 females underwent lung transplantation for the following diagnoses: emphysema, 118; cystic fibrosis, 35; primary pulmonary hypertension, 27; usual interstitial pneumonia, 26; lymphangioleiomyomatosis, 4; sarcoidosis, 2; and pneumoconiosis, 2. Four neoplasms were found in the explanted lungs, representing a 2% incidence. All four neoplasms were bronchogenic carcinomas, including three adenocarcinomas and one squamous cell carcinoma. Three of four neoplasms were found in the setting of emphysema and were detected at an early stage (stage I), and the fourth presented as stage IV in the setting of usual interstitial fibrosis. No recurrence of tumor was seen in the stage I cases. The stage IV case died in the perioperative period. Retrospective review of the imaging studies showed that, in all four cases, a portable chest radiograph performed immediately before transplant failed to identify the lesions. A chest computerized tomogram was performed in all four cases from 3 to 27 months prior to transplantation and revealed a suspicious lesion in one of the four. CONCLUSIONS: Undetected neoplasms in explanted lungs at transplantation are uncommon, with an incidence of 2% at our institution. Adenocarcinoma was the most common cell type. In long-term survivors, no recurrences were found. The 3-year survival was 50% and this approaches the 3-year survival of transplant recipients without lung tumors (58.8%) at our institution. Chest radiographs appear to have a very low sensitivity for the detection of small lesions suspicious for a neoplasm. Chest computerized tomograms performed immediately prior to transplantation may be of benefit in detecting these neoplasms.

Transient strain driven by a dense electron-hole plasma.

We measure transient strain in ultrafast laser-excited Ge by time-resolved x-ray anomalous transmission. The development of the coherent strain pulse is dominated by rapid ambipolar diffusion. This pulse extends considerably longer than the laser penetration depth because the plasma initially propagates faster than the acoustic modes. X-ray diffraction simulations are in agreement with the observed dynamics.

The incidence of invasive aspergillosis among solid organ transplant recipients and implications for prophylaxis in lung transplants.

BACKGROUND: Invasive aspergillosis (IA) is associated with significant morbidity and mortality in solid organ transplant recipients but data on the incidence rates stratified by type of solid organ are limited. OBJECTIVE: To describe the attack rates and incidence of IA in solid organ transplant recipients, and the impact of universal Aspergillus prophylaxis (aerosolized amphotericin B or oral itraconazole) in lung transplant recipients. PATIENTS: The 2,046 patients who received solid organ transplants at the Cleveland Clinic Foundation from January 1990 through 1999 were studied. METHODS: Cases were ascertained through computerized records of microbiology, cytology, and pathology reports. Definite IA was defined as a positive culture and pathology showing septate hyphae. Probable IA was clinical disease and either a positive culture or histopathology. Disseminated IA was defined as involvement of two or more noncontiguous anatomic sites. RESULTS: We identified 33 cases of IA (28% disseminated) in 2,046 patients (attack rate = 1.6%) for an incidence of 4.8 cases per 1,000 patient-years (33 cases/6,813 pt-years). Both the attack and the incidence rates were significantly higher for lung transplant recipients vs. other transplant recipients: lung 12.8% (24 cases/188 patients) or 40.5 cases/1,000-pt year vs. heart 0.4% (3/686) or 1.4 per 1,000-pt year vs. liver 0.7% (3/439) or 2.1 per 1,000-pt year vs. renal 0.4% (3/733) or 1.2 per 1,000-pt year (P < 0.01). The incidence of IA was highest during the first year after transplantation for all categories, but cases occurred after the first year of transplantation only in lung transplant recipients. The attack rate of IA in lung transplant recipients was significantly lower after institution of routine Aspergillus prophylaxis (4.9% vs. 18.2%, P < 0.05). CONCLUSIONS: The highest incidence and attack rate of invasive aspergillosis among solid organ transplant recipients occurs in lung transplant recipients and supports the routine use of Aspergillus prophylaxis for at least one year after transplantation in this group.

Superficial adenocarcinoma of the esophagus.

OBJECTIVE: Experience with treatment and outcome of superficial adenocarcinoma of the esophagus is limited. The purpose of this study was to evaluate the results of surgical management and identify predictors of survival. METHODS: Between September 1985 and December 1999, 122 patients underwent resection. Eighty-nine percent were men (mean age 63 +/- 10 years; range 35-83 years). Sixty (49%) patients were in endoscopic surveillance programs and 48 (39%) had the preoperative diagnosis of high-grade dysplasia. Forced expiratory volume in 1 second was less than 2 L in 12 (12%). Seventy-five (61%) patients underwent transhiatal esophagectomy. Pathologic stage was N1 in 8 (7%). Pulmonary complications necessitating reintubation (respiratory failure) occurred in 10 (8%) patients. Time-related survival models were developed for decision-making (preoperative), prognosis (operative), and hospital care (postoperative). RESULTS: Operative mortality was 2.5%. Survival at 1, 5, and 10 years was 89%, 77%, and 68%. Preoperative decision-making factors associated with ideal outcome were 1-second forced expiratory volume of more than 2 L, surveillance, preoperative diagnosis of high-grade dysplasia, and planned transhiatal esophagectomy. Prognosis was decreased in younger patients and in those with N1 disease. Postoperative respiratory failure increased mortality. CONCLUSIONS: Surgery is the treatment of choice for superficial adenocarcinoma of the esophagus. The ideal patient has a preoperative diagnosis of high-grade dysplasia found at surveillance, good pulmonary function, and undergoes a transhiatal esophagectomy. Discovery of N1 disease or development of postoperative respiratory failure reduces the benefits of surgery.

Coherent control of pulsed X-ray beams.

Synchrotrons produce continuous trains of closely spaced X-ray pulses. Application of such sources to the study of atomic-scale motion requires efficient modulation of these beams on timescales ranging from nanoseconds to femtoseconds. However, ultrafast X-ray modulators are not generally available. Here we report efficient subnanosecond coherent switching of synchrotron beams by using acoustic pulses in a crystal to modulate the anomalous low-loss transmission of X-ray pulses. The acoustic excitation transfers energy between two X-ray beams in a time shorter than the synchrotron pulse width of about 100 ps. Gigahertz modulation of the diffracted X-rays is also observed. We report different geometric arrangements, such as a switch based on the collision of two counter-propagating acoustic pulses: this doubles the X-ray modulation frequency, and also provides a means of observing a localized transient strain inside an opaque material. We expect that these techniques could be scaled to produce subpicosecond pulses, through laser-generated coherent optical phonon modulation of X-ray diffraction in crystals. Such ultrafast capabilities have been demonstrated thus far only in laser-generated X-ray sources, or through the use of X-ray streak cameras.

Contralateral pulmonary artery stenosis after left pneumonectomy.

Contralateral pulmonary artery stenosis is a rare complication following pneumonectomy. When extensive intrapericardial dissection is warranted, one must be wary of this potential complication and take measures to avoid it. Postoperatively, a high index of suspicion must be maintained in a patient with a new onset of right-sided heart failure after intrapericardial pneumonectomy. We discuss intraoperative risk factors, postoperative clinical findings, and our strategy for repair.