Demonstration of Machine Learning-Based Model-Independent Stabilization of Source Properties in Synchrotron Light Sources.

Synchrotron light sources, arguably among the most powerful tools of modern scientific discovery, are presently undergoing a major transformation to provide orders of magnitude higher brightness and transverse coherence enabling the most demanding experiments. In these experiments, overall source stability will soon be limited by achievable levels of electron beam size stability, presently on the order of several microns, which is still 1-2 orders of magnitude larger than already demonstrated stability of source position and current. Until now source size stabilization has been achieved through corrections based on a combination of static predetermined physics models and lengthy calibration measurements, periodically repeated to counteract drift in the accelerator and instrumentation. We now demonstrate for the first time how the application of machine learning allows for a physics- and model-independent stabilization of source size relying only on previously existing instrumentation. Such feed-forward correction based on a neural network that can be continuously online retrained achieves source size stability as low as 0.2 µm (0.4%) rms, which results in overall source stability approaching the subpercent noise floor of the most sensitive experiments.

Correlation-Driven Insulator-Metal Transition in Near-Ideal Vanadium Dioxide Films.

We use polarization- and temperature-dependent x-ray absorption spectroscopy, in combination with photoelectron microscopy, x-ray diffraction, and electronic transport measurements, to study the driving force behind the insulator-metal transition in VO_{2}. We show that both the collapse of the insulating gap and the concomitant change in crystal symmetry in homogeneously strained single-crystalline VO_{2} films are preceded by the purely electronic softening of Coulomb correlations within V-V singlet dimers. This process starts 7 K (±0.3 K) below the transition temperature, as conventionally defined by electronic transport and x-ray diffraction measurements, and sets the energy scale for driving the near-room-temperature insulator-metal transition in this technologically promising material.

Routine labour epidural analgesia versus labour analgesia on request: a randomised non-inferiority trial.

OBJECTIVE: To assess the effect on mode of delivery of the routine use of labour epidural analgesia (EA) compared with analgesia on request. DESIGN: Randomised non-inferiority trial. SETTING: One university and one non-university teaching hospital in The Netherlands. POPULATION: Women with a singleton pregnancy in cephalic presentation beyond 36 + 0 weeks' gestation. METHODS: Participants were randomly allocated to receive either routine EA or analgesia on request. Intention-to-treat (ITT) and per-protocol (PP) analyses were performed, with confidence intervals (CI) calculated for the differences in percentages or means. MAIN OUTCOME MEASURES: Rate of operative delivery (instrumental vaginal or caesarean), labour characteristics, and adverse labour and neonatal outcomes. RESULTS: A total of 488 women were randomly allocated to the routine EA (n = 233) or analgesia on request group (n = 255). In the routine EA group, 89.3% (208/233) received EA. According to ITT analysis, 34.8% (81/233) women in the routine EA group had an operative delivery, compared with 26.7% (68/255) in the analgesia on request group (difference 8.1%, 95% CI -0.1 to 16.3). The difference in rate of operative deliveries according to the PP analysis was statistically significant (difference 8.9%, 95% CI 0.4 to 17.4). Inferiority of EA could not be rejected, as in both analyses the upper bound of the confidence interval exceeded the pre-specified inferiority criterion of +10%. Women in the routine EA group had more adverse effects, including hypotension (difference 9.5%, 95% CI 4.2 to 14.9), and motor blockade (difference 6.8%, 95% CI 1.1 to 12.5). CONCLUSION: Non-inferiority of routine EA could not be demonstrated in this trial. Routine EA use is likely to lead to more operative deliveries and more maternal adverse effects. The results of our study do not justify routine use of EA.

Neonatal sepsis is mediated by maternal fever in labour epidural analgesia.

Women delivering with EA (EA group) were matched on parity with 453 women with deliveries without EA (non-EA group). Significantly more neonates born in the EA-group had fever ≥ 38.0°C (11.6% vs 1.8%, p < 0.001) at birth. The overall incidence of neonatal sepsis, based on clinical symptoms and defined as proven (by a positive blood culture) or suspected (no positive blood culture), was significantly higher in the EA group (6.0% vs 2.2%; p = 0.002), but the incidence of proven neonatal sepsis alone was not (0.4% vs 0%; p = 0.250). EA turned out to be an independent risk factor for neonatal sepsis (adjusted OR 2.43, 95% CI 1.15-5.13; p = 0.020). However, in the EA group as well as the non-EA group, the incidence of neonatal sepsis was significantly higher in mothers with intrapartum fever compared with afebrile mothers (11.0% vs 2.9% in the EA group; p = 0.004; 8.2% vs 1.3% in the non-EA group; p = 0.006). Therefore we conclude, that the positive association between neonatal sepsis and labour EA is possibly mediated by maternal intrapartum fever.

Platelet concentrate transport in pneumatic tube systems--does it work?

Blood sample transport via pneumatic tube systems (PTS) reduces the turnaround time of laboratories, but it might influence analysis results. Its effect on platelet concentrates (PCs) is not known. Platelet function was investigated after single and multiple PTS transport in comparison with storage and irradiation. Optical and impedance aggregation, CD-62, and microparticles changed as a result of storage, but not due to transport. Irradiation lowered platelet function independently. Multiple transport impaired thrombin receptor-activating peptide-induced aggregation. This investigation demonstrates the feasibility of PTS transport. As platelet function depends on storage, it may be more important to transfuse fresh PCs.

Perioperative dilutional coagulopathy treated with fresh frozen plasma and fibrinogen concentrate: a prospective randomized intervention trial.

BACKGROUND AND OBJECTIVES: Treatment of dilutional coagulopathy by transfusing fresh frozen plasma (FFP) remains sub-optimal. We hypothesized that partial replacement of transfused FFP by fibrinogen concentrate results in improved coagulant activity and haemostasis. This was tested in a controlled clinical intervention trial with patients experiencing massive bleeding during major surgery. METHODS: Patients undergoing major elective surgery were treated according to current protocols. When transfusion with FFP was required, patients were randomized as follows: group A received 4 units FFP and group B received 2 units FFP plus 2 g fibrinogen concentrate. Blood samples were taken before and after the intervention. Analysts were blinded to the treatment type. RESULTS: Group A (B) consisted of 21 (22) patients, in 16 (17) of whom bleeding stopped after intervention. Plasma fibrinogen increased significantly more in group B (0·57 g/l) than in group A (0·05 g/l). However, levels of prothrombin and factors VIII, IX and X increased more in group A than in group B. Rotational thromboelastometry (ROTEM) of whole blood and plasma revealed improved fibrin clot formation in group B but not in group A. Thrombin generation [calibrated automated thrombogram (CAT)] in plasma increased more in group A. Principal parameters determining whole-blood thromboelastometry were the fibrinogen level and platelet count. In vitro addition of fibrinogen and prothrombin complex concentrate to pre-intervention samples restored both ROTEM and CAT parameters. CONCLUSIONS: Partial replacement of transfused FFP by fibrinogen increases fibrin clot formation at the expense of less improved thrombin generation. Coagulation factors other than fibrinogen alone are required for full restoration of haemostasis.

Endotracheal intubation using videolaryngoscopy causes less cardiovascular response compared to classic direct laryngoscopy, in cardiac patients according a standard hospital protocol.

INTRODUCTION: Previous studies comparing Glidescope and classic direct laryngoscopy did not show an attenuation of CV responses to endotracheal intubation. In the present study, we hypothesize that indirect videolaryngoscopy can attenuate cardiovascular responses to endotracheal intubation. METHODS: In a randomized cross-over study, eighty adults (ASA PS II-III) were included. Both direct and indirect videolaryngoscopies were used in a random order, in the same patient. Cardiovascular responses to intubation were recorded as a relative change in rate pressure product (RPP = systolic blood pressure times heart rate) from baseline values. A linear mixed model was used to study the association between the outcome variable RPP and the type of laryngoscope used. RESULTS: The relative increase of the RPP at intubation was significantly smaller (i.e. 27%, P < 0.001) using videolaryngoscopy compared to the classic direct laryngoscopy. Cardiovascular responses were blunted by an additional 10.2% (P = 0.029), when the patient was on beta blockade. CONCLUSIONS: Our study shows less hemodynamic responses during endotracheal intubation using indirect videolaryngoscopy compared to classic direct laryngoscopy.

Early versus late epidural analgesia and risk of instrumental delivery in nulliparous women: a systematic review.

OBJECTIVE: Review of the literature regarding the relation between the timing of epidural analgesia and the rate of caesarean or instrumental vaginal deliveries. SEARCH STRATEGY: Pubmed, Embase and the Cochrane Library were searched for articles published until 31 July 2010. SELECTION CRITERIA: Studies were selected in which the effects of early latent phase (defined as a cervical dilatation of 3 cm or less) epidural analgesia (including combined-spinal epidural) and late active phase epidural analgesia on the mode of delivery in nulliparous women at 36 weeks of gestation or more were evaluated. DATA COLLECTION AND ANALYSIS: Data extraction was completed by using a data-extraction form. Risk ratio and its 95% confidence intervals were calculated for caesarean delivery and instrumental vaginal delivery. Pooled data were calculated. MAIN RESULTS: The search retrieved 20 relevant articles, of which six fulfilled the selection criteria of inclusion. These six studies reported on 15,399 nulliparous women in spontaneous or induced labour with a request for analgesia. Risk of caesarean delivery (pooled risk ratio 1.02, 95% CI 0.96-1.08) or instrumental vaginal delivery (pooled risk ratio 0.96, 95% CI 0.89-1.05) was not significantly different between groups. AUTHORS' CONCLUSIONS: This systematic review showed no increased risk of caesarean delivery or instrumental vaginal delivery for women receiving early epidural analgesia at cervical dilatation of 3 m or less in comparison with late epidural analgesia.

Predictors of physical and emotional recovery 6 and 12 months after surgery.

BACKGROUND: A proportion of patients do not recover fully from surgery or they develop chronic postsurgical pain. The aim of this study was to examine the incidence and predictors of unfavourable long-term outcome after surgery using a prospective cohort design. METHODS: Some 401 patients undergoing various elective surgical procedures filled in the RAND 36-item Health Survey 1.0 health-related quality-of-life questionnaire before operation and at 6 and 12 months of follow-up to assess changes in pain, physical functioning, mental health and vitality. Preoperative psychological assessment was obtained. RESULTS: Most patients showed improvement in the various aspects of health-related quality of life after surgery, but a considerable proportion (14-24 per cent) still showed deterioration at 6 and 12 months. Multivariable linear regression analysis identified acute postoperative pain, duration of the operation and preoperative physical condition as the most important predictors of long-term pain and physical functioning. Preoperative surgical fear also had a small but significant contribution. The main predictors of mental health and vitality were physical condition before surgery, surgical fear and optimism. CONCLUSION: Up to a quarter of patients experienced suboptimal recovery after surgery. Both somatic and psychological factors were associated with the long-term outcome. Optimal recovery could be promoted by effective interventions on malleable factors.

[Old and new anticoagulants. Antidotes and measures for acute hemorrhaging and urgent interventions]. / Alte und neue Gerinnungshemmer. Antidota und Massnahmen bei akuter Blutung sowie dringenden Eingriffen.

Anticoagulation medications are frequently used for primary and secondary treatment of several thrombo-embolic disorders. An important side effect of all anticoagulants is hemorrhagic diathesis which necessitates acute treatment, ideally using medicinal therapy with an antidote. Much experience has been gained in treating bleeding while on traditional anticoagulants, such as heparins and vitamin K antagonists by the use of antagonists. A multitude of factor-specific anticoagulants have recently been introduced or will soon receive approval. With this new generation of anticoagulants no valid laboratory parameters or effective antagonists are presently available. Due to a lack of adequate studies regarding acute treatment this can at present only be carried out on a symptomatic basis.

Kinetic resonance Raman spectroscopy: dynamics of deprotonation of the Schiff base of bacteriorhodopsin.

We have developed a kinetic technique, combining resonance Raman spectroscopy and variable-speed continuous flow methods, to study molecular dynamics of isolated sites in macromolecules. Kinetic resonance Raman spectra of the retinylidence chromophore of bacteriorhodopsin have been obtained and the dynamics of the deprotonation of the Schiff base linkage is discussed.

Subpicosecond spectroscopy of bacteriorhodopsin.

Subpicosecond pulses have been used to study the ultrafast dynamics of the photochemistry of bacteriorhodopsin. An optically induced absorption that appears in about 1.0 picosecond at physiological temperatures has been resolved in time. The data can be interpreted in terms of the photochemical formation of bathobacteriorhodopsin and provide support for an excitation mechanisms involving molecular rearrangement in the protein induced by electron redistribution in the chromophore.

The prevalence of postoperative pain in a sample of 1490 surgical inpatients.

BACKGROUND AND OBJECTIVE: To measure the prevalence of postoperative pain, an assessment was made of 1490 surgical inpatients who were receiving postoperative pain treatment according to an acute pain protocol. METHODS: Measurements of pain (scores from 0 to 100 on a visual analogue scale) were obtained three times a day on the day before surgery and on days 0-4 postoperatively; mean pain intensity scores were calculated. Patients were classified as having no pain (score 0-5), mild pain (score 6-40), moderate pain (score 41-74) or severe pain (score 75-100). RESULTS: Moderate or severe pain was reported by 41% of the patients on day 0, 30% on days 1 and 19%, 16% and 14% on days 2, 3 and 4. The prevalence of moderate or severe pain in the abdominal surgery group was high on postoperative days 0-1 (30-55%). A high prevalence of moderate or severe pain was found during the whole of days 1-4 in the extremity surgery group (20-71%) and in the back/spinal surgery group (30-64%). CONCLUSION: We conclude that despite an acute pain protocol, postoperative pain treatment was unsatisfactory, especially after intermediate and major surgical procedures on an extremity or on the spine.

Hartmann characterization of the PEEM-3 aberration-corrected X-ray photoemission electron microscope.

Aberration correction by an electron mirror dramatically improves the spatial resolution and transmission of photoemission electron microscopes. We will review the performance of the recently installed aberration corrector of the X-ray Photoemission Electron Microscope PEEM-3 and show a large improvement in the efficiency of the electron optics. Hartmann testing is introduced as a quantitative method to measure the geometrical aberrations of a cathode lens electron microscope. We find that aberration correction leads to an order of magnitude reduction of the spherical aberrations, suggesting that a spatial resolution of below 100 nm is possible at 100% transmission of the optics when using x-rays. We demonstrate this improved performance by imaging test patterns employing element and magnetic contrast.

The CatWalk method: a detailed analysis of behavioral changes after acute inflammatory pain in the rat.

Experimental pain research is often complicated by the absence of an objective and detailed method to analyze behavioral changes. In the present study, acute pain was induced into the right knee of the rat (n=15) through the injection of 2mg carrageenan (CAR) in saline. A control group received vehicle injection into the knee (n=15). With the use of an automated quantitative gait analysis system, the CatWalk, it was possible to quantitatively analyze behavioral changes at post-injection time 2.5, 4, 24 and 48h. The CatWalk analysis of individual paw parameters like the intensity of the paw print or the time contact with the floor showed a significant effect after CAR injection into the knee. These CatWalk parameters were highly correlated with von Frey data and thus representative for the development of mechanical allodynia. Furthermore, detailed CatWalk analysis of the gait (i.e. coordinated interaction between left and right hindlimb) showed very fine, accurate and significant coordination changes in the experimental rats from 4h post-injection. In conclusion, the CatWalk method allows an objective and detailed detection of both pain-induced gait adaptations as well as the development of mechanical allodynia in an acute inflammatory pain model.

X-ray spectroscopic study of the charge state and local ordering of room-temperature ferromagnetic Mn-doped ZnO.

The charge state and local ordering of Mn doped into a pulsed laser deposited single-phase thin film of ZnO are investigated by using x-ray absorption spectroscopy at the O K-edge, Mn K-edge and L-edge, and x-ray emission spectroscopy at the O K-edge and Mn L-edge. This film is ferromagnetic at room temperature. EXAFS measurement shows that Mn(2+) replaces the Zn site in tetrahedral symmetry, and there is no evidence for either metallic Mn or MnO in the film. Upon Mn doping, the top of O 2p valence band extends into the bandgap, indicating additional charge carriers being created.

Cross-resistance responses of CrylAc-selected Heliothis virescens (Lepidoptera: Noctuidae) to the Bacillus thuringiensis protein vip3A.

One susceptible and three Cry1Ac-resistant strains of tobacco budworm, Heliothis virescens (F.) (Lepidoptera: Noctuidae), were used in laboratory studies to determine the level of cross-resistance between the Bacillus thuringiensis (Berliner) toxins Cry1Ac and Vip3A by using concentration-mortality and leaf tissue experiments. Concentration-mortality data demonstrated that the three Cry1Ac-resistant H. virescens strains, YHD2, KCBhyb, and CxC, were at least 215- to 316-fold resistant to Cry1Ac compared with the susceptible strain, YDK. Results from Vip3A concentration-mortality tests indicated that mortality was similar among all four H. virescens strains. Relative larval growth on Cry1Ac reflected concentration-mortality test results, because YHD2 larval growth was mostly unaffected by the Cry1Ac concentrations tested. Growth ratios for KCBhyb and CXC indicated that they had a more moderate level of resistance to Cry1Ac than did YHD2. Relative larval growth on Vip3A was highly variable at lower concentrations, but it was more consistent on concentrations of Vip3A above 25 microg/ml. Differences in larval growth among strains on Vip3A were not as pronounced as seen in Cry1Ac experiments. Mortality and larval growth also was assessed in leaf tissue bioassays in which YDK, CxC, and KCBhyb neonates were placed onto leaf disks from non-Bt and Bt cotton, Gossypium hirsutum L., for 5 d. Three Bt lines were used in an initial bioassay and consisted of two Vip3A-containing lines, COT203 and COT102, and a Cry1Ac-producing line. Mortality of KCBhyb and CXC was lower than that of YDK larvae in the presence of leaf tissue from the Cry1Ac-producing line. Additionally, increased larval growth and leaf tissue consumption on Cry1Ac-containing leaf disks was observed for KCBhyb and CXC. Mortality and larval weights were similar among strains when larvae were fed leaf tissue of either non-Bt, COT203, or COT102. A subsequent leaf tissue bioassay was conducted that evaluated four cotton lines: non-Bt, Cry1Ab-expressing, Vip3A-expressing, and pyramided-toxin plants that produced both Cry1Ab and Vip3A. Mortality levels were similar among strains when fed non-Bt, Vip3A-expressing, or pyramided-toxin leaf tissues. Mortality was higher for YDK than for KCBhyb or CXC on Cry1Ab-expressing leaf tissues. No differences in larval weights were observed among strains for any genotype tested. Results of these experiments demonstrate that cross-resistance is nonexistent between CrylAc and Vip3A in H. virescens. Thus, the introduction of Vip3A-producing lines could delay Cry1Ac-resistance evolution in H. virescens, if these lines gain a significant share of the market.

Evaluation of two different epidural catheters in clinical practice. narrowing down the incidence of paresthesia!

Although epidural anesthesia is considered safe, several complications may occur during puncture and insertion of a catheter. Incidences of paresthesia vary between 0.2 and 56%. A prospective, open, cohort-controlled pilot study was conducted in 188 patients, ASA I-III, age 19-87 years, scheduled for elective surgery and epidural anesthesia. We evaluated a 20 G polyamide (standard) catheter and a 20 G combined polyurethane-polyamide (new) catheter. Spontaneous reactions upon catheter-insertion, paresthesia on questioning, inadvertent dural or intravascular puncture, and reasons for early catheter removal were recorded. The incidence of paresthesia reported spontaneously was 21.3% with the standard catheter and 16.7% with the new catheter. Systematically asking for paresthesia almost doubled the paraesthesia rate. Intravascular cannulation occurred in 5%. No accidental dural punctures occurred. An overall incidence of 13.3% of technical problems led to early catheter removal. The new catheter was at least equivalent to the standard regarding epidural success rate and safety : rate of paresthesia, intravascular and dural cannulation.

Accuracy, Precision, and Trending Ability of Electrical Cardiometry Cardiac Index versus Continuous Pulmonary Artery Thermodilution Method: A Prospective, Observational Study.

INTRODUCTION: Evaluation of accuracy, precision, and trending ability of cardiac index (CI) measurements using the Aesculon™ bioimpedance electrical cardiometry (Aesc) compared to the continuous pulmonary artery thermodilution catheter (PAC) technique before, during, and after cardiac surgery. METHODS: A prospective observational study with fifty patients with ASA 3-4. At six time points (T), measurements of CI simultaneously by continuous cardiac output pulmonary thermodilution and thoracic bioimpedance and standard hemodynamics were performed. Analysis was performed using Bland-Altman, four-quadrant plot, and polar plot methodology. RESULTS: CI obtained with pulmonary artery thermodilution and thoracic bioimpedance ranged from 1.00 to 6.75 L min-1 and 0.93 to 7.25 L min-1, respectively. Bland-Altman analysis showed a bias between CIBIO and CIPAC of 0.52 liters min-1 m-2, with LOA of [-2.2; 1.1] liters min-1 m-2. Percentage error between the two techniques was above 30% at every time point. Polar plot methodology and 4-quadrant analysis showed poor trending ability. Skin incision had no effect on the results. CONCLUSION: CI obtained by continuous PAC and CI obtained by Aesculon bioimpedance are not interchangeable in cardiac surgical patients. No effects of skin incision were found. International clinical trial registration number is ISRCTN26732484.

Insulin sensitivity and serum triglyceride level in obese white and black women: relationship to visceral and truncal subcutaneous fat.

Although independent associations of visceral fat with the insulin resistance syndrome were previously reported in obese women, the importance of truncal subcutaneous fat with regard to insulin sensitivity is still controversial. We measured the insulin sensitivity index (S(I)), serum triglyceride (TG) level, and regional fat by two methods: (1) the sum of five truncal and four peripheral skinfolds (TrSUM and PerSUM) in 38 white and black obese nondiabetic premenopausal women, and (2) abdominal visceral (VFM) and subcutaneous fat mass (AbdSCFM) by a combination of magnetic resonance imaging (MRI) and dual x-ray absorptiometry (DXA) in a subset of 26 of these women. After adjusting for the total body fat mass, TrSUM and VFM were independently and negatively related to S(I) (n = 38, P < .012 and n = 26, P < .035, respectively), whereas PerSUM and AbdSCFM were not related (P > .50). Based on multiple regression modeling, TrSUM significantly predicted S(I) independently of the VFM (n = 26, P < .001). Black women had lower S(I) at all levels of TrSUM (n = 38, P = .061 for the slope and P = .03 for the intercept of the regression lines). After adjusting for the total body fat mass, only VFM showed an independent positive relation to serum TG, and race did not affect this relationship (n = 26, P < .001). In conclusion, (1) we confirmed the independent association of the VFM with insulin resistance and elevated TG in obese women; (2) the AbdSCFM measured by a combination of MRI and DXA did not show an independent association with S(I) in obese women; and (3) the independent association of TrSUM with S(I) suggests that truncal subcutaneous fat depots contribute to insulin resistance in obese women independently of the degree of visceral fat.