31P MAS NMR spectroscopy with 93Nb decoupling and DFT calculations: A structural characterization of defects in a niobium-phosphate phase.

The present study has investigated the structure of four niobium phosphates compounds using 31P MAS NMR spectroscopy. Niobium 93Nb decoupling, applied during 31P NMR acquisition led to a resolution enhancement by a factor of 2-3, which allowed distinguish phosphorous sites separated by 1 ppm or less. The assignment of 31P spectra has been completed by use of first-principles calculations derived from the original XRD structures. One of the compounds, Na3.04Nb7P4O29, contains a sodium vacancy, clearly revealed in the 31P MAS spectrum obtained with 93Nb decoupling. A series of structural models were proposed to account for the sodium distribution in the structure of Na3.04Nb7P4O29 and the assignment was possible using DFT calculation and a statistical analysis of the NMR parameters.

A serpentinite-hosted ecosystem in the Southern Mariana Forearc.

Several varieties of seafloor hydrothermal vents with widely varying fluid compositions and temperatures and vent communities occur in different tectonic settings. The discovery of the Lost City hydrothermal field in the Mid-Atlantic Ridge has stimulated interest in the role of serpentinization of peridotite in generating H(2)- and CH(4)-rich fluids and associated carbonate chimneys, as well as in the biological communities supported in highly reduced, alkaline environments. Abundant vesicomyid clam communities associated with a serpentinite-hosted hydrothermal vent system in the southern Mariana forearc were discovered during a DSV Shinkai 6500 dive in September 2010. We named this system the "Shinkai Seep Field (SSF)." The SSF appears to be a serpentinite-hosted ecosystem within a forearc (convergent margin) setting that is supported by fault-controlled fluid pathways connected to the decollement of the subducting slab. The discovery of the SSF supports the prediction that serpentinite-hosted vents may be widespread on the ocean floor. The discovery further indicates that these serpentinite-hosted low-temperature fluid vents can sustain high-biomass communities and has implications for the chemical budget of the oceans and the distribution of abyssal chemosynthetic life.

On the track to silica-supported tungsten oxo metathesis catalysts: input from 17O solid-state NMR.

The grafting of an oxo chloro trisalkyl tungsten derivative on silica dehydroxylated at 700 °C was studied by several techniques that showed reaction via W-Cl cleavage, to afford a well-defined precatalyst for alkene metathesis. This was further confirmed by DFT calculations on the grafting process. (17)O labeling of the oxo moiety of a series of related molecular and supported tungsten oxo derivatives was achieved, and the corresponding (17)O MAS NMR spectra were recorded. Combined experimental and theoretical NMR studies yielded information on the local structure of the surface species. Assessment of the (17)O NMR parameters also confirmed the nature of the grafting pathway by ruling out other possible grafting schemes, thanks to highly characteristic anisotropic features arising from the quadrupolar and chemical shift interactions.

Smart meters and routers radiofrequency disturbances study with pacemakers and implantable cardiac defibrillators.

BACKGROUND: There is no scientific literature that examines radiofrequency (RF) interference from Smart Meters with cardiac implantable electronic devices (CIEDs). The objective of this in vitro study was to assess any potential interference with Medtronic CIEDs (Medtronic Inc., Minneapolis, MN, USA). METHODS: In the Quebec testing, five models of Medtronic CIEDs were placed in an acrylic cylinder filled with a saline solution and faced a Landis+Gyr Smart Meter or Router (Landis+Gyr AG, Zug, Switzerland). The distance between CIEDs and the meter casing or router antenna was 10 cm. The Meter's normal operating conditions were modified to artificially set the number of impulsions at an abnormally high level (one, two, and three impulses per second). Each scenario was repeated one to five times, for 1 minute each. In the U.S. testing, 6 cm and 15 cm (∼2.25' and ∼6') separated the six models of Medtronic CIEDs from the Schlumberger Smart Meter (Itron Inc., Liberty Lake, WA, USA), which generally sent out a 96-bit Standard Consumption Message over 3 seconds. The transmission varied in frequencies along with the interval between cycles. RESULTS: A total of 6,966 RF transmissions were completed during the 34 tests conducted in Quebec. In the United States, the CIED was exposed to the meter for 10 minutes to provide a minimum of 200 completed RF transmissions. No interference was observed in worst-case scenarios (testing of meters and CIEDs at their performance limits). CONCLUSIONS: Landis+Gyr Smart Meters/Routers and Schlumberger Smart Meters do not interfere with the functioning of the Medtronic CIEDs tested, when placed, respectively, 10 cm and 6 cm and 15 cm apart.

Risk Factors for Anal Continence Impairment Following a Second Delivery after a First Traumatic Delivery: A Prospective Cohort Study.

Postpartum anal incontinence is common. After a first delivery (D1) with perineal trauma, follow-up is advised to reduce the risk of anal incontinence. Endoanal sonography (EAS) may be considered to evaluate the sphincter and in case of sphincter lesions to discuss cesarean section for the second delivery (D2). Our objective was to study the risk factors for anal continence impairment following D2. Women with a history of traumatic D1 were followed before and 6 months after D2. Continence was measured using the Vaizey score. An increase ≥2 points after D2 defined a significant deterioration. A total of 312 women were followed and 67 (21%) had worse anal continence after D2. The main risk factors for this deterioration were the presence of urinary incontinence and the combined use of instruments and episiotomy during D2 (OR 5.12, 95% CI 1.22-21.5). After D1, 192 women (61.5%) had a sphincter rupture revealed by EAS, whereas it was diagnosed clinically in only 48 (15.7%). However, neither clinically undiagnosed ruptures nor severe ruptures were associated with an increased risk of continence deterioration after D2, and cesarean section did not protect against it. One woman out of five in this population had anal continence impairment after D2. The main risk factor was instrumental delivery. Caesarean section was not protective. Although EAS enabled the diagnosis of clinically-missed sphincter ruptures, these were not associated with continence impairment. Anal incontinence should be systematically screened in patients presenting urinary incontinence after D2 as they are frequently associated.

Effect of monopolar radiofrequency energy on pacemaker function.

BACKGROUND: This study aimed to quantify the clinical parameters of mono- and bipolar instruments that inhibit pacemaker function. The specific aims were to quantify pacer inhibition resulting from the monopolar instrument by altering the generator power setting, the generator mode, the distance between the active electrode and the pacemaker, and the location of the dispersive electrode. METHODS: A transvenous ventricular lead pacemaker overdrive paced the native heart rate of an anesthetized pig. The primary outcome variable was pacer inhibition quantified as the number of beats dropped by the pacemaker during 5 s of monopolar active electrode activation. RESULTS: Lowering the generator power setting from 60 to 30 W decreased the number of dropped paced events (2.3 ± 1.2 vs 1.6 ± 0.8 beats; p = 0.045). At 30 W of power, use of the cut mode decreased the number of dropped paced beats compared with the coagulation mode (0.6 ± 0.5 vs 1.6 ± 0.8; p = 0.015). At 30 W coagulation, firing the active electrode at different distances from the pacemaker generator (3.75, 7.5, 15, and 30 cm) did not change the number of dropped paced beats (p = 0.314, analysis of variance [ANOVA]). The dispersive electrode was placed in four locations (right/left gluteus, right/left shoulder). More paced beats were dropped when the current vector traveled through the pacemaker/leads than when it did not (1.5 ± 1.0 vs 0.2 ± 0.4; p < 0.001). CONCLUSIONS: Clinical parameters that reduce the inhibition of a pacemaker by monopolar instruments include lowering the generator power setting, using cut (vs coagulation) mode, and locating the dispersive electrode so the current vector does not traverse the pacemaker generator or leads.

Carbetocin versus Oxytocin for the Prevention of Postpartum Hemorrhage in Cesarean Deliveries: A Retrospective Study of Two Consecutive Periods.

Objective The aim of the study is to investigate whether carbetocin prevents postpartum hemorrhage (PPH) more effectively than oxytocin Methods This historical retrospective single-center cohort study compares women who underwent cesarean deliveries during two periods. During period A, oxytocin was used as a 10-unit bolus immediately after delivery, with 20 units thereafter infused for 24 hours. During period B, carbetocin in a single 100-µg injection replaced this protocol. The main outcome was PPH, defined as a decline in hemoglobin of more than 2 g/dL after the cesarean. The analysis was performed on the overall population and then stratified by the timing of the cesareans (before or during labor). A logistic regression analysis was performed. Results This study included 1,796 women, 52% of whom had a cesarean before labor; 15% had a PPH. The crude PPH rate was lower in period B than in period A (13 vs. 17%, respectively, odds ratio 0.75, 95% confidence interval [CI]: 0.58-0.98). The difference was no longer significant in the multivariate analysis (adjusted odds ratio: 0.81, 95% CI 0.61-1.06). Results were similar when stratified by the timing of the cesareans (before or during labor). Conclusion Carbetocin is not superior to oxytocin in preventing PPH. However, it does provide the advantage of requiring a single injection.

Sexual health and fertility for individuals with inflammatory bowel disease.

The impact of a chronic disease such as inflammatory bowel disease (IBD) on sexual functioning and body image can significantly impair the quality of life of patients. This review considers the sexual and fertility aspects of IBD patients and their daily management. Modern IBD healthcare management should include appropriate communication on sexuality and consider psychological, physiological, and biological issues. Patients with IBD have less children than the general population, and voluntary childlessness is frequent. The most influential factors reported by IBD patients who experience fertility alteration are psychological and surgery-related problems. Pregnancy is a major concern for patients, and any pregnancy for IBD patients should be closely followed-up to keep the chronic disease in a quiescent state. Preconceptional consultation is of great help.

Randomized blinded trial of standardized written patient information before total knee arthroplasty.

BACKGROUND: The effect of patient education before total knee arthroplasty (TKA) is controversial. No consensus exists about the optimal content of educational interventions. In a previous study, we developed and validated an educational booklet on the peri-TKA management of knee osteoarthritis. PURPOSES: Our primary purpose was to evaluate the impact of the educational booklet on knowledge among patients awaiting TKA. PATIENTS AND METHODS: This randomized controlled single-blind trial evaluated standard information by the surgeon with or without delivery of the educational booklet 4-6 weeks before primary noncomplex TKA in patients aged 55-75 years with incapacitating knee osteoarthritis. Patients were enrolled at a French surgical center between June 2011 and January 2012. A patient knowledge score was determined at baseline, on the day before TKA, and 3-6 weeks after TKA, using a self-administered questionnaire developed for our previous study. The assessor was blinded to group assignment. RESULTS: Of 44 eligible patients, 42 were randomized, 22 to the intervention and 20 to the control group, all of whom were included in the analysis. The groups were comparable at baseline. The intervention was associated with significantly better patient knowledge scores. CONCLUSIONS: An educational booklet improves knowledge among patients awaiting TKA. A study assessing the impact of the booklet combined with a exercise program would be helpful. LEVEL OF EVIDENCE: Level I, randomized controlled double-blind trial; see S1 CONSORT Checklist. TRIAL REGISTRATION: clinicaltrials.gov #NCT01747759.

Selective rather than universal screening for gestational diabetes mellitus?

OBJECTIVES: To estimate the proportion of women with gestational diabetes mellitus (GDM) who would be missed by selective versus universal screening and to describe their pregnancy outcomes. STUDY DESIGN: An observational cohort study in a single center performing universal screening for GDM with a 75 g oral glucose challenge test (OGTT) at 24-28 weeks gestation. We excluded women with pregestational or first trimester diabetes, those not screened and deliveries <34 weeks. Risk factors were age ≥ 35 years, BMI ≥ 25, family history of diabetes, GDM in a previous pregnancy or macrosomia in a previous pregnancy. Main outcomes were large for gestational age (LGA>90th centile for gestational age, adjusted for gender) and small for gestational age<10th centile. RESULTS: Among 2187 women screened, 309 (14%) had GDM, of whom 256 (83%) had one or more risk factors. The proportion of women who had GDM despite the absence of any risk factor was 2.4%. In multivariate analysis, LGA was significantly associated with GDM only in case of risk factors. Mean fasting blood glucose was lower in GDM without risk factors than in GDM with risk factors (87 ± 1 mg/dl versus 94 ± 14, p<0.001) and fewer required insulin (6% versus 26%, respectively, p<0.001). CONCLUSION: Selective screening would have missed one-sixth of GDM cases, but these cases seemed milder, with normal fasting blood glucose, and thus less likely to lead to perinatal complications. Whereas an opt-in approach relies heavily on accurate patient screening, we suggest that screening tests could be avoided in low-risk women by an opt-out approach.

Electromagnetic interference caused by common surgical energy-based devices on an implanted cardiac defibrillator.

BACKGROUND: Surgical energy-based devices emit energy, which can interfere with other electronic devices (eg, implanted cardiac pacemakers and/or defibrillators). The purpose of this study was to quantify the amount of unintentional energy (electromagnetic interference [EMI]) transferred to an implanted cardiac defibrillator by common surgical energy-based devices. METHODS: A transvenous cardiac defibrillator was implanted in an anesthetized pig. The primary outcome measure was the average maximum EMI occurring on the implanted cardiac device during activations of multiple different surgical energy-based devices. RESULTS: The EMI transferred to the implanted cardiac device is as follows: traditional bipolar 30 W .01 ± .004 mV, advanced bipolar .004 ± .003 mV, ultrasonic shears .01 ± .004 mV, monopolar Bovie 30 W coagulation .50 ± .20 mV, monopolar Bovie 30 W blend .92 ± .63 mV, monopolar instrument without dispersive electrode .21 ± .07 mV, plasma energy 3.48 ± .78 mV, and argon beam coagulator 2.58 ± .34 mV. CONCLUSION: Surgeons can minimize EMI on implanted cardiac defibrillators by preferentially utilizing bipolar and ultrasonic devices.

Influence of ethnicity on the clinical and biologic expression of pre-eclampsia in the ECLAXIR study.

OBJECTIVE: To determine whether ethnic origin is related to the clinical and biologic expression of pre-eclampsia. METHODS: In a secondary analysis of information collected in the ECLAXIR study in France between May 2003 and October 2006, the data from 284 white European, 84 Maghrebian and 158 African women were evaluated in a case-control study of the genetic and endothelial determinants of pre-eclampsia. RESULTS: African origin was a risk factor for pre-eclampsia before 28 weeks of gestation. Symptoms related to hypertension, such as neurologic signs and changes in biologic parameters (e.g. hemolysis elevated liver enzymes, low platelet count [HELLP] syndrome), occurred more frequently among white European women. After logistic regression, gestational age at delivery was lower for African women than for white European women (33.4 weeks versus 34.4 weeks of gestation, P=0.04). CONCLUSION: The results suggest that ethnic origin may have a role in the expression of pre-eclampsia, and should therefore be taken into account in prenatal surveillance. Further research on the genetic factors involved in endothelial dysfunction is warranted.

Diagnosis of Mullerian anomalies in adults: evaluation of practice.

OBJECTIVE: To evaluate the circumstances associated with the diagnosis of Mullerian anomalies in adults. DESIGN: Retrospective observational study. SETTING: University hospital. PATIENT(S): All patients with Mullerian anomalies referred for evaluation. INTERVENTION(S): All patients underwent radiologic and operative diagnostic workup using ultrasonography, or ultrasonography and hysteroscopy, and in some cases laparoscopy. MAIN OUTCOME MEASURE(S): Clinical symptoms and radiologic investigations leading to the diagnosis. Mode and number of investigations before the diagnosis, and the time since the initial symptoms to the final diagnosis. RESULT(S): One hundred ten patients were diagnosed with Mullerian anomalies: 73 septate uteri, 20 bicornuate uteri, 10 uterine hypoplasia, 4 unicornuate uteri, and 3 with Mayer- Mayer-Rokitansy-Küster-Hauser syndrome. The circumstances leading to the diagnosis were infertility (33.6%), repeat miscarriage (18.2%), ultrasonography during pregnancy (12.7%), pregnancy complications during last trimester (11%), abnormal examination (8.2%), and miscellaneous causes (16.3%). Up 50% of patients complained of gynecologic signs before the appropriate diagnosis. Radiologic diagnosis required two complementary imaging techniques in 62% of patients and more than two in 28%. The correct diagnosis was established in only 40% of cases before hospitalization. Most of the anomalies were initially diagnosed at hysterosalpingography and ultrasonography. The mean time between the first imaging examination and the diagnosis in a specialized department was 6.7 (+/-7.1) months. CONCLUSION(S): The diagnosis of Mullerian anomalies in adults is often made at the time of conception and obstetric complications. There is a tendency toward the use of multiple imaging techniques and this delayed the diagnosis.

Laser ablation threshold dependence on pulse duration for fused silica and corneal tissues: experiments and modeling.

The surface ablation threshold fluence of fused silica and two porcine cornea layers, the epithelium and the stroma, is characterized as a function of the laser pulse duration in the range of 100 fs-5 ps for a wavelength of 800 nm (Ti:sapphire laser system). The plateaulike region observed between 100 fs and 1 ps for the corneal layers indicates that for use in laser surgery, laser pulse durations chosen within this range should be practically equivalent. Our model predicts that the ablation threshold will decrease rapidly for pulse durations in the low end of the femtosecond regime.