Erratum: Highly Adiabatic Time-Optimal Quantum Driving at Low Energy Cost [Phys. Rev. Lett. 129, 180402 (2022)].

This corrects the article DOI: 10.1103/PhysRevLett.129.180402.

The reactivity of cyclopropyl cyanide in titan's atmosphere: a possible pre-biotic mechanism.

Cyclopropyl cyanide and other simple nitriles detected in Titan's atmosphere could be precursors leading to the formation of organic macromolecules in the atmosphere of Saturn's largest satellite. Proposing a thermodynamically possible mechanism that explains their formation and supports experimental results represents a difficult challenge. Experiments done in the Atomic and Molecular Physics Laboratory at the University of Trento (AMPL) have studied the ion-molecule reaction between cyclopropyl cyanide and its protonated form, with reaction products being characterized by mass spectrometry. In addition to the expected ion-molecule adduct stabilized by non-covalent long-range interactions, in this work we prove that another distinct species having the same mass to charge ratio (m/z) of 135 is also produced. Moreover, from a previous study of the neutral cyclopropyl cyanide potential energy surface (PES) which shows a partial biradical character it has been possible to characterize the formation through the bimolecular reaction of a new covalent cyclic organic molecule. Calculations have been carried out at the ab initio Møller-Plesset (MP2) level of theory, ensuring the connectivity of the stationary points by using the intrinsic reaction coordinate (IRC) procedure. In order to characterize the reaction transition state, multireference calculations were done using a complete active space involving six electrons and six molecular orbitals [CAS (6 e-, 6 m.o.)]. This study opens the possibility of exploring the formation of new organic molecules by gaseous phase ion-molecule interaction schemes, with such molecules having relevance in interstellar space and in astrobiology (and may be involved in prebiotic molecular evolution).

The role of Li+ ions in the gas phase dehydrohalogenation and dehydration reactions of i-C3H7Br and i-C3H7OH molecules studied by radiofrequency-guided ion beam techniques and ab initio methods.

Gas phase reactive collisions between lithium ions and i-C3H7X (X = Br, OH) molecules have been studied under single collision conditions in the center of mass (CM) 0.01-10.00 eV energy range using a radiofrequency-guided ion beam apparatus. Mass spectrometry analysis of the products did show the presence of [C3H6-Li]+, [HX-Li]+, C3H7+, and C2H3+ as well as of the [Li-i-C3H7Br]+ adduct while [Li-i-C3H7OH]+ was hardly detected. For all these reactive processes, the corresponding cross sections have been measured in absolute units as a function of the CM collision energy. Quantum chemistry ab initio calculations done at the second order Möller Plesset level have provided relevant information on the topology of the potential energy surfaces (PESs) where a reaction takes place allowing the characterization of the stationary points on the respective PESs along their reaction pathways. The connectivity of the different stationary points localized on the PESs was ensured by using the intrinsic reaction coordinate (IRC) method, confirming the adiabatic character of the reactions. The main topology features of the reactive PESs, in the absence of dynamical calculations, were used to interpret at the qualitative level the behavior of the experimental excitations functions, evidencing the role played by the potential energy barriers on the experimental dynamics of the reactions. Reaction rate constants at 303.2 K for different reactions have been calculated from measured excitation functions.

Dehydrohalogenation and Dehydration Reactions of i-C3H7Br and i-C3H7OH by Sodium Ions Studied by Guided Ion Beam Techniques and Quantum Chemical Methods.

Dehydrohalogenation and dehydration reactions of gas-phase i-C3H7Br and i-C3H7OH molecules induced by collision with Na(+), all participants being in their electronic ground state, were studied experimentally in our laboratory using a radiofrequency-guided ion beam apparatus and covering the 0.10-10.00 eV center of mass (CM) energy range. In Na(+) + i-C3H7Br collisions the formation of [C3H6-Na](+) and [HBr-Na](+) by dehydrohalogenation was observed and quantified, as well as that of the ion-molecule adduct [Na-i-C3H7Br](+) together with its decomposition products C3H7(+) and NaBr. In Na(+) + i-C3H7OH collisions the dehydration product [H2O-Na](+) was also found, while [C3H6-Na](+) was hardly detected. Moreover, the [Na-i-C3H7OH](+) adduct formation as well as its decomposition into C3H7(+) and NaOH were also quantified. For all these processes, absolute reaction cross sections were measured as a function of the CM collision energy. From measured excitation functions, rate constants for the formation of [C3H6-Na](+), [HBr-Na](+), and [H2O-Na](+) at 303 K were obtained. Complementing the experiments, exhaustive ab initio structure calculations at the MP2 level of theory were performed, giving information on the most relevant features of the potential energy surfaces (PESs) where the dehydrohalogenation, dehydration, and decomposition reactions take place adiabatically for both collision systems. On these PESs different stationary points associated with potential energy minima and transition state barriers were characterized, and their connectivity was ensured using the intrinsic-reaction-coordinate method. The main topology features of the ab initio calculated PESs allowed a qualitative interpretation of the experimental data also exposing the role of the sodium ion as a catalyst in elimination reactions.

Experimental and ab initio studies of the reactive processes in gas phase i-C3H7Br and i-C3H7OH collisions with potassium ions.

Collisions between potassium ions and neutral i-C3H7Br and i-C3H7OH, all in their electronic ground state, have been studied in the 0.10-10.00 eV center of mass (CM) collision energy range, using the radiofrequency-guided ion beam technique. In K(+) + i-C3H7Br collisions KHBr(+) formation was observed and quantified, while the analogous KH2O(+) formation in K(+) + i-C3H7OH was hardly detected. Moreover, formation of the ion-molecule adducts and their decomposition leading to C3H7(+) and either KBr or KOH, respectively, have been observed. For all these processes, absolute cross-sections were measured as a function of the CM collision energy. Ab initio structure calculations at the MP2 level have given information about the potential energy surfaces (PESs) involved. In these, different stationary points have been characterized using the reaction coordinate method, their connectivity being ensured by using the intrinsic-reaction-coordinate method. From the measured excitation function for KHBr(+) formation the corresponding thermal rate constant at 303 K has been calculated. The topology of the calculated PESs allows an interpretation of the main features of the reaction dynamics of both systems, and in particular evidence the important role played by the potential energy wells in controlling the reactivity for the different reaction channels.

Crossed molecular beams study of inelastic non-adiabatic processes in gas phase collisions between sodium ions and ZnBr2 molecules in the 0.10-3.50 keV energy range.

Inelastic electronically non-adiabatic reactions between Na(+) ions and neutral ZnBr(2) molecules, both in their electronic ground state, have been studied using crossed beams techniques and measuring the decaying emission radiation of the excited species produced. The fluorescent emission corresponding to Na(3 (2)P) produced by a charge transfer reaction was observed, as well as that corresponding to the decay of Zn(4s 5s (3)S), generated by dissociation of the neutral target molecule, to Zn(4s 4p (3)P). The phosphorescent decaying emission of Zn*(4s 4p (3)P) to the zinc ground state was also observed. For each emission process, the cross section energy dependences have been measured in the 0.10-3.50 keV energy range in the laboratory system. The ground electronic state of the (NaZnBr(2))(+) collision system has been characterized by ab initio chemical structure calculations at the second order Möller-Plesset perturbation level of theory using pseudo-potentials. By performing restricted open shell Hartree-Fock calculations for C(2v) geometries, four singlet and four triplet potential energy surfaces of the system have been calculated and used to interpret qualitatively the observed reactions. A simple two-state dynamical model is presented that allows an estimation of the maximum values for measured cross sections at high collision energies to be made.

Cross-section energy dependence of the [C6H6-M]+ adduct formation between benzene molecules and alkali ions (M = Li, Na, K).

The association reactions of benzene molecules with alkali ions M(+) (Li(+), Na(+) and K(+)) under single collision conditions have been studied using a radiofrequency-guided-ion-beam apparatus and mass spectrometry characterization of the different adducts. Cross-section energy dependences for [M-C(6)H(6)](+) adduct formation have been measured at collision energies up to 1.20 eV in the center of mass frame. All excitation functions decrease when collision energy increases, showing the expected behaviour for barrierless reactions. From ab initio chemical structure calculations at the MP2(full) level, the formation of the adducts makes evident the alkali ion-benzene non-covalent chemical bond. The cross-section energy dependence and the role of radiative cooling rates and unimolecular decomposition on the stabilization of the energized collision complex are also discussed.

Guided-ion-beam and ab initio study of the Li+, K+, and Rb+ association reactions with gas-phase butanone and cyclohexanone in their ground electronic states.

The association reactions between Li(+), K(+), and Rb(+) (M) and butanone and cyclohexanone molecules under single collision conditions have been studied using a radiofrequency-guided ion-beam apparatus, characterizing the adducts by mass spectrometry. The excitation function for the [M-(molecule)](+) adducts (in arbitrary units) has been obtained at low collision energies in the 0.10 eV up to a few eV range in the center of mass frame. The measured relative cross sections decrease when collision energy increases, showing the expected energy dependence for adduct formation. The energetics and structure of the different adducts have been calculated ab initio at the MP2(full) level, showing that the M(+)-molecule interaction takes place through the carbonyl oxygen atom, as an example of a nontypical covalent chemical bond. The cross-section energy dependence and the role of radiative cooling rates allowing the stabilization of the collision complexes are also discussed.

An experimental guided-ion-beam and ab initio study of the ion-molecule gas-phase reactions between Li+ ions and iso-C3H7Cl in their ground electronic state.

Reactive collisions between Li(+) ions and i-C(3)H(7)Cl molecules have been studied in the 0.20-12.00 eV center-of-mass energy range using an octopole radio frequency guided-ion beam apparatus recently developed in our laboratory. At low collision energies, dehydrohalogenation reactions giving rise to Li(C(3)H(6))(+) and Li(HCl)(+) are the main reaction channels, while at higher ones C(3)H(7)(+) and C(2)H(3)(+) become dominant, all their reactive cross sections having been measured as a function of the collision energy. To obtain information about the potential energy surfaces (PESs) on which the reactive processes take place, ab initio calculations at the MP2 level have been performed. For dehydrohalogenations, the reactive ground singlet PES shows ion-molecule adduct formation in both the reactant and product sides of the surface. Following the minimum energy path connecting both minima, an unstable intermediate and the corresponding barriers, both lying below the reactant's energy, have been characterized. The entrance channel ion-molecule adduct is also involved in the formation of C(3)H(7)(+), which then generates C(2)H(3)(+) via an CH(4) unimolecular elimination. A qualitative interpretation of the experimental results based on ab initio calculations is also included.

Efficacy of fulvestrant in the treatment of postmenopausal women with endocrine-resistant advanced breast cancer in routine clinical practice.

INTRODUCTION: This study aimed to describe the efficacy of fulvestrant 500 mg in postmenopausal women with estrogen receptor (ER)-positive advanced/metastatic breast cancer who had disease progression after receiving anti-estrogen therapy in clinical practice, getting real-world data. MATERIALS AND METHODS: Multicenter, retrospective, observational study conducted in Spain. Postmenopausal women with locally advanced/metastatic ER-positive breast cancer who received treatment with fulvestrant 500 mg after progression with a previous anti-estrogen therapy were eligible. The primary endpoint was progression-free survival (PFS); secondary endpoints were overall survival (OS), clinical benefit rate (CBR), duration of clinical benefit (DoCB), and safety profile. RESULTS: A total of 263 women were evaluated (median age, 65.8 years). At a median follow-up of 21.5 months, median PFS and OS were 10.6 and 43.2 months, respectively. PFS according to 1st, 2nd, 3rd, and ≥ 4th lines were 11.5, 10.6, 9.9, and 8.5 months, respectively (p = 0.0245). PFS in patients with visceral involvement was 10 months vs 10.6 months in patients without visceral involvement (p = 0.6604), 9.6 months in patients with high Ki67 vs 10 months in patients with low Ki67 (p = 0.7224), and 10.2 months in HER2+ patients vs 10.3 months in HER2- patients (p = 0.6809). The CBR was 56.5% and the DoCB was 18.4 months. The most frequently adverse events were injection site pain (10.3%) and musculoskeletal disorders (7.6%). CONCLUSIONS: Fulvestrant 500 mg administered in clinical practice was shown to be effective (PFS, 10.6 months; CBR, 56.5%) and well tolerated, in accordance with previous trials.

Correction to: Efficacy of fulvestrant in the treatment of postmenopausal women with endocrine-resistant advanced breast cancer in routine clinical practice.

A sentence under 'Results' heading in the Abstract section was published incorrectly. The correct sentence should read as follows.

Defining the optimal sequence for the systemic treatment of metastatic breast cancer.

Metastatic breast cancer is a heterogeneous disease that presents in varying forms, and a growing number of therapeutic options makes it difficult to determine the best choice in each particular situation. When selecting a systemic treatment, it is important to consider the medication administered in the previous stages, such as acquired resistance, type of progression, time to relapse, tumor aggressiveness, age, comorbidities, pre- and post-menopausal status, and patient preferences. Moreover, tumor genomic signatures can identify different subtypes, which can be used to create patient profiles and design specific therapies. However, there is no consensus regarding the best treatment sequence for each subgroup of patients. During the SABCC Congress of 2014, specialized breast cancer oncologists from referral hospitals in Europe met to define patient profiles and to determine specific treatment sequences for each one. Conclusions were then debated in a final meeting in which a relative degree of consensus for each treatment sequence was established. Four patient profiles were defined according to established breast cancer phenotypes: pre-menopausal patients with luminal subtype, post-menopausal patients with luminal subtype, patients with triple-negative subtype, and patients with HER2-positive subtype. A treatment sequence was then defined, consisting of hormonal therapy with tamoxifen, aromatase inhibitors, fulvestrant, and mTOR inhibitors for pre- and post-menopausal patien ts; a chemotherapy sequence for the first, second, and further lines for luminal and triple-negative patients; and an optimal sequence for treatment with new antiHER2 therapies. Finally, a document detailing all treatment sequences, that had the agreement of all the oncologists, was drawn up as a guideline and advocacy tool for professionals treating patients with this disease.

[Obtaining a formula that improves maximum oxygen consumption estimation in cycle ergometer exercise tests]. / Obtención de una fórmula que mejora la estimación del consumo máximo de oxígeno en las pruebas de esfuerzo con bicicleta ergométrica.

OBJECTIVES: To evaluate if the estimation of the maximal oxygen consumption (MO2C) in METs (metabolic equivalents) by means of the table proposed in the guidelines of the Spanish Society of Cardiology is a sufficiently reliable method when applied to the bicycle exercise test. MATERIAL AND METHODS: The MO2C in METs was obtained by gas-exchange analysis on bicycle ergometer tests in 97 healthy subjects (group i). It was compared with the estimate of METs using the table in which only watts and patient's weight were included. A better-adjusted formula was validated in 289 subjects with normal exercise myocardial perfusion gated-SPECT (group ii) using the introduction of clinical and ergometric variables. RESULTS: In group i individuals a good correlation between METs estimated with the table and those obtained through gas-exchange analysis (CCI: 0.93) was observed. However, the best adjusted formula to estimate METs in group ii subjects included watts, body mass index (BMI), age and gender (METS=11.820-0.054×age-0.189×BMI+1.031×gender+0.020×watts) (women: 0, men: 1). This formula allowed the reclassification of 46.9% of group ii subjects into the category <5METs versus the estimation by table. CONCLUSIONS: Estimating the METs with the conventional table is reliable. However, the best adjustment in subjects with normal bicycle exercise SPECT was obtained when, in addition to watts and BMI, age and gender were also considered.

The origin of endothelin-1 in patients with severe preeclampsia.

OBJECTIVE: To determine the site of origin of increased concentrations of plasma endothelin-1 in patients with severe preeclampsia. METHODS: Twelve patients with severe preeclampsia undergoing an indicated abdominal delivery had endothelin-1 levels measured from plasma specimens drawn from right and left uterine and antecubital veins before delivery and after placenta removal with uterine curettage. Twelve uncomplicated control patients undergoing abdominal delivery had endothelin-1 concentrations drawn by an identical protocol. Clinical staff members were blinded to endothelin-1 results and laboratory staff were blinded to patient group assignment and sample source. Endothelin-1 plasma concentrations were determined by radioimmunoassay and data were analyzed by paired t test. RESULTS: No difference in endothelin-1 concentration was noted with respect to placental location, central versus peripheral, or predelivery versus postdelivery sampling procedures. Overall, patients with preeclampsia had higher plasma concentrations of endothelin-1 (mean 11.0 +/- 6.6 pg/mL) compared with normotensive patients (mean 8.4 +/- 6.7 pg/mL, P < .005). CONCLUSION: The decidual-placental interface does not appear to be the source of increased plasma endothelin-1 concentrations found in severe preeclampsia. The origin of this increase remains uncertain.

A randomized trial of two vacuum extraction techniques.

OBJECTIVE: To determine whether two techniques of vacuum extraction delivery-continuous vacuum and intermittent vacuum-have different effects on maternal-fetal outcomes. METHODS: Patients to be delivered by vacuum extraction were randomized to receive continuous or intermittent vacuum. All deliveries were performed using the M-cup. In the continuous group, the level of vacuum was brought to 600 mmHg between contractions and was maintained at that level until delivery of the infant. Active efforts were made to prevent fetal loss-of-station between contractions by maintaining traction. In the intermittent group, the level of vacuum was decreased to 100 mmHg between contractions and no effort was made to prevent fetal loss-of-station. RESULTS: A total of 322 patients were randomized: 164 in the continuous arm and 158 in the intermittent group. The continuous method did not effect delivery faster (continuous 167 +/- 175 seconds versus intermittent 167 +/- 150 seconds; P = .97), nor did it lead to a reduction in method failures (continuous 12, intermittent nine; P = .72). The intermittent method did not appear to offer any benefit to the neonate regarding cephalhematoma formation (continuous 20, intermittent 17; P = .686) or any other measure of neonatal outcome. Maternal lacerations and episiotomy extensions were evenly distributed between the groups. Overall, the efficacy rate of the vacuum cup was 93.5% and the cephalhematoma rate was 11.5%. CONCLUSION: No differences in maternal or fetal outcome could be demonstrated if the level of vacuum was decreased between contractions or if an effort was made to prevent fetal loss-of-station. The clinical results obtained in this trial using the M-cup are similar to the published results with the stainless-steel Malmstrom cup.

Forceps and vacuum delivery: a survey of North American residency programs.

OBJECTIVE: To document resident instruction in operative vaginal delivery by forceps and vacuum. METHODS: A survey was sent to all 291 obstetrics-gynecology training programs in the United States and Canada. RESULTS: The overall response rate was 72% (210 of 291). Most programs (60%) have an operative vaginal delivery rate of 10% or less. Nearly all of the responding programs (199 of 209, 95%) teach operative vaginal delivery via the vacuum route; metallic cups are used in only 14% of centers. Forceps are the primary instrument in most programs (68%), but nearly one-third of responding centers use the vacuum method more often than forceps. Instruction in midpelvic operative vaginal delivery is offered in 64% of the programs, with forceps being more common by nearly a two-to-one ratio. Deep transverse arrest is handled initially by forceps by half of the respondents, whereas 28 and 22% would proceed with cesarean or attempt a vacuum extraction, respectively. CONCLUSION: Instruction in both types of operative vaginal delivery is found in most programs. The forceps are used more commonly, but vacuum is the preferred instrument in about one-third of training programs. Instruction in midpelvic delivery is offered in 64% of programs, but we noted a declining trend.

Operative vaginal delivery: a survey of fellows of ACOG.

OBJECTIVE: To document operative vaginal delivery rates of ACOG Fellows and to stratify practice patterns with regard to mid-pelvic delivery and deep transverse arrest by the time elapsed since residency. METHODS: A survey was mailed to a random sample of 1600 ACOG Fellows. Of the 597 respondents (37%), 558 who still practice obstetrics formed the study group. Selection bias regarding recipients of the survey was reduced by randomization by an uninvolved third party. The length of time since residency was categorized as 10 years or fewer ("recent," 31%), 11-20 years ("intermediate," 43%), and more than 20 years ("remote," 26%). RESULTS: The majority of respondents (338 of 558, 61%) reported an operative vaginal delivery rate of 15% or less. One hundred forty-two (25%) use only forceps, whereas 78 (14%) use vacuum extraction exclusively. More than half have abandoned mid-pelvic operative vaginal deliveries, and of the 41% who still perform these operations, about half use forceps. In cases of deep transverse arrest, about 25% perform cesarean delivery, whereas 26% and 42% use forceps or vacuum, respectively. Resident training and practice in vacuum delivery were more common in the recently trained groups (recent > intermediate > remote; P < .001). There were no differences among the groups with respect to attempting mid-pelvic operative vaginal delivery (P = .29), but the remote group was more likely to use forceps, whereas the recent group was more likely to use vacuum (P = .039). A large disparity existed among the groups regarding the management of deep transverse arrest, with vacuum use associated with group assignment (P < .001). CONCLUSIONS: The majority of respondents have an operative vaginal delivery rate of no more than 15%. Most respondents have abandoned mid-pelvic operative vaginal delivery. Practice patterns reflect differences in residency training; the more recently trained Fellows more often were taught and use vacuum for delivery.

Time of exposure as a prognostic factor in avian hypersensitivity pneumonitis.

Spirometric values were subsequently evaluated in 22 patients suffering from hypersensitivity pneumonitis caused by avian problems. First spirometric values were abnormal in 18/22 (82%) of patients. A restrictive pattern was observed in 16/22 (72%) of patients and an obstructive pattern in 6/22 (27%). The TLCO was reduced in all cases (12/12). Improvement or normalization of the respiratory function occurred 3.4 +/- 2.4 months after the avian contact had ceased. At the end of the follow-up, parameters were normal in 13/22 (59%) of patients. The restrictive pattern remained unchanged in 7/22 (32%), and the obstructive pattern persisted in 4/22 (18%) of the patients. The TLCO was normal in 6/12 (50%) of patients. Neither age nor treatment with corticosteroids (13 patients) had a significant influence upon the evolution of the lung function. However, total recovery or significant improvement was observed in 12/12 (100%) of patients who had been in contact with birds less than 2 years, in contrast to 6/10 (60%) of patients with more than 2 years of contact (P = 0.002).

Obstetric sonography. Who to scan, when to scan, and by whom.

Most patients in the United States have an indication for and receive sonography during pregnancy. The issue of routine sonography for low-risk women continues to be contentious even though the randomized trials have not been able to demonstrate a clear benefit. Clinics that routinely offer sonography for all pregnancies usually schedule such a procedure at 16 to 20 weeks of gestation. Although great progress is being made in the first-trimester diagnoses of congenital anomalies, most targeted studies are performed at 18 to 20 weeks of gestation. Although many private obstetricians perform in-office sonography, the highest rates of detection of congenital anomalies are seen in tertiary care settings such as a university medical center. In difficult or otherwise high-risk cases, a consulting perinatologist is commonly the physician most likely to integrate the ultrasound findings with a rational management plan for the remainder of the pregnancy and for delivery.

Maternal hypoglycemia: is it associated with adverse perinatal outcome?

OBJECTIVE: To determine if maternal hypoglycemia is associated with adverse perinatal outcome, particularly low birth weight. STUDY DESIGN: In this prospective study, all patients after 24 weeks' gestation were screened for gestational diabetes using 50 gm of glucola (oral) followed by a 1-hour plasma glucose measurement and hypoglycemia was defined as < or = 88 mg/dl. RESULTS: In these 426 women the mean (+/- SD) 1-hour plasma glucose value was 99.8 +/- 22.7 mg/dl. Of these, 16 were diagnosed with gestational diabetes and 46 were lost to follow-up leaving 364 patients; 116 with hypoglycemia and 248 with euglycemia. Women with hypoglycemia weighed less at the beginning of pregnancy and at delivery, but total weight gain during pregnancy was similar between both groups. There was no difference between groups in maternal symptomatology, birth weight, or the rate of fetal growth restriction. CONCLUSION: Hypoglycemia on the 1-hour glucola screen is not predictive of fetal growth restriction or other adverse perinatal consequence.