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In quantum mechanics, when an electron is quickly ripped off from a molecule, a superposition of new eigenstates of the cation creates an electron wave packet that governs the charge flow inside which has been called charge migration (CM). Experimentally, to extract such dynamics at its natural (attoseconds) timescale is quite difficult. Here, we report the first such experiment in a linear carbon-chain molecule, butadiyne (C4H2), via high harmonic spectroscopy (HHS). By employing advanced theoretical and computational tools, we showed that the wave packet and the CM of a single molecule is reconstructed from the harmonic spectra for each fixed-in-space angle of the molecule. For this one-dimensional molecule, we calculate the center of charge (t) to obtain v_{cm}, to quantify the migration speed and how it depends on the orientation angle. The findings also uncover how the electron dynamics at the first few-tens to hundreds attoseconds depends on molecular structure. The method can be extended to other molecules where HHS technique can be employed.

Additional file 1: Table S1. List of primers sequences and their reaction conditions used in the present study. Table S2 List of antibodies used in the present study. Figure S1. Representative standard sequencing diagram for bisulfite direct sequencing of the TMEM240 gene. Figure S2 Copy number variation (CNV) analysis and chromosomal distribution of localized CNVs. (A) The workflow of CNV analysis. (B) CNV gain is shown as a red peak. (C) CNV loss is shown in the blue peak. Figure S3. The cell morphology was determined by microscopy in MDA-MB-231 cells (original magnification, ×100). Figure S4. Representative figures showing the TMEM240 mRNA expression by RNA sequencing in breast cancer patients from TCGA. Figure S5. Pathway Maps analysis of TMEM240 involvement in the epithelial–mesenchymal transition (EMT) process. MetaCore Pathway Maps analysis indicated that TMEM240 expression led to decreases in FGF2, NFkB, MMP2, and Oncostatin M and increases in E-cedherin and VE-cadherin. Figure S6. Pathway maps analysis of TMEM240 involvement in the SDF-1 pathway. MetaCore pathway maps analysis indicated that TMEM240 expression led to decreases in SDF-1, G-protein alpha-i2, and VAV-1 expression.

We report theoretical investigations of vibronic quantum beats (QBs) which can be observed in the molecular dissociation under the intense infrared (IR) laser pump-IR laser probe scheme. We show how the vibronic coherences can be probed by analyzing the interchannel QB signals obtained from the numerical solution of the time-dependent Schr\"odinger equation (TDSE) and the quantum Liouville equation in combination with the strong-field approximation for the treatment of coherences between multiple states of the target ion. The validities of our methods are first tested on a one-dimensional model of ${{\mathrm{H}}_{2}}^{+}$, for which exact solutions of the TDSE can be obtained. We then illustrate our method using an example of ${\mathrm{O}}_{2}$, for which various experiments have been reported recently. The case of an attosecond pump pulse is also considered. Our results indicate that the strong-field dissociation pump-probe experiments are capable of providing information on the vibronic coherences that complements other techniques such as attosecond transient absorption spectroscopy.

Visualizing molecular transformations in real-time requires a structural retrieval method with Ångström spatial and femtosecond temporal atomic resolution. Imaging of hydrogen-containing molecules additionally requires an imaging method that is sensitive to the atomic positions of hydrogen nuclei, with most methods possessing relatively low sensitivity to hydrogen scattering. Laser-induced electron diffraction (LIED) is a table top technique that can image ultrafast structural changes of gas-phase polyatomic molecules with sub-Ångström and femtosecond spatiotemporal resolution together with relatively high sensitivity to hydrogen scattering. Here, we image the umbrella motion of an isolated ammonia molecule (NH3) following its strong field ionization. Upon ionization of a neutral ammonia molecule, the ammonia cation (NH+3) undergoes an ultrafast geometrical transformation from a pyramidal (FHNH=107°) to planar (FHNH=120°) structure in approximately 8 femtoseconds. Using LIED, we retrieve a near-planar (FHNH=117±5°) field-dressed NH+3 molecular structure 7.8-9.8 femtoseconds after ionization. Our measured field-dressed NH+3 structure is in excellent agreement with our calculated equilibrium field dressed structure using quantum chemical ab initio calculations. J.B. and group acknowledge financial support from the European Research Council for ERC Advanced Grant “TRANSFORMER” (788218), ERC Proof of Concept Grant “miniX” (840010), FET-OPEN “PETACom” (829153), FET-OPEN “OPTOlogic” (899794), Laserlab- Europe (EU-H2020 654148), MINECO for Plan Nacional FIS2017-89536-P; AGAUR for 2017 SGR 1639, MINECO for “Severo Ochoa” (SEV- 2015-0522), Fundació Cellex Barcelona, CERCA Programme / Generalitat de Catalunya, and the Alexander von Humboldt Foundation for the Friedrich Wilhelm Bessel Prize. J.B., K.A. and R.Moszynski. acknowledge the Polish National Science Center within the project Symfonia, 2016/20/W/ST4/00314. J.B and B.B. acknowledge Severo Ochoa” (SEV- 2015-0522). J.B. and A.S. acknowledge funding from the Marie Sklodowska-Curie grant agreement No. 641272. C.D.L is supported in part by Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U. S. Department of Energy under Grant No. DE-FG02-86ER13491. J.S. and S.G. highly acknowledges support from the European Research Council (ERC) for the ERC Consolidator Grant QUEM-CHEM (772676). The authors thank Alejandro Saenz for helpful discussions.

Mở đầu Yếu tố quan trọng trong sự phát triển du lịch của các quốc gia Nam Á và Đông Nam Á bao gồm việc thành lập một thế giới các vật thể nhân tạo, bằng nhựa, bê tông và thạch cao, nhằm tạo ra sự trang trí rập khuôn ở các khu du lịch, dựa trên đặc tính kitsch. Thuật ngữ này đã xuất hiện vào khoảng năm 1860 ở vùng Bavaria, nói về những sản phẩm có chất lượng kém (Menon, 2006). Ban đầu, thuật ngữ chỉ đề cập đến việc « sản xuất các sản phẩm mang tính nghệ thuật và công nghiệp rẻ tiền » (Legrand,...

Mở đầu Yếu tố quan trọng trong sự phat triển du lịch của cac quốc gia Nam A va Đong Nam A bao gồm việc thanh lập một thế giới cac vật thể nhân tạo, bằng nhựa, be tong va thạch cao, nhằm tạo ra sự trang tri rập khuon ở cac khu du lịch, dựa tren đặc tinh kitsch. Thuật ngữ nay đa xuất hiện vao khoảng nam 1860 ở vung Bavaria, noi về những sản phẩm co chất lượng kem (Menon, 2006). Ban đầu, thuật ngữ chỉ đề cập đến việc « sản xuất cac sản phẩm mang tinh nghệ thuật va cong nghiệp rẻ tiền » (Legrand,...

Realizado en el marco del programa ANR AQAPA (2014-2019), este trabajo parte del analisis de tres regiones turisticas de Asia caracterizadas por la presencia de minorias etnicas –las regiones de Dalat en Vietnam, Pokhara en Nepal y Sandu en China- y centra su interes en la estereotipada puesta en escena de los lugares y centros turisticos que se basa en la utilizacion del kitsch. Esta construccion turistica de decorados se apoya, principalmente, en la utilizacion de lo falso (Baudrillard, 1981), lo que Umberto Eco (1985) califica de « mentira artistica », pretendiendo proveer al individuo de « una vision tranquilizante, aunque artificial, de las cosas » (Menon, 2006). El estudio aborda, asi, esta utilizacion del kitsch en el paisaje que se pone a disposicion del turista en la interrelacion de lo rural y lo urbano (escenografia, experiencia que se proporciona a los turistas, procesos implementados), asi como los objetivos que esta puesta en escena pretende alcanzar, de modo que podamos aproximarnos e interpretar el mensaje o los mensajes que subyacen en ella.

In a recent paper [C. Jin, S.-J. Wang, X. Zhao, S.-F. Zhao, and C. D. Lin, Phys. Rev. A 101, 013429 (2020)], we reported that the position and depth of the minima in the harmonic spectra of ${\mathrm{CO}}_{2}$ molecules can be dramatically manipulated by a slight change of the degree of alignment, thus providing a convenient method of shaping attosecond pulses which could lead to the splitting of a typical single attosecond burst into two. Here, we demonstrate that harmonic minima can also be dramatically controlled by changing the pump-probe angles to shape attosecond pulses. In the meanwhile, since the pump-probe angle-dependent harmonic spectra are very sensitive to the degree of alignment, harmonic spectra can also be used to calibrate the alignment distribution of molecules. We identify such robust control of harmonic generation is due to the optical property of ${\mathrm{CO}}_{2}$ and the coherent harmonic emission from the oriented molecules. The photoionization transition dipoles (PITDs) of ${\mathrm{CO}}_{2}$ exhibit deep minima that change rapidly with molecular orientations accompanied by large phase changes of $\ensuremath{\pi}$ in PITDs, thus leading to strong interference when the dipoles are added up coherently.

We report the results of a time-resolved coincident ion momentum imaging experiment probing nuclear wave packet dynamics in the strong-field ionization and dissociation of iodomethane (CH3I), a prototypical polyatomic system for photochemistry and ultrafast laser science. By measuring yields, kinetic energies, and angular distributions of CH3+ + I+ and CH3+ + I++ ion pairs as a function of the delay between two 25 fs, 790 nm pump and probe pulses, we map both, bound and dissociating nuclear wave packets in intermediate cationic states, thereby tracking different ionization and dissociation pathways. In both channels, we find oscillatory features with a 130 fs periodicity resulting from vibrational motion (C–I symmetric stretch mode) in the first electronically excited state of CH3I+. This vibrational wave packet dephases within 1 ps, in good agreement with a simple wave packet propagation model. Our results indicate that the first excited cationic state plays a key role in the dissociative ionization of CH3I and that it represents an important intermediate in the sequential double and multiple ionization at moderate intensities.

Objectives: (1) To assess the bone mineral density by dual energy X-ray absorptiometry in women aged 45 and older with overweight, obesity. (2) To approach the relationship between the bone mineral density and osteoporosis risk factors in women aged 45 and older with overweight, obesity. Materials and method: 207 women aged 45 and older receiving treatment at Medic - Binh Duong hospital were divided into 2 groups: 147 women with overweight, obesity and 60 women without overweight, obesity. Research was designed as a cross-sectional descriptive study and comparative control group. Results: The femoral bone mineral density in terms of women with overweight, obesity is (0.795 ± 0.121) and the control group is (0.731± 0.116). The bone mineral density of lumbar spine in women with overweight, obesity is (0.800 ± 0.138) and the control group is (0.757 ± 0.148). Conclusions: The bone mineral of femora in women with overweight, obesity was higher than that of the control group (p0.05). There was a statistically significant relationship between the bone mineral density and age, menopause state, and duration of menopause in women aged 45 and older with overweight, obesity (p

Objectives To evaluate the efficacy of an intervention on the practice of venous thromboembolism prevention. Design A multicenter, prospective, controlled, cluster-randomized, multifaceted intervention trial consisting of educational lectures, posters, and pocket cards reminding physicians of the guidelines for thromboprophylaxis use. Settings Twelve geriatric departments with 1861 beds total, of which 202, 803, and 856 in acute care, post-acute care, and long-term care wards, respectively. Participants Patients hospitalized between January 1 and May 31, 2015, in participating departments. Measurements The primary endpoint was the overall adequacy of thromboprophylaxis prescription at the patient level, defined as a composite endpoint consisting of indication, regimen, and duration of treatment. Geriatric departments were divided into an intervention group (6 departments) and control group (6 departments). The preintervention period was 1 month to provide baseline practice levels, the intervention period 2 months, and the postintervention period 1 month in acute care and post-acute care wards or 2 months in long-term care wards. Multivariable regression was used to analyze factors associated with the composite outcome. Results We included 2962 patients (1426 preintervention and 1536 postintervention), with median age 85 [79;90] years. For the overall 18.9% rate of inadequate thromboprophylaxis, 11.1% was attributable to underuse and 7.9% overuse. Intervention effects were more apparent in post-acute and long-term care wards although not significantly [odds ratio 1.44 (95% confidence interval 0.78;2.66), P = .241; and 1.44 (0.68, 3.06), P = .345]. Adequacy rates significantly improved in the postintervention period for the intervention group overall (from 78.9% to 83.4%; P = .027) and in post-acute care (from 75.4% to 86.3%; P = .004) and long-term care (from 87.0% to 91.7%; P = .050) wards, with no significant trend observed in the control group. Conclusions/Implications This study failed to demonstrate improvement in prophylaxis adequacy with our intervention. However, the intervention seemed to improve practices in post-acute and long-term care but not acute care wards.

// Yekaterina Y. Zaytseva 1 , Piotr G. Rychahou 2, 3 , Anh-Thu Le 3 , Timothy L. Scott 4 , Robert M. Flight 4 , Ji Tae Kim 2 , Jennifer Harris 3 , Jinpeng Liu 2 , Chi Wang 2 , Andrew J. Morris 5 , Theru A. Sivakumaran 2 , Teresa Fan 4 , Hunter Moseley 4 , Tianyan Gao 2 , Eun Y. Lee 6 , Heidi L. Weiss 2 , Timothy S. Heuer 7 , George Kemble 7 and Mark Evers 2, 3 1 Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY, USA 2 Markey Cancer Center, University of Kentucky, Lexington, KY, USA 3 Department of Surgery, University of Kentucky, Lexington, KY, USA 4 RC-SIRM, University of Kentucky, Lexington, KY, USA 5 Cardiovascular Research, University of Kentucky, Lexington, KY, USA 6 Department of Pathology and Laboratory Medicine, University of Kentucky, Lexington, KY, USA 7 3-V Biosciences, Menlo Park, CA, USA Correspondence to: Yekaterina Y. Zaytseva, email: yyzayt2@email.uky.edu Keywords: colorectal cancer; FASN; lipogenesis; patient-derived xenografts; TVB-3664 Received: March 27, 2018 Accepted: April 26, 2018 Published: May 15, 2018 ABSTRACT Fatty Acid Synthase (FASN), a key enzyme of de novo lipogenesis, is upregulated in many cancers including colorectal cancer (CRC); increased FASN expression is associated with poor prognosis. Potent FASN inhibitors (TVBs) developed by 3-V Biosciences demonstrate anti-tumor activity in vitro and in vivo and a favorable tolerability profile in a Phase I clinical trial. However, CRC characteristics associated with responsiveness to FASN inhibition are not fully understood. We evaluated the effect of TVB-3664 on tumor growth in nine CRC patient-derived xenografts (PDXs) and investigated molecular and metabolic changes associated with CRC responsiveness to FASN inhibition. CRC cells and PDXs showed a wide range of sensitivity to FASN inhibition. TVB-3664 treatment showed significant response (reduced tumor volume) in 30% of cases. Anti-tumor effect of TVB-3664 was associated with a significant decrease in a pool of adenine nucleotides and alterations in lipid composition including a significant reduction in fatty acids and phospholipids and an increase in lactosylceramide and sphingomyelin in PDXs sensitive to FASN inhibition. Moreover, Akt, Erk1/2 and AMPK were major oncogenic pathways altered by TVBs. In summary, we demonstrated that novel TVB inhibitors show anti-tumor activity in CRC and this activity is associated with a decrease in activation of Akt and Erk1/2 oncogenic pathways and significant alteration of lipid composition of tumors. Further understanding of genetic and metabolic characteristics of tumors susceptible to FASN inhibition may enable patient selection and personalized medicine approaches in CRC.

Journal of optics 24(2), 025502 (2022). doi:10.1088/2040-8986/ac4318, We present the results of an experiment investigating the generation of high-order harmonics by a femtosecond near-infrared (NIR) laser pulse in the presence of an extreme ultraviolet (XUV) field provided by a free-electron laser (FEL), a process referred to as XUV-assisted high-order harmonic generation (HHG). Our experimental findings show that the XUV field can lead to a small enhancement in the harmonic yield when the XUV and NIR pulses overlap in time, while a strong decrease of the HHG yield and a red shift of the HHG spectrum is observed when the XUV precedes the NIR pulse. The latter observations are in qualitative agreement with model calculations that consider the effect of a decreased number of neutral emitters but are at odds with the predicted effect of the correspondingly increased ionization fraction on the phase matching. Our study demonstrates the technical feasibility of XUV-assisted HHG experiments at FELs, which may provide new avenues to investigate correlation-driven electron dynamics as well as novel ways to study and control propagation effects and phase matching in HHG., Published by IOP Publ., Bristol

A significant proportion of patients never receive curative-intent surgery for resectable gastric cancer (GC). The primary aims of this study were to identify disparities and targetable risk factors associated with failure to operate in the context of national trends in surgical rates for resectable GC.The National Cancer Database was used to identify patients with resectable GC (adenocarcinoma, clinical stage IA-IIIC, 2004-2013). Multivariate modeling was used to identify predictors of resection and to analyze the impact of surgery on overall survival (OS).Of 46,970 patients with resectable GC, 18,085 (39%) did not receive an appropriate operation. Among unresected patients, 69% had no comorbidities. Failure to resect was associated with reduced median OS (44.4 versus 11.8 mo, hazard ratio [HR]: 2.09, P 0.001). In the multivariate analysis, the most critical factors affecting OS were resection (HR: 2.09) and stage (reference IA; HR range: 1.16-3.50, stage IB-IIIC). Variables independently associated with no surgery included insurance other than private or Medicare (odds ratio [OR]: 1.60/1.54), nonacademic/nonresearch hospital (OR: 1.16), non-Asian race (OR: 1.72), male (OR: 1.19), older age (OR: 1.04), Charlson-Deyo score1 (OR: 1.17), residing in areas with median income$48,000 (OR: 1.23), small urban populations20,000 (OR: 1.41), and stage (reference IA; OR range: 1.36-3.79, stage IB-IIIC, P 0.001).Over one-third of patients with resectable GC fail to receive surgery. Suitable insurance coverage and treatment facility are the most salient (and only modifiable) risk factors for omitting surgery. To mitigate national disparities in surgical care, policymakers should consider improving insurance coverage in underserved areas and regionalization of gastric cancer care.

Although adjuvant therapy (AT) is a necessary component of multimodality therapy for pancreatic ductal adenocarcinoma (PDAC), its application can be hindered by post-pancreaticoduodenectomy (PD) complications. The primary aim of this study was to evaluate the impact of post-PD complications on AT utilization and overall survival (OS).Patients undergoing PD without neoadjuvant therapy for stages I-III PDAC at a single institution (2007-2015) were evaluated. Ninety-day postoperative major complications (PMCs) were defined as grade ≥3. Records were linked to the Kentucky Cancer Registry for AT/OS data. Early AT was given8 wk; late 8-16 wk. Initiation16 wk was not considered to be AT. Complication effects on AT timing/utilization and OS were evaluated.Of 93 consecutive patients treated with surgery upfront with AT data, 64 (69%) received AT (41 [44%] early; 23 [25%] late). There were 32 patients (34%) with low-grade complications and 24 (26%) with PMC. With PMC, only six of 24 patients (25%) received early AT and 13 of 24 (54%) received any (early/late) AT versus 35 of 69 (51%) early AT and 51 of 69 (74%) any AT without PMC. PMCs were associated with worse median OS (7.1 versus 24.6 mo, without PMC, P 0.001). Independent predictors of OS included AT (hazard ratio [HR]: 0.48), tumor2 cm (HR: 3.39), node-positivity (HR: 2.16), and PMC (HR: 3.69, all P 0.02).Independent of AT utilization and biologic factors, PMC negatively impacted OS in patients treated with surgery first. These data suggest that strategies to decrease PMC and treatment sequencing alternatives to increase multimodality therapy rates may improve oncologic outcomes for PDAC.

Synopsis We use laser-induced electron diffraction (LIED) to self-image the molecular structure of an isolated water molecular ion using its own retuning attosecond electron wave packet (EWP). Using LIED’s sub-femtosecond and picometre spatio-temporal resolution imaging capabilities, we observe the symmetric stretching of the O-H and H-H internuclear distances with increasing laser field strength.

Synopsis We present experimental results of linear-to-bent transition of field-dressed molecules, mediated by Renner-Teller effect. Using the state-of-the-art laser-induced electron diffraction (LIED) technique, we image a bent and symmetrically stretched carbon disulfide (CS2) molecule populating an excited electronic state under the influence of strong laser field. Our findings are well-supported by ab initio quantum mechanical calculations.

We present a theoretical investigation of high-order-harmonic generation (HHG) from impurity-doped materials. Based on the analysis of the exact numerical solutions of the time-dependent Schr\"odinger equation (TDSE) for one-dimensional models, we demonstrate the factorization of HHG yields as a product of an electron wave packet and the recombination cross section, in analogy to HHG from atoms and molecules in the gas phase. Furthermore, we show that the quantitative rescattering model based on this factorization accurately reproduces the TDSE results. This opens up new possibilities to study impurities in materials using the available techniques from strong-field physics.

Background\ud Low-income and middle-income countries (LMICs) are under-represented in reports on the burden of antimicrobial resistance. We aimed to quantify the clinical effect of carbapenem resistance on mortality and length of hospital stay among inpatients in LMICs with a bloodstream infection due to Enterobacteriaceae.\ud \ud Methods\ud The PANORAMA study was a multinational prospective cohort study at tertiary hospitals in Bangladesh, Colombia, Egypt, Ghana, India, Lebanon, Nepal, Nigeria, Pakistan, and Vietnam, recruiting consecutively diagnosed patients with carbapenem-susceptible Enterobacteriaceae (CSE) and carbapenem-resistant Entero-bacteriaceae (CRE) bloodstream infections. We excluded patients who had previously been enrolled in the study and those not treated with curative intent at the time of bloodstream infection onset. There were no age restrictions. Central laboratories in India and the UK did confirmatory testing and molecular characterisation, including strain typing. We applied proportional subdistribution hazard models with inverse probability weighting to estimate the effect of carbapenem resistance on probability of discharge alive and in-hospital death, and multistate modelling for excess length of stay in hospital. All patients were included in the analysis.\ud \ud Findings\ud Between Aug 1, 2014, and June 30, 2015, we recruited 297 patients from 16 sites in ten countries: 174 with CSE bloodstream infection and 123 with CRE bloodstream infection. Median age was 46 years (IQR 15–61). Crude mortality was 20% (35 of 174 patients) for patients with CSE bloodstream infection and 35% (43 of 123 patients) for patients with CRE bloodstream infection. Carbapenem resistance was associated with an increased length of hospital stay (3·7 days, 95% CI 0·3–6·9), increased probability of in-hospital mortality (adjusted subdistribution hazard ratio 1·75, 95% CI 1·04–2·94), and decreased probability of discharge alive (0·61, 0·45–0·83). Multilocus sequence typing showed various clades, with marginal overlap between strains in the CRE and CSE clades.\ud \ud Interpretation\ud Carbapenem resistance is associated with increased length of hospital stay and mortality in patients with bloodstream infections in LMICs. These data will inform global estimates of the burden of antimicrobial resistance and reinforce the need for better strategies to prevent, diagnose, and treat CRE infections in LMICs.

Visualizing molecular transformations in real-time requires a structural retrieval method with Ångström spatial and femtosecond temporal atomic resolution. Imaging of hydrogen-containing molecules additionally requires an imaging method sensitive to the atomic positions of hydrogen nuclei, with most methods possessing relatively low sensitivity to hydrogen scattering. Laser-induced electron diffraction (LIED) is a table-top technique that can image ultrafast structural changes of gas-phase polyatomic molecules with sub-Ångström and femtosecond spatiotemporal resolution together with relatively high sensitivity to hydrogen scattering. Here, we image the umbrella motion of an isolated ammonia molecule (NH

The putative goal of surveillance is the early detection of recurrence while both the cancer and patient are still treatable. To be cost and clinically effective, surveillance requires a tailored approach based on stage, tumor biology, conditional survival, and available treatment options. Although surveillance is the major component of care for cancer patients after potentially curative treatment, current guidelines for surveillance lack the high-level data seen on the treatment side of the patient care continuum. J. Surg. Oncol. 2016;114:329-335. © 2016 Wiley Periodicals, Inc.

Observing changes in molecular structure requires atomic-scale Ångstrom and femtosecond spatio-temporal resolution. We use the Fourier transform (FT) variant of laser-induced electron diffraction (LIED), FT-LIED, to directly retrieve the molecular structure of H2O + with picometer and femtosecond resolution without a priori knowledge of the molecular structure nor the use of retrieval algorithms or ab initio calculations. We identify a symmetrically stretched H2O + field-dressed structure that is most likely in the ground electronic state. We subsequently study the nuclear response of an isolated water molecule to an external laser field at four different field strengths. We acknowledge financial support from the Spanish Ministry of Economy and Competitiveness (MINECO), through the “Severo Ochoa” Programme for Centres of Excellence in R&D (Grant No. SEV-2015-0522) Fundació Cellex Barcelona and the CERCA Programme/Generalitat de Catalunya. X.L., K.A., T.S., A.S., B.B., M.S., and J.B. acknowledge the European Research Council (ERC) for ERC Advanced Grant TRANSFORMER (Grant No. 788218), MINECO for Plan Nacional Grant No. FIS2017-89536-P, AGAUR for 2017 Grant No. SGR1639, and Laserlab-Europe (EU-H2020 654148). K.A., J.B., and R. Moszynski acknowledge the Polish National Science Center within the project Symfonia, 2016/20/W/ST4/00314. X.L. and J.B. acknowledge financial support from China Scholarship Council. A.S. and J.B. acknowledge Marie Sklodowska-Curie Grant Agreement No. 641272. J.S. and S.G. acknowledge the ERC Consolidator Grant QUEMCHEM (Grant No. 772676). C.D.L. is supported by the U.S. Department of Energy under Grant No. DE-FG02-86ER13491.

We demonstrate an angular high-harmonic spectroscopy method to probe the spinning dynamics of a molecular rotation wave packet in real time. With the excitation of two time-delayed, polarization-skewed pump pulses, the molecular ensemble is impulsively kicked to rotate unidirectionally, which is subsequently irradiated by another delayed probe pulse for high-order harmonic generation (HHG). The spatiotemporal evolution of the molecular rotation wave packet is visualized from the time-dependent angular distributions of the HHG yields and frequency shift measured at various polarization directions and time delays of the probe pulse. The observed frequency shift in HHG is demonstrated to arise from the nonadiabatic effect induced by molecular spinning. Different from the previous spectroscopic and Coulomb explosion imaging techniques, the angular high-harmonic spectroscopy method can reveal additionally the electronic structure and multiple orbitals of the sampled molecule. All the experimental findings are well reproduced by numerical simulations. Further extension of this method would provide a powerful tool for probing complex polyatomic molecules with HHG spectroscopy.

One of the grand goals of scientific endeavour in the 21st century is to probe and control chemical reactions and biological function in real time. Ideally, this requires tempororal resolution of few to tens of femtoseconds and spatial resolution of sub-angstroms. For gas-phase molecules, ultrafast electron diffraction (UED) and laser-induced electron diffraction (LIED) have been shown to be powerful tools where the change of atomic positions in a molecule can be extracted from the measured electron momentum spectra, thus creating a “molecular movie” that reveals the molecular dynamics in real time. In this chapter we address the structure retrieval methods for both UED and LIED, especially for diffraction images created from molecules that are partially aligned. The basic principle of the LIED and a recent experiment observing bond breaking using LIED are also illustrated.

Structural information on electronically excited neutral molecules can be indirectly retrieved, largely through pump–probe and rotational spectroscopy measurements with the aid of calculations. Here, we demonstrate the direct structural retrieval of neutral carbonyl disulfide (CS2) in the B ∼ 1 B 2 excited electronic state using laser-induced electron diffraction (LIED). We unambiguously identify the ultrafast symmetric stretching and bending of the field-dressed neutral CS2 molecule with combined picometer and attosecond resolution using intrapulse pump–probe excitation and measurement. We invoke the Renner–Teller effect to populate the B ∼ 1 B 2 excited state in neutral CS2, leading to bending and stretching of the molecule. Our results demonstrate the sensitivity of LIED in retrieving the geometric structure of CS2, which is known to appear as a two-center scatterer.