Coulomb-correlated few-electron states in a transmission electron microscope beam

We observe Coulomb-correlated electron pair and triple states generated by femtosecond photoemission from a nanoscale field emitter inside a transmission electron microscope. Event-based electron spectroscopy allows for spatial and spectral characterization of the electrons emitted by each laser pulse. Distinctive energy and momentum correlations of two- and three-electron states are identified, revealing a strong few-body Coulomb interaction at an energy scale of about two electronvolts. State-sorted beam caustics show a discrete increase in virtual source size and longitudinal source shift for few-electron states, associated with transverse momentum correlations. The pronounced spatial and spectral characteristics of these electron number states allow for filtering schemes that control the statistical distribution of the pulse charge. In this way, the fraction of specific few-electron states can be actively suppressed or enhanced, facilitating the preparation of highly non-Poissonian electron beams for microscopy and lithography, including future schemes in correlated two-electron probing

OmpA family proteins and Pmp-like autotransporter: new adhesins of Waddlia chondrophila.

Waddlia chondrophila is a obligate intracellular bacterium belonging to the Chlamydiales order, a clade that also includes the well-known classical Chlamydia responsible for a number of severe human and animal diseases. Waddlia is an emerging pathogen associated with adverse pregnancy outcomes in humans and abortion in ruminants. Adhesion to the host cell is an essential prerequisite for survival of every strict intracellular bacteria and, in classical Chlamydia, this step is partially mediated by polymorphic outer membrane proteins (Pmps), a family of highly diverse autotransporters that represent about 15% of the bacterial coding capacity. Waddlia chondrophila genome however only encodes one putative Pmp-like protein. Using a proteomic approach, we identified several bacterial proteins potentially implicated in the adhesion process and we characterized their expression during the replication cycle of the bacteria. In addition, we demonstrated that the Waddlia Pmp-like autotransporter as well as OmpA2 and OmpA3, two members of the extended Waddlia OmpA protein family, exhibit adhesive properties on epithelial cells. We hypothesize that the large diversity of the OmpA protein family is linked to the wide host range of these bacteria that are able to enter and multiply in various host cells ranging from protozoa to mammalian and fish cells

Ultrafast transmission electron microscopy using a laser-driven field emitter: Femtosecond resolution with a high coherence electron beam

We present the development of the first ultrafast transmission electron microscope (UTEM) driven by localized photoemission from a field emitter cathode. We describe the implementation of the instrument, the photoemitter concept and the quantitative electron beam parameters achieved. Establishing a new source for ultrafast TEM, the Göttingen UTEM employs nano-localized linear photoemission from a Schottky emitter, which enables operation with freely tunable temporal structure, from continuous wave to femtosecond pulsed mode. Using this emission mechanism, we achieve record pulse properties in ultrafast electron microscopy of 9 Å focused beam diameter, 200 fs pulse duration and 0.6 eV energy width. We illustrate the possibility to conduct ultrafast imaging, diffraction, holography and spectroscopy with this instrument and also discuss opportunities to harness quantum coherent interactions between intense laser fields and free-electron beams

Supplementary Material for: Total or Subtotal Colectomy in Patients Undergoing Surgery for Primary or Recurrent Epithelial Ovarian Cancer

<b><i>Background: </i></b>There is controversy as to whether performing a total or subtotal colectomy is justified in patients with advanced ovarian cancer, given its potential for morbidity and a negative effect on long-term quality of life. The aim of this study was to assess the perioperative complications, mortality and outcomes of patients who underwent total or subtotal colectomy as part of the surgical procedure for primary or recurrent epithelial ovarian cancer. <b><i>Patients and Methods: </i></b>All patients who had undergone surgery including a total or subtotal colectomy for advanced or recurrent ovarian cancer between 2005 and 2013 at our institution were retrospectively identified. <b><i>Results: </i></b>In this time period, 339 patients underwent surgery for epithelial ovarian cancer, which in 11 (3%) patients included a total or subtotal colectomy. Severe grade 3-4 postoperative complications occurred in 3 (27%) patients, and 1 (9%) patient died within 60 days of surgery. <b><i>Conclusion: </i></b>A total or subtotal colectomy is associated with increased but acceptable morbidity in selected patients undergoing primary cytoreductive surgery. However, in the recurrent/palliative setting, total or subtotal colectomy should be avoided as the prognosis is poor and the morbidity outweighs the clinical benefit