Innovative Technique of Vascular Repair in Intra-Operative IVC Rupture During Lumbar Microdiscectomy: A Case Report

Background: Major vascular injury during a spinal surgery is a rare but most dreaded complication. Case Presentation: A 39 years old female undergoing microscopic lumbar discectomy suddenly developed severe hypotension on table. The procedure was abandoned and the patient turned supine. It was diagnosed to be a major vessel tear and the patient was taken up for immediate successful vascular repair. To best of our knowledge such a repair procedure has not been described in literature. Conclusions: Majority of such vascular injuries are dealt with primary repair of the defect by a vascular surgeon; however in our case the rent was big and placed on the undersurface making it very difficult for the vascular surgeon to approach or repair it primarily

Does femtosecond time-resolved second-harmonic generation probe electron temperatures at surfaces?

Femtosecond pump-probe second-harmonic generation (SHG) and transient linear reflectivity measurements were carried out on polycrystalline Cu, Ag and Au in air to analyze whether the electron temperature affects Fresnel factors or nonlinear susceptibilities, or both. Sensitivity to electron temperatures was attained by using photon energies near the interband transition threshold. We find that the nonlinear susceptibility carries the electron temperature dependence in case of Ag and Au, while for Cu the dependence is in the Fresnel factors. This contrasting behavior emphasizes that SHG is not a priori sensitive to electron dynamics at surfaces or interfaces, notwithstanding its cause.Comment: 11 pages, 4 figure

Resonant hyper-Raman scattering in spherical quantum dots

A theoretical model of resonant hyper-Raman scattering by an ensemble of spherical semiconductor quantum dots has been developed. The electronic intermediate states are described as Wannier-Mott excitons in the framework of the envelope function approximation. The optical polar vibrational modes of the nanocrystallites (vibrons) and their interaction with the electronic system are analized with the help of a continuum model satisfying both the mechanical and electrostatic matching conditions at the interface. An explicit expression for the hyper-Raman scattering efficiency is derived, which is valid for incident two-photon energy close to the exciton resonances. The dipole selection rules for optical transitions and Fr\"ohlich-like exciton-lattice interaction are derived: It is shown that only exciton states with total angular momentum $L=0,1$ and vibrational modes with angular momentum $l_p=1$ contribute to the hyper-Raman scattering process. The associated exciton energies, wavefunctions, and vibron frequencies have been obtained for spherical CdSe zincblende-type nanocrystals, and the corresponding hyper-Raman scattering spectrum and resonance profile are calculated. Their dependence on the dot radius and the influence of the size distribution on them are also discussed.Comment: 12 pages REVTeX (two columns), 2 tables, 8 figure

Impact of cervical screening on cervical cancer mortality: estimation using stage-specific results from a nested case-control study

Cancer Research UK (A16892 to P.S.)

Programmable antivirals targeting critical conserved viral RNA secondary structures from influenza A virus and SARS-CoV-2

Influenza A virus’s (IAV’s) frequent genetic changes challenge vaccine strategies and engender resistance to current drugs. We sought to identify conserved and essential RNA secondary structures within IAV’s genome that are predicted to have greater constraints on mutation in response to therapeutic targeting. We identified and genetically validated an RNA structure (packaging stem–loop 2 (PSL2)) that mediates in vitro packaging and in vivo disease and is conserved across all known IAV isolates. A PSL2-targeting locked nucleic acid (LNA), administered 3 d after, or 14 d before, a lethal IAV inoculum provided 100% survival in mice, led to the development of strong immunity to rechallenge with a tenfold lethal inoculum, evaded attempts to select for resistance and retained full potency against neuraminidase inhibitor-resistant virus. Use of an analogous approach to target SARS-CoV-2, prophylactic administration of LNAs specific for highly conserved RNA structures in the viral genome, protected hamsters from efficient transmission of the SARS-CoV-2 USA_WA1/2020 variant. These findings highlight the potential applicability of this approach to any virus of interest via a process we term ‘programmable antivirals’, with implications for antiviral prophylaxis and post-exposure therapy