Occult herniae are difficult to diagnose clinically and hence require pre-operative imaging. There is a need to inspect all the hernia orifices at the operating table to facilitate their needful ...repairs. A laparoscopic approach to repair these defects is essential as in this view, all the hernial orifices can be visualized. We are presenting a case of bilateral recurrent inguinal hernia, where two occult herniae were discovered on the table, all of which were repaired either by plication alone or Lichtenstein’s tension-free mesh repair.
Breast cancer is one of the leading killers among women the world over. Widespread mammographic screening programs have led to almost 20% of breast cancers being detected when they are radiologically ...visible but clinically impalpable. For the localization of these cancers before surgical excision, the Kopan hook wire is the standard technique, but the extent of margins excised still needs to be determined. In this study, we have evaluated the accuracy of specimen mammogram (SM) with digital breast tomosynthesis (DBT) for margin assessment by comparing it to the excised margins as measured in final histopathology. This is a prospective observational study of patients with radiologically suspicious impalpable breast lesions. The patients underwent ultrasound-guided hook wire placement followed by excision of the lesion, subjected to digital tomosynthesis mammogram, and margins were revised on table when indicated. These findings were correlated with final histopathological margin. Our study included 30 patients and out of the 6 lesions, which showed positive margins on specimen mammography, 4 were histologically confirmed to have tumour at the surgical margin and 2 were confirmed to be tumour free. All DBT-positive margins were re-excised at the time of primary surgery. Individual comparison of the margins revealed a good agreement and high level of correlation between DBT and histopathology margins. None of the cases required a second surgery for margin revision. It can be concluded that specimen mammogram with DBT can be used as a reliable tool for intraoperative surgical margin assessment in non-palpable breast lesions to reduce rate of margin revision as well as reduce the volume of breast excised without compromising the oncological safety of the procedure.
An intrinsic gamma-ray burst afterglow
Long gamma-ray bursts (GRBs) are emitted by relativistic jets generated during the collapse of a massive star in a distant galaxy. The GRB itself lasts only a ...few seconds but is followed by an afterglow that can persist for hours or days. The H.E.S.S. Collaboration observed the afterglow of GRB 190829A, a nearby long GRB. The proximity of this burst allowed it to be detected at tera–electron volt energies that would otherwise be absorbed in the intergalactic medium. By analyzing the spectrum and light curve at x-ray and gamma-ray wavelengths, the authors show that the afterglow cannot be explained by standard models.
Science
, abe8560, this issue p.
1081
Observations of a nearby gamma-ray burst at tera–electron volt energies cannot be explained by standard models.
Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays from the afterglow of GRB 190829A, between 4 and 56 hours after the trigger, using the High Energy Stereoscopic System (H.E.S.S.). The low luminosity and redshift of GRB 190829A reduce both internal and external absorption, allowing determination of its intrinsic energy spectrum. Between energies of 0.18 and 3.3 tera–electron volts, this spectrum is described by a power law with photon index of 2.07 ± 0.09, similar to the x-ray spectrum. The x-ray and VHE gamma-ray light curves also show similar decay profiles. These similar characteristics in the x-ray and gamma-ray bands challenge GRB afterglow emission scenarios.
Vanadium pentoxide (V
2
O
5
) is a transition metallic oxide which is suitable for strain gauge application because of its good electrical properties and conductivity. Considering this, cerium oxide ...(CeO
2
)-doped vanadium oxide (V
2
O
5
) nanoparticles are synthesized with the varied concentrations of 5, 10, and 15 wt%, to study its characteristics for fabrication of thin film strain gauges. The structural, transmission spectral, morphological, compositional and the electrical properties of synthesized nanoparticles are characterized using XRD, FTIR, SEM, HRTEM, EDX and CLR meter respectively. The characterization results depict favorable changes within the nanoparticle samples on the addition of dopant. The transformation from amorphous to crystalline phase orthorhombic cubic structure is visible from the x-ray diffraction results. The morphological data depict improvement in the structural appearance of the samples without any cracks on its surface. The shift in transmission spectral peaks towards the lower wave number indicates the improved electronic transitioning due to high activation energy. The drastic improvement in its conductivity from 1 to 4.3 S/m, along with better temperature characteristics specially in case of 10-wt% CeO
2
:V
2
O
5
, depicts the improved sensitivity of the samples. The resulting gauge factor of 45.21 obtained through four-point bending arrangement highlights the better strain resistance behavior of synthesized nanoparticles.
Recurrent novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated when ejected material ...slams into the companion star's wind can accelerate particles. We report very-high-energy (VHE; Formula: see text) gamma rays from the recurrent nova RS Ophiuchi, up to 1 month after its 2021 outburst, observed using the High Energy Stereoscopic System (H.E.S.S.). The temporal profile of VHE emission is similar to that of lower-energy giga-electron volt emission, indicating a common origin, with a 2-day delay in peak flux. These observations constrain models of time-dependent particle energization, favoring a hadronic emission scenario over the leptonic alternative. Shocks in dense winds provide favorable environments for efficient acceleration of cosmic rays to very high energies.
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