Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Virtual staining of colon cancer tissue by label-free Raman micro-spectroscopy

The great capability of the label-free classification of tissue via vibrational spectroscopy, like Raman or infrared imaging, is shown in numerous publications (review: Diem et al., J. Biophotonics, 2013, 6, 855-886). Herein, we present a new approach, virtual staining, that improves the Raman spectral histopathology (SHP) images of colorectal cancer tissue by combining the integrated Raman intensity image in the C-H stretching region (2800-3050 cm^-1) with the pseudo-colour Raman image. This allows the display of fine structures such as the filamentous composition of muscle tissue. The morphology of the virtually stained images is in agreement with the gold standard in medical diagnosis, the haematoxylin-eosin staining. The virtual staining image also represents the whole biochemical fingerprint, and several tissue components including carcinoma were identified automatically with high sensitivity and specificity. For fast tissue classifications, a similar approach was applied on coherent anti-Stokes Raman scattering (CARS) spectral data that is faster and therefore potentially more suitable for clinical applications.

Raman fiber-optical method for colon cancer detection: Cross-validation and outlier identification approach

Endoscopy plays a major role in early recognition of cancer which is not externally accessible and therewith in increasing the survival rate. Raman spectroscopic fiber-optical approaches can help to decrease the impact on the patient, increase objectivity in tissue characterization, reduce expenses and provide a significant time advantage in endoscopy. In gastroenterology an early recognition of malign and precursor lesions is relevant. Instantaneous and precise differentiation between adenomas as precursor lesions for cancer and hyperplastic polyps on the one hand and between high and low-risk alterations on the other hand is important. Raman fiber-optical measurements of colon biopsy samples taken during colonoscopy were carried out during a clinical study, and samples of adenocarcinoma (22), tubular adenomas (141), hyperplastic polyps (79) and normal tissue (101) from 151 patients were analyzed. This allows us to focus on the bioinformatic analysis and to set stage for Raman endoscopic measurements. Since spectral differences between normal and cancerous biopsy samples are small, special care has to be taken in data analysis. Using a leave-one-patient-out cross-validation scheme, three different outlier identification methods were investigated to decrease the influence of systematic errors, like a residual risk in misplacement of the sample and spectral dilution of marker bands (esp. cancerous tissue) and therewith optimize the experimental design. Furthermore other validations methods like leave-one-sample-out and leave-one-spectrum-out cross-validation schemes were compared with leave-one-patient-out cross-validation. High-risk lesions were differentiated from low-risk lesions with a sensitivity of 79%, specificity of 74% and an accuracy of 77%, cancer and normal tissue with a sensitivity of 79%, specificity of 83% and an accuracy of 81%. Additionally applied outlier identification enabled us to improve the recognition of neoplastic biopsy samples.

Laparoscopic repair of perineal hernia after abdominoperineal excision

PURPOSE

Perineal hernia is a challenging complication after abdominoperineal excision (APE) of the rectum. Surgical repair can be accomplished using challenging abdominal or transperineal approaches. A laparoscopic repair using a Proceed mesh might be an easy and effective alternative.

METHODS

We describe a multi-center case-series of twelve patients with a symptomatic perineal hernia treated by laparoscopic mesh repair. A cone-shaped 10 × 15 cm Proceed Mesh was tacked to the promontory or sacrum and sutured to the pelvic sidewalls and the anterior peritoneum.

RESULTS

Twelve patients underwent laparoscopic repair of their perineal hernia. Four men and eight women presented with a symptomatic perineal hernia after abdominoperineal excision between 2008 and 2013 and underwent a laparoscopic repair with a Proceed mesh. The median age at presentation was 53 years (range 39-68 years). The mean total theater time was 119 min (range 75-200 min). No conversion to an open procedure was needed. No early complications where seen. The mean hospital stay was 2.25 days (range 1-4 days). Three patients showed recurrence, of whom two had a defect in the middle of the proceed mesh, one had a defect anterior to the previous perineal hernia. All 3 patients underwent a redo-laparoscopic repair with mesh.

CONCLUSION

In this case series we present an alternative approach for the surgical repair of perineal hernias. Based on our experience, perineal hernia after APE can be repaired safely and effectively using the described laparoscopic technique.

Are we burying our heads in the sand? Preventing small bowel obstruction from the V-loc® suture in laparoscopic ventral rectopexy

AIM

There have been increasing reports in the literature highlighting the complication of V-loc® associated small bowel obstruction in patients after laparoscopic ventral rectopexy.

METHODS AND RESULTS

Using clinical and experimental evidence, we demonstrate that bowel obstruction from the V-loc® following laparoscopic ventral rectopexy will still occur despite the technical recommendations to bury or cut its barbed end flush.

CONCLUSION

The risk of bowel obstruction from the V-loc® following laparoscopic ventral rectopexy is not negated by burying or cutting its barbed end flush. We have proposed its pathogenesis to refute commonly held assumptions about its prevention.

Surgical outcomes in steroid refractory acute severe ulcerative colitis: the impact of rescue therapy

AIM

The advent of rescue medical therapy (cyclosporin or infliximab) and laparoscopic surgery has shifted the paradigm in managing steroid refractory acute severe ulcerative colitis (ASUC). We investigated prospectively the impact of rescue therapy on timing and postoperative complications of urgent colectomy and subsequent restorative surgery for steroid refractory ASUC.

METHOD

All consecutive presentations of steroid refractory ASUC at the Royal Brisbane Hospital (1996-2009) were entered in the study. Data collated included demographics, clinical and laboratory parameters on admission, medical therapy and operative and postoperative details. Steroid refractory ASUC patients undergoing immediate colectomy were compared with those failing rescue therapy and requiring same admission colectomy.

RESULTS

Of 108 steroid refractory ASUC presentations, 19 (18%) received intravenous steroids only and proceeded directly to colectomy. Rescue medical therapy was instituted in 89 (82%) patients with 30 (34%) failing to respond and proceeding to colectomy. There was no significant difference in the median time from admission to colectomy for rescue therapy compared with steroid-only cases (12 vs 10 days, P = 0.70) or 30-day complication rates (27%vs 47%, P = 0.22). The interval from colectomy to a subsequent restorative procedure was significantly longer for patients who failed rescue therapy (12 vs 5 months, P = 0.02). Furthermore 30-day complications following pouch surgery were significantly higher in patients who failed rescue therapy (32%vs 0%, P = 0.01).

CONCLUSION

Rescue therapy in steroid refractory ASUC is not related to delay in urgent colectomy or increased post-colectomy complications.

Isolated lympho-histiocytic inflammation of the Gasserian ganglion mimicking trigeminal schwannoma

We present an unusual case of a patient with trigeminal pain and hypesthesia suggesting trigeminal schwannoma, where histology demonstrated an inflammatory lesion of the Gasserian ganglion.

CLINICAL PRESENTATION

Patient history and imaging were typical for a trigeminal schwannoma with a dumbbell growth in the middle and posterior fossa. Surgery was performed and resection of a firm mass intermingled with fascicles originating from the ganglion and the mandibular branch was carried out via a subtemporal approach. Histological diagnosis revealed a non-caseating, vaguely granulomatous lymphocyte- and histiocyte-rich inflammation.

CONCLUSION

Inflammatory lesions of the Gasserian ganglion are rare but may mimic tumors. Intraoperative biopsies should be taken prior to complete resection to limit neurological deterioration.

Premotor Gray Matter Volume is Associated with Clinical Findings in Idiopathic and Genetically Determined Parkinson's Disease

In the present voxel-based morphometric study, we investigated whether the severity and duration of disease are associated with alterations in gray matter volume (GMV) in symptomatic Parkin mutation carriers (sPARKIN-MC) and patients with idiopathic Parkinson’s disease (iPD). Regression analyses revealed different negative correlations between GMV in cortical motor areas and the severity as well as the disease duration in sPARKIN-MC and iPD patients. SPARKIN-MC showed a less involvement of cortical motor areas, in particular in the supplementary motor area (SMA) than iPD patients. Specifically, in iPD patients, but not in sPARKIN-MC, there was a negative correlation between the SMA degeneration and the UPDRS-II item freezing. The different degeneration patterns may mirror diverse kinetics of the disease progress in these two groups of PD patients with different underlying etiologies.