A massive rock and ice avalanche caused the 2021 disaster at Chamoli, Indian Himalaya.

On 7 February 2021, a catastrophic mass flow descended the Ronti Gad, Rishiganga, and Dhauliganga valleys in Chamoli, Uttarakhand, India, causing widespread devastation and severely damaging two hydropower projects. More than 200 people were killed or are missing. Our analysis of satellite imagery, seismic records, numerical model results, and eyewitness videos reveals that ~27 × 106 cubic meters of rock and glacier ice collapsed from the steep north face of Ronti Peak. The rock and ice avalanche rapidly transformed into an extraordinarily large and mobile debris flow that transported boulders greater than 20 meters in diameter and scoured the valley walls up to 220 meters above the valley floor. The intersection of the hazard cascade with downvalley infrastructure resulted in a disaster, which highlights key questions about adequate monitoring and sustainable development in the Himalaya as well as other remote, high-mountain environments.

Efficacy of the postoperative management after microsurgical free tissue transfer.

INTRODUCTION: The physical and medical postoperative measures after free flap reconstruction vary substantially between surgical units. The objective of this review was to identify the postoperative measures which proved a significant positive effect on free flap survival. METHOD: A review was conducted in the MEDLINE database on the English and French literature. RESULTS AND DISCUSSION: Twenty-eight articles were retained. A meta-analysis of 4984 patients who were given antithrombotics (viz. antiplatelets and anticoagulants) postoperatively found that these treatments were of no significant benefit to free flap survival and increased the risk of postoperative hematoma. Postoperative transfusions did not favor free flap survival and were associated with a higher incidence of medical complications. Preoperative anemia was a risk factor for free flap failure. Blood pressure control, vasodilators, antioxidants, corticotherapy, oxygen therapy, and prolonged immobilization were of no proven benefit. CONCLUSION: No postoperative therapy, whether drug-based or not, has been shown to have a significant positive effect on free flap survival.

Association of surgical excision and brachytherapy for the management of keloids.

Many techniques have been described to prevent the appearance and relapse of keloids but most of them have an efficacy lower than 50%. Our objective is to describe our standardized management of keloids by associated surgery and brachytherapy. Surgery-brachytherapy is usually given only when less invasive treatments failed. Both a surgeon and a radiotherapist are involved. Forty-eight hours of hospitalization in a surgery unit are required. The extra-lesional excision is performed and a brachytherapy sheath is placed in the dermis plane. An iridium source with an initial activity of 300 GBq is used to deliver high dose rate brachytherapy. The brachytherapy sessions are held in a lead-shielded room in a radiotherapy unit: the first session at 6 h after surgical excision, while the second and third on the following day. The total dose administered is 18 Gy. A surgical workup is scheduled at 10 days. The patient is followed-up closely by the radiotherapist for an 18-month period. The recurrence rate after 2 years is 8 to 12%. The main complaints are dyschromia, telangiectasia and skin atrophy.

Nuclear lesions during rat hepatocarcinogenesis. I. Measuring the sister-chromatid exchanges during initiation, promotion and progression of rat hepatocarcinogenesis induced with diethylnitrosamine.

Cytogenetic endpoints such as sister-chromatid exchanges (SCEs), chromosomal aberrations and micronuclei (MNs) have been widely used as indicators of genetic damage. However, no systematic attempts have been made to correlate the levels of these cytogenetic endpoints with the different steps of carcinogenesis. In the present report, the induction, accumulation and persistence of SCEs and high frequency cells (HFCs) were measured in liver cells during the initiation, promotion and progression steps of rat hepatocarcinogenesis induced by diethylnitrosamine (DEN). The results indicate that lesions leading to SCEs accumulate during initiation only. When DEN administration is longer than the duration of this first step, SCE values stabilize. After stopping the carcinogenic treatment, the SCE levels decrease to control values whether or not promotion and progression occur.