RNA design via structure-aware multifrontier ensemble optimization.

MOTIVATION: RNA design is the search for a sequence or set of sequences that will fold to desired structure, also known as the inverse problem of RNA folding. However, the sequences designed by existing algorithms often suffer from low ensemble stability, which worsens for long sequence design. Additionally, for many methods only a small number of sequences satisfying the MFE criterion can be found by each run of design. These drawbacks limit their use cases. RESULTS: We propose an innovative optimization paradigm, SAMFEO, which optimizes ensemble objectives (equilibrium probability or ensemble defect) by iterative search and yields a very large number of successfully designed RNA sequences as byproducts. We develop a search method which leverages structure level and ensemble level information at different stages of the optimization: initialization, sampling, mutation, and updating. Our work, while being less complicated than others, is the first algorithm that is able to design thousands of RNA sequences for the puzzles from the Eterna100 benchmark. In addition, our algorithm solves the most Eterna100 puzzles among all the general optimization based methods in our study. The only baseline solving more puzzles than our work is dependent on handcrafted heuristics designed for a specific folding model. Surprisingly, our approach shows superiority on designing long sequences for structures adapted from the database of 16S Ribosomal RNAs. AVAILABILITY AND IMPLEMENTATION: Our source code and data used in this article is available at https://github.com/shanry/SAMFEO.

Design and Development of a Broadband Vibration Energy Harvester Suitable for Tractor Exhaust Cylinder Vibration.

A large amount of vibration energy exists in the working environment of tractors. Therefore, the use of vibration energy harvesting technology to convert the vibration energy into electrical energy is a feasible way to supply power to low-power sensor equipment in agricultural machinery. Aiming at the problem in which the internal sensors of traditional tractors require built-in batteries or overlapping cables, this work proposes a broadband piezoelectric vibration energy harvester that could harvest the vibration energy from the tractor exhaust cylinder when the tractor is working. The vibration energy can be converted into electrical energy to power the air pressure sensor device. This experimental investigation shows that the energy harvester is composed of a folded piezoelectric energy harvester and a multi-source input synchronous electronic charge extraction circuit.The circuit has a high power density of 12,398 µW/(mm3·g2). Hence, it can convert vibration energy into a wide frequency range between 90-140 Hz and cause the air pressure sensor to operate.

Survival and prognostic factors of patients with esophageal fistula in advanced esophageal squamous cell carcinoma.

The aim of the present study was to investigate the survival and prognostic factors of patients who were with advanced esophageal squamous cell carcinoma (ESCC) and developed an esophageal fistula. The data from 221 patients with advanced ESCC developed esophageal fistula from January 2008 to December 2017 at the Harbin Medical University Cancer Hospital was retrospectively analyzed. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by the Cox proportional hazard models. The median survival time after a diagnosis of the esophageal fistula was calculated using the Kaplan-Meier method. We found that the pathogens infected by patients are common bacteria in nosocomial infection. Besides, the incidence rate of esophagomediastinal fistula was the highest (54.2%) in the lower third of the esophagus. Kaplan-Meier analysis revealed a median survival time of 11.00 months and a median post-fistula survival time of 3.63 months in patients who developed esophageal fistula in advanced esophageal cancer. In the univariate analysis, gender, therapies for ESCC before the development of fistula, type of esophageal fistula, treatment of esophageal fistula and hemoglobin (Hb) level were the factors with significant prognostic value. Gender, type of esophageal fistula and Hb level were identified as independent prognostic factors in further multivariate analysis. In summary, our study demonstrated that several factors are significantly related to patients with esophageal fistula and should be concerned about in clinical practice.

Long-term survival of an elderly patient with advanced gastric cancer after combination therapy: a case report and literature review.

BACKGROUND: Gastric cancer ranks the fifth most common cancer, and the third leading cause of cancer-related deaths worldwide. Gastric cancer with liver metastasis (GCLM) has devastating prognosis, however, optimal treatment of GCLM, especially in elderly patients, has yet to be clarified. CASE PRESENTATION: A 75-year-old man was diagnosed with advanced gastric cancer (GC), presenting with acute gastrointestinal bleeding and synchronous metastatic lesion in liver. Based on multidisciplinary team (MDT)'s decision, this patient underwent distal palliative gastrectomy with R1 margin. Histopathological diagnosis was stage IV gastric adenocarcinoma (pT3N2M1), HER2 negative. The patient was treated with chemotherapy and argon-helium cryoablation of liver and lung metastases.HER-2 gene amplification was identified in peripheral blood at later stage of therapy. The patient had been followed-up for 39 months, in sharp contrast to a median survival time of 13.8 months for majority of advanced GC. CONCLUSIONS: Palliative distal gastrectomy in combination with chemotherapy and cryoablation significantly prolongs overall survival of an elderly patient with GCLM.