Thermodynamic analysis of a dual-loop organic Rankine cycle (ORC) for waste heat recovery of a petrol engine

Huge amounts of low-grade heat energy are discharged to the environment by vehicular engines. Considering the large number of vehicles in the world, such waste energy has a great impact on our environment globally. The Organic Rankine Cycle (ORC), which uses an organic fluid with a low boiling point as the working medium, is considered to be the most promising technology to recover energy from low-grade waste heat. In this study, a dual-loop ORC is presented to simultaneously recover energy from both the exhaust gases and the coolant of a petrol engine. A high-temperature (HT) ORC loop is used to recover heat from the exhaust gases, while a low-temperature (LT) ORC loop is used to recover heat from the coolant and the condensation heat of the HT loop. Figure 1 shows the schematic of the dual-loop ORC. Differing from previous research, two more environmentally friendly working fluids are used, and the corresponding optimisation is conducted. First, the system structure and operating principle are described. Then, a mathematical model of the designed dual-loop ORC is established. Next, the performance of the dual-loop cycle is analysed over the entire engine operating region. Furthermore, the states of each point along the cycle and the heat load of each component are compared with the results of previous research. The results show that the dual-loop ORC can effectively recover the waste heat from the petrol engine, and that the effective thermal efficiency can be improved by about 20 ~ 24%, 14~20%, and 30% in the high-speed, medium-speed, and low-speed operation regions, respectively. The designed dual-loop ORC can achieve a higher system efficiency than previous ORCs of this structure. Therefore, it is a good choice for waste heat recovery from vehicle engines

Natural Response Generation for Chinese Reading Comprehension

Machine reading comprehension (MRC) is an important area of conversation agents and draws a lot of attention. However, there is a notable limitation to current MRC benchmarks: The labeled answers are mostly either spans extracted from the target corpus or the choices of the given candidates, ignoring the natural aspect of high-quality responses. As a result, MRC models trained on these datasets can not generate human-like responses in real QA scenarios. To this end, we construct a new dataset called Penguin to promote the research of MRC, providing a training and test bed for natural response generation to real scenarios. Concretely, Penguin consists of 200k training data with high-quality fluent, and well-informed responses. Penguin is the first benchmark towards natural response generation in Chinese MRC on a relatively large scale. To address the challenges in Penguin, we develop two strong baselines: end-to-end and two-stage frameworks. Following that, we further design Prompt-BART: fine-tuning the pre-trained generative language models with a mixture of prefix prompts in Penguin. Extensive experiments validated the effectiveness of this design.Comment: 15 page

4-(4-Chloro­phen­yl)-5-(4-nitro­phen­yl)-3-phenyl-4H-1,2,4-triazole

The title compound, C20H13ClN4O2, was synthesized by the condensation of 4-nitro­benzohydrazide and N-(4-chlorophen­yl)­benzimidoyl chloride in N,N-dimethyl­acetamide. The asymmetric unit contains two independent mol­ecules. In one molecule, the triazole ring is oriented at dihedral angles of 23.1 (5), 85.4 (1) and 10.5 (1)° with respect to the phenyl, chlorophenyl and nitrophenyl rings, respectively. In the other molecule, the corresponding dihedral angles are 29.8 (9), 73.4 (7) and 16.4 (3)°

Co-administration of a DNA vaccine encoding the prostate specific membrane antigen and CpG oligodeoxynucleotides suppresses tumor growth

BACKGROUND: Prostate-specific membrane antigen (PSMA) is a well characterized prostate-specific tumor associated antigen. Its expression is elevated in prostate carcinoma, particularly in metastatic and recurrent lesions. These observations suggest that PSMA can be used as immune target to induce tumor cell-specific recognition by the host and, consequently tumor rejection. We utilized a DNA-based vaccine to specifically enhance PSMA expression. An immune modulator, such as CpG oligodeoxynucleotides which promote Th1-type immune responses was combined to increase the efficacy of tumor recognition and elimination. METHODS: A eukaryotic expression plasmid pCDNA3.1-PSMA encoding full-length PSMA was constructed. C57BL/6 mice were immunized with endotoxin-free pCDNA3.1-PSMA alone or in combination with CpG oligodeoxynucleotides by intramuscular injection. After 4 immunizations, PSMA specific antibodies and cytotoxic T lymphocyte reactivity were measured. Immunized C57BL/6 mice were also challenged subcutaneously with B16 cells transfected with PSMA to evaluate suppression of tumor growth. RESULTS: Vaccine-specific cytotoxic T lymphocytes reactive with B16 cells expressing PSMA could be induced with this treatment schedule. Immune protection was observed in vaccinated mice as indicated by increased tumor growth in the control group (100%) compared with the groups vaccinated with DNA alone (66.7%) or DNA plus CpG oligodeoxynucleotides (50%) respectively. Average tumor volume was smaller in vaccinated groups and tumor-free survival time was prolonged by the vaccination. CONCLUSION: The current findings suggest that specific anti-tumor immune response can be induced by DNA vaccines expressing PSMA. In addition, the suppression of in vivo growth of tumor cells expressing PSMA was augmented by CpG oligodeoxynucleotides. This strategy may provide a new venue for the treatment of carcinoma of prostate after failure of standard therapy

Ketamine Inhibits Lung Fluid Clearance through Reducing Alveolar Sodium Transport

Ketamine is a broadly used anaesthetic for analgosedation. Accumulating clinical evidence shows that ketamine causes pulmonary edema with unknown mechanisms. We measured the effects of ketamine on alveolar fluid clearance in human lung lobes ex vivo. Our results showed that intratracheal instillation of ketamine markedly decreased the reabsorption of 5% bovine serum albumin instillate. In the presence of amiloride (a specific ENaC blocker), fluid resolution was not further decreased, suggesting that ketamine could decrease amiloride-sensitive fraction of AFC associated with ENaC. Moreover, we measured the regulation of amiloride-sensitive currents by ketamine in A549 cells using whole-cell patch clamp mode. Our results suggested that ketamine decreased amiloride-sensitive Na+ currents (ENaC activity) in a dose-dependent fashion. These data demonstrate that reduction in lung ENaC activity and lung fluid clearance following administration of ketamine may be the crucial step of the pathogenesis of resultant pulmonary edema

Cladding waveguide splitters fabricated by femtosecond laser inscription in Ti:Sapphire crystal

Highly-compact devices capable of beam splitting are intriguing for a broad range of photonic applications. In this work, we report on the fabrication of optical waveguide splitters with rectangular cladding geometry in a Ti:Sapphire crystal by femtosecond laser inscription. Y-splitters are fabricated with 30 μm × 15 μm and 50 μm × 25 μm input ends, corresponding to two 15 μm × 15 μm and 25 μm × 25 μm output ends, respectively. The full branching angle θ between the two output arms are changing from 0.5° to 2°. The performances of the splitters are characterized at 632.8 nm and 1064 nm, showing very good properties including symmetrical output ends, single-mode guidance, equalized splitting ratios, all-angle-polarization light transmission and intact luminescence features in the waveguide cores. The realization of these waveguide splitters with good performances demonstrates the potential of such promising devices in complex monolithic photonic circuits and active optical devices such as miniature tunable lasers.This work is supported by the National Natural Science Foundation of China (No. 11404194). Authors acknowledge support from Junta de Castilla y León (Project SA046U16) and MINECO (FIS2015-71933-REDT). Authors would like to thank Prof. Xiaotao Hao from Shandong University for the help on micro-photoluminescence measurement

Gut stem cell aging is driven by mTORC1 via a p38 MAPK-p53 pathway.

Nutrients are absorbed solely by the intestinal villi. Aging of this organ causes malabsorption and associated illnesses, yet its aging mechanisms remain unclear. Here, we show that aging-caused intestinal villus structural and functional decline is regulated by mTORC1, a sensor of nutrients and growth factors, which is highly activated in intestinal stem and progenitor cells in geriatric mice. These aging phenotypes are recapitulated in intestinal stem cell-specific Tsc1 knockout mice. Mechanistically, mTORC1 activation increases protein synthesis of MKK6 and augments activation of the p38 MAPK-p53 pathway, leading to decreases in the number and activity of intestinal stem cells as well as villus size and density. Targeting p38 MAPK or p53 prevents or rescues ISC and villus aging and nutrient absorption defects. These findings reveal that mTORC1 drives aging by augmenting a prominent stress response pathway in gut stem cells and identify p38 MAPK as an anti-aging target downstream of mTORC1

Incision pressing, a simple and effective intervention to reduce colorectal surgical site infection: A propensity score-matched study

BackgroundColorectal surgery is associated with a high risk of surgical site infection (SSI). In March 2017, we developed an intervention, called “PRESS”, with the aim of reducing colorectal superficial SSI. This study assessed the effect of the new intervention in reducing the rates of superficial SSI in colorectal surgery.MethodsThis study was a retrospective review of 312 PRESS+ patients compared to 171 historical control PRESS− patients who were 18 years of age or older and underwent elective colorectal surgery with clean-contaminated wounds from January 2015 to June 2020. In the PRESS+ groups, we pressed the incision downward hard with clean gauze after the interrupted suturing of the skin. Propensity score matching with 15 variables was performed in a 1:1 ratio to reduce selection bias. Univariate analysis and multivariate analysis were performed to identify risk factors associated with SSI.ResultsThe characteristics of the PRESS+ (n = 160) and PRESS− (n = 160) groups were well balanced after propensity score matching. The PRESS+ group had a lower superficial SSI rate (1.9% vs. 6.9%, P = 0.029) and a lower overall SSI rate (2.5% vs. 10.0%, P = 0.006) than the PRESS− group. Furthermore, multivariate analysis showed that the incisional press was an effective protective factor for superficial SSI (adjusted odds ratio = 0.215, 95% confidence interval = 0.057–0.818, P = 0.024). In addition, female sex (P = 0.048) and blood transfusion (P = 0.011) were demonstrated to be independent risk factors for superficial SSI.ConclusionThe incisional press after suturing is a simple, costless, and effective intervention in reducing superficial incisional SSI