Effect of non-condensable gas on the startup of a loop heat pipe

It is essential to address the startup issues prior to the wide application of loop heat pipes (LHPs) in both space and terrestrial surroundings. As non-condensable gas (NCG) is an important factor affecting the startup behavior, its effects on the startup performance of an ammonia-stainless steel LHP with and without preconditioning were experimentally investigated in this work. Nitrogen with controlled amounts was used to simulate the NCG, and the temperature overshoot, liquid superheat and startup time were employed as the evaluation criteria. Four situations relating to initial liquid/vapor distribution in the evaporator were examined: (1) both evaporator core and vapor grooves are filled with liquid, (2) vapor exists in vapor grooves and the evaporator core is filled by liquid, (3) vapor grooves are filled by liquid and vapor exists in the evaporator core, and (4) vapor exists in both evaporator core and vapor grooves. Experimental results showed that with NCG presence in the LHP, the startup could only proceed in situation 1 with preconditioning, while it could proceed in situations 1, 3 or 4 without preconditioning. For the startup in situation 1, a larger NCG inventory led to much degraded startup performance, and a higher startup heat load could benefit the startup. For the startup in situation 3, the most difficult startup situation, NCG resulted in a very high temperature overshoot, which may even exceed the maximum allowable value. For the startup in situation 4, the existence of NCG in the vapor grooves could facilitate the evaporation there, leading to a very desirable startup

Isolation and Purification of a Peptide from Bullacta exarata and Its Impaction of Apoptosis on Prostate Cancer Cell

Abstract: Bullacta exarata was hydrolyzed with trypsin to prepare peptides; Hydrolysates were isolated by ultrafiltration and purified using G-25 gel filtration. The purity of the Bullacta exarata was demonstrated by HPLC and its peptide sequence analysis was detected. The effects of BEPT II and BEPT II-1 on the proliferation of PC-3 cells were examined using a MTT assay. BEPT II and BEPT II-1 significantly inhibited the proliferation of PC-3 cells in a time- and dose-dependent manner. Annexin V/PI double staining studies showed exposing PC-3 cells to 5, or 15 mg/mL BEPT II-1 for 24 h increased the percentage of the early stage of apoptotic cells from 11.22 % to 22.09%. In addition, typical morphologic changes were observed in the cells with acridine orange/ethidium bromide staining. These data support that BEPT II-1 has anticancer properties and merits further investigation to understand the mechanisms of BEPT II-1-induced apoptosis in PC-3 cells

Heat shock protein 27 is over-expressed in tumor tissues and increased in sera of patients with gastric adenocarcinoma

Background: In a previous study, we found that heat shock protein 27 (HSP27) was over-expressed in gastric adenocarcinoma (GA) tissue. In this study, our goal was to further verify the expression profile of HSP27 in patients with GA. Methods: Western blot and immunohistochemistry were employed to determine HSP27 expression in 50 paired tumor and adjacent normal tissue. ELISA was used to quantify serum HSP27 concentrations in the same 50 GA patients and 50 healthy individuals. Results: Compared to adjacent normal tissues, HSP27 was over-expressed in 25 (50%, p=0.000) and 24 (48%, p=0.000) cases of GA tissue by Western blot and immunohistochemistry, respectively. ELISA revealed significantly higher serum concentrations of HSP27 in patients with GA patients (mean=986 pg/mL) compared to healthy individuals (mean=573 pg/mL) (p=0.003). In addition, infection with Helicobacter pylori (HP) in healthy individuals was associated with increased expression of HSP27 in both gastric mucosa and serum. Conclusions: These data suggest that HSP27 is over-expressed in GA tissue and serum concentrations of HSP27 are increased in patients with GA. Over-expression of HSP27 may indicate a gastric malignant/infectious process. The detection of serum HSP27 concentrations by ELISA may be useful for screening for GA. Clin Chem Lab Med 2010;48:263–9.Peer Reviewe

A novel estimation model for hysteresis loss based on semi-minor loops

This paper proposes an estimation model of hysteresis loss based on the mapping of the hysteresis loop conducted through tiny material samples with the aid of the Superconducting Quantum Interference Device (SQUID). This approach allows precise measurement of hysteresis loops. The aim of this paper is to develop a precise estimation model for hysteresis loss, one component of core loss, so as to improve the overall estimation accuracy of the entire core loss under complex excitations. First, with the help of the SQUID system and measurements conducted on tiny samples, the proposed model manages to minimize the impact of eddy current throughout the measurement and the modeling of hysteresis loss. This contrasts with the use of the conventional Steinmetz model and its modifications. Moreover, compared with methods including the modified Steinmetz equation (MSE) and the generalized Steinmetz equation (GSE) which merely focuses on the overall iron loss under simple non-sinusoidal excitations, the model presented here enables the estimation of hysteresis loss under complex excitations where multiple peaks and DC-bias take place. This approach will be very useful in situations such as those requiring pulse-width modulation (PWM) excited converters which are quite common on occasions including wind power systems. The estimation error of this model on the actual coil is within 15% under given excitations

Comprehensive Utilization of Immature Honey Pomelo Fruit for the Production of Value-Added Compounds Using Novel Continuous Phase Transition Extraction Technology

The immature honey pomelo fruit (IPF) is a huge agro-industrial by-product generated during pomelo planting. Although IPF is rich in nutrients, more than 95% of IPF is discarded annually, which causes resource waste and a serious environmental problem. Here, we report a novel continuous phase transition extraction technology (CPTE) to improve the comprehensive utilization of IPF by sequentially generating high value products and solve pollution problems related to their disposal. First, essential oil was successively extracted by CPTE at a yield of 1.12 ± 0.36%, in which 43 species were identified. Second, naringin extraction parameters were optimized using the response surface methodology (RSM), resulting in a maximum extraction rate of 99.47 ± 0.15%. Finally, pectin was extracted at a yield of 20.23 ± 0.66%, which is similar to the contents of commercial pectin. In conclusion, this study suggested that IPF was an excellent potential substrate for the production of value-added components by CPTE

Low-dose PPI to prevent bleeding after ESD: A multicenter randomized controlled study

Background: Although proton pump inhibitors (PPIs) are widely used in the prevention of gastric bleeding caused by endoscopic submucosal dissection (ESD), there is no consensus on the optimal regimen for these patients. Therefore, we aim to investigate whether intermittent use of low-dose PPI is sufficient to prevent post-ESD bleeding. Methods: This multicenter, non-inferiority, randomized controlled trial was conducted at 9 hospitals in China. Consecutive eligible patients with a diagnosis of gastric mucosal lesions after ESD treatment were randomly assigned (1:1) to receive either intermittent low-dose or continuous high-dose PPIs treatment. After three days, all patients administered orally esomeprazole 40 mg once a day for 8 weeks. The primary endpoint was post-ESD bleeding within 7 days. Analysis was done according to the intention-to-treat principle with the non-inferiority margin (Δ) of 5%. Results: 526 consecutive patients were assessed for eligibility from 30 September 2017 to 30 July 2019, of whom 414 were randomly assigned to low-dose (n = 209) or high-dose (n = 205) esomeprazole treatment group without dropouts within7 days. The total post-ESD bleeding is occurred in 13 (6.2 %, 95 % CI 3.3–9.6) of 209 within 7 days in the intermittent low-dose group, and 12 (5.9 %, 95 % CI 2.9–9.3) of 205 in the continuous high-dose group. The absolute risk reduction (ARR) was 0.4 % (−4.2, 4.9). One month after ESD, There are 44 patients (21.1 %, 95 % CI 15.8, 26.8) and 39 patients (19.0 % 95 % CI 13.7, 24.4) in scar stage respectively in low-dose group and high-dose group (P = 0.875).The hospital costs in the low-dose PPI group was lower than high -dose group (P = 0.005). Conclusion: The intermittent use of low-dose PPIs is sufficient to prevent post-ESD bleeding. It might be applied in clinical practice to prevent post-ESD bleeding and reduce the costs related to PPIs