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排序方式: 共有1412条查询结果,搜索用时 0 毫秒
211.
This study investigated the effect of a postharvest 1-methylcyclopropene (1-MCP) treatment, controlled atmosphere and storage time on the total antioxidant activity (TAA) and phenolic compounds in the peel and flesh of ‘Cripps Pink’ apples (Malus domestica Borkh.). Preclimacteric apples were harvested and treated with 1-MCP then stored in normal atmosphere (NA) or controlled atmosphere (CA) at 0 °C for up to 160 days. In general, the level of phenolics decreased by 9% in the peel and significantly increased twofold in the flesh during cold storage, regardless of storage atmosphere or 1-MCP treatment. However, treatment with 1-MCP resulted in significantly lower concentrations of chlorogenic acid and procyanidin B2 in apple flesh, and catechin and epicatechin in the peel compared to the control fruits. There was no significant effect of CA on the phenolic compounds during long-term storage, except for quercetin 3-galactoside and quercetin 3-glucoside, which both significantly increased under CA storage. Total antioxidant activity (TAA) is an important nutritional attribute of apples in the human diet. The results showed that TAA in the peel tissue was about eight times higher than that of the flesh, with mean values of 4.75 g TE/kg FW and 0.56 TE/kg FW, respectively. The TAA in both the peel and flesh tissue increased significantly during storage by 40% and 70%, respectively. The storage atmosphere did not significantly affect TAA in either the peel or flesh, whilst the 1-MCP treatment significantly reduced the TAA in the peel tissue only. These results show the beneficial combined effects of pre-storage 1-MCP treatment and CA on ‘Cripps Pink’ apple phenolic composition and antioxidant capacity during long term storage. 相似文献
212.
Sae-Yeol-Rim Paik Hoang Hai Nguyen Jina Ryu Jeong-Hwan Che Tae Seok Kang Jong Kwon Lee Chi Won Song Sanghoon Ko 《Food chemistry》2013
In polymeric nanoparticle preparation, despite similar conditions, large fluctuations in particle size distributions are usually observed. Herein, we demonstrate that the intermittent addition of a desolvating agent can improve reproducibility in the preparation of polymeric bovine serum albumin (BSA) nanoparticles. Using this modification, BSA nanoparticles of controlled size can be manufactured with narrow particle size distributions. In our study, ethanol as a desolvating agent was added intermittently to 1% BSA solutions at different pHs with stirring at 700 rpm. The effect of the preparation parameters on size and optical density of the fabricated nanoparticles were studied. The average particles sizes of BSA nanoparticles prepared at pH values of 6, 7 and 9 were approximately 100, 200 and 300 nm, respectively. As ethanol addition increased, desolvation of BSA molecules resulted in formation of loose-structured particles with pH-dependent size. Beyond that, only particle density increased, but size remained unchanged with further addition of ethanol. Consistently uniform particle size distribution was achieved by adding ethanol intermittently. 相似文献
213.
214.
Emission of polycyclic aromatic hydrocarbons, toxicity, and mutagenicity from domestic cooking using sawdust briquettes, wood, and kerosene 总被引:1,自引:0,他引:1
Smoke samples, in both gas and particulate matter (PM) phases, of the three domestic stoves were collected using U.S. EPA modified method 5 and were analyzed for 17 PAH (HPLC-UV), acute toxicity (Microtox test), and mutagenicity (Amestest). The gas phase of smoke contributed > or = 95% of 17 PAH, > or = 96% of toxicity, and > or = 60% of mutagenicity. The highest emission factor of 17 PAH was from sawdust briquettes (260 mg/kg), but the highest emission of 11 genotoxic PAH was from kerosene (28 mg/kg). PM samples of kerosene smoke were not toxic. The total toxicity emission factor was the highest from sawdust, followed by kerosene and wood fuel. Smoke samples from the kerosene stove were not mutagenic. TA98 indicated the presence of both direct and indirect mutagenic activities in PM samples of sawdust and wood fuel but only direct mutagenic activities in the gas phase. TA100 detected only direct mutagenic activities in both PM and gas-phase samples. The higher mutagenicity emission factor was from wood fuel, 12 x 10(6) revertants/kg (TA100-S9) and 3.5 x 10(6) (TA98-S9), and lower from sawdust, 2.9 x 10(6) (TA100-S9) and 2.8 x 10(6) (TA98-S9). The low burning rate and high efficiency of a kerosene stove have resulted in the lowest PAH, toxicity, and mutagenicity emissions from daily cooking activities. The bioassays produced toxicity and mutagenicity results in correspondence with the PAH content of samples. The tests could be used for a quick assessment of potential health risks. 相似文献
215.
Hoang V. Le Phuong T. Pham Ly T. Le Anh D. Nguyen Ngoc Quang Tran Phong D. Tran 《International Journal of Hydrogen Energy》2021,46(44):22852-22863
WO3 is a potential material candidate for construction of photoanode for solar driven water splitting. In this work, μm-thick porous WO3 photoanode is prepared by depositing a stable ink made of WO3 nanoparticles and Aristoflex velvet polymer in water using the doctor blade technique, followed by a sintering in air. The nature of WO3 nanoparticles, its loading mass on F-doped tin oxide electrode as well as sintering temperature are examined in order to optimize the photocatalytic activity of the resultant WO3 photoanode. The operation of WO3 photoanode is investigated by varying the light illumination direction and light incident intensity as well as changing the nature of the electrolyte. Dissolved tungsten in electrolyte is quantified by ICP-MS providing insights into the influences of electrolyte nature and operating conditions to the corrosion of WO3. It is proposed that the H2O2 and OH. radical generated as by-products of the photo-driven water oxidation on the photoanode surface are harmful species that accelerate the dissolution of WO3. 相似文献
216.
P. R. Gibson K. Hoang 《The International Journal of Advanced Manufacturing Technology》1994,9(3):147-155
This work deals with the implementation of automatic statistical process control (ASPC) on a CNC turning centre using automatic in-cycle gauging with tool offsets and tool change. Owing to the increasing need for a fast and reliable quality control system and in order to cope with the high output rates achievable in manufacturing industry today, a closed-loop ASPC system has been proposed. The technique of automatic in-cycle gauging is introduced in preparation for a detailed examination of the ASPC system which has been procured for this work. 相似文献
217.
NH Schulman 《Canadian Metallurgical Quarterly》1997,38(4):309-13; discussion 313-4
This program enhances residency training in aesthetic surgery. It provides hands-on operating experience in a supervised hospital setting. Concerns of financial support and liability are addressed. Four chief residents from two university programs each spend 3 months conducting a "private" practice in a service population. A separate resident operative consent form unambiguously specifies the resident as the operating surgeon. Patients are derived from an advertised, free screening clinic every 3 months. The hospital has a special aesthetic surgical fee schedule for the residents. A resident operative fee is collected in support of resident salaries and insurance. An additional fee is collected on behalf of our anesthesiologists. During their 3 months the residents perform 30 to 40 operations as primary surgeon and 50 to 60 as the first assistant. Patient discontent, though rare, is resolved in conference with the patient, the resident, the attending surgeon, and the chief of section. Didactic training consists of monthly surgical conferences, journal club, and guest speaker presentations. Residents experience a practice setting by overseeing appointments to their clinic, booking operating room cases, and providing all paperwork for preadmission testing and certification, as well as fulfilling utilization and quality assurance requirements. They are responsible for their operative patients 24 hours a day, 7 days a week. The program is in its seventh year and its success is noted by continued full certification of the two participating university programs and absence of litigation. 相似文献
218.
Reliability, a measure of software, deals in total number of faults count up to a certain period of time. The present study aims at estimating the total number of software faults during the early phase of software life cycle. Such estimation helps in producing more reliable software as there may be a scope to take necessary corrective actions for improving the reliability within optimum time and cost by the software developers. The proposed interval type-2 fuzzy logic-based model considers reliability-relevant software metric and earlier project data as model inputs. Type-2 fuzzy sets have been used to reduce uncertainties in the vague linguistic values of the software metrics. A rule formation algorithm has been developed to overcome inconsistency in the consequent parts of large number of rules. Twenty-six software project data help to validate the model, and a comparison has been provided to analyse the proposed model’s performance. 相似文献
219.
Novel view synthesis from sparse and unstructured input views faces challenges like the difficulty with dense 3D reconstruction and large occlusion. This paper addresses these problems by estimating proper appearance flows from the target to input views to warp and blend the input views. Our method first estimates a sparse set 3D scene points using an off‐the‐shelf 3D reconstruction method and calculates sparse flows from the target to input views. Our method then performs appearance flow completion to estimate the dense flows from the corresponding sparse ones. Specifically, we design a deep fully convolutional neural network that takes sparse flows and input views as input and outputs the dense flows. Furthermore, we estimate the optical flows between input views as references to guide the estimation of dense flows between the target view and input views. Besides the dense flows, our network also estimates the masks to blend multiple warped inputs to render the target view. Experiments on the KITTI benchmark show that our method can generate high quality novel views from sparse and unstructured input views. 相似文献
220.
Duong Chi Nhan Quach Kha Gia Luu Khoa Le T. Hoang Ngan Savvides Marios Bui Tien D. 《International Journal of Computer Vision》2019,127(6-7):957-971
International Journal of Computer Vision - This paper presents a novel subject-dependent deep aging path (SDAP), which inherits the merits of both generative probabilistic modeling and inverse... 相似文献