695 research outputs found
AAS227 - Synthesizing Understanding from Data with yt
No full textThis is a talk I gave at the AAS227 about yt. yt is available at yt-project.org.<div><br></div><div>While I am listed as the author of this talk, the yt community is composed of more than a hundred code contributors and mailing list participants, and we are grateful to their involvement and support.</div><div><br></div><div>Additionally, the yt project is built on other members of the scientific software ecosystem such as Jupyter, NumPy, Cython, h5py and hdf5, Matplotlib, and Sympy.</div
Antioxidant activities and phytochemical characteristics of leaf extracts from 18 indigenous tree species in Taiwan.
No full textAntihypertensive effects of lactobacillus -fermented milk orally administered to spontaneously hypertensive rats.
No full textScreening and characterization of lactic acid bacterial strains possessing benzo[a]pyrene-removing ability
No full text燒烤食物含苯并[a]芘（benzo[a]pyrene），經過人體代謝後容易形成致癌物。近年來的相關研究指出，可以利用乳酸菌和致癌劑之結合，進而降解或代謝成毒性較低之物質，減低對人體腸胃道的潛在危險。本研究為了篩選出具有清除苯并[a]芘之能力的乳酸菌，從嬰兒糞便中，先進行菌株之初篩選，再根據清除苯并[a]芘的能力及抗突變之分析情形，篩選出具有較高清除率之菌株，進行基本特性分析。結果顯示，初篩選出28株類乳酸菌，進一步在苯并[a]芘清除試驗中，利用添加1 ppm苯并[a]芘至不同篩選出的菌株之培養基中，進而篩選出YT 2、YT 5及YT 17乳酸菌株對苯并[a]芘具有較強之清除率，分別為97.66 %、 97.66 %及97.79 %。將活菌體經過熱處理與超音波破碎法來製備熱致死菌體、細胞壁及細胞內萃取物，結果顯示活菌體結合率大於熱致死菌體，而細胞壁結合率大於細胞內萃取物，可以推測乳酸菌株清除苯并[a]芘以吸附作用為主，細胞壁為重要的結合因子。進一步使用安氏試驗法之測試菌株Salmonella typhimurium TA100來分析乳酸菌對苯并[a]芘誘導突變之預防效果，結果顯示，三株乳酸菌對S. typhimurium TA100並不具有毒性與致突變性，並對苯并[a]芘誘突變性具有超過50%的抑制效果。連續的預反應研究顯示抗突變性的主要機制是去致突變作用。經革蘭氏染色法、API 50 CHL及16S rRNA鑑定結果顯示YT 2及YT 5屬於Enterococcus feacium，而YT 17屬於Enterococcus feaclis。以模擬宿主腸胃道環境的耐酸及膽鹽耐受性試驗顯示，此三株菌可在pH 2的環境中存活，並可於含有0.3% oxgall的MRS培養液中生長；細胞吸附試驗顯示此三株菌對人類大腸癌細胞Caco-2具有吸附能力。綜合以上結果，E. feacium YT 2、E. feacium YT 5及E. feaclis YT 17不僅具有清除苯并[a]芘之能力及抗致突變作用，且具有多項益生菌的特性，故後續將可應用於健康食品之開發。Colorectal cancer (CRC) ranks the third most common malignant disease worldwide. The risk factors of CRC include the diet and lifestyle of people. Meat-related compounds, especially benzo(a)pyrene (BaP) is one of the best-characterised PAHs compound in the diet. Recently, studies have confirmed a correlation between probiotics and CRC that removing of carcinogens and mutagens has been considered as a possible mechanism in CRC prevention. The object of this study was to screen probiotic strains that have the BaP-removing ability. Then, the isolated strains exhibited high efficiency in removing BaP will be further evaluated for their functional properties and for its potential application as probiotic. As the results, the 28 bacterial strains were isolated from infant feces and then treated with 1 ppm BaP to analyze their BaP-removing ability. Three strains (YT 2, YT 5 and YT 17) had the best removing rate (97.66 %, 97.66 % and 97.79 %). The viability of the bacteria has significant effect on the removing of BaP. Cell walls of strains showed higher binding ability than heat-treated bacteria and intracellular extract. Therefore, we proposed that peptidoglycans played an important role in binding BaP. Antimutagenic activities of three strains were examined by Ames test. The results shows that the test strains didn’t have the cytotoxicity and mutagenicity against Salmonella typhimurium TA100 and the cultures incubated with potent mutagen BaP displayed high antimutagenic activities. After identification, YT 2 and YT 5 were classified as Enterococcus feacium, and YT 17 were Enterococcus feaclis. In the probiotic activity assay, all the test strains could survive in pH 2 solutions and grow in MRS broth containing 0.3% oxgall. In the Caco-2 cell adhesion assay, the test strains were able to adhere to Caco-2 cell. In conclusion, E. feacium YT 2, E. feacium YT 5 and E. feaclis YT 17 not only have the capable of removing BaP, but also possess antimutagenic activities, acid resistance, and bile salt tolerance ability. Therefore, E. feacium YT 2, E. feacium YT 5 and E. feaclis YT 17 have a potential to be applied in the human diet and animal feed
An efficient and accurate method for the relaxation of multiview registration error
No full text[[abstract]]This paper presents a new method for the relaxation of multiview registration error. The multiview registration problem is represented using a graph. Each node and each edge in the graph represents a 3-D data set and a pairwise registration, respectively. Assuming that all the pairwise registration processes have converged to fine results, this paper shows that the multiview registration problem can be converted into a quadratic programming problem of Lie algebra parameters. The constraints are obtained from every cycle of the graph to eliminate the accumulation errors of global registration. A linear solution is proposed to distribute the accumulation error to proper positions in the graph, as specified by the quadratic model. Since the proposed method does not involve the original 3-D data, it has low time and space complexity. Additionally, the proposed method can be embedded into a trust-region algorithm and, thus, can correctly handle the nonlinear effects of large accumulation errors, while preserving the global convergence property to the first-order critical point. Experimental results confirm both the efficiency and the accuracy of the proposed method.[[note]]SC
Correction to: Chemoradiation in elderly patients with glioblastoma from the multiinstitutional GBMmolRPA cohort: is shortcourse radiotherapy enough or is it a matter of selection?
No full textThe name of author Do Hoon Lim was incorrect in the initial online publication. The original article has been corrected
Effect of donepezil on transcranial magnetic stimulation parameters in Alzheimer's disease
Get PDFIntroduction: There is a need for a reliable, noninvasive biomarker for Alzheimer's disease (AD). We assessed whether short-latency afferent inhibition (SAI), a transcranial magnetic stimulation paradigm that assesses cholinergic circuits of the brain, could become such a biomarker.
Methods: Nineteen patients with AD underwent four SAI testing sessions. The timing of their usual donepezil dose was altered to create different cholinergic states for each session. This was compared to the SAI results from 20 healthy subjects.
Results: SAI was not able to distinguish the different cholinergic states assessed in our study. There appeared to be a diurnal variation in cholinergic function in the control group, which was not present in the AD cohort.
Discussion: SAI does not appear to have a role in diagnosis and assessment of AD patients. The loss of diurnal variation, however, warrants further investigation as it may provide further biochemical insights about AD
Autofocus of Iris Patterns Using a Triangle Aperture
No full text[[abstract]]This paper shows that, by simply adding a triangle aperture (TA) in front of a camera lens, iris autofocus can be easily achieved. Through the TA, the corneal reflection of a light source forms a triangle glint on the image plane. The size and orientation of the glint can be used to infer the amount and the direction of the focus adjustment. A gradient-descent autofocus control law is proposed for uncalibrated lenses. Results from theoretical analysis and real experiments show that the proposed method is more efficient and accurate than the conventional circular aperture approach.[[note]]SC
Surface excitation parameter for allotropic forms of carbon
Get PDFThe surface excitation parameter (SEP) is calculated for five carbon allotropes: amorphous carbon, graphite, glassy carbon, C 60-fullerite and diamond for electron energies between 300 eV and 3400 eV, and for angles between 0° and 60° to the surface normal. SEP, defined as the change in excitation probability, for an electron, caused by the presence of the surface in comparison with an electron moving the same distance in an infinite medium, is calculated within two dielectric response models due to Yubero and Tougaard (YT) and Tung, Chen, Kwei and Chou (TCKC) respectively. We show that SEP results obtained from TCKC are roughly independent of the allotrope while values calculated from YT are clearly material dependent. Moreover we find that SEP calculated from TCKC is on average 40% larger than those calculated from YT, the difference being largest for materials with large band gap energy. This difference is due to the simplified description of surface excitations in TCKC</p
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