[Analysis and comparison of metabolic processes of salvianolic acid A and salvianolic acid B in rats based on UHPLC-LTQ-Orbitrap MS technology].

The metabolites of salvianolic acid A and salvianolic acid B in rats were analyzed and compared by ultra-high-perfor-mance liquid chromatography with linear ion trap-orbitrap mass spectrometry(UHPLC-LTQ-Orbitrap MS). After the rats were administrated by gavage, plasma at different time points and urine within 24 hours were collected to be treated by solid phase extraction(SPE), then they were gradient eluted by Acquity UPLC BEH C_(18) column(2.1 mm×100 mm, 1.7 µm) and 0.1% formic acid solution(A)-acetonitrile(B) mobile phase system, and finally all biological samples of rats were analyzed under negative ion scanning mode. By obtaining the accurate relative molecular mass and multi-level mass spectrometry information of metabolites, combined with the characteristic cleavage law of the reference standard and literature reports, a total of 30 metabolites, including salvianolic acid A and B, were identified. Among them, there were 24 metabolites derived from salvianolic acid A, with the main metabolic pathways including ester bond cleavage, dehydroxylation, decarboxylation, hydrogenation, methylation, hydroxylation, sulfonation, glucuronidation, and their multiple reactions. There were 15 metabolites of salvianolic acid B, and the main biotransformation pathways were five-membered ring cracking, ester bond cleavage, decarboxylation, dehydroxylation, hydrogenation, methylation, sulfonation, glucuronidation, and their compound reactions. In this study, the cross-metabolic profile of salvianolic acid A and B was elucidated completely, which would provide reference for further studies on the basis of pharmacodynamic substances and the exploration of pharmacological mechanism.

[Enzyme activity of neuraminidase 1 correlated with the biological behavior of prostate cancer PC3 and DU145 cell lines].

OBJECTIVE: To investigate the effects of the enzyme activity of neuraminidase 1 (Neu1) on the biological behavior of prostate cancer PC3 and DU145 cell lines. METHODS: We detected the expression of Neul in the prostate cancer PC3 and DU145 cell lines by Western blot. Using sialidase inhibitors and antibody blocking, we suppressed the enzyme activity of Neu1 and then measured the proliferation and invasiveness of the two cell lines by CCK-8 and Transwell assay, respectively. RESULTS: No statistically significant difference was found in the Neu1 expression between the PC3 and DU145 cell lines. The proliferation and invasiveness of the two types of cells were both increased after inhibition of the Neu1 enzyme activity. CONCLUSIONS: The enzyme activity of Neu1 is correlated with the biological behavior of prostate cancer PC3 and DU145 cells and capable of inhibiting the proliferation and invasiveness of the two types of cells.

DyIII single-molecule magnets from ligands incorporating both amine and acylhydrazine Schiff base groups: the centrosymmetric {Dy2} displaying dual magnetic relaxation behaviors.

The novel multidentate chelating ligands N'-(2-pyridylmethylidene)-2-(2-pyridylmethylideneamino)benzohydrazide (Hpphz) and N'-(2-salicylmethylidene)-2-(2-salicylmethylideneamino)benzohydrazide (H3sshz), which incorporate both amine and acylhydrazine Schiff base groups, were synthesized and investigated in DyIII coordination chemistry. The reactions of Hpphz and Dy(OAc)3·4H2O have yielded two {Dy2} featuring double OAc- bridges: [Dy2(H2aphz)2(OAc)4(ROH)2] [R = Me (1) and Et (2)], where the Hpphz ligands were in situ hydrolyzed into 2-amino-(2-pyridylmethylideneamino)benzohydrazide ions (H2aphz-). Besides, the reaction between H3sshz and Dy(NO)3·6H2O afforded a [Dy6(sshz)4(µ3-OH)4(µ4-O)(MeOH)4]2·17.5MeOH·2H2O cluster (3). This cluster contained two discrete {Dy6} cores, each of which consisted of a pair of {Dy3} triangular units. All the complexes displayed a single relaxation process of single-molecule magnet (SMM) behaviors under a zero dc field. Both 1 and 2 showed field-induced dual magnetic-relaxation behaviors. However, their diluted samples (1@Y and 2@Y) only showed one-step relaxation behaviors whether under a zero or applied dc field, indicating that the dual magnetic-relaxation behaviors of 1 and 2 were absent after the dilution. Combined with ab initio calculations, it could be infered that the dual magnetic-relaxation behaviors of 1 and 2 might be ascribled to the joint contributions of the single ion anisotropy and magnetic interactions. Examples of this type are rather rare in previous studies. Ab initio calculations also suggested that the discrepancy between the relaxation processes of 1 and 2 may be caused by the small difference between their magnetic interactions.

Topographic distribution features of the choroidal and retinal nerve fiber layer thickness in Chinese school-aged children.

AIM: To explore the topographic distribution features of choroidal thickness (CT) and retinal nerve fiber layer thickness (RNFLT), and determine the relationship between CT and ocular parameters in school-aged children. METHODS: The healthy school-aged children with low ametropia or emmetropia in Wenzhou were recruited for this cross-sectional study. With high-density optical coherence tomography (HD-OCT) combined with MATLAB software, the CT and RNFLT values in the macular area were measured at different locations and compared. Statistical analyses were performed to evaluate the correlation between CT and ophthalmic parameters, such as spherical equivalent (SE) and the axial length (AL). RESULTS: A total of 279 school-aged children with 8.00±1.35 years of mean age (range, 6-10y) were included. The mean AL was 23.66±0.86 mm. The mean CT in CT-C (264.31±48.93 µm) was thicker than that in CT-N1 (249.54±50.52 µm), and the average CT in the parafoveal region was also thicker than that in CT-N2 (235.65±50.63 µm). The subfoveal CT also varied substantially across refractive errors (P<0.001), and those with myopia (250.59±47.01 µm) exhibited a thinner choroid compared with those with emmetropia (278.74±48.06 µm). CT negatively correlated with AL (y=-21.72x+779.17; R 2=0.1458), and positively correlated with SE (y=15.76x+271.9; R 2=0.0727, OD; y=18.31x+269.8; R 2=0.1007, OS). The average RNFLT was thickest in the peripapillary region (236.35±19.03 µm), the mean RNFLT-S (131.10±15.16 µm) was thicker than the RNFLT-I (128.20±16.59 µm), and the mean RNFLT-T (76.54±11.99 µm) was thicker than the RNFLT-N (64.28±8.55 µm). The variations in the RNFLT between quadrants did differ between those with myopia and emmetropia (P<0.05). CONCLUSION: We establish demographic information for the choroid and RNFLT. These findings provide information that should be considered in future analyses of the CT and RNFLT in OCT studies in school-aged children.

[Analysis of carnosic acid metabolites in rats by UHPLC-Q-Exactive MS].

A method of ultra-high performance liquid chromatography coupled with quadrupole/electrostatic field Obitrap high-resolution mass spectrometry(UHPLC-Q-Exactive MS) was established to comprehensively identify the metabolites of carnosic acid in rats. After oral gavage of carnosic acid CMC-Na suspension in rats, urine, plasma and feces samples were collected and pretreated by solid phase extraction(SPE). Acquity UPLC BEH C_(18 )column(2.1 mm×100 mm, 1.7 µm) was used with 0.1% formic acid solution(A)-acetonitrile(B) as the mobile phase for the gradient elution. Biological samples were analyzed by quadrupole/electrostatic field Obitrap high-resolution mass spectrometry in positive and negative ion mode. Based on the accurate molecular mass, fragment ion information, and related literature reports, a total of 28 compounds(including carnosic acid) were finally identified in rat samples. As a result, the main metabolic pathways of carnosic acid in rats are oxidation, hydroxylation, methylation, glucuronide conjugation, sulfate conjugation, S-cysteine conjugation, glutathione conjugation, demethylation, decarbonylation and their composite reactions. The study showed that the metabolism of carnosic acid in rats could be efficiently and comprehensively clarified by using UHPLC-Q-Exactive MS, providing a reference for clarifying the material basis and metabolic mechanism of carnosic acid.

Topographic distribution features of the choroidal and retinal nerve fiber layer thickness in Wenzhou school-aged children.

AIM: To explore the topographic distribution features of choroidal thickness (CT) and retinal nerve fiber layer thickness (RNFLT), and determine the relationship between CT and ocular parameters in school-aged children. METHODS: The healthy school-aged children with low myopia or emmetropia in Wenzhou were recruited for this cross-sectional study. With high-density optical coherence tomography (HD-OCT) combined with MATLAB software, the CT and RNFLT values in the macular area were measured at different locations and compared. Statistical analyses were performed to evaluate the correlation between CT and ophthalmic parameters, such as spherical equivalent (SE) and the axial length (AL). RESULTS: A total of 279 school-aged children with 8.00±1.35 years of mean age (range, 6-10y) were included. The mean AL was 23.66±0.86 mm. The mean CT in CT-C (264.31±48.93 µm) was thicker than that in CT-N1 (249.54±50.52 µm), and the average CT in the parafoveal region was also thicker than that in CT-N2 (235.65±50.63 µm). The subfoveal CT also varied substantially across refractive errors (P<0.001), and those with myopia (250.59±47.01 µm) exhibited a thinner choroid compared with those with emmetropia (278.74±48.06 µm). CT positively correlated with AL (y=11.12x-4.15; R 2=0.18), and positively correlated with SE (y=90.07x+17.916; R 2=14.2). The average RNFLT was thickest in the peripapillary region (236.35±19.03 µm), the mean RNFLT-S (131.10±15.16 µm) was thicker than the RNFLT-I (128.20±16.59 µm), and the mean RNFLT-T (76.54±11.99 µm) was thicker than the RNFLT-N (64.28±8.55 µm). The variations in the RNFLT between quadrants did differ between those with myopia and emmetropia (P<0.05). CONCLUSION: We establish demographic information for the choroid and RNFLT. These findings provide information that should be considered in future analyses of the CT and RNFLT in OCT studies in school-aged children.

Visual requirement for Chinese reading with normal vision.

OBJECTIVES: Reading performance has been considered as an effective functional endpoint for low vision. Contrary to many extensive studies for reading performance in English, there are few systematic studies for Chinese reading. METHODS: In the present study, the reading performance of 30 normally sighted Chinese college students was systematically investigated. All participants passed the equivalent test of Cambridge ESOL PET in China. The reading speeds for Chinese and English text at a variety of text sizes were measured with rapid serial visual presentation (RSVP). The threshold acuities for Chinese characters and English letters were measured. Maximum reading speed, critical font size, and critical acuity reserve were derived according to the individual's reading speed curve. RESULTS: The maximum reading speed for Chinese characters was 259.5 ± 38.2 characters/min, which was significantly faster than that for English letters (135.7 ± 18.5 words/min, p = 2.8 × 10-18 ). The critical font size for Chinese characters was larger than that for English letters (24.2 ± 2.8 arcmin vs. 20.7 ± 1.0 arcmin, p = 1.6 × 10-7 ). Interestingly, the critical acuity reserve was similar for these two languages (3.4 ± 0.4 for Chinese and 3.4 ± 0.2 for English, p = 0.4). CONCLUSION: The present study provides the first step for establishing visual functional endpoints for Chinese reading. Our findings pose rigorous constrains on present theories in language information processing and brain plasticity.

Role of epithelial-mesenchymal transition in gastric cancer initiation and progression.

Gastric cancer is one of the most common malignant tumors worldwide. Due to its intricate initiation and progression mechanisms, early detection and effective treatment of gastric cancer are difficult to achieve. The epithelial-mesenchymal transition (EMT) is characterized as a fundamental process that is critical for embryonic development, wound healing and fibrotic disease. Recent evidence has established that aberrant EMT activation in the human stomach is closely associated with gastric carcinogenesis and tumor progression. EMT activation endows gastric epithelial cells with increased characteristics of mesenchymal cells and reduces their epithelial features. Moreover, mesenchymal cells tend to dedifferentiate and acquire stem cell or tumorigenic phenotypes such as invasion, metastasis and apoptosis resistance as well as drug resistance during EMT progression. There are a number of molecules that indicate the stage of EMT (e.g., E-cadherin, an epithelial cell biomarker); therefore, certain transcriptional proteins, especially E-cadherin transcriptional repressors, may participate in the regulation of EMT. In addition, EMT regulation may be associated with certain epigenetic mechanisms. The aforementioned molecules can be used as early diagnostic markers for gastric cancer, and EMT regulation can provide potential targets for gastric cancer therapy. Here, we review the role of these aspects of EMT in gastric cancer initiation and development.

[The key parameters of design research and analysis of the Chinese reading visual acuity chart].

OBJECTIVE: Reading is a visual function human being used to understand environmental events based on writing materials. This study investigated the feasibility of reading visual acuity chart in assessment of reading ability by analysis of the key factors involved in the design of the visual acuity chart. METHODS: The reading level was determined as grade 3 primary school with Song as the font and 30 characters included in the sentences. Each of the sentences consisted of 27 commonly-used Chinese characters (9 characters between any two punctuations) and 3 punctuations. There were no contextual clues between the 80 sentences selected. The characters had 13 different sizes with an increment of 0.1 log unit (e.g.1.2589) and 2.5 pt was determined as the critical threshold. Readable test for visual target was followed as (1) 29 candidates with a raw or corrected visual acuity (VA)of at least 1.0 were selected to read 80 selected sentences with the size of characters of 2.5 pt at a distance of 40 cm, (2) the time used for reading with the number of characters wrongly read was recorded, (3) 39 sentences were selected as visual targets based on reading speed, effective reading position and total number of character strokes, (4) The 39 selected sentences were then randomly divided into 3 groups with no significant difference among the groups in the 3 factors listed at (3) with paired t-test. RESULTS: This reading visual chart was at level of Grade 3 primary school with a total stroke number of 165-210(Mean 185 ± 10), 13 font sizes a 0.1 log unit increment, a song pattern and 2.5 pt as the critical threshold. All candidates achieved 100% correct in reading test under 2.5 pt with an effective reading speed as 120.65-162 wpm (Mean 142.93 ± 11.80) and effective reading position as 36.03-61.48(Mean 48.85 ± 6.81). The reading test for the 3 groups of sentences showed effective reading speed as (142.49 ± 12.14) wpm,(142.86 ± 12.55) wpm and (143.44 ± 11.63) wpm respectively(t1-2 = -0.899, t2-3 = -1.295, t1-3 = -1.435). The reading position was 48.55 ± 6.69, 48.99 ± 7.49 and 49.00 ± 6.76, respectively(t1-2 = -1.019, t2-3 = -0.019, t1-3 = -0.816). The total number of character strokes was 185.54 ± 7.55, 187.69 ± 13.76 and 182.62 ± 8.17, respectively(t1-2 = 0.191, t2-3 = 1.385, t1-3 = 1.686). CONCLUSIONS: A practical design of the Chinese reading visual chart should consider size, increment, legibility in selection of reading sentences. Reading visual acuity, critical threshold and effective reading speed could be used to express the reading visual function.

[Selection of Chinese characters for visual acuity charts using psychophysical methods].

OBJECTIVE: This study investigated the legibility in use of psycho-physical methods to select Chinese characters for visual acuity charts. METHODS: Twenty-eight subjects with the raw visual acuity or best corrected visual acuity of -0.11 ± 0.06 (LogMAR) were recruited for this study. Ninety Chinese characters with similar Fourier frequency spectrum were used as candidates for the selection of visual targets. Thirty-seven Chinese characters with each consisted of horizontal, vertical and oblique strokes were selected from these candidates. Six different-sized BMP images for each selected Chinese character were made based on the average visual acuity threshold of all the selected characters. The accuracy rate for all subjects to read each size of the BMP images was averaged. Graphs correlating the font sizes with the accuracy rates were formed using Weibull function imitation, which provided a visual acuity (VA) threshold and slope for each Chinese character selected. RESULTS: Among the 37 Chinese characters selected, 17 had a VA threshold 6.16 ± 0.54 (unit: arc) and 20 had a VA threshold of 8.20 ± 0.71. The slope for characters with low stroke number and medium stroke number was 5.91 ± 2.18 and 11.18 ± 3.55, respectively. Based on the similarity in VA thresholds and slopes, 10 Chinese characters were finally determined as the visual targets for a lower stroke-number Chinese visual acuity chart (tb: 5.84 ± 0.36, ß: 4.72 ± 0.85). Another 10 characters "rdquo; (tb: 8.38 ± 0.24, ß: 10.47 ± 3.9) were determined as the visual targets for a medium stroke-number Chinese visual chart. CONCLUSION: Analysis using Fourier frequency spectrum provides an objective method in the selection of Chinese characters for Chinese visual acuity charts. A psychological test for this selection would further confirm the legibility of the method used in this study.

[Selection of Chinese visual targets by fourier frequency spectrum analysis].

OBJECTIVE: To select Chinese characters for Chinese visual acuity chart by using the method of Fourier frequency spectrum analysis. METHODS: BMP images were made for 1062 Chinese characters with small or medium number of strokes. The images were processed to derive frequency spectrum at the frequency domain by using a MatLab program. Euclidean distance from Cluster analysis was then used to classify and select the Chinese characters for optotypes of the visual acuity chart, based on their mean frequency spectrum from all the characters analyzed. RESULTS: Fifty and forty Chinese characters were selected from the groups of the small and the middle number of strokes respectively. CONCLUSIONS: It is important and interesting to select Chinese characters by using Fourier analysis method for designing Chinese visual acuity chart that is consisting with the property of the visual system of the eye.

[A comparison of Chinese reading parameters among rapid serial visual presentation, full screen and printed displays].

OBJECTIVE: This study investigated reading speed of Chinese in rapid serial visual presentation (RSVP), full screen and printed display among young adults with normal vision. The critical font size and critical acuity reserve in RSVP were also evaluated. METHODS: Thirty university students with a visual acuity of at least 20/20 in both eyes (uncorrected or corrected) were recruited in this study. The visual acuity threshold (VAT) (3 m distance) was evaluated for all subjects using a self-designed visual acuity chart presented on a computer screen. The reading speed for Chinese was measured under RSVP (10 font sizes from 4 to 33 pt), full screen and printed display (2 font sizes: 10 and 13 pt). The reading speed (wpm) was expressed as the percentage of words read correctly x 60 x total number of words/time used (second). The acuity reserve (RA) was expressed as RA = SP/ST, where SP was the font size of the reading material for the reader and ST was the acuity threshold expressed as a font size. RESULTS: The visual acuity threshold (VAT) at a distance of 40 cm in these 30 subjects was (2.2 +/- 0.3) pt (mean +/- SD). The reading speed increased significantly with the increasing font sizes until the font size reached (7.8 +/- 0.4) pt where the maximum reading speed (258.0 +/- 34.4 wpm) was achieved. The reading speed remained at a constant value in font sizes ranging from 7.8 to 33 pt. The reading speed increased with the increasing R(A) until the R(A) reached 3.5:1 and then remained unchanged. There was no significant difference in reading speed between full screen and printed displays (P > 0.05). The reading speed in full screen or printed display was significantly faster than in RSVP (10 pt: full screen display versus RSVP: t = -10.15, P < 0.01; printed display versus RSVP: t = -8.77, P < 0.01. 13 pt: full screen display versus RSVP: t = -11.64, P < 0.01; printed display versus RSVP: t = -10.79, P < 0.01). CONCLUSIONS: Young readers who use the computer as a reading tool can achieve a maximum reading speed for Chinese when the font size of the reading text is larger than 7.8 pt. A font size of at least 3.5 times the acuity threshold can attain a maximum reading speed for RSVP.