[Detection of the spontaneous blinking pattern of dry eye patients using the machine learning method].

Objective: To establish a method to record the spontaneous blink pattern with a machine learning model, and to clarify the spontaneous blink pattern in patients with dry eye. Methods: It was a cross-setional study.We selected 357 dry eye patients (102 males and 255 females), aged (46.2±13.3) years, who visited corneal specialist clinics of Beijing Tongren Eye Center in 2019, as the dry eye group. The control group enrolled 152 normal controls, including 32 males and 120 females, aged (48.1±13.9) years. All participants completed the Ocular Surface Disease Index questionnaire, blink video capture, lipid layer thickness measurement, tear break-up time measurement, corneal fluorescein staining, and Schirmer Ⅱ test. Based on the assembled model built using UNet image segmentation algorithm and ResNet image classification algorithm, single frames of the blink video were analyzed, and then the palpebral opening height of each frame was obtained in order to establish a spontaneous blink wave. Finally, the characteristics of spontaneous blinks in dry eye patients were analyzed based on different types of complete blinks (types A, B and C) and partial blinks (types Ⅰ, Ⅱ and Ⅲ). Independent sample t test and Wilcoxon rank-sum test were used to judge if there was significant difference between the dry eye group and the normal group. Results: The accuracy of the segmentation model and the classification model was 96.3% and 96.0%, respectively, and the consistency with the manual analysis was 97.9%. In dry eye patients, the number of blinks was 30 (18, 42)/min, which was higher than that in normal controls [20 (9, 46)/min] (U=18 132.50, P=0.002). The number of complete blinks in dry eye cases was significantly lower than that in normal controls [6 (3, 24)/min vs. 12 (3,33)/min; U=12 361.00, P=0.016], and the number of partial blinks was significantly higher than that in normal controls [15 (6, 27)/min vs. 3 (0, 10)/min; U=22 839.00, P<0.001]. In complete blinks, the proportion of type A blinks in dry eye patients was significantly higher than that in normal controls [53.7% (2 796/5 177) vs. 39.3% (633/1 698); χ²=101.83, P<0.001]; in partial blinks, the proportion of type Ⅱ blinks in dry eye patients was significantly higher than that in normal controls [36.0%(2 334/6 477) vs. 29.6%(126/426); χ²=6.99, P=0.007]. The average interblink interval of dry eye patients was 1.2 s, which was not significantly different from that of normal controls (1.1 s; U=15 230.00, P=0.093). The eyelid closed phase of dry eye patients was 0.8 s, which was significantly shorter than that of normal controls (1.3 s; U=16 291.50, P=0.006). There were no significant differences in eyelid closing phase, early opening phase and late opening phase between the two groups (all P>0.05). Conclusions: In dry eye patients, the number of partial blinks increased, the number of complete blinks decreased, and the duration of eyelid closed phase shortened significantly. The main blink patterns of dry eye patients included type Ⅱ partial blinks with a reduced closure amplitude and type A complete blinks with a shortened closure time.

First Report of Cherry green ring mottle virus on Cherry and Peach Grown in China.

Cherry green ring mottle virus (CGRMV; a member of the genus Foveavirus in the family Flexiviridae) has a single-stranded, positive-sense RNA genome of approximately 8.4 kb (4). The viral infection on several Prunus spp. has been mainly reported in Japan, New Zealand, and some countries in Africa, Europe, and North America (3). The virus can cause leaf yellowing on sour and tart cherry. Sweet cherry plants are symptomless hosts of the virus. During the growing season of 2010, leaf samples were collected randomly from one ornamental cherry (Prunus serrulata L.) and 26 sweet cherry (P. avium (L.) L.) plants grown in Shangdong and Henan provinces in northern China and 64 peach (P. persica L. Batsch) plants grown in Hubei Province in central China and tested for the presence of CGRMV by reverse transcription (RT)-PCR. Total RNA was extracted from leaves using the CTAB protocol reported by Li et al (2). Primer set, CGRMV1/CGRMV2 (1), was used for the amplification of a 949-bp fragment, which contains the complete CP gene of 807 bp. PCR products with the expected size were identified in one ornamental cherry, seven sweet cherry, and eight peach plants. Although some of sampled plants showed leaf chlorosis, we did not find the specific association between the symptom and CGRMV infection. The obtained PCR products were cloned into the vector pMD18-T (TaKaRa, Dalian, China). Three independent clones from each isolate were sequenced by Genscript Corp., Nanjing, China. Results showed that CP sequences from the Chinese CGRMV isolates shared 87.7 to 99.8% nucleotide and 93.3 to 100% deduced amino acid similarities, and clones intra each isolate shared more than 99% nt similarities. The CP gene sequences of two representative isolates from cherry (YT-Ch-1) and peach (Pe-HB-18) were submitted to GenBank with Accession Nos. HQ539656 and JF810672, respectively. The neighbor-joining phylogenetic trees generated with nucleotide and amino acid sequences of CP genes by Clustal X v1.8 revealed that all Chinese CGRMV isolates fell into two well-resolved clades. Most of the Chinese CGRMV isolates (12 of 16 isolates, including the isolate YT-Ch-1) were grouped in a large clade represented by isolate ITA5 (GenBank Accession No. AF533159). Four isolates from peach (including the isolate Pe-HB-18) clustered into another clade represented by isolate ITA6 (GenBank Accession No. AF533160). In July 2010, peach GF305 seedlings were inoculated by side grafting with budwoods from two CGRMV positive cherry plants. In May 2011, some newly developed leaves from all inoculated plants showed vein yellowing. The CGRMV infection in these inoculated peach GF305 plants was detected by RT-PCR and protein A sandwich-ELISA using antiserum raised against the recombinant CP of CGRMV isolate YT-Ch-1 (unpublished data). These results further confirmed the CGRMV infection on field cherry plants as detected by RT-PCR. To our knowledge, this is the first record of the presence of CGRMV in ornamental and sweet cherry and peach plants in China, which provides valuable information for further evaluating the sanitary status of the virus in sweet cherry and peach orchards in China. References: (1) R. Li and R. Mock. J. Virol. Methods 129:162, 2005. (2) R. Li et al. J. Virol. Methods 154:48, 2008. (3) K. G. Parker et al. USDA. Agric. Handb. No. 437:193, 1976. (4) Y. Zhang et al. J. Gen. Virol. 79:2275, 1998.