[A new analysis method for 24-hour intraocular pressure data]

The study aimed to introduce a new analysis method of 24-hour intraocular pressure (IOP) and to propose the concept of overall IOP. Data of 24-hour IOP of a patient with a confirmed diagnosis of normal tension glaucoma was selected. Based on the present indexes including peak IOP, trough IOP, maximum difference, and mean IOP, new indexes were proposed, which included main IOP, duration of main IOP, and rate of IOP increase. A radar chart was drawn, and overall IOP was calculated. Overall IOP value = IOP distribution (sum of IOP value multiplied by the corresponding duration) × IOP fluctuation (standard deviation) × rate of IOP increase/100. By comparing two series of IOP data, the advantages of the new IOP indexes were demonstrated. The introduction of the concept of overall IOP expands the description of IOP from a single static state to a comprehensive dynamic state, which enables us to analyze the results of 24-hour IOP monitoring more thoroughly. (Chin J Ophthalmol, 2021, 57: 228-231).

Transcription factor CaNAC1 regulates low-temperature-induced phospholipid degradation in green bell pepper

Phospholipids constitute the main component of biomembranes. During low-temperature storage and transportation of harvested bell peppers (Capsicum annuum), chilling injury participates in their decay. A primary cause of this chilling injury is phospholipid degradation. In this study, three genes encoding phospholipase D (PLD) were identified from bell peppers and their activities were examined under cold stress. Low temperature (4 °C) induced strong accumulation of the CaPLDα4 transcript, suggesting that it is associated with the phenomenon of phospholipid degradation and destruction of cell membranes. Low temperature also significantly induced increased amounts of NAM-ATAF1/2-CUC2 (NAC) domain transcription factors. CaNAC1 was found to interact with the promoter of CaPLD4 in a yeast one-hybrid screen. Electrophoretic mobility shift and ß-glucuronidase reporter assays demonstrated that CaNAC1 binds to the CTGCAG motif in the CaPLDα4 promoter, thereby activating its transcription and controlling phospholipid degradation. The ubiquitination sites of the CaNAC1 protein were characterized by liquid chromatography-tandem mass spectrometry. We conclude that CaNAC1 is a transcriptional activator of CaPLDα4 and suggested that it participates in the degradation of membrane lipids in bell peppers when they are stored at low temperature.

Transcriptome analysis of harvested bell peppers (Capsicum annuum L.) in response to cold stress

Bell peppers are valued for their plentiful vitamin C and nutritional content. Pepper fruits are susceptible to cold storage, which leads to chilling injury (CI); however, the crucial metabolic product and molecular basis response to cold stress have not been elucidated definitely yet. To comprehensively understand the gene regulation network and CI mechanisms in response to cold stress on a molecular level, we performed high-throughput RNA-Seq analysis to investigate genome-wide expression profiles in bell peppers at different storage temperatures (4 °C and 10 °C). A total of 61.55 Gb of clean data were produced; 3863 differentially expressed genes (DEGs) including 1669 up-regulated and 2194 down-regulated were annotated and classified between the CI group and control. Together, a total of 41 cold-induced transcription factor families comprising 250 transcription factors (TFs) were identified. Notably, numerous DEGs involved in biomembrane stability, dehydration and osmoregulation, and plant hormone signal transduction processes were discovered. The transcriptional level of 20 DEGs was verified by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Our results present transcriptome profiles of bell peppers in response to cold stress; the data obtained may be useful for the identification of key candidate genes and elucidation of the mechanisms underlying membrane damage during chilling injury.

Transcriptome profiling reveals the roles of pigment mechanisms in postharvest broccoli yellowing

Postharvest broccoli is prone to yellowing during storage, which is the key factor leading to a reduction in value. To explore appropriate control methods, it is important to understand the mechanisms of yellowing. We analyzed the genes related to the metabolism of chlorophyll, carotenoids, and flavonoids and the transcription factors (TFs) involved in broccoli yellowing using transcriptome sequencing profiling. Broccoli stored at 10 °C showed slight yellowing on postharvest day 5 and serious symptoms on day 12. There were significant changes in chlorophyll fluorescence kinetics, mainly manifesting as a decrease in the Fv/Fm value and an increase in nonphotochemical quenching, during the yellowing process. Transcriptome sequencing profiles from samples of fresh broccoli and broccoli with slight and severe yellowing revealed 6, 5, and 4 differentially expressed genes involved in chlorophyll metabolism, carotenoid biosynthesis, and flavonoid biosynthesis, respectively. The transcription factor gene ontology categories showed that the MYB, bHLH, and bZip gene families were involved in chlorophyll metabolism. In addition, the transcription factor families included NACs and ethylene response factors (ERFs) that regulated carotenoid biosynthesis. Reverse transcription polymerase chain reaction further confirmed that bHLH66, PIF4, LOB13, NAC92, and APL were vital transcription factors that potentially regulated the CAO and HYD genes and were involved in chlorophyll metabolism and the carotenoid biosynthetic process. The flavonoid biosynthetic pathway was mainly regulated by MYBs, NACs, WRKYs, MADSs, and bZips. The results of the differentially expressed gene (DEG) and pigment content analyses indicated that the transcriptome data were accurately and positively associated with broccoli yellowing.

[The function-structure impairment pattern of optic nerves in primary open-angle glaucoma and normal-tension glaucoma]

Objective: To investigate the characteristics of impairment of the visual field (VF) and retinal nerve fiber layer (RNFL) and the differences of progression pattern of early, middle and late stages of primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG) , and to analyze the correspondence of structure and function. Methods: Cross-sectional study. POAG patients, NTG patients and healthy volunteers who were enrolled from February 2008 to May 2017 at Department of Ophthalmology, Eye & ENT Hospital of Fudan University, underwent basic ophthalmic examination, Humphrey central 24-2 threshold test and optical coherence tomography. Patients were divided into early, middle and late stages according to the mean defect (MD) index of the VF test. According to the RNFL distributional characteristics, the pattern deviation map and RNFL were divided into 6 sectors. The differences of each sector's MD and RNFL thickness in the healthy group and groups of patients at 3 stages were analyzed using the Kruskal-Wallis test, and the correlation of MD and RNFL thickness of each sector was analyzed using the Pearson coefficient. Results: In the POAG group, there were 84 cases (84 eyes) including 35 eyes of early stage, 20 eyes of middle stage and 29 eyes of late stage, with a male/female ratio of 43∶41, aged (45±15) years. In the NTG group, 69 cases (69 eyes) included 30 eyes of early stage, 20 eyes of middle stage and 19 eyes of late stage, with a male/female ratio of 33∶36, aged (49±13) years. The control group had 23 cases (23 eyes), with a male/female ratio of 16∶17 and an age of (44±10) years. There was no significant difference in male/female ratio, age or best corrected visual acuity among the three groups. (1) In the middle stage of POAG, the VF defects of inferior hemi-fields were more severe than the superior (t=21.62, P=0.000), which was opposite to the late stage of POAG (t=-3.28, P=0.003). In each stage of NTG, there was no significant difference between two hemi-fields. In the control group, the MD values(antilog) of VF in the superior peripheral arch (PEA), superior paracentral arch (PAA), inferior PEA and PAA, temporal and central regions were 0.87 (0.63-1.11)/L, 0.74 (0.61-0.83)/L, 0.72 (0.55-0.97)/L, 0.65 (0.51-0.87)/L, 0.69 (0.57-0.97)/L, and 0.82 (0.54-0.93)/L, respectively. The sectoral MD values in the VF sectors of POAG were significant compared with the control group (P<0.05): superior PAA for early stage [0.61 (0.18-0.92)/L, H=21.58], superior PEA and PAA for middle stage [0.61 (0.15-0.87)/L, 0.21 (0.00-0.78)/L, H=25.99, 34.91], superior PEA and PAA, inferior PEA and PAA for late stage [0.01 (0.00-1.13)/L, 0.00 (0.00-0.76)/L, 0.41 (0.00-1.07)/L, 0.21 (0.00-0.95)/L, H=46.27, 54.19, 25.64, 28.10]. With the aggravation of POAG, superior PAA had the largest reduction percentage of sectoral MD. The sectoral MD values in the VF sectors of NTG were significant compared with the control group (P<0.05): superior PAA for early stage [0.54 (0.19-0.80)/L, H=20.93], superior PAA for middle stage [0.60 (0.02-1.01)/L, H=22.13], superior PEA and PAA, inferior PEA and PAA for late stage [0.33 (0.00-0.90)/L, 0.05 (0.00-0.92)/L, 0.16 (0.01-0.87)/L, 0.64 (0.02-1.10)/L, H=37.66, 42.78, 35.15, 37.15]. With the aggravation of NTG, the largest reduction percentage of sectoral MD was found in superior PAA at the beginning but in inferior PAA at last. (2) The RNFL thickness of the control group in Region 1NI, 2TI, 3NS, 4TS, 5N, and 6T was 112.76 (63.54-150.99) μm, 134.89 (89.44-198.55) μm, 96.52 (57.32-158.79) μm, 120.96 (69.25-148.48) μm, 71.85 (65.03-95.47) μm, and 66.24 (55.44-90.97) μm, respectively. The sectoral thickness in the RNFL sectors of POAG were significant compared with the control group (P<0.05): 2TI for early stage [109.17 (43.77-173.86) μm, H=31.50], 1NI, 2TI and 4TS for middle stage [71.54 (49.92-94.98) μm, 62.92 (42.33-102.73) μm, 84.20 (45.98-120.13) μm, H=38.91, 49.89, 30.60], 1NI, 2TI, 3NS, 4TS, 5N and 6T for late stage [61.76 (39.32-97.99) μm, 59.59 (42.80-108.69) μm, 67.28 (42.56-117.96) μm, 65.16 (41.96-138.02) μm, 59.45 (21.04-78.48) μm, 53.74 (27.88-92.71) μm, H=52.76, 55.06, 35.76, 41.72, 41.32, 29.93]. With the aggravation of POAG, at the beginning 2TI had the largest reduction percentage of RNFL thickness but 4TS had it at last. The sectoral thickness in the RNFL sectors of NTG were significantly different from the control group (P<0.05): 2TI for early stage [78.97 (47.77-131.45) μm, H=28.86], 1NI, 2TI, 3NS and 4TS for middle stage [61.46 (49.69-97.38) μm, 74.51 (40.25-135.16) μm, 86.36 (42.70-105.06) μm, 83.60 (54.75-117.35) μm, H=38.76, 35.64, 22.47, 24.14], 1NI, 2TI, 3NS, 4TS and 6T for late stage [61.45 (49.09-92.64) μm, 54.35 (37.40-102.62) μm, 63.72 (28.68-105.55) μm, 61.00 (44.92-108.49) μm, 50.33 (35.62-82.09) μm, H=42.56, 51.50, 36.11, 47.44, 25.50]. With the aggravation of NTG, the sector with the largest reduction percentage of thickness changed from 2TI to NI and 4TS. (3) The VF superior PAA-RNFL 2TI had the highest Pearson correlation coefficient in POAG (r=0.630, P<0.001), while it was the inferior PAA-4TS in NTG (r=0.645, P<0.001). Conclusions: The impairment patterns of VF and RNFL in each stage of POAG and NTG are distinctly different from certain rules of aggravation. The sector with the strongest correlation of function-structure is the VF superior PAA-RNFL inferior temporal sector in POAG and inferior PAA-superior temporal sector in NTG. (Chin J Ophthalmol, 2018, 54: 811-819).

[Study of retinal microvascular perfusion alteration and structural damage at macular region in primary open-angle glaucoma patients]

Objective: To investigate the alteration of retinal microcirculation and structural damage at macular region and evaluate their associations in primary open angle glaucoma (POAG) eyes. Methods: Cross-sectional study. Fifty-nine POAG patients (male/femal=35/24) were recruited from July 2015 to December 2015 in Eye, Ear, Nose and Throat Hospital of Fudan University. Twenty-eight eyes of early-stage POAG group (EG), 11 eyes of moderate-stage POAG group (MG) and 20 eyes of severe-stage POAG group (SG) were enrolled in this study. All patients underwent complete ophthalmological examinations and the general information was collected. The macular perfusion parameters (flow index & vessel area density) and the global/hemimacular retina thickness were derived from the 3D angio-retina and retina map procedures in the single optic coherence tomography (OCT) system with split-spectrum amplitude decorrelation angiography (SSADA) algorithm, respectively. One-way ANOVA analysis was conducted to compare the macular perfusion parameters, retinal thickness and visual field defects among three groups. Pearson partial regression analysis was used to calculate the correlations between different variables. Results: The mean flow index and vessel area density of MG eyes were 0.05±0.01 and 60.8%±7.9%, which were significantly lower than those indexes (0.06±0.01; 71.9%±4.6%) in EG eyes (t=5.11, P=0.001; t=5.05, P<0.01). The full and inner retinal layer thicknesses of MG eyes were (270.3±24.6) μm and (98.4±13.3) μm, which were obviously thinner than those indexes (293.0±12.0 μm, 113.0±7.4 μm) in EG eyes (t=3.60, P<0.01; t=4.06, P<0.01). However, there was no significant alteration of macular perfusion parameters and retinal thickness between MG and SG eyes. Furthermore, there was a significantly positive correlation between macular perfusion (flow index/vessel area density) and the macular retina thickness (full/inner thickness) (R=0.35-0.71, All P<0.01). Conclusions: The microvascular perfusion and retinal thickness in MG eyes were lower than those in EG eyes. There was significant positive association between the retinal microvascular perfusion and structural damage. Furthermore, the association between microvascular perfusion and inner inferior retinal thickness is the strongest. (Chin J Ophthalmol, 2017, 53: 98-103).

Population-production-pollution nexus based air pollution management model for alleviating the atmospheric crisis in Beijing, China

In recent years, increscent emissions in the city of Beijing due to expanded population, accelerated industrialization and inter-regional pollutant transportation have led to hazardous atmospheric pollution issues. Although a number of anthropogenic control measures have been put into use, frequent/severe haze events have still challenged regional governments. In this study, a hybrid population-production-pollution nexus model (PPP) is proposed for air pollution management and air quality planning (AMP) with the aim to coordinate human activities and environmental protection. A fuzzy-stochastic mixed quadratic programming method (FSQ) is developed and introduced into a PPP for tackling atmospheric pollution issues with uncertainties. Based on the contribution of an index of population-production-pollution, a hybrid PPP-based AMP model that considers employment structure, industrial layout pattern, production mode, pollutant purification efficiency and a pollution mitigation scheme have been applied in Beijing. Results of the adjustment of employment structure, pollution mitigation scheme, and green gross domestic product under various environmental regulation scenarios are obtained and analyzed. This study can facilitate the identification of optimized policies for alleviating population-production-emission conflict in the study region, as well as ameliorating the hazardous air pollution crisis at an urban level.

Gradient and sensitivity enhanced multiple-quantum coherence in heteronuclear multidimensional NMR experiments

Recent studies have indicated that the relaxation rate of the (1)H-(13)C multiple-quantum coherence is much slower than that of the (1)H-(13)C single-quantum coherence for non-aromatic methine sites in (13) C labeled proteins and in nucleic acids at the slow tumbling limit. Several heteronuclear experiments have been designed to use a multiple-quantum coherence transfer scheme instead of the single-quantum transfer method, thereby increasing the sensitivity and resolution of the spectra. Here, we report a constant time, gradient and sensitivity enhanced HMQC experiment (CT-g/s-HMQC) and demonstrate that it has a significant sensitivity enhancement over constant time HMQC and constant time gradient and sensitivity enhanced HSQC experiments (CT-g/s-HSQC) when applied to a (13)C and (15) N labeled calmodulin sample in D(2)O. We also apply this approach to 3D NOESY-HMQC and doubly sensitivity enhanced TOCSY-HMQC experiments, and demonstrate that they are more sensitive than their HSQC counterparts.

Gradient and sensitivity enhancement of 2D TROSY with water flip-back, 3D NOESY-TROSY and TOCSY-TROSY experiments

Previously we demonstrated a sensitivity enhancement of the original TROSY experiment by a factor of [Formula: see text] by the use of the sensitivity enhanced TROSY (en-TROSY) scheme. Here, we develop a gradient and sensitivity enhanced TROSY experiment (gs-TROSY), which is designed to select magnetization transfer pathways that suppress spectral artifacts and reduce the number of required phase cycles while having minimal loss of sensitivity. Both of these experimental methods (en-TROSY and gs- TROSY) have been combined with a water flip-back scheme which provides a further increase in sensitivity for labile NH groups by avoiding water saturation. We also apply these TROSY schemes to 3D NOESY-TROSY and 3D TOCSY-TROSY experiments.

The influence of diet on necrotic enteritis in broiler chickens

Necrotic enteritis was reproduced in broiler chickens by mixing cultures of Clostridium perfringens in the feed. Mortality due to necrotic enteritis was higher among chickens fed rations based on wheat, rye, barley, and oat groats than among chickens fed corn-based rations. Addition of pentosanase to a wheat-based diet did not affect the level of mortality due to necrotic enteritis. Addition of pectin and guar gum to different rations severely reduced growth rate and eliminated necrotic enteritis from test birds. Addition of glucose to a corn-based diet caused a small increase in mortality due to necrotic enteritis.