Dual contrastive learning for synthesizing unpaired fundus fluorescein angiography from retinal fundus images.

Background: Fundus fluorescein angiography (FFA) is an imaging method used to assess retinal vascular structures by injecting exogenous dye. FFA images provide complementary information to that provided by the widely used color fundus (CF) images. However, the injected dye can cause some adverse side effects, and the method is not suitable for all patients. Methods: To meet the demand for high-quality FFA images in the diagnosis of retinopathy without side effects to patients, this study proposed an unsupervised image synthesis framework based on dual contrastive learning that can synthesize FFA images from unpaired CF images by inferring the effective mappings and avoid the shortcoming of generating blurred pathological features caused by cycle-consistency in conventional approaches. By adding class activation mapping (CAM) to the adaptive layer-instance normalization (AdaLIN) function, the generated images are made more realistic. Additionally, the use of CAM improves the discriminative ability of the model. Further, the Coordinate Attention Block was used for better feature extraction, and it was compared with other attention mechanisms to demonstrate its effectiveness. The synthesized images were quantified by the Fréchet inception distance (FID), kernel inception distance (KID), and learned perceptual image patch similarity (LPIPS). Results: The extensive experimental results showed the proposed approach achieved the best results with the lowest overall average FID of 50.490, the lowest overall average KID of 0.01529, and the lowest overall average LPIPS of 0.245 among all the approaches. Conclusions: When compared with several popular image synthesis approaches, our approach not only produced higher-quality FFA images with clearer vascular structures and pathological features, but also achieved the best FID, KID, and LPIPS scores in the quantitative evaluation.

Transcriptomics Provide Insights into the Photoperiodic Regulation of Reproductive Diapause in the Green Lacewing, Chrysoperla nipponensis (Okamoto) (Neuroptera: Chrysopidae).

Chrysoperla nipponensis (Okamoto) displays typical adult reproductive diapause under short photoperiods; however, our understanding of the molecular mechanism underlying photoperiod-sensitive reproduction remains limited. In this study, we performed transcriptome profiling of four treatments (the diapause-sensitive stage and pre-diapause phase under long and short photoperiods) of C. nipponensis using RNA sequencing (RNA-seq). A total of 71,654 unigenes were obtained from the samples. Enrichment analysis showed that fatty acid metabolism-related pathways were altered under a short photoperiod. Moreover, ß-oxidation-related gene expression was active during the diapause-sensitive period under a short photoperiod. The knockdown of juvenile hormone acid methyltransferase 1 (Jhamt1) prolonged the pre-oviposition period but did not affect the reproductive ability of female individuals in C. nipponensis. These findings provided us with a more comprehensive understanding of the molecular mechanisms of photoperiod-sensitive diapause and show that groundwork is crucial for bolstering the long-term storage and biocontrol potential of C. nipponensis.

[Removal of Cr(â ¥) via a Nickel Ferrite@Activated Carbon Composite Under Batch Experiments: Study of Characterization, Performance, and Mechanism].

A magnetic activated carbon adsorbent named NiFe2O4@AC was synthesized by modifying activated carbon with NiFe2O4 and used for the adsorption of Cr(Ⅵ) ions from waste water. The influencing factors, adsorption kinetics, and adsorption isotherms of Cr(Ⅵ) adsorption by the adsorbent were investigated. The results showed that the removal rate of Cr(Ⅵ) adsorption by NiFe2O4@AC reached 96.92%, and the adsorption amount reached 72.62 mg·g-1 at the adsorption conditions of temperature (298 K), pH 2, Cr(Ⅵ) initial concentration (150 mg·L-1), adsorbent dosage (0.1 g), and contact time (720 min). The experimental data were best described by the proposed secondary kinetics and Langmuir model, indicating that the adsorption process was a monolayer chemisorption process. The increase in temperature favored the adsorption of Cr(Ⅵ) on NiFe2O4@AC because the adsorption process was a spontaneous, heat-absorbing reaction. The adsorption mechanism of NiFe2O4@AC was mainly through complexation and electrostatic attraction to adsorb Cr(Ⅵ); meanwhile, the applied magnetic field could be separated from the solution, which has good application prospects.

Quantitative transcriptomic and proteomic analyses reveal the potential maintenance mechanism of female adult reproductive diapause in Chrysoperla nipponensis.

BACKGROUND: The green lacewing Chrysoperla nipponensis is an important natural enemy of many insect pests and exhibits reproductive diapause to overwinter. Our previous studies showed that adult C. nipponensis enters reproductive diapause under a short-day photoperiod. However, the molecular mechanism underlying diapause maintenance in C. nipponensis is still unknown. RESULTS: The total lipid and triglyceride content showed the reservation and degradation of energy during diapause in C. nipponensis. Thus, we performed combined transcriptomic and proteomic analyses of female reproductive diapause in C. nipponensis at three ecophysiological phases (initiation, maintenance and termination). A total of 64 388 unigenes and 5532 proteins were identified from the transcriptome and proteome. In-depth dissection of the gene-expression dynamics revealed that differentially expressed genes and proteins were predominately involved in the lipid and carbohydrate metabolic pathways, in particular fatty acid metabolism, metabolic pathways and the citrate cycle. Among of these genes, TIM, CLK, JHAMT2, PMK, HMGS, HMGR, FKBP39, Kr-h1, Phm, ECR, IR1, ILP3, ILP4, mTOR, ACC, LSD1 and LSD2 were differentially expressed in diapause and non-diapause female adults of C. nipponensis. The expression patterns of these genes were consistent with the occurrence of vitellogenesis and expression of either Vg or VgR. CONCLUSION: Our findings indicated that diapause adult C. nipponensis accumulate energy resources to overwinter. Transcriptomic and proteomic analyses suggested candidate key genes involved in the maintenance of C. nipponensis during adult reproductive diapause. Taken together, these results provide in-depth knowledge to understand the maintenance mechanism of C. nipponensis during adult reproductive diapause. © 2023 Society of Chemical Industry.

The impact of different geometrical restrictions on the nonadiabatic photoisomerization of biliverdin chromophores.

The photoisomerization mechanism of the chromophore of bacterial biliverdin (BV) phytochromes is explored via nonadiabatic dynamics simulation by using the on-the-fly trajectory surface-hopping method at the semi-empirical OM2/MRCI level. Particularly, the current study focuses on the influence of geometrical constrains on the nonadiabatic photoisomerization dynamics of the BV chromophore. Here a rather simplified approach is employed in the nonadiabatic dynamics to capture the features of geometrical constrains, which adds mechanical restrictions to the specific moieties of the BV chromophore. This simplified method provides a rather quick approach to examine the influence of geometrical restrictions on photoisomerization. As expected, different constrains bring distinctive influences on the photoisomerization mechanism of the BV chromophore, giving either strong or minor modification of both involved reaction channels and excited-state lifetimes after the constrains are added in different ring moieties. These observations not only contribute to the primary understanding of the role of the spatial restriction caused by biological environments in photoinduced dynamics of the BV chromophore, but also provide useful ideas for the artificial regulation of the photoisomerization reaction channels of phytochrome proteins.

Selection of Reference Genes for Quantitative Real-Time PCR in Chrysoperla nipponensis (Neuroptera: Chrysopidae) Under Tissues in Reproduction and Diapause.

Chrysoperla nipponensis (Okamoto), which has the unique diapause phenotype distinguishable from nondiapause adult, is an ideal model organism for studying the mechanism of reproductive diapause. However, there is no reliable and effective reference genes used for the reproductive diapause study of C. nipponensis. Therefore, in this study, we evaluated the expression stability of 10 candidate reference genes (Tub1, Arpc5, EF1a, 128up, RpS5, RpS26e, GAPDH, Arp3, Actin, α-Tub) in adults under diapause and nondiapause induction conditions using four statistical algorithms including GeNorm, NormFinder, Bestkeeper, and ∆CT method. Results showed that Arp3 and Tub1 were the most stable reference genes in all samples and in the adult tissues group. Arp3 and RpS5 were the most stable reference genes in the development degree group. α-Tub and EF1a were unstable reference genes under the conditions of this study. Meanwhile, to verify the reliability of the reference genes, we evaluated the relative expression levels of Vg and VgR in different treatments. Significant upregulation and downregulation in expression level of two genes in response to diapause termination and diapause fat body tissue was, respectively, observed when using Arp3 as the reference gene but not when using an unstable reference gene. The reference genes identified in this work provided not only the basis for future functional genomics research in diapause of C. nipponensis and will also identify reliable normalization factors for real-time quantitative real-time polymerase chain reaction data for other related insects.

A new method of recycling gallium from yellow phosphorus flue dust by vacuum thermal reduction process.

Gallium is widely used in the field of semiconductors, and is mainly recovered as a by-product from other production processes utilizing metals such as aluminum and zinc. As a waste generated during the production of yellow phosphorus, yellow phosphorus flue dust is a potential resource for recovery of gallium. In this study, vacuum carbothermic reduction technology was applied to extract gallium from yellow phosphorus flue dust. Under the optimal conditions of 1323 K, 40 min holding time, 50 wt% carbon content, and 1-10 Pa, the recovery rate of gallium was 92.5 %. The condensate was analyzed and the enrichment area of gallium in the condensation zone was determined. No hazardous gases and materials were generated during the process. Compared with other methods of recovering gallium from yellow phosphorus flue dust by hydrometallurgical process, this study has the advantages of short process, easy collection of products, low energy consumption. Overall, this work demonstrates a new and environmentally friendly method for the recovery of gallium from yellow phosphorus flue dust, and also provides a reference value for the comprehensive utilization of this material.

A comparative study of mud-like and coralliform calcium carbonate gallbladder stones.

To gain insight to underlying mechanism of the formation of calcium carbonate (CaCO3 ) gallbladder stones, we did comparative study of stones with mud appearance and those with coralliform appearance. A total of 93 gallbladder stones with mud appearance and 50 stones with coralliform appearance were analyzed. The appearance, color, texture, and the detection of Clonorchis sinensis eggs by microscopic examination were compared between the two groups. Then, the material compositions of stones were analyzed using Fourier Transform Infrared spectroscopy and the spectrogram characteristics were compared. Moreover, microstructure characteristics of the two kinds of stones were observed and compared with Scanning Electron Microscopy. Mud-like gallbladder stones were mainly earthy yellow or brown with brittle or soft texture, while coralliform stones were mainly black with extremely hard texture, the differences between the two groups was significant (p < .05). The analytic results of FTIR spectroscopy showed that 95.7% (89/93) of the mud-like gallbladder stones were CaCO3 stones, and mainly aragonite; while all of the coralliform stones were CaCO3 stones, and mainly calcite (p < .05). Meanwhile, microscopic examination indicated that the detection rate of Clonorchis sinensis eggs in mud-like CaCO3 stones was lower than that in coralliform CaCO3 stones (p < .05), and that in aragonite CaCO3 stones was lower than that in calcite CaCO3 stones(p < .05). Mud-like CaCO3 stones mainly happened to patients with cystic duct obstruction. Clonorchis sinensis infection was mainly associated with coralliform (calcite) CaCO3 stones. Cystic duct obstruction was mainly associated with mud-like (aragonite) CaCO3 stones.