Mediating effect of psychological capital on the relationship between mental health literacy and coping styles among newly recruited nurses.

BACKGROUND: Newly recruited nurses face multiple sources of stress and their coping styles need to be focused on to ensure good mental health. This study aimed to examine the relationship among mental health literacy, psychological capital and coping styles in newly recruited nurses. METHODS: A cross-sectional study was conducted in August and September 2022. A total of 315 newly recruited nurses were recruited in a tertiary hospital in Henan Province, central China, employing the convenience sampling method. The self-reported questionnaires were sent through a QR code, including the Mental Health Literacy Scale for Healthcare Students, Psychological Capital Questionnaire, and Simplified Coping Style Questionnaire. Pearson correlation analysis was used to evaluate the relationships among the variables. Mediation analysis was performed to identify the mediating effect of psychological capital on the relationship between mental health literacy and coping styles. RESULTS: Positive coping showed a positive relationship with psychological capital and mental health literacy, while negative coping showed a negative relationship with psychological capital and mental health literacy. For positive coping, psychological capital was a partial mediator with an effect of 0.140, accounting for 62.8%. For negative coping, a full mediating effect was shown by psychological capital between mental health literacy and negative coping, with an indirect effect of -0.048. CONCLUSION: Psychological capital plays a partial and complete mediating role between mental health literacy and different coping styles among newly recruited nurses. Diversified training and personalized guidance in improving mental health literacy and increasing psychological capital simultaneously can be provided to newly recruited nurses continuously to adjust their coping styles.

Proteomic variation in metamorphosing Paralichthys olivaceus induced by exogenous thyroid hormone.

Thyroid hormone (TH) is essential for Paralichthys olivaceus metamorphosis. Exogenous TH treatment induces premature metamorphosis in P. olivaceus larvae and a series of studies have been conducted to identify thyroid hormone-regulated functional genes and microRNAs involved in the metamorphosis of P. olivaceus; however, the proteins involved in this process remain to be fully clarified. In this study, the differential proteomic responses of P. olivaceus larvae to exogenous TH treatment were examined using tandem mass tags (TMT) for quantitation labeling followed by liquid chromatography tandem mass spectrometry (LC-MS/MS). The expression levels of 629 cellular proteins were identified to be significantly affected by TH treatment. The reliability of our TMT-labeled LC-MS/MS analysis was verified by examining the mRNA and protein levels of four selected proteins using quantitative real-time reverse-transcription PCR and western blot analyses. The possible biological significance of these proteins was further investigated by Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, and protein-protein interaction analyses. Notably, we identified and described five groups of proteins involved in different important life events that were significantly regulated by exogenous TH treatment. Our study provides an improved understanding of the molecular mechanisms by which TH regulates the metamorphosis of P. olivaceus.

Characterization and expression of lin-28a involved in lin28/let-7signal pathway during early development of P. olivaceus.

Heterochronic lin-28 is a conserved RNA-binding protein that plays a key role in the timing of developmental events in organisms. As a crucial heterochronic gene, the protein controls developmental events of the second of four larval stages in Caenorhabditi elegans. Heterochronic let-7 miRNAs are often present in various species and highly conserved in sequence and biological function and are required for various biological processes. Previous studies showed that ten let-7 miRNAs were identified in the Japanese flounder (Paralichthys olivaceus) and that they were primarily expressed during metamorphosis. In this study, we clone and characterize the lin-28a gene from P. olivaceus and exhibit its dynamic expression pattern at different developmental stages and various adult tissues. The results show that the P. olivaceus lin-28a gene has high sequence similarity with other species and is highly expressed in the embryonic stage but weakly expressed in the larval stage. In addition, lin-28a overexpression causes cell proliferation and significantly promotes the levels of pre-let-7a and pre-let-7d while markedly depressing let-7a and let-7d expression in FEC (Flounder Embryonic Cell), which indicate that lin-28 possibly blocks the maturation of let-7 miRNAs. Additionally, lin-28a is identified as a target gene of let-7 miRNAs, and let-7 miRNAs directly regulate lin-28a expression by targeting its 3' UTR. Taken together, lin-28a along with let-7 miRNA participates in a lin-28/let-7 axis pathway that regulates cell division and timing of embryonic and metamorphic events in P. olivaceus.

Coordinated expression and regulation of deiodinases and thyroid hormone receptors during metamorphosis in the Japanese flounder (Paralichthys olivaceus).

In vertebrates, thyroid hormone receptors (TRs) and deiodinases are essential for developmental events driven by the thyroid hormones (THs). However, the significance of deiodinases during the metamorphosis of the Japanese flounder (Paralichthys olivaceus) remains unclear. Moreover, regulation and response of the TRs and deiodinases to THs in this fish are poorly understood. Therefore, we detected the expression patterns of THs, deiodinases, and TRs in drug-treated larvae and untreated larvae of P. olivaceus by using enzyme-linked immunosorbent assay and quantitative real-time PCR during P. olivaceus metamorphosis. To further understand the roles of these elements, a rescue assay was performed. Our results show the importance of THs, TRs, and deiodinases in flatfish metamorphosis. Our results also confirm that D1 and D2 activate THs and D3 plays the opposite and complementary role. Moreover, we demonstrated that both TRα and TRß have important but different roles during P. olivaceus metamorphosis.

A key gene of the small RNA pathway in the flounder, Paralichthys olivaceus: identification and functional characterization of dicer.

Dicer is critical for producing mature microRNAs (miRNAs) from precursor molecules and small interfering RNAs and plays an important role in controlling development and metabolism. In the present study, we cloned the flounder dicer gene, which is 6585 nucleotides (nt), including a 5'-untranslated region (UTR) of 231 nt, a 3'-UTR of 663 nt and an open reading frame of 5691 nt encoding a polypeptide of 1897 amino acids, and analyzed the conservation and expression pattern of dicer. The tissue distribution analysis indicated that dicer is abundantly expressed in the brain, heart, liver, spleen, stomach, kidney, gill, muscle, intestine and gonad of adult fish. Temporal expression analysis indicated that dicer mRNA is highly expressed during the embryonic and early larval stages, and exhibits low expression during the metamorphic stages. Treatment with thyroid hormone (TH) or thiourea indirectly or directly up-regulated dicer mRNA levels at 17 and 23 dph, whereas treatment with TH down-regulated dicer mRNA levels at 36 dph. The dicer-specific siRNA significantly down-regulated dicer mRNA and pol-let-7d levels, while pol-let-7d precursor levels were not differentially changed compared with the control (NC). These results demonstrated that dicer plays a key role in development and metabolism through the production of mature miRNAs, providing basic information for further studies concerning the role of dicer in Paralichthys olivaceus development.

Identification and expression of SRF targeted by miR-133a during early development of Paralichthys olivaceus.

Serum response factor (SRF) is a MADS-box transcription factor that regulates the expression of genes involved in development, metabolism, cell proliferation, and differentiation. In the present study, we cloned the full-length SRF cDNA which includes the coding region of 1503 bp, a 573-bp 5'untranslated region (UTR) and a 400-bp 3'-UTR. The deduced 501 amino acid sequence of the SRF protein contained a MADS domain and NLS at the N terminus, similar to other organisms, and it also is highly phylogenetically conserved. SRF mRNA is ubiquitously expressed in various tissues, with the highest level in the kidneys, and it is also highly expressed during the embryonic and metamorphic stages. During metamorphosis, the SRF mRNA levels are down-regulated by exogenous thyroid hormone (TH) at 17 dph and by thiourea (TU) at 29, 36, and 41 dph, whereas SRF mRNA levels were significantly up-regulated by the added exogenous TH to the TU-treated larvae at 41 dph, which indicates that thyroid hormone is essential for expression of SRF mRNA, so, higher levels of TH did not result in changes of SRF mRNA levels, while TH deficiency or inhibited by the non-specific TU toxicity cause down-regulation of SRF mRNA, which indicated that TH can indirectly affect the SRF mRNA levels. Meanwhile, using a luciferase reporter assay, we verified that SRF is a common target gene of miR-133a which is a muscle-specific microRNA (miRNA), which indicated that SRF may be involved in the signaling pathway of miRNA that regulates muscle development.

Interaction of diet and the masou salmon Δ5-desaturase transgene on Δ6-desaturase and stearoyl-CoA desaturase gene expression and N-3 fatty acid level in common carp (Cyprinus carpio).

The masou salmon Δ5-desaturase-like gene (D5D) driven by the common carp ß-actin promoter was transferred into common carp (Cyprinus carpio) that were fed two diets. For P1 transgenic fish fed a commercial diet, Δ6-desaturase-like gene (D6D) and stearoyl-CoA desaturase (SCD) mRNA levels in muscle were up-regulated (P < 0.05) 12.7- and 17.9-fold, respectively, and the D6D mRNA level in the gonad of transgenic fish was up-regulated 6.9-fold (P < 0.05) compared to that of non-transgenic fish. In contrast, D6D and SCD mRNA levels in transgenic fish were dramatically down-regulated (P < 0.05), 50.2- and 16.7-fold in brain, and 5.4- and 2.4-fold in liver, respectively, in comparison with those of non-transgenic fish. When fed a specially formulated diet, D6D and SCD mRNA levels in muscle of transgenic fish were up-regulated (P < 0.05) 41.5- and 8.9-fold, respectively, and in liver 6.0- and 3.3-fold, respectively, compared to those of non-transgenic fish. In contrast, D6D and SCD mRNA levels in the gonad of transgenic fish were down-regulated (P < 0.05) 5.5- and 12.4-fold, respectively, and D6D and SCD mRNA levels in the brain were down-regulated 14.9- and 1.4-fold (P < 0.05), respectively, compared to those of non-transgenic fish. The transgenic common carp fed the commercial diet had 1.07-fold EPA, 1.12-fold DPA, 1.07-fold DHA, and 1.07-fold higher observed total omega-3 fatty acid levels than non-transgenic common carp. Although these differences were not statistically different (P > 0.05), there were significantly (P < 0.10) higher omega-3 fatty acid levels when considering the differences for all of the individual omega-3 fatty acids. The genotype × diet interactions observed indicated that the potential of desaturase transgenesis cannot be realized without using a well-designed diet with the needed amount of substrates.

Efficient Reinforcement Learning With the Novel N-Step Method and V-Network.

The application of reinforcement learning (RL) in artificial intelligence has become increasingly widespread. However, its drawbacks are also apparent, as it requires a large number of samples for support, making the enhancement of sample efficiency a research focus. To address this issue, we propose a novel N -step method. This method extends the horizon of the agent, enabling it to acquire more long-term effective information, thus resolving the issue of data inefficiency in RL. Additionally, this N -step method can reduce the estimation variance of Q -function, which is one of the factors contributing to estimation errors in Q -function estimation. Apart from high variance, estimation bias in Q -function estimation is another factor leading to estimation errors. To mitigate the estimation bias of Q -function, we design a regularization method based on the V-function, which has been underexplored. The combination of these two methods perfectly addresses the problems of low sample efficiency and inaccurate Q -function estimation in RL. Finally, extensive experiments conducted in discrete and continuous action spaces demonstrate that the proposed novel N -step method, when combined with classical deep Q -network, deep deterministic policy gradient, and TD3 algorithms, is effective, consistently outperforming the classical algorithms.

XRayWizard: Reconstructing 3-D lung surfaces from a single 2-D chest x-ray image via Vision Transformer.

BACKGROUND: Chest x-ray is widely utilized for the evaluation of pulmonary conditions due to its technical simplicity, cost-effectiveness, and portability. However, as a two-dimensional (2-D) imaging modality, chest x-ray images depict limited anatomical details and are challenging to interpret. PURPOSE: To validate the feasibility of reconstructing three-dimensional (3-D) lungs from a single 2-D chest x-ray image via Vision Transformer (ViT). METHODS: We created a cohort of 2525 paired chest x-ray images (scout images) and computed tomography (CT) acquired on different subjects and we randomly partitioned them as follows: (1) 1800 - training set, (2) 200 - validation set, and (3) 525 - testing set. The 3-D lung volumes segmented from the chest CT scans were used as the ground truth for supervised learning. We developed a novel model termed XRayWizard that employed ViT blocks to encode the 2-D chest x-ray image. The aim is to capture global information and establish long-range relationships, thereby improving the performance of 3-D reconstruction. Additionally, a pooling layer at the end of each transformer block was introduced to extract feature information. To produce smoother and more realistic 3-D models, a set of patch discriminators was incorporated. We also devised a novel method to incorporate subject demographics as an auxiliary input to further improve the accuracy of 3-D lung reconstruction. Dice coefficient and mean volume error were used as performance metrics as the agreement between the computerized results and the ground truth. RESULTS: In the absence of subject demographics, the mean Dice coefficient for the generated 3-D lung volumes achieved a value of 0.738 ± 0.091. When subject demographics were included as an auxiliary input, the mean Dice coefficient significantly improved to 0.769 ± 0.089 (p < 0.001), and the volume prediction error was reduced from 23.5 ± 2.7%. to 15.7 ± 2.9%. CONCLUSION: Our experiment demonstrated the feasibility of reconstructing 3-D lung volumes from 2-D chest x-ray images, and the inclusion of subject demographics as additional inputs can significantly improve the accuracy of 3-D lung volume reconstruction.

Graphical modeling of causal factors associated with the postoperative survival of esophageal cancer subjects.

PURPOSE: To clarify the causal relationship between factors contributing to the postoperative survival of patients with esophageal cancer. METHODS: A cohort of 195 patients who underwent surgery for esophageal cancer between 2008 and 2021 was used in the study. All patients had preoperative chest computed tomography (CT) and positron emission tomography-CT (PET-CT) scans prior to receiving any treatment. From these images, high throughput and quantitative radiomic features, tumor features, and various body composition features were automatically extracted. Causal relationships among these image features, patient demographics, and other clinicopathological variables were analyzed and visualized using a novel score-based directed graph called "Grouped Greedy Equivalence Search" (GGES) while taking prior knowledge into consideration. After supplementing and screening the causal variables, the intervention do-calculus adjustment (IDA) scores were calculated to determine the degree of impact of each variable on survival. Based on this IDA score, a GGES prediction formula was generated. Ten-fold cross-validation was used to assess the performance of the models. The prediction results were evaluated using the R-Squared Score (R2 score). RESULTS: The final causal graphical model was formed by two PET-based image variables, ten body composition variables, four pathological variables, four demographic variables, two tumor variables, and one radiological variable (Percentile 10). Intramuscular fat mass was found to have the most impact on overall survival month. Percentile 10 and overall TNM (T: tumor, N: nodes, M: metastasis) stage were identified as direct causes of overall survival (month). The GGES casual model outperformed GES in regression prediction (R2  = 0.251) (p < 0.05) and was able to avoid unreasonable causality that may contradict common sense. CONCLUSION: The GGES causal model can provide a reliable and straightforward representation of the intricate causal relationships among the variables that impact the postoperative survival of patients with esophageal cancer.

Insulin-like growth factor binding protein-2 (IGFBP-2) in Japanese flounder, Paralichthys olivaceus: molecular cloning, expression patterns and hormonal regulation during metamorphosis.

In this study, we cloned and characterized cDNA sequences of two insulin-like growth factor binding protein-2 (IGFBP-2a and IGFBP-2b) from Japanese flounder, Paralichthys olivaceus. The full-length cDNA of IGFBP-2a is 1,046 bp long and consists an open frame (ORF) of 876 bp, a 5'-untranslated region (UTR) of 125 bp and a 3'-UTR of 45 bp. IGFBP-2b is 1,067 bp, including a 5'-UTR of 53 bp, a 3'-UTR of 198 bp and an ORF of 816 bp. Real-time quantitative PCR results revealed that IGFBP-2a -2b mRNA was expressed in all detected tissues. Interestingly, the levels of IGFBP-2a mRNA in all detected tissues were higher in female than male, but IGFBP-2b was precisely the opposite. At different embryonic stages, the levels of IGFBP-2a mRNA were typically higher than IGFBP-2b. After hatching, IGFBP-2a mRNA was gradually decreased to a relatively lower level. However, the expression of IGFBP-2b mRNA was increased after hatching, including 3, 7, 10, 14, 17, 20 and 23 days post-hatching (dph), and it presents a higher level until 29 (metamorphic climax), 36 (post-climax) and 41 dph (the end of metamorphosis). In levothyroxine sodium salt (T4, the main form of thyroid hormone in animals)-treated and thiourea (TU)-treated larvae, the expressions of IGFBP-2a had not visibly changed, except in T4-treated 17 dph larvae. The expressions of IGFBP-2b mRNA were distinctly increased from 17 to 23 dph, but suddenly dropped to a lower level in and after 29 dph. However, the levels of IGFBP-2b mRNA during metamorphosis were greatly down-regulated after TU treatment. These results provided basic information for further studies on the role of IGF system in flatfish development and metamorphosis.

Moderating effect of organizational climate on the relationship between research motivation and learning engagement among nurses taking part-time master's program: A cross-sectional study.

AIMS: To investigate the moderating effects of perceived organizational climate on the relationship between research motivation and learning engagement in research among nurses pursuing a part-time master's degree. BACKGROUND: Research motivation positively affects learning engagement in research. However, the role of perceived organizational climate has not been explored in nurses taking part-time master's program in China. This study examined the relationships between various types of research motivation and learning engagement in research and whether the perceived organizational climate moderates the relationship between the other variables. METHODS: This cross-sectional one-center study was performed on 230 nurses by assessing learning engagement in research, research motivation and perceived organizational climate. RESULTS: The mean age of participants was 31.3 ± 3.5 years and 91.3% were female. Participants who had been assigned a supervisor showed higher learning engagement in research than those without a supervisor (3.65 ± 0.60 vs. 3.48 ± 0.61; P < 0.001). Participants who had experience conducting research reported higher learning engagement in research than those with no experience (3.30 ± 0.71 vs. 3.14 ± 0.83; P < 0.05). The mean score of learning engagement in research was 3.39 ± 0.63. The mean scores for intrinsic, extrinsic and failure-avoidance motivation were 3.72 ± 0.61, 3.71 ± 0.71 and 3.43 ± 0.70, respectively. As for perceived organizational climate, the mean score was 122.70 out of 148. Learning engagement in research was significantly positively correlated with intrinsic research motivation, extrinsic research motivation and perceived organizational climate scores (r = 0.441, 0.336, 0.307, p < 0.001, respectively). Perceived organizational climate moderated the correlation between intrinsic and extrinsic research motivation and learning engagement in research. CONCLUSION: Nurses taking the master's program perceived a higher level of perceived organizational climate could strengthen the relationship between intrinsic and extrinsic research motivation and learning engagement in research. More organizational support can enhance learning engagement in research by reinforcing intrinsic and extrinsic research motivation. IMPLICATIONS FOR NURSING MANAGEMENT: Universities can assign supervisors promptly. Universities and hospitals can provide education about the importance of research in nursing and reinforce their intrinsic and extrinsic research motivation. Hospitals can adjust policies based on the needs of nurses taking the master's program to provide organizational support, to facilitate the research learning process.

Pregnancy-related low back/pelvic girdle pain: Prevalence, severity, and risk factors in Zhengzhou, China.

BACKGROUND: Pregnancy-related low back pain (LBP) and pelvic girdle pain (PGP) significantly affect the quality of life of pregnant women. Understanding their severity and risk factors may help prevent and alleviate such pain and their resulting dysfunction. OBJECTIVE: This study investigated the prevalence, severity, and biopsychosocial risk factors of pregnancy-related LBP and PGP in Zhengzhou, China. METHODS: The Numeric Pain Rating Scale (NPRS), Chinese version of the Roland-Morris Disability Questionnaire (RMDQ), and other questionnaires were self-administered by 1020 pregnant women undergoing treatment at a tertiary hospital between July and December 2019. Binary logistic regression was used to identify factors associated with pregnancy-related LBP and/or PGP. RESULTS: The prevalence of LBP and/or PGP during pregnancy was 63.0%, and most participants (80.4%) had both. The mean NPRS and RMDQ disability scores were 2.44 ± 2.10 and 6.66 ± 4.65, respectively. A higher gestational body mass index, LBP and/or PGP during menstruation, history of pregnancy-related LBP and/or PGP, and constant pressure were significantly associated with pregnancy-related LBP and/or PGP. Subjective support was a protective factor against LBP and/or PGP. CONCLUSION: The prevalence of LBP and/or PGP was high. The risk factors should be included in routine prenatal care to identify patients at risk of LBP and/or PGP.

Batch-balanced focal loss: a hybrid solution to class imbalance in deep learning.

Purpose: To validate the effectiveness of an approach called batch-balanced focal loss (BBFL) in enhancing convolutional neural network (CNN) classification performance on imbalanced datasets. Materials and Methods: BBFL combines two strategies to tackle class imbalance: (1) batch-balancing to equalize model learning of class samples and (2) focal loss to add hard-sample importance to the learning gradient. BBFL was validated on two imbalanced fundus image datasets: a binary retinal nerve fiber layer defect (RNFLD) dataset (n=7,258) and a multiclass glaucoma dataset (n=7,873). BBFL was compared to several imbalanced learning techniques, including random oversampling (ROS), cost-sensitive learning, and thresholding, based on three state-of-the-art CNNs. Accuracy, F1-score, and the area under the receiver operator characteristic curve (AUC) were used as the performance metrics for binary classification. Mean accuracy and mean F1-score were used for multiclass classification. Confusion matrices, t-distributed neighbor embedding plots, and GradCAM were used for the visual assessment of performance. Results: In binary classification of RNFLD, BBFL with InceptionV3 (93.0% accuracy, 84.7% F1, 0.971 AUC) outperformed ROS (92.6% accuracy, 83.7% F1, 0.964 AUC), cost-sensitive learning (92.5% accuracy, 83.8% F1, 0.962 AUC), and thresholding (91.9% accuracy, 83.0% F1, 0.962 AUC) and others. In multiclass classification of glaucoma, BBFL with MobileNetV2 (79.7% accuracy, 69.6% average F1 score) outperformed ROS (76.8% accuracy, 64.7% F1), cost-sensitive learning (78.3% accuracy, 67.8.8% F1), and random undersampling (76.5% accuracy, 66.5% F1). Conclusion: The BBFL-based learning method can improve the performance of a CNN model in both binary and multiclass disease classification when the data are imbalanced.

Thyroid Hormone Signaling Is Required for Dynamic Variation in Opsins in the Retina during Metamorphosis of the Japanese Flounder (Paralichthys olivaceus).

In the present study, we investigated the function of thyroid hormones (TH) in visual remodeling during Japanese flounder (Paralichthys olivaceus) metamorphosis through cellular molecular biology experiments. Our results showed that the expression of the five opsin genes of the flounder were highest in eye tissue and varied with the metamorphosis process. The expression of rh1, sws2aß and lws was positively regulated by exogenous TH, but inhibited by thiourea (TU) compared to the control group. In addition, there was a significant increase in sws2aß and lws in the rescue experiments performed with TU-treated larvae (p < 0.05). Meanwhile, T3 levels in flounder larvae were increased by TH and decreased by TU. Based on the differences in the expression of the three isoforms of the thyroid hormone receptor (TR) (Trαa, Trαb and Trß), we further hypothesized that T3 may directly or indirectly regulate the expression of sws2aß through Trαa. This study demonstrates the regulatory role of TH in opsins during flounder metamorphosis and provides a basis for further investigation on the molecular mechanisms underlying the development of the retinal photoreceptor system in flounders.

Strolling in Room-Scale VR: Hex-Core-MK1 Omnidirectional Treadmill.

The natural locomotion interface is critical to the development of many VR applications. For household VR applications, there are two basic requirements: natural immersive experience and minimized space occupation. The existing locomotion strategies generally do not simultaneously satisfy these two requirements well. This article presents a novel omnidirectional treadmill (ODT) system named Hex-Core-MK1 (HCMK1). By implementing two kinds of mirror-symmetrical spiral rollers to generate the omnidirectional velocity field, this proposed system is capable of providing real walking experiences with a full-degree of freedom in an area as small as 1.76 m 2, while delivering great advantages over several existing ODT systems in terms of weight, volume, latency and dynamic performance. Compared with the sizes of Infinadeck and HCP, the two best motor-driven ODTs so far, the 8 cm height of HCMK1 is only 20% of Infinadeck and 50% of HCP. In addition, HCMK1 is a lightweight device weighing only 110 kg, which provides possibilities for further expanding VR scenarios, such as terrain simulation. The system latency of HCMK1 is only 9ms. The experiments show that HCMK1 can deliver a starting acceleration of 16.00 m/s 2 and a braking acceleration of 30.00 m/s 2.

Expression of insulin-like growth factor I receptors at mRNA and protein levels during metamorphosis of Japanese flounder (Paralichthys olivaceus).

Insulin-like growth factor I (IGF-I) is an important regulator of fish growth and development, and its biological actions are initiated by binding to IGF-I receptor (IGF-IR). Our previous study has revealed that IGF-I could play an important role during metamorphosis of Japanese flounder, Paralichthys olivaceus. The analysis of IGF-IR expression thus helps further elucidate the IGF-I regulation of metamorphic processes. In this study, the spatial-temporal expression of two distinct IGF-IR mRNAs was investigated by real-time RT-PCR. The spatial distribution of two IGF-IR mRNAs in adult tissues is largely overlapped, but they exhibit distinct temporal expression patterns during larval development. A remarkable decrease in IGF-IR-2 mRNA was detected during metamorphosis. In contrast, a significant increase in IGF-IR-1 mRNA was determined from pre-metamorphosis to metamorphic completion. These indicate that they may play different function roles during the flounder metamorphosis. The levels and localization of IGF-IR proteins during larval development were further studied by Western blotting and immunohistochemistry. Immunoreactive IGF-IRs were detected throughout larval development, and the IGF-IR proteins displayed a relatively abundant expression during metamorphosis. Moreover, the IGF-IR proteins appeared in key tissues, such as thickened skin beneath the migrating eye, developing intestine, gills and kidney during metamorphosis. These results further suggest that the IGF-I system may be involved in metamorphic development of Japanese flounder.

Study on immune regulation in Hyriopsis cumingii Lea: effect of pearl-nucleus insertion in the visceral mass on immune factors present in the hemolymph.

This study was aimed at elucidating the mechanism of immune responses in fresh water mussels during pearl culture. Alpha-2 macroglobulin gene (alpha(2)M) expression, acid phosphatase (ACP) and superoxide dismutase (SOD) activities, and hemocyte counts were evaluated after inserting a pearl nucleus into the visceral mass of Hyriopsis cumingii Lea (H. Lea). We selected 60 H. Leas and randomly assigned them to 2 groups (each group contained 3 replicates of 10 individuals), and individuals among one group were treated by inserting pearl nucleus into the visceral mass. Real-time quantitative polymerase chain reaction (Q-PCR) was used to evaluate alpha(2)M gene expression, and the activities of ACP and SOD in hemocytes and serum were determined after 1, 2, 3, 5, and 10 days after nucleus insertion. Hemocyte morphologies and numbers on the 5th day after insertion were studied using phase-contrast microscope (PCM), optical microscope and flow cytometry (FCM). All observations suggested that the insertion of the pearl nucleus in the visceral mass had a significant effect on alpha(2)M gene expression, ACP and SOD activities, and hemocyte characteristics. The alpha(2)M gene expression was sharply up-regulated on the 3rd day after nucleus insertion, and it was significantly higher in the test groups on the 3rd, 5th, and 10th days than those in the control groups (P < 0.05). On the 1st to 3rd after treatment, ACP activity in the test group was higher than that in the control group (P < 0.05). SOD activity in the serum was remarkably higher in the test groups than in the control group, and exhibited significant differences on the 3rd, 5th, and 10th days (P < 0.05). However, the SOD activity in hemocytes was lower in the test group than in the control group, and it exhibited significant differences on all days, except on the 3rd day (P < 0.05). The hemocytes were divisible into 2 types: granulocytes (GR) and hyalinocytes (HY). The hemocyte morphology, protuberances, vesicle-like bodies, and density increased significantly (P < 0.05), and the number of GR increased, while that of HY decreased after nucleus insertion. These results indicated that the insertion of pearl nucleus enhanced the immune response in H. Lea.

Establishment and in-house validation of simplex and duplex PCR methods for event-specific detection of maize SYN-E3272-5 using a new reference molecule.

Despite rapid developments in the detection techniques for genetically modified organisms (GMOs), the event-specific PCR method with high specificity is still the most used technique. In this study, event-specific simplex and duplex qualitative and quantitative detection systems were developed targeting the 3' insertion site of GM maize SYN-E3272-5 (3272) construct. A reference molecule p3272 was constructed to act as positive control and as calibrator for quantitative analysis. The LOD for simplex and duplex qualitative PCR assays was 10 copies of p3272 control DNA. LOD and the LOQ for simplex and duplex quantitative PCR assays were 10 and 25 copies of p3272 DNA, respectively. Furthermore, four practical GM maize samples were quantified using the established simplex and duplex quantitative PCR systems by in-house validation. Results from five operators showed that the bias ranged from 3.44 to 17.24% in the simplex system and from 0.42 to 16.06% in the duplex system, respectively. These results demonstrated that the established event-specific simplex and duplex qualitative and quantitative PCR systems combined with the reference molecule p3272 are suitable for the detection of GM maize 3272 and its derived products.

Integrative cytological analysis of the effects of Ca2+ and vitamin D3 on extracellular Ca2+ flux and intracellular Ca2+ reserves in the mantle of the pearl oyster (Hyriopsis cumingii Lea).

To examine Ca2+ absorption and transportation in the freshwater pearl oyster, Hyriopsis cumingii Lea, we studied the effects of different levels of either extracellular Ca2+ or 1,25(OH)2D3 on extracellular Ca2+ flux and intracellular Ca2+ concentrations in mantle cells using the non-invasive micro-test technique and laser scanning confocal microscopy. The inner and outer mantle (IM and OM) cells from mussels were cultured and then treated with different concentrations of Ca2+ and 1,25(OH)2D3. Extracellular Ca2+ flux and intracellular Ca2+ reserves were analyzed. The results showed that both extracellular Ca2+ and 1,25(OH)2D3 had significant effects on Ca2+ flux and reserves in mantle cells, especially in IM cells (P < .05). The increase in extracellular Ca2+ concentrations resulted in the conversion of extracellular Ca2+ flux into influx with an increase in flow rate (P < .05). The calcium ion fluorescence intensity of OM cells was higher than that of IM cells (P < .05). 1,25(OH)2D3 addition also significantly increased the influx rate of extracellular Ca2+, especially in IM cells, which were more sensitive to 1,25(OH)2D3 addition and had significantly higher Ca2+ influx rates than did OM cells (P < .05). Fluorescence intensities of intracellular Ca2+ first increased and then decreased with increasing 1,25(OH)2D3 levels. The study showed that IM cells play an important role in absorbing Ca2+ from the environment, while OM cells mainly function in the temporary storage and transportation of Ca2+ in the body. The current results suggested that high levels of extracellular Ca2+ (1.25 mM) or 1,25(OH)2D3 (over 100 IU/L) were favorable for Ca2+ uptake and maintenance in the body.