The longitudinal associations between internet addiction and ADHD symptoms among adolescents.

Background and aims: Internet addiction has been linked to ADHD-related symptoms. However, the direction of the relationship and its potential for reciprocal relations is not well understood. This study examined the potential reciprocal relations between the three components of ADHD and Internet addiction, as well as the moderating effects of gender on these relations. Methods: Using a longitudinal design, we collected data of 865 Chinese adolescents across three waves (Mage = 13.78, SD = 1.56 in wave 1), with a time interval of 6 months. Results: Cross-lagged analyses revealed bidirectional associations between hyperactivity, inattention, impulsivity, and Internet addiction over time. Multi-group analyses did not yield any significant gender differences in these relationships. Discussion and conclusions: These findings enhance our understanding of the complex link between ADHD components and Internet addiction and have implications for interventions aimed at reducing the prevalence of Internet addiction and ADHD.

The relationship between parenting styles and adolescent problematic Internet use: A three-level meta-analysis.

Background and aims: Problematic Internet use (PIU) has become a global public health problem. It has been suggested that parenting style is associated with adolescent PIU. However, the evidence in favor of this view is mixed. Based on the PRISMA method, the present study employed three-level meta-analysis approach to investigate the relationship between these two variables and further explore potential moderators. Methods: After a systematic search for published articles, 35 studies were included, reporting 171 effect sizes (N = 40,587). Results: The results showed that positive parenting styles were significantly negatively related to PIU. This association was moderated by gender, age, publication year, and measurements of PIU, but was not by culture and measurements of parenting styles. Negative parenting styles were significantly positively related to PIU, which was moderated by publication year, culture, and sub-types of negative parenting, but not by gender, age, and measurements of both parenting styles and PIU. In addition, the correlation of PIU with negative parenting styles was stronger than that with positive parenting styles. Discussion and Conclusions: The present results demonstrated that parenting styles, especially punitive parenting styles, should be attached to more important when treating adolescent PIU.

Matrine regulates Th1/Th2 inflammatory responses by inhibiting the Hsp90/NF-κB signaling axis to alleviate atopic dermatitis.

Atopic dermatitis (AD) is a common inflammatory skin disease. Matrine is the main component of the traditional Chinese medicine Sophora flavescens, and it poses good therapeutic effects on inflammatory diseases. This study aimed to explore the pharmacological effects of matrine on AD and its underlying mechanism. An AD mouse model and inflamed human epidermal keratinocyte cells (HaCaT) cells were established. Histopathological aspects were examined using hematoxylin and eosin staining, toluidine blue staining, and immunohistochemistry. The mRNA and protein expressions were assessed using quantitative real-time polymerase chain reaction and Western blot, respectively. The secretions of cytokines and chemokines were examined by enzyme-linked immunosorbent assay. Flow cytometry was carried out to analyze the proportions of T-helper (Th) 1 and Th2 cells. Herein, our results displayed that matrine diminished AD symptoms and decreased heat shock protein 90 (Hsp90) expression. Matrine decreased the Th2 cytokine levels in the ear tissues and serum, and it also significantly repressed inflammatory cytokines (thymus activation regulated chemokine and interleukin-6) secretions by repressing the Hsp90/NF-κB signaling axis in inflamed HaCaT cells. Furthermore, matrine inhibited Th2 differentiation of CD4+ T cells when co-cultured with inflamed HaCaT cells. Matrine can regulate the Th1/Th2 inflammatory response by inhibiting the Hsp90/NF-κB signaling axis to alleviate AD. Therefore, it may be a candidate for AD treatment.

[Effects of harvest residue management on soil organic nitrogen fractions in young Cunninghamia lanceolata plantation]. / 采伐剩余物不同处理方式对杉木幼林土壤有机氮组分的影响.

Different treatments of harvest residues will change the quantity and quality of soil organic matter, with direct or indirect effects on the composition and content of soil nutrient. Nitrogen is one of the most important soil nutrients. However, the response of soil organic nitrogen fractions to different harvest residue treatments is still unclear. In this study, harvest residue treatments, including harvest residue removed, residue retained and residue burnt, were set up after clear-cutting a 50-year-old mature Cunninghamia lanceolata forest in Sanming City, Fujian, China. The H2SO4 hydrolysis method was used to determine soil organic nitrogen fractions and their driving factors in the 0-10 cm and 10-20 cm soil layers after 5 years of harvest residue treatments. The results showed that residue retained treatment significantly enhanced the contents of soil organic nitrogen and its liable fractions. In the 0-10 cm soil layer, soil organic nitrogen content under residue retained treatment (3.36 g·kg-1) was 1.5 and 1.3 times as those of residue removed and residue burnt treatments, respectively. Residue retained treatment had the highest contents of labile nitrogen Ⅰ and Ⅱ fractions. In 10-20 cm soil layer, the contents of soil organic nitrogen and labile nitrogen Ⅱ fraction were also significantly higher in residue retained treatment (2.20, 0.73 g·kg-1) than that in residue removed and residue burnt treatments. The labile nitrogen index Ⅱ in residue retained treatment (33.9%) was significantly higher than in residue burnt treatment (26.1%). The contents of total carbon, dissolved organic carbon, dissolved organic nitrogen, microbial biomass under residue retained treatment were the highest in both soil layers. Compared with residue removed treatment, residue retained treatment significantly enhanced the abundance of soil bacteria (Gram-positive bacteria and Gram-negative bacteria) in 0-10 cm soil layer. In 10-20 cm soil layer, residue retained treatment had the highest content of fungi and the lowest content of actinomycetes. Pearson analysis showed that there were significant positive correlations of labile fractions of soil organic nitrogen with total carbon, dissolved organic carbon, dissolved organic nitrogen, microbial biomass carbon, microbial biomass nitrogen, bacteria (Gram-positive bacteria, Gram-negative bacteria), and fungi, and negative correlations with actinomycetes. It was concluded that the retention of harvest residue was beneficial to increase the content of soil organic nitrogen and labile fractions, improve soil biochemical properties and had a positive effect on soil microbial community composition. Retention of harvest residue was an effective management measure to maintain soil fertility and improve forest productivity.

High-continuity genome assembly of the jellyfish Chrysaora quinquecirrha.

The Atlantic sea nettle ( Chrysaora quinquecirrha) has an important evolutionary position due to its high ecological value. However, due to limited sequencing technologies and complex jellyfish genomic sequences, the current C. quinquecirrha genome assembly is highly fragmented. Here, we used the most advanced high-throughput chromosome conformation capture (Hi-C) technology to obtain high-coverage sequencing data of the C. quinquecirrha genome. We then anchored these data to the previously published contig-level assembly to improve the genome. Finally, a high-continuity genome sequence of C. quinquecirrha was successfully assembled, which contained 1 882 scaffolds with a N50 length of 3.83 Mb. The N50 length of the genome assembly was 5.23 times longer than the previously released one, and additional analysis revealed that it had a high degree of genomic continuity and accuracy. Acquisition of the high-continuity genome sequence of C. quinquecirrha not only provides a basis for the study of jellyfish evolution through comparative genomics but also provides an important resource for studies on jellyfish growth and development.

1H NMR spectroscopy-based metabolic profiling of Ophiocordyceps sinensis and Cordyceps militaris in water-boiled and 50% ethanol-soaked extracts.

Ophiocordyceps sinensis, a well-known Chinese complementary herb, is a rare and valuable therapeutic resource. Cordyceps militaris (C. militaris) is a commonly used substitute for O. sinensis. A metabolomic-based approach for exploring the similarities and differences in the metabolites of O. sinensis and C. militaris in water-boiled and 50% ethanol-soaked extracts is of great significance. To distinguish between the global metabolite profiles of O. sinensis and C. militaris extracts obtained from either the water-boiled or 50% ethanol-soaked methods, we investigated the herb samples using 1HNMR-based metabolic fingerprints combined with multivariate statistical analysis. This study revealed that a total of 52 primary metabolites were identified and quantified from O. sinensis and C. militaris samples. Forty-three (83% of 52) metabolites were detectable in both O. sinensis and C. militaris. According to the variable importance in projection (VIP) value and p-value from the Mann-Whitney test, 7 metabolites (alanine, aspartate, glutamate, mannitol, ornithine, serine, and trehalose) differed between O. sinensis and C. militaris. Arginine, glucose, putrescine, pyroglutamate, betaine, O-phosphocholine, and xylose differed significantly between the water-boiled and 50% ethanol-soaked methods used to prepare the herb extracts. This study demonstrated that water-boiled extraction was a much faster method (30 min. vs 360 days) that resulted in a 30% higher number of extracted metabolites (compared to 50% for the ethanol-soaked method) for both O. sinensis and C. militaris.

The Association Between Mobile Game Addiction and Depression, Social Anxiety, and Loneliness.

As a new type of addictive behaviors and distinct from traditional internet game addiction on desktop computers, mobile game addiction has attracted researchers' attention due to its possible negative effects on mental health issues. However, very few studies have particularly examined the relationship between mobile game addiction and mental health outcomes, due to a lack of specified instrument for measuring this new type of behavioral addiction. In this study, we examined the relationship between mobile game addition and social anxiety, depression, and loneliness among adolescents. We found that mobile game addiction was positively associated with social anxiety, depression, and loneliness. A further analysis on gender difference in the paths from mobile game addiction to these mental health outcomes was examined, and results revealed that male adolescents tend to report more social anxiety when they use mobile game addictively. We also discussed limitations and implications for mental health practice.

The relationship between perceived stress and problematic social networking site use among Chinese college students.

BACKGROUND AND AIMS: Perceived stress has been regarded as a risk factor for problematic social networking site (SNS) use, yet little is known about the underlying processes whereby confounding variables may mediate or moderate this relationship. To answer this question, this study examined whether depression and anxiety mediated the relationship between perceived stress and problematic SNS use, and whether these mediating processes were moderated by psychological resilience and social support. METHODS: Participants were 641 Chinese college students who completed anonymous questionnaires measuring perceived stress, depression/anxiety, psychological resilience, social support, and problematic SNS use. RESULTS: The results showed that (a) depression/anxiety mediated the relationship between perceived stress and problematic SNS use; (b) the mediating effects of depression/anxiety on the association between perceived stress and problematic SNS use were moderated by psychological resilience. Specifically, the mediating effects of depression/anxiety were stronger for individuals with lower levels of psychological resilience, compared with those with higher levels of psychological resilience; and (c) the mediating effects of depression/anxiety were not moderated by social support, although social support was negatively related to depression/anxiety. DISCUSSION AND CONCLUSION: This study can contribute to a better understanding of how and when perceived stress increases the risk of problematic SNS use, and implies the importance of enhancing psychological resilience in preventing problematic SNS use.

RETRACTED: Function of the PLZF gene in early development and self-renewal of T cells in mice.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).. This article has been retracted at the request of < the Editor in Chief. The Editor in Chief has been made aware of numerous problems with this paper regarding authorship, poor or insufficient supervision of researchers and the unauthorized use of data acquired from a lab visit by one of the authors.

Analysis of the Gynaephora qinghaiensis pupae immune transcriptome in response to parasitization by Thektogaster sp.

As a pest on the Qinghai-Tibet Plateau, Gynaephora qinghaiensis causes severe damage to grassland vegetation and its pupae are also natural hosts of Thektogaster sp. To successfully parasitize, endoparasitoids generally introduce or secrete multiple parasitic factors into the host body during the spawning stage to suppress the host immune response. To study the parasitic effects of Thektogaster sp. on G. qinghaiensis, a transcriptome analysis of immune-related genes in parasitized and nonparasitized G. qinghaiensis pupae was performed. A total of 371,260,704 clean reads were assembled into 118,144 unigenes with an average length of 884.33 base pairs. Of these, 23,660 unigenes were annotated in at least one database and 94,484 unigenes were not annotated in any databases. These findings indicated that the majority of the genetic resources (79.97% of all unigenes) in Gynaephora should be further explored. Parasitization significantly affected the transcriptional profile of G. qinghaiensis pupae. The present study identified 12,322 differentially expressed genes and 57 immune-related genes were identified in parasitized G. qinghaiensis pupae. Most immune-related genes were downregulated, potentially resulting from the inhibitory effect of Thektogaster sp. on G. qinghaiensis pupae after parasitization. Overall, the transcriptome analysis sheds valuable light on the molecular mechanisms of G. qinghaiensis parasitization by Thektogaster sp. and promotes the development of novel biocontrol strategies for Gynaephora based on immune defense.

Induction and Suppression of Innate Antiviral Responses by Hepatitis A Virus.

Hepatitis A virus (HAV) belongs to the family Picornaviridae. It is the pathogen of acute viral hepatitis caused by fecal-oral transmission. RNA viruses are sensed by pathogen-associated pattern recognition receptors (PRRs) such as Toll-like receptor 3 (TLR3), retinoic acid-inducible gene I (RIG-I), and melanoma differentiation-associated gene 5 (MDA5). PRR activation leads to production of type 1 interferon (IFN-α/ß), serving as the first line of defense against viruses. However, HAV has developed various strategies to compromise the innate immune system and promote viral propagation within the host cells. The long coevolution of HAV in hosts has prompted the development of effective immune antagonism strategies that actively fight against host antiviral responses. Proteases encoded by HAV can cleave the mitochondrial antiviral signaling protein (MAVS, also known as IPS-1, VISA, or Cardif), TIR domain- containing adaptor inducing IFN-ß (TRIF, also known as TICAM-1) and nuclear factor-κB (NF-κB) essential modulator (NEMO), which are key adaptor proteins in RIG-I-like receptor (RLR), TLR3 and NF-κB signaling, respectively. In this mini-review, we summarize all the recent progress on the interaction between HAV and the host, especially focusing on how HAV abrogates the antiviral effects of the innate immune system.

[Role of endoplasmic reticulum stress-induced apoptosis of trophoblasts in intrahepatic cholestasis during pregnancy].

OBJECTIVE: To investigate the role of endoplasmic reticulum stress (ERS)-induced trophoblast apoptosis in the development of intrahepatic cholestasis during pregnancy (ICP). METHODS: Twenty pregnant women with ICP and 20 normal pregnant women undergoing cesarean section were enrolled in this study. The number of placenta syncytial knots in these women was determined using HE staining. The mRNA expressions of GRP78, CHOP, caspase-3, and caspase-7 were detected using RT-PCR in the placental tissues of the women and also in HTR-8/SVneo cells treated with different doses of deoxycholic acid (DCA). Caspase-3 and caspase-7 activities were also detected in DCA-treated HTR-8/SVneo cells using commercial assay kits, and the presence of apoptotic bodies in the cells were detected with electron microscopy. RESULTS: Compared with normal placental tissues, the placenta from women with ICP showed significantly increased syncytial knots (P<0.01) and obviously enhanced mRNA expressions of GRP78, CHOP, caspase-3, and caspase-7 (P<0.05). In HTR-8/SVneo cells treated with different doses of DCA (0, 10, 50, and 100 µmol/L), the mRNA expressions of GRP78, CHOP, caspase-3 and caspase-7 were significantly increased in a dose-dependent manner (P<0.05) and the protein levels of GRP78 and CHOP were also increased dose-dependently. Treatment with DCA at 50 µmol/L for 24 h significantly upregulated caspase-3 and caspase-7 activity in the cells (P<0.05), and the cells treated with 50 µmol/L DCA for 12 h showed the presence of apoptotic bodies. CONCLUSION: The activation of ERS and enhanced apoptosis of the trophoblasts occur in the placenta of women with ICP. DCA can significantly increase the expressions of ERS markers and thus lead to trophoblast apoptosis, suggesting that ERS-induced trophoblasts apoptosis may play a key role in the development of ICP.

[Expectant therapy versus curettage for retained products of conception after second trimester termination of pregnancy: analysis of outcomes and complications].

OBJECTIVE: To evaluate the prognosis and complications of expectant therapy and curettage for retained product of conception (RPOC) after second trimester termination of pregnancy (TOP). METHODS: A total of 270 patients with RPOC following second trimester TOP in Nanfang Hospital between January, 2014 and December, 2015 were included in this study. The duration of vaginal bleeding time and menstruation recovery interval were compared between patients receiving expectant therapy and curettage for RPOC, and binary logistic regression was used to assess the risk factors for complications in bivariate and multivariate analyses. RESULTS: The duration of vaginal bleeding time was significantly longer in expectant therapy group than in curettage group (P=0.005), while the menstruation recovery interval did not differ significantly between the two groups. The incidence of vaginal bleeding time for over 42 days was significantly higher in curettage group than in expectant therapy group (P=0.040), and the incidence of a menstruation recovery interval beyond 60 days was comparable between them. The incidence of complications was significantly higher in curettage group than in expectant therapy group either with adjustment of age, gravidity, parity, history of uterine surgery status, gestational age, type of indications, regimens for TOP and induction-abortion interval (OR=18.26 [95% CI: 3.57-93.42], P<0.001) or without adjustment (OR=10.60, [95% CI: 2.36-47.66], P=0.002). CONCLUSION: Expectant therapy and curettage for RPOC after second trimester TOP have comparable prognosis, but curettage is associated with a significantly higher rate of complications.

The Mediating Roles of Upward Social Comparison and Self-esteem and the Moderating Role of Social Comparison Orientation in the Association between Social Networking Site Usage and Subjective Well-Being.

The increased pervasiveness of social media use has raised questions about potential effects on users' subjective well-being, with studies reaching contrasting conclusions. To reconcile these discrepancies and shed new light on this phenomenon, the current study examined: (1) whether upward social comparison and self-esteem mediate the association between social networking site (SNS) usage and users' subjective well-being, and (2) whether the association between SNS usage and upward social comparison is moderated by users' social comparison orientation. Data from 696 participants were collected. Structural equation modeling revealed that upward social comparison and self-esteem mediated the relationship between SNS usage and users' subjective well-being. We found that social comparison orientation moderated the association between passive SNS usage and users' upward social comparison. Specifically, social comparison orientation strengthened the association between passive SNS usage and upward social comparison. The results might suggest a process through which passive SNS usage is related to subjective well-being, and identify a context under which these associations may differ.

[Role of changes in sodium pump activity and endoplasmic reticulum stress in the ischemia/reperfusion induced injury of isolated hearts].

OBJECTIVE: To investigate the roles of change in sodium pump activity and endoplasmic reticulum stress (ERS) in ischemia/reperfusion (I/R) injury of the isolated rat hearts. METHODS: Sixty male SD rats were randomly divided into 6 groups (n=10 each):normal control group (NC), I/R group (I/R), ouabain-I/R group (OUA-I/R), anti-digoxin antiserum-I/R group (Anti-Dig-I/R), PP2 (Src kinase inhibitor)-ouabain-I/R group (PP2-OUA-I/R),U73122 (PLC inhibitor)-ouabain-I/R group (PP2-OUA-I/R). The isolated rat hearts were perfused on the Langendorff apparatus. Except for NC group, all the hearts were subjected to 30 min global ischemia and followed by 120 min reperfusion. The cardiac function indexes were recorded at the same time. The coronary effluent was collected for estimating the activity of lactate dehydrogenase (LDH) and creatine kinase (CK). The activity of Na+-K+-ATPase and intracellular calcium concentration in myocardial tissue were measured. Apoptosis was evaluated by Flow cytometric analysis. The expressions of sodium pump α1 subunit, glucose regulated protein(GRP78),C/EBP homologous protein (CHOP) and Bcl-2/Bax were determined by Western blot. RESULTS: Pretreatment with ouabain significantly reduced the recovery of cardiac function, increased the levels of CK, LDH and intracellular calcium concentration, decreased the activity of Na+-K+-ATPase. In addition, ouabain markedly increased the myocardial apoptosis index, down-regulated the expressions of sodium pump α1 subunit and Bcl-2, up-regulated the expressions of GRP78,CHOP and Bax; while these changes were significantly improved in the Anti-Dig-I/R group compared with those in the I/R group; PP2 or U73122 partially blocked the effects of ouabain on myocardial I/R injury. Compared with the OUA-IR group, the recovery of cardiac function, the activity of Na+-K+-ATPase and the expressions of sodium pump α1 subunit and Bcl-2 were significant higher, meanwhile the leakage of CK and LDH, intracellular calcium concentration, myocardial apoptosis index and the expressions of GRP78 and Bax were significantly lower in PP2-OUA-I/R and U73122-OUA-I/R group. CONCLUSIONS: Changes in sodium pump function and endoplasmic reticulum stress all participate in the process of I/R injury. Current findings further suggest that sodium pump mediates ERS by activating signals of Src and PLC pathway, which may be one of the mechanisms of apoptosis induced by I/R injury.

[Effects of total flavonoids of propolis on apoptosis of myocardial cells of chronic heart failure and its possible mechanism in rats].

OBJECTIVE: To investigate the effects of total flavonoids of propolis (TFP) on apoptosis of myocardial cells of chronic heart failure and its possible mechanism in rats. METHODS: Six male SD rats were randomly selected as normal control group, the remaining rats were made as chronic heart failure (CHF) model by intraperitoneal injection of adriamycin. The rats in the successful model were randomly divided into five groups (n = 6): CHF group, total flavonoids of propolis low dose group (LD group), total flavonoids of propolis middle dose group (MD group), total flavonoids of propolis high dose group (HD group), digoxin group (DIG group). After six week treatment, cardiac function indexes of rats were recorded by signal acquisition system; brain natriuretic peptide (BNP), cardiac troponin I (cTnI), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) content in plasma were detected; Myocardial morphological changes and collagen fiber hyperplasia by HE and Masson staining were observed; Myocardial apoptosis was detected with TUNEL method and protein connexin 43(P-Cx43) expression was detected by Western blot method. RESULTS: Compared with NC group, left ventricular systolic pressure(LVSP) and maximal rise/fall velocity of left ventriculad pressure (± dP/dt(max)) absolute value in CHF group were significantly lowered (P < 0.01) while left ventricular end diastolic pressure (LVEDP) was increased significantly (P < 0.01); Contents of plasma BNP, cTnI, TNF-α and IL-6 in the CHF group were significantly improved (P < 0.01). Compared with CHF group, LVSP, ± dP/dt(max) absolute value in MD and HD groups were increased (P < 0.05), and LVEDP was significantly lowered (P < 0.01); LVEDP in LD group was significantly lowered (P < 0.01), changes in LVSP and ± dp/dt(max) absolue value were not obvious (P > 0.05). BNP, cTnI, TNF-α and IL-6 contents in MD and HD groups were significantly reduced (P < 0.01), but those plasma indicator changes were not obvious in LD group (P > 0.05). Western blot showed that P-Cx43 expression in CHF group was significantly higher than that in NC group (P < 0.01) and that in all TFP treatment groups it was decreased compared with CHF group (P < 0.05, P < 0.01), among which pairwise comparisons also showed differences (P < 0.05), myocardial apoptosis index (%)(22.62 ± 3.39) in CHF group was higher than that in NC group( 1.12 ± 0.24) (P < 0.01); compared with CHF group, the apoptosis index of myocardial cells (%) in LD,MD and HD groups, (15.79 + 2.8), (9.28 + 2.1) and (4.73 + 1.14) respectively, were significantly lower than those in the CHF group( P < 0.01). The expression level of P-Cx43 positively correlated with the apoptotic index (r = 0. 861, P < 0.01). CONCLUSION: Total flavonaids of propolis have inhibitory effect on apoptosis of myocardial cells of chronic heart failure induced by adriamycin in rats, and the mechanism may be closely related to the regulation of Cx43 expression, especially the regulatory phosphorylation status.

Emodin-provoked oxidative stress induces apoptosis in human colon cancer HCT116 cells through a p53-mitochondrial apoptotic pathway.

Emodin, a natural anthraquinone isolated from the traditional Chinese medicine Radix rhizoma Rhei, can induce apoptosis in many kinds of cancer cells. This study demonstrated that emodin induces apoptosis in human colon cancer HCT116 cells by provoking oxidative stress, which subsequently triggers a p53-mitochondrial apoptotic pathway. Emodin induced mitochondrial transmembrane potential loss, increase in Bax and decrease in Bcl-2 expression and mitochondrial translocation and release of cytochrome c to cytosol in HCT116 cells. In response to emodin-treatment, ROS increased rapidly, and subsequently p53 was overexpressed. Pretreatment with the antioxidant NAC diminished apoptosis and p53 overexpression induced by emodin. Transfecting p53 siRNA also attenuated apoptosis induced by emodin, Bax expression and mitochondrial translocation being reduced compared to treatment with emodin alone. Taken together, these results indicate that ROS is a trigger of emodin-induced apoptosis in HCT116 cells, and p53 expression increases under oxidative stress, leading to Bax-mediated mitochondrial apoptosis.

[Effects of water temperature, salinity and pH on sex differentiation of Oreochromis niloticus].

By using Box-Behnken design and response surface methodology, this paper studied the effects of three major environmental factors, i. e., water temperature (20-36 degrees C), salinity (0-16), and pH (5.5-8.5), on the sex differentiation of GIFT strain Nile tilapia (Oreochromis niloticus). It was observed that water temperature had highly significant linear and quadratic effects on the sex differentiation, water salinity and pH had non-significant linear and quadratic effects, and the two-factor interactions of the three factors were not significant. The analysis with response surface methodology showed that the male rate of the GIFT tilapia increased with increasing water temperature, and at water temperature 36 degrees C, salinity 8, and pH 8.5, the male rate reached the maximum (80%). A model equation about the relationships of the male rate with the three major environmental factors was established, and after eliminating the related non-significant factors, an optimal model equation about the relationship between the male rate and water temperature was attained, which could predict the variation of the GIFT tilapia male rate.