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Xylitol has reported to decrease gingival inflammation and nasopharyngeal pneumonia, which indicated that xylitol may have potential application in respiratory diseases. Although some studies have reported the inhalation toxicity of xylitol, however, the longest period tested was only for 14 days. The inhalation toxicity of xylitol is insufficient. This work investigated the potential subacute toxicity of xylitol according to the OECD TG 412. Rats were randomly divided into a control group and different dosage groups (2 g/m3, 3 g/m3, 5 g/m3), and exposed for 6 hours/day, 5 days/week for 28 days. At the end of the exposure or recovery period, clinical signs, mortality, body weight, food consumption, hematology, blood biochemistry, gross pathology, organ weight, and histopathology were examined. Compared with the control group, rats of both sexes in the exposure groups exhibited no significant changes in body weight, organ mass, and food uptake. After the xylitol exposure, aspartate aminotransferase activity in the xylitol group (3 g/m3) was significantly higher than that in the control group, while other blood indicators and pathological changes of liver and the analysis of the recovery group showed no changes, suggesting that xylitol exerted no observable toxic effect on the liver. Finally, other observations including the histopathology of target organs and hematology also showed no alterations. These results indicated that xylitol had no significant inhalation toxicity at doses up to 5 g/m3. These subacute inhalation toxicity results of xylitol showed that its no-observed-adverse-effect concentration (NOAEC) in rats was determined to 5 g/m3.

Rosacea is a chronic inflammatory disease characterized by facial flushing, erythema, telangiectasia, papules, and pustules. Its pathogenesis has not been fully understood. In 2017, the global ROSacea COnsensus (ROSCO) panel updated the diagnosis, classification, and assessment of rosacea. Phenotype-based treatments and long-term managements have also been recommended. Murine models are a powerful tool in unveiling and dissecting the mechanisms of human diseases. Here, we summarized murine models of rosacea developed or used in previous research, including LL-37 intradermal injection model, KLK-5-induced inflammation model, croton oil inflammation model, 12-O-Tetradecanoylphorbol-13-acetate inflammation model, arachidonic acid inflammation model, RTX-induced vasodilation model, and UVB-induced model. LL-37 injection model has become the most intensively used model in rosacea research. Each model could show the pathophysiological and clinical features of rosacea to some extent. However, no model can show the full picture of the characteristics of rosacea. Improving existed murine models, developing new murine models, and applying them to pathogenesis and treatment research on rosacea are highly warranted in the future.

Suppressive regulatory T cells (Treg cells) play a vital role in preventing autoimmunity and restraining excessive immune response to both self- and non-self-antigens. Studies on humans and mice show that the Forkhead box p3 (Foxp3) is a key regulatory gene for the development and function of Treg cells. In zebrafish, Treg cells have been identified by using foxp3a as a reliable marker. However, little is known about the function of foxp3a and Treg cells in gonadal development and sex differentiation. Here, we show that foxp3a is essential for maintaining immune homeostasis in zebrafish testis development. We found that foxp3a was specifically expressed in a subset of T cells in zebrafish testis, while knockout of foxp3a led to deficiency of foxp3a-positive Treg cells in the testis. More than 80% of foxp3a-/- mutants developed as subfertile males, and the rest of the mutants developed as fertile females with decreased ovulation. Further study revealed that foxp3a-/- mutants had a delayed juvenile ovary-to-testis transition in definite males and sex reversal in about half of the definite females, which led to a dominance of later male development. Owing to the absence of foxp3a-positive Treg cells in the differentiating testis of foxp3a-/- mutants, abundant T cells and macrophages expand to disrupt an immunosuppressive milieu, resulting in defective development of germ cells and gonadal somatic cells and leading to development of infertile males. Therefore, our study reveals that foxp3a-positive Treg cells play an essential role in the orchestration of gonadal development and sex differentiation in zebrafish.

The clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology has been widely utilized for knocking out genes involved in various biological processes in zebrafish. Despite this technology is efficient for generating different mutations, one of the main drawbacks is low survival rate during embryogenesis when knocking out some embryonic lethal genes. To overcome this problem, we developed a novel strategy using a combination of CRISPR/Cas9 mediated gene knockout with primordial germ cell (PGC) transplantation (PGCT) to facilitate and speed up the process of zebrafish mutant generation, particularly for embryonic lethal genes. Firstly, we optimized the procedure for CRISPR/Cas9 targeted PGCT by increasing the efficiencies of genome mutation in PGCs and induction of PGC fates in donor embryos for PGCT. Secondly, the optimized CRISPR/Cas9 targeted PGCT was utilized for generation of maternal-zygotic (MZ) mutants of tcf7l1a (gene essential for head development), pou5f3 (gene essential for zygotic genome activation) and chd (gene essential for dorsal development) at F1 generation with relatively high efficiency. Finally, we revealed some novel phenotypes in MZ mutants of tcf7l1a and chd, as MZtcf7l1a showed elevated neural crest development while MZchd had much severer ventralization than its zygotic counterparts. Therefore, this study presents an efficient and powerful method for generating MZ mutants of embryonic lethal genes in zebrafish. It is also feasible to speed up the genome editing in commercial fishes by utilizing a similar approach by surrogate production of CRISPR/Cas9 targeted germ cells.

The surrogate reproduction technique, such as inter-specific spermatogonial stem cells (SSCs) transplantation (SSCT), provides a powerful tool for production of gametes derived from endangered species or those with desirable traits. However, generation of genome-edited gametes from a different species or production of gametes from a phylogenetically distant species such as from a different subfamily, by SSCT, has not succeeded. Here, using two small cyprinid fishes from different subfamilies, Chinese rare minnow (gobiocypris rarus, for brief: Gr) and zebrafish (danio rerio), we successfully obtained Gr-derived genome-edited sperm in zebrafish by an optimized SSCT procedure. The transplanted Gr SSCs supported the host gonadal development and underwent normal spermatogenesis, resulting in a reconstructed fertile testis containing Gr spermatids and zebrafish testicular somatic cells. Interestingly, the surrogate spermatozoa resembled those of host zebrafish but not donor Gr in morphology and swimming behavior. When pou5f3 and chd knockout Gr SSCs were transplanted, Gr-derived genome-edited sperm was successfully produced in zebrafish. This is the first report demonstrating surrogate production of gametes from a different subfamily by SSCT, and surrogate production of genome-edited gametes from another species as well. This method is feasible to be applied to future breeding of commercial fish and livestock.

Hemocyanin is primarily a respiratory copper-containing glycoprotein present in the hemolymph of mollusks and arthropods. Recently, hemocyanin has attracted huge research interest due to its multifunctionality and polymorphism. Most previous immune-related studies on shrimp hemocyanin have focused on the C-terminal. Moreover, we previously reported that the C-terminal domain of Litopenaeus vannamei hemocyanin possesses single nucleotide polymorphisms (SNPs), but little is known about the molecular diversity of the N-terminal domain. In the current study, diversity within the N-terminal domain of L. vannamei hemocyanin (LvHMC-N) was explored using bioinformatics and molecular biology techniques as well as immune challenge. Twenty-five LvHMC-N variants were identified using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and DNA sequencing, with multiple sequence alignment showing that the 25 variants shared 87%–99 % sequence homology with LvHMC (AJ250830.1). In different shrimp individuals and different shrimp tissues (i.e., hemocytes, stomach, muscle and hepatopancreas), the LvHMC-N variants were expressed differently. Pathogen challenge could modulate the molecular diversity of LvHMC-N, as three LvHMC-Nr variants (LvHMC-Nr1, LvHMC-Nr2 and LvHMC-Nr3) were identified by sequencing following Vibrio parahaemolyticus challenge. Most importantly, recombinant proteins of these three variants (rLvHMC-Nr1, rLvHMC-Nr2 and rLvHMC- Nr3) had relatively high in vitro agglutinative activities against V. parahaemolyticus, Vibrio alginolyticus and Streptoccocus iniae. Our present data indicates that the N-terminus of L. vannamei hemocyanin also possess molecular diversity, which seems to be associated with immune resistance to pathogenic infections.

The association between hemoglobin A1c (HbA1c) and clinical outcomes of acute ischemic stroke is uncertain. We aimed to evaluate the association between initial hemoglobin A1c level and clinical outcome after acute ischemic stroke.A total of 408 patients with first-ever acute ischemic stroke were included in this study. We divided the patients into three groups according to HbA1c level: low HbA1c level (HbA1c5.7%), moderate HbA1c level (HbA1c 5.7-6.4%), and high HbA1c level (HbA1c ≥6.5%). Poor neurological outcomes were defined as modified Rankin Scale (mRS) score of 2-6 at 3 months after stroke. The relation between HbA1c value and clinical outcomes were evaluated by using multivariate logistic regression analyses.Moderate HbA1c level was present in 126 (30.9%) patients and high HbA1c level in 129 (31.6%) patients. After adjustment for potential confounding variables, both patients in the high HbA1c level group (adjusted odds ratio [OR]: 2.387; 95% confidence interval [CI], 1.201-4.745; P = .013) and moderate HbA1c level group (adjusted OR: 1.797; 95% CI, 1.005-3.214; P = .048) had a significantly higher poor neurological outcomes than the group in the low HbA1c level. When separately analyzed according to with or without diabetes, the HbA1c level as continuous variable was also associated with poor functional outcome at 3 months in the diabetic patients (adjusted OR: 1.482, 95% CI, 1.013-2.167, P = .042), nor in nondiabetic group.Higher HbA1c on admission was an independent predictor of adverse functional outcome in ischemic stroke patients. Based on this point, tight glycemic control must be necessary for high-risk diabetic patients.

Previous studies in animal model have demonstrated that neurotrophins were associated with functional outcome following stroke. However, the relationship between serum nerve growth factor (NGF) and functional outcome in stroke patients has not been explored. Our objective was to investigate the association between serum NGF concentrations at admission and functional outcome of patients at 3 month after stroke.One-hundred eight-five patients with acute ischaemic stroke were recruited in our study. Serum NGF concentrations were measured by ELISA at admission. The stroke severity at admission was assessed by the National Institute of Health Stroke Scale (NIHSS). The modified Rankin Scale (mRS) was used to assess the functional outcome of patients at 3 month after stroke. In addition, 100 healthy controls were recruited.Serum NGF concentrations were higher in good functional outcome group (mRS score of 0-2) than that in poor functional outcome group (mRS score of 3-6) (9.51 ± 2.33 vs. 8.12 ± 1.61, P 0.001). Meanwhile, the serum NGF concentrations in healthy group were lower than that in acute ischemic stroke patients (7.17 ± 1.49 vs. 9.15 ± 2.24, P 0.001). Moreover, our results demonstrated that high serum NGF concentrations (9.21 ng/l) were independently associated with the better functional prognosis at 3 months following the occurrence of stroke (OR 0.048, 95% CI 0.012-0.185, P 0.001).High concentrations of serum NGF at admission may predict good functional outcome of patients at 3 months after acute cerebral ischemia stroke.

Xylitol is a hygroscopic compound known to protect nasal cavity against bacteria. It has also been developed into nasal spray and evaluated as a potential candidate drug for respiratory diseases. Consequently, it is necessary to study its inhalation toxicity. Based on our previous study on its subacute inhalation toxicity, this study aimed to investigate the safety of xylitol inhalation for long-term use. According to the OECD Test Guideline 413, Sprague-Dawley rats were randomly divided into six groups and exposed with different concentrations of xylitol aerosol or air. After exposure for 90-day, the recovery groups were continued to observe for a recovery period of 28-day. No significant changes in body weight were observed between sham and xylitol groups. Several significant differences in hematological, clinical chemistry, bronchoalveolar lavage fluid were observed, which either had no dose-effect relationship for both male and female rats or were restored during the recovery period. Finally, except for high dose group of xylitol, two rats showed a small amount of inflammatory exudate in alveolar and bronchial cavities, which was restored in the recovery period. The rest of rats showed no obvious difference. For the recovery groups, no significant difference was observed between these two groups. In conclusion, the no observable adverse effect level (NOAEL) of xylitol in our subchronic inhalation toxicological experiments was 2.9 mg/L, which indicated that xylitol for rats' long-time inhalation is tolerant and safe.

The surrogate reproduction technique provides a powerful tool for production of allogenic or xenogeneic gametes derived from endangered species or those with valuable genetic traits. Production of functional donor-derived gametes through intra- or inter-specific spermatogonial stem cell transplantation (SSCT) has been achieved in many species. However, generation of functional gametes from a phylogenetically distant species such as from a different subfamily by SSCT has never been successful. Here, using two small cyprinid fishes, Chinese rare minnow (gobiocypris rarus, for brief:Gr) and zebrafish (danio rerio), which belong to different subfamilies, as donors and recipients for SSCT, we optimized the SSCT technique and successfully obtainedGr-derived sperm carrying targeted genome modifications in zebrafish. We revealed that the transplantedGrspermatogonia supported the host gonadal development and underwent normal spermatogenesis, resulting in a reconstructed fertile testis containingGrspermatids and zebrafish testicular somatic cells. Interestingly, the surrogate spermatozoa resembled those of host zebrafish but not donorGrin morphology and swimming behavior. Finally, we showed thatGr-derived genome edited sperm was successfully produced in zebrafish by cross-subfamily SSCT, when thepou5f3andchdgene knockoutGrSSCs were used as surrogate donors. This is the first report demonstrating the surrogate production of genome edited sperm from a phylogenetically distant species, and this method is feasible to be applied to future breeding of commercial fishes.

Interleukin-10 (IL-10) is a pathophysiological factor in acute ischaemic stroke (AIS) and is relevant to mood disorders after stroke. We evaluated the predictive value of IL-10 in patients with post-stroke depression (PSD).A total of 350 stroke patients were recruited at baseline, and 151 AIS patients were screened and completed a 1-month follow-up. Serum IL-10 levels were measured within 24 h of admission. We used the 17-item Hamilton Depression Scale (HAMD-17) to evaluate depression symptoms; PSD was defined as an HAMD score ≥ 7.Fifty-one (33.8%) patients showed a more serious stroke degree, larger infarction volume, and poorer daily life activities and prognosis (P0.05) and were diagnosed with PSD at the 1-month follow-up. Their IL-10 level decreased significantly compared to the non-PSD group (P0.001). After adjusting for confounders, IL-10 could be used as an independent predictor for PSD with an adjusted odds ratio (OR) of 0.615 (95% CI 0.410-0.923, P = 0.019). In addition, the optimal cut-off value of IL-10 was 0.615 pg/mL based on an area under the receiver operating characteristic curve of 0.692 (95% CI 0.604-0.781, P0.001), demonstrating that IL-10 could predict the occurrence of PSD. Moreover, IL-10 was an indicator of stroke severity, living ability, and functional outcomes (P0.05).IL-10 was only measured upon admission; dynamic changes need to be further monitored. This was also a single-centre study with a relatively small sample.Lower IL-10 levels may be used to predict PSD.

Objectives Interleukin‐33, a newly identified member of interleukin‐1 family, had been confirmed to play a crucial role in regulating inflammatory responses in various disease. However, the exact role of interleukin‐33 in the disease process of acute ischemic stroke still remains unclear. This study aims to demonstrate the relationship between interleukin‐33 levels and long‐term functional outcome as well as ischemic stroke recurrence. Methods Three hundred and four first‐ever acute ischemic stroke patients were recruited and basic information and history of all subjects taken within 72 hr on admission. The functional outcome was estimated by Barthel index. The multivariate logistic regression was used to analyze the prognosis, while the Cox proportional hazard model was applied to assess the recurrence risk. Results Out of 304 subjects, 259 patients successfully completed scheduled two‐year follow‐up. We found that higher interleukin‐33 levels correlated positively with better prognosis as compared with those with lower interleukin‐33 levels who presented with poorer outcome (62.45 ± 20.50 ng/ml vs. 51.58 ± 19.16 ng/ml, p

The CRISPR/Cas9 technology has been widely utilized for knocking out genes involved in various biological processes in zebrafish. Despite this technology is efficient for generating different mutations, one of the main drawbacks is low survival rates during embryogenesis when knocking out some embryonic lethal genes. To overcome this problem, we developed a novel strategy using a combination of CRISPR/Cas9 mediated gene knockout with primordial germ cells (PGCs) transplantation to facilitate and speed up the process of zebrafish mutant generation, particularly for embryonic lethal genes. First, we optimized the procedure for gRNA targeted PGCs transplantation (PGCT), by increasing the efficiencies of genome mutation in PGCs and induction of PGCs fates in donor embryos for PGCT. Second, the combined CRISPR/Cas9 with PGCT was utilized for generation of maternal zygotic (MZ) mutants oftcf7l1a(essential gene for head development),pou5f3(essential gene for zygotic genome activation) andchd(essential gene for dorsal development) at F1 generation with high efficiency. Finally, we revealed some novel phenotypes in the maternal zygotic mutant oftcf7l1aandchd, while MZtcf7l1ashowed elevated neural crest development, and MZchdhave stronger ventralization than its zygotic counterparts. Therefore, this study presents an efficient and powerful method for generating MZ mutants of embryonic lethal genes in zebrafish.

Water-saving irrigation technology is an effective way for agriculture to adapt to the arid climate. Shortening farmers’ waiting times to adopt such technology is important for saving water resources and stabilizing agricultural production. This study analyzed the impact of capital endowment on Xinjiang cotton farmers' adoption willingness, adoption decisions, and waiting time. Results showed that capital endowments significantly affect cotton farmers' adoption of water-saving technologies (WST) in all dimensions. Specifically, the scale of cotton planting had a significant positive impact on the willingness and decision of cotton farmers to adopt WST, and it could significantly reduce the adoption wait time. Simultaneously, neighbors’ adoption decisions, policy subsidies, and membership of a cooperative could reduce cotton farmers’ wait times. Land transfer was one of the livelihood strategies cotton farmers used to adjust household resource allocations or to adapt to arid climate. Land rental also could help reduce the wait time for WST. These results and impacts provided policy optimization direction to reduce the waiting time of farmers to adopt water-saving technology, which was helpful to save agricultural water and for farmers adapt to drought climate change quickly. At the end of the study, combined with the situation of China, from the crop planting structure, land system reform, and effective community governance, we discussed several research directions to improve farmers' drought climate adaptability.

Von Willebrand factor-binding protein (vWbp), secreted by Staphylococcus aureus (S. aureus), can activate host prothrombin, convert fibrinogen to fibrin clots, induce blood clotting, and contribute to pathophysiology of S. aureus-related diseases, including infective endocarditis, staphylococcal sepsis and pneumonia. Therefore, vWbp is an promising drug target in the treatment of S. aureus-related infections. Here, we report that dryocrassin ABBA (ABBA), a natural compound derived from Dryopteris crassirhizoma, can significantly inhibit the coagulase activity of vWbp in vitro by directly interacting with vWbp without killing the bacteria or inhibiting the expression of the vWbp. Using molecular dynamics simulations, we demonstrate that ABBA binds to the “central cavity” in the elbow of vWbp by interacting with Arg-70, His-71, Ala-72, Gly-73, Tyr-74, Glu-75, Tyr-83, and Gln-87 in vWbp, thus interfering with the binding of vWbp to prothrombin. Furthermore, in vivo studies demonstrated that ABBA can attenuate injury and inflammation of mouse lung tissues caused by S. aureus and increase survival of mice. Together these findings indicate that ABBA is a promising lead drug for the treatment of S. aureus-related infections. This is the first report of potential inhibitor which inhibit the coagulase activity of vWbp by directly interacting with vWbp.

To investigate the prognostic value of platelet-to-neutrophil ratio (PNR) in acute ischemic stroke (AIS) patients. In this study, a total of 400 AIS patients were included. Demographic, clinical, laboratory data were collected on admission, and PNR was calculated according to platelet and neutrophil counts on admission. The prognosis after 3 months was evaluated by the Barthel index (BI), where BI ≤85 was defined as poor prognosis and BI85 was defined as good prognosis. Regression analyses were performed, adjusting for confounders. (1) Compared with good prognosis group, PNR level on admission in poor prognosis group was significantly lower, the difference between the two groups was statistically significant (P 0.05). (2) The difference in PNR level between the large infarct volume group and small infarct volume group was no statistically significant, nor between the moderate to severe group and the mild group (all P 0.05). (3) In multivariate logistic regression analysis, PNR, platelet-to-lymphocyte ratio (PLR), platelet-to-white blood cell ratio (PWR) level were correlated with the 3 month prognosis of AIS. PNR may be an independent protective factor for predicting the prognosis of AIS. PNR level has a higher accuracy in the 3 month prognosis of acute ischemic cerebral infarction than the level of PLR and PWR. The level of PNR is correlated with the 3 month prognosis of acute ischemic cerebral infarction. The level of PNR may be an independent protective factor for predicting the prognosis of AIS.

Objective Leukocytes play a crucial role in inflammation and immune response. This study aims to demonstrate the value of changes in leukocytes levels 24 hours after intravenous thrombolysis to predict prognosis in acute ischemic stroke (AIS). Methods From Jan 2016 to Oct 2017, the patients who suffered AIS to our center within 4.5 hours of symptom onset were all treated with recombinant tissue-type plasminogen activator. Data from 213 AIS patients were analyzed. Patients were divided into 4 groups: persistent leukocytosis (PL), transient leukocytosis (TL), leukocytosis 24 hours (L24H) and no leukocytosis (NL). By comparison, the factors with statistically significant were selected in pairwise multiple comparisons. Good clinical outcome was defined as the Modified Rankin Scale score of 2 or lower. Multivariate logistic regression was used to assess the association of the indicators with clinical outcome. Results By pairwise multiple comparisons, PL and L24H had higher baseline National Institutes of Health Stroke Scale (NIHSS) score than NL and were likely to lead poor clinical outcomes. TL had a better prognosis than L24H. As the results of multivariable analyses shown, PL and L24H were risk factors to poor functional outcomes (odds ratio [OR] = 2.668, 95% confidence interval [CI] = 1.139-6.249, P = .024; OR = 6.648, 95%CI = 2.048-21.584, P = .002). Conclusion Persistent leukocytosis and leukocytosis 24 hours both had higher baseline NIHSS scores, more serious stroke and were more likely to lead to unfavorable outcome. Therefore, changes in leukocytes levels 24 hours after intravenous thrombolysis could be predicted the short-term functional outcome of AIS patients.

Objective The role of sLOX‐1 in acute ischemic stroke still remains unclear. This study aims to demonstrate the value of sLOX‐1 in evaluating degrees of intracranial artery stenosis and to predict prognosis in stroke. Methods Two hundred and seventy‐two patients were included in this study and basic data were collected within 72 hr on admission. We assessed the association between sLOX‐1 levels and stroke conditions in one‐year duration. After adjusting for potential confounders, regression analyses were performed. Results We found that sLOX‐1 levels were increased significantly in severe patients compared to the mild stroke group (p = .011). After adjusting confounders, sLOX‐1 was associated with a poor functional outcome in patients with an adjusted OR of 2. 946 (95% CI, 1.788–4.856, p

In recent years, electronic mutual-inductor and IEC61850 serial standards are adopted in digital substation. Once electronic mutual-inductor has been used, the input signals of relay protection and other secondary devices are not the traditional analog quantities any more. The simulation system cannot offer such interface up to now, so the secondary devices which are based on electronic mutual-inductor in digital substation cannot be tested and researched in this way. A kind of testing system aiming to real-time digital relay protection is introduced in this paper. By adding secondary interface to the primary simulation system, such as ADPSS (invented by China Electric Power Research Institute), a closed-loop testing system which is based on IEC61850 standards is established. The testing results verify that the system has great significance on improving the application of digital substation, and it has great use value.

The single-copied gyrB gene, encoding the subunit B of gyrase and distributing universally in all bacteria, has the average substitution rate of 0.7%-0.8% per million years. It's proved that this region could be used to discriminate and identify the closely related species of different bacteria such as Pseudomonoas, Bacillus, Vibrio, Enterobacteriaceae, Mycobacteria, Aeromonas, Lactic acid bacteria et.al. It also can be used of quantitative or restriction fragment analysis of bacteria with the aid of species-specific primers or combined with DGGE (denaturing gradient gel electrophoresis). It really brings new promise for the identifying closest isolates or fingerprinting population due to overcoming the shortage of undistinguishing them acutely with the non-protein-encoding genes such as 16S rDNA or ITS (internal transcribed spacer) DNA. It's an important new molecular marker for researches of closely related species and becoming an attractive topic in current microbial research world.

Mudsnails and sediments from an electronic waste recycling region in South China were chosen to study the polybrominated diphenyl ethers (PBDEs) bioavailability of mudsnail in different ambient levels. Significant (p < 0.05) correlations of biota-sediment accumulation factor (BSAF) versus the reciprocal of PBDE concentration in sediment (1/Sed) occurred in all quantitative PBDE congeners except BDE-209, showed that the BSAFs of PBDEs in mudsnails were increased with reciprocal increasing ambient levels. The BDE-183 correlation of mudsnail versus sediment (r = 0.580) was much lower than the correlation of BDE-209 versus BDE-183 in mudsnails (r = 0.812), indicated the main source of BDE-183 in mudsnails was from the debromination of higher brominated PBDEs.