Aloe polysaccharide promotes osteogenesis potential of adipose-derived stromal cells via BMP-2/Smads and prevents ovariectomized-induced osteoporosis.

BACKGROUND: Aloe polysaccharide (AP) is a type of an active macromolecule of Aloe vera, which contributes to its function. However, whether AP possesses anti-osteoporosis properties is unknown. METHODS: Adipose-derived stromal cells were treated with different concentrations of AP. Early and late osteogenesis were, respectively, evaluated by ALP and Alizarin Red S staining. The effect of AP on the processes of adipogenesis inhibition in ADSCs was analyzed by oil red O staining. Western blot was used to assess the expression of osteogenic and adipogenic related factors. Then, Noggin was administered to further confirm the mechanism by which AP promotes the osteogenesis of ADSCs. Finally, 40 female SD rats were classified into a bilateral laparotomy group (Sham group) and three bilateral ovariectomy groups: OVX group, OVX + AP group, and OVX + AP + Noggin group. The bilateral rat femurs were collected to perform micro-CT scanning, HE, Masson trichrome, and Oil red O staining. RESULTS: The results indicated that AP could increase ALP expression and calcium deposition. Through molecular mechanisms, AP promotes the protein expression of COL1A1, OPN, and ALP in ADSCs, but downregulates the expression of PPARγ. Also, AP directs ADSCs' fate by stimulating the BMP2/Smads signaling pathway. In vivo, the rat AP-treated had more trabecular bone than the OVX rat, indicating partial protection from cancellous bone loss after treatment with AP. CONCLUSION: Our results show that AP may promote osteogenesis of ADSCs through BMP-2/Smads signaling pathway and inhibits lipogenic differentiation. Thus, AP might be a promising alternative medicine to treat postmenopausal osteoporosis.

Multi-institutional validation of novel models for predicting the prognosis of patients with huge hepatocellular carcinoma.

The population of patients with huge hepatocellular carcinoma (H-HCC diameter > 10.0 cm) is an odd group that is not well adjudicated in the current staging systems, whose prognosis after curative resection varies. We aimed to develop novel models to predict the long-term outcomes of patients with H-HCC without portal vein tumor thrombus after hepatectomy. There were 1076 H-HCC patients enrolled who underwent curative liver resection in five institutions in China. In total, 670 patients were recruited from our center and randomly divided into the training cohort (n = 502) and internal validation (n = 168) cohorts. Additionally, 406 patients selected from other four centers as the external validation cohort. Novel models were constructed based on independent preoperative and postoperative predictors of postsurgical recurrence (PSR) and postsurgical mortality (PSM) determined in multivariable cox regression analysis. The predictive accuracy and discriminative ability of the model were measured using Harrell's concordance index (C index) and calibration curve and compared with five conventional HCC staging systems. PSR model and PSM model were constructed based on tumor number, microscopic vascular invasion, tumor differentiation, preoperative alpha-fetoprotein level, albumin-bilirubin grade, liver segment invasion, neutrophil-to-lymphocyte ratio or platelet-to-neutrophil ratio, and surgical margin or intraoperative blood transfusion. The C-indexes were 0.84 (95% CI, 0.78-0.90) and 0.85 (95% CI, 0.78-0.91) for the PSR and PSM models, respectively, which were substantially higher than those of the five conventional HCC staging systems (0.63-0.75 for PSR; 0.66-0.77 for PSM). The two novel models achieved more accurate prognostic predictions of PSR and PSM for H-HCC patients after curative liver resection.

Novel Models Predict Postsurgical Recurrence and Overall Survival for Patients with Hepatitis B Virus-Related Solitary Hepatocellular Carcinoma ≤10 cm and Without Portal Venous Tumor Thrombus.

BACKGROUND: The predictive model of postsurgical recurrence for solitary early hepatocellular carcinoma (SE-HCC) is not well established. The aim of this study was to develop a novel model for prediction of postsurgical recurrence and survival for patients with hepatitis B virus (HBV)-related SE-HCC ≤10 cm. PATIENTS AND METHODS: Data from 1,081 patients with HBV-related SE-HCC ≤10 cm who underwent curative liver resection from 2003 to 2016 in our center were collected retrospectively and randomly divided into the derivation cohort (n = 811) and the internal validation cohort (n = 270). Eight hundred twenty-three patients selected from another four tertiary hospitals served as the external validation cohort. Postsurgical recurrence-free survival (RFS) and overall survival (OS) predictive nomograms were generated. The discriminatory accuracies of the nomograms were compared with six conventional hepatocellular carcinoma (HCC) staging systems. RESULTS: Tumor size, differentiation, microscopic vascular invasion, preoperative α-fetoprotein, neutrophil-to-lymphocyte ratio, albumin-to-bilirubin ratio, and blood transfusion were identified as the risk factors associated with RFS and OS. RFS and OS predictive nomograms based on these seven variables were generated. The C-index was 0.83 (95% confidence interval [CI], 0.79-0.87) for the RFS-nomogram and 0.87 (95% CI, 0.83-0.91) for the OS-nomogram. Calibration curves showed good agreement between actual observation and nomogram prediction. Both C-indices of the two nomograms were substantially higher than those of the six conventional HCC staging systems (0.54-0.74 for RFS; 0.58-0.76 for OS) and those of HCC nomograms reported in literature. CONCLUSION: The novel nomograms were shown to be accurate at predicting postoperative recurrence and OS for patients with HBV-related SE-HCC ≤10 cm after curative liver resection. IMPLICATIONS FOR PRACTICE: This multicenter study proposed recurrence or mortality predictive nomograms for patients with hepatitis B virus-related solitary early hepatocellular carcinoma ≤10 cm after curative liver resection. A close postsurgical surveillance protocol and adjuvant therapy should be considered for patients at high risk of recurrence.

Association between body mass index and postoperative morbidity after liver resection of hepatocellular carcinoma: A multicenter study of 1,324 patients.

BACKGROUND: Morbidity remains a common problem following hepatic resection. The aim of this study was to investigate the association between preoperative body mass index (BMI) and morbidity in patients undergoing liver resection for hepatocellular carcinoma (HCC). METHODS: Patients were divided into three groups according to preoperative BMI: low-BMI (≤18.4 kg/m2), normal-BMI (18.5-24.9 kg/m2) and high-BMI (≥25.0 kg/m2). Baseline characteristics, operative variables, postoperative 30-day mortality and morbidity were compared. Univariable and multivariable analyses were performed to identify independent risk factors associated with postoperative morbidity. RESULTS: Among 1324 patients, 108 (8.2%), 733 (55.4%), and 483 (36.5%) were low-BMI, normal-BMI, and high-BMI, respectively. There were no differences in postoperative 30-day mortality among patients based on BMI (P = 0.199). Postoperative 30-day morbidity was, however, higher in low-BMI and high-BMI patients versus patients with a normal-BMI (33.3% and 32.1% vs. 22.9%, P = 0.018 and P < 0.001, respectively). Following multivariable analysis low-BMI and high-BMI remained independently associated with an increased risk of postoperative morbidity (OR: 1.701, 95%CI: 1.060-2.729, P = 0.028, and OR: 1.491, 95%CI: 1.131-1.966, P = 0.005, respectively). Similar results were noted in the incidence of postoperative 30-day surgical site infection (SSI). CONCLUSION: Compared with normal-BMI patients, low-BMI and high-BMI patients had higher postoperative morbidity, including a higher incidence of SSI after liver resection for HCC.

Triphenyltin exposure affects mating behaviors and attractiveness to females during mating in male guppies (Poecilia reticulata).

The impacts of triphenyltin (TPT) on ecological health have been of great concern due to their widespread use and ubiquity in aquatic ecosystems. However, little is known about the effects of TPT on the reproductive behaviors of fishes. Therefore, the present study was conducted to investigate the effects of TPT at environmentally relevant concentrations (0, 1 and 10 ng Sn/L) on the mating behaviors and the attractiveness to females during mating in male guppies (Poecilia reticulata). The results showed that TPT exposure disturbed the mating behaviors; the TPT-exposed male fish performed more sneaking attempts, but no changes in sigmoid courtship were displayed. The increases in sneaking attempts might be related to increases in testosterone levels induced by TPT exposure. In the context of a competing male, the TPT-exposed males were less attractive to females during mating. The decreases in attractiveness might be related to decreases in carotenoid-based coloration, shown as decreases in caudal fin redness values and skin carotenoid contents. In addition, TPT-induced total antioxidant capacities, the activities of superoxide dismutase and catalase, and the contents of malondialdehyde in liver and intestinal tissues indicated increases in oxidative stress. Both oxidative stress and coloration are linked to carotenoids. Thus, we speculated that the TPT-exposed males might use carotenoids to cope with increases in oxidative stress at the expense of carotenoid-based coloration. The disruption of mating behaviors and the decrease in attractiveness to females in male fish could result in reproductive failure. The present study underscores the importance of using behavioral tests as a sensitive tool in assessing the impact of pollutants present in aquatic environments.

[Chromosome polymorphisms and their influence on semen quality and sperm DNA integrity in males undergoing IVF/ICSI].

OBJECTIVE: To investigate the incidence of chromosome polymorphisms and their influence on semen quality and sperm DNA integrity in male patients receiving in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). METHODS: We retrospectively analyzed the chromosomal karyotypes and the types and incidence rate of chromosome polymorphisms in 2 370 male patients undergoing IVF/ICSI between June 2016 and June 2018. We classified the patients into groups A (with variation in the secondary constriction region in the autosomal long arm), B (with variation in the short arm of the D/G group chromosomes), C (with interbrachial inversion of chromosome 9) and D (with Y chromosome polymorphisms), and compared the semen parameters and sperm DNA fragmentation indexes (DFI) between the patients with chromosome polymorphisms and those with normal chromosomes. RESULTS: Totally, 154 (6.50%) of the patients undergoing IVF/ICSI were found with chromosome polymorphisms, including 34 cases of secondary constriction variation in the long arm of the autosome (1.43% ï¼»34/2 370ï¼½, 22.08% ï¼»34/154ï¼½), 82 cases of short arm polymorphisms of the D/G group chromosomes (3.46% ï¼»82/2 370ï¼½, 53.25% ï¼»82/154ï¼½), 26 cases of interbrachial inversion of chromosome 9 (1.10% ï¼»26/2 370ï¼½, 16.88% ï¼»26/154ï¼½), 10 cases of Y chromosome polymorphisms (0.42% ï¼»10/2 370ï¼½, 6.50% ï¼»10/154ï¼½), and 2 cases of mixed chromosome polymorphisms (0.08% ï¼»2/2 370ï¼½, 1.42% ï¼»2/154ï¼½). The total sperm count was lower in group D than in the other polymorphism groups and the normal chromosome group, but with no statistically significant difference among the five groups (P > 0.05). The sperm progressive motility was also lower in group D than in the other five groups, with statistically significant difference from group B (27.5 ± 13.5 vs. 41.5 ± 21.1, P = 0.027), but not from the other groups (P > 0.05). No statistically significant difference was observed in the sperm DFI between the polymorphism groups and the normal chromosome group (P > 0.05), or among the polymorphism groups (P > 0.05). The proportion of normal semen was lower in group D than in the other four groups, but with no statistically significant difference among the five groups (P > 0.05). The incidence rate of asthenospermia was higher in group D than in the other four groups, but with no statistically significant difference among the five groups (P > 0.05), and so was that of oligoasthenospermia, with statistically significant difference from the normal chromosome group (30.0% vs 8.0%, P = 0.041), but not from the other polymorphism groups (P > 0.05). CONCLUSIONS: Short arm polymorphisms of the D/G group chromosomes are the most common type of chromosome polymorphisms in male patients undergoing IVF/ICSI. Polymorphisms of the Y chromosome have a negative effect on semen quality, while those of the other chromosomes do not significantly affect semen quality and sperm DNA integrity.

Regulation of IL-17 by lncRNA of IRF-2 in the pearl oyster.

Long noncoding RNAs (lncRNAs), once thought to be nonfunctional, have recently been shown to participate in the multilevel regulation of transcriptional, posttranscriptional and epigenetic modifications and to play important roles in various biological processes, including immune responses. However, the expression and roles of lncRNAs in invertebrates, especially nonmodel organisms, remain poorly understood. In this study, by comparing a transcriptome to the PfIRF-2 genomic structure, we identified lncIRF-2 in the PfIRF-2 genomic intron. The results of the RNA interference (RNAi) and the nucleus grafting experiments indicated that PfIRF-2 might have a negative regulatory effect on lncIRF-2, and PfIRF-2 and lncIRF-2 may have a positive regulatory effect on PfIL-17. Additionally, lncIRF-2, PfIRF-2 and PfIL-17 were involved in responses to the nucleus graft. These results will enhance the knowledge of lncIRF-2, IRF-2, and IL-17 functions in both pearl oysters and other invertebrates.

Transcriptomic analyses of tributyltin-induced sexual dimorphisms in rare minnow (Gobiocypris rarus) brains.

The brain of fish displays sexual dimorphisms and exhibits remarkable sexual plasticity throughout their life span. Although reproductive toxicity of tributyltin (TBT) in fish is well documented in fish, it remains unknown whether TBT interrupts sexual dimorphisms of fish brains. In this work, brain transcriptomic profiles of rare minnow (Gobiocypris rarus) was characterized and sex-biased genes were identified using RNA sequencing. Functional annotation and enrichment analysis were performed to reveal differences of gene products and pathways between the brains of male and female fish. Furthermore, transcriptomic responses of male and female brains to TBT at 10 ng/L were also investigated to understand effects of TBT on brain sexual dimorphisms. Only 345 male-biased and 273 female-biased genes were found in the brains. However, significant female-biased pathways of circadian rhythm and phototransduction were identified in the brains by enrichment analysis. Interestingly, following TBT exposure in the female fish, the circadian rhythm pathway was significantly disrupted based on enrichment analysis, while in the male fish, the phototransduction pathway was significantly disrupted. In the female fish, expression of genes (Per, Cry, Rev-Erb α, Ror, Dec and CK1δ/ε) in the circadian rhythm pathway was down-regulated after TBT exposure; while in the male fish, expression of genes (Rec, GNAT1_2, GNGT1, Rh/opsin, PDE and Arr) in the phototransduction pathway was up-regulated after TBT exposure. Overall, our results not only provide key data on the molecular basis of brain sexual dimorphisms in fish, but also offer valuable resources for investigating molecular mechanisms by which environmental chemicals might influence brain sexual plasticity.

Overexpression of Long Non-Coding RNA MEG3 Inhibits Proliferation of Hepatocellular Carcinoma Huh7 Cells via Negative Modulation of miRNA-664.

Evidence is accumulating that long non-coding RNAs (lncRNAs) are involved in human tumorigenesis and dysregulated in many cancers, including hepatocellular carcinoma (HCC). Because lncRNAs can regulate essential pathways that contribute to tumor initiation and progression with their tissue specificity, lncRNAs are valuable biomarkers and therapeutic targets. Maternally expressed gene 3 (MEG3) is a lncRNA overexpressed in HCC cells that inhibits HCC progression, however, the mechanism remains largely unknown. Recently, a novel regulatory mechanism has been proposed in which RNAs can cross-talk with each other via competing for shared microRNAs (miRNAs). The proposed competitive endogenous RNAs could mediate the bioavailability of miRNAs on their targets, thus imposing another level of post-transcriptional regulation. In the current study, we demonstrated that MEG3 is down-regulated in HCC tissues. MEG3 over-expression imposes another level of post-transcriptional regulation, whereas MEG3 overexpression increase the expression of the miR-664 target gene, ADH4, through competitive "sponging" miR-664. In addition, NF-κB may affect transcription of MEG3 by directly binding to the promoter region. Our data revealed that NF-κB may affect the transcript of MEG3. MEG3 overexpression inhibited the proliferation of HCC cells, at least in part by affecting miR-664mediated regulation of ADH4. Together, these results suggest that MEG3 is a suppressor of tumor which acts in part through "sponging" miR-664. J. Cell. Biochem. 118: 3713-3721, 2017. © 2017 Wiley Periodicals, Inc.

Snail-activated long non-coding RNA PCA3 up-regulates PRKD3 expression by miR-1261 sponging, thereby promotes invasion and migration of prostate cancer cells.

Rapidly accumulated evidence has shown that long non-coding RNA (lncRNAs) disregulation is involved in human tumorigenesis in many cancers, including prostate cancer (PCa). LncRNAs can regulate essential pathways that contribute to tumor initiation and progression with tissue specificity, which suggests that lncRNAs could be valuable biomarkers and therapeutic targets. Prostate cancer antigen 3 (PCA3), also known as differential display code 3 (DD3), is one such lncRNA that maps to chromosome 9q21-22. PCA3 expression is highly specific to PCa. In the present study, the level of PCA3 expression in prostate cancer cells was reduced by small interfering RNA (siRNA). Subsequently, the ability of LNCaP cell proliferation, invasion, and migration of PCa was compromised both in vivo and in vitro with the occurrence of cell autophagy. Recently, a novel regulatory mechanism has been proposed in which RNAs cross talk via competing with the shared microRNAs (miRNAs). In addition, lncRNAs can directly interact with RNA-binding proteins and then bind to the gene promoter region to further regulate gene expression. The proposed competitive endogenous RNAs mediate the bioavailability of miRNAs on their targets, thus imposing another level of post-transcriptional regulation. Here, we demonstrated that binding of Snail to the promoter region of PCA3 could activate the expression of PCA3. Down-regulation of PCA3 by silencing could increase the expression of the miRNA-1261, which then targeted at the PRKD3 gene (protein kinase D3) through competitive sponging. In summary, these results suggest that the transcription factor, Snail, activated the expression of lncRNA PCA3, which could inhibit the translation of PRKD3 protein via competitive miR-1261 sponging, and thus high expression of PRKD3 further promoted invasion and migration of prostate cancer.

[Normal sperm morphology and the outcomes of routine in vitro fertilization].

OBJECTIVE: To explore the application value of morphology assessment of sperm from fresh semen in routine in vitro fertilization (IVF). METHODS: We analyzed the morphology of the sperm from fresh or optimized semen samples and, based on the sperm morphology of the raw semen, allocated 908 IVF cycles due to the pure tubal factor to different groups: morphologically normal sperm (MNS) ≤ 4%, > 4% - ≤ 15%, and > 15% in Trial 1 and MNS ≤ 1%, > 1% - ≤ 2%, > 2% - ≤ 3%, and > 3%-- ≤ 4% in Trial 2. We compared the rates of fertilization, cleavage, high-quality embryo, -blastocyst formation, and pregnancy among different groups. RESULTS: The total fertilization rate was significantly lower in the MNS ≤ 4% than in the MNS > 4% - ≤ 15% and >15% groups (74.40% vs 78.61% and 80.03%, P < 0.01). Compared with the MNS ≤ 1%, > 1% - ≤ 2%, and > 2% - ≤ 3% groups, the MNS > 3% - ≤ 4% group showed remarkably increased rates of 2PN normal fertilization (77.23%, 78.97% and 78.99% vs 85.47%, P < 0.01), cleavage (95.71%, 96.01% and 97.27% vs 98.73%, P < 0.05), and blastocyst formation (53.85%, 49.01% and 49.55% vs 63.41%, P < 0.01). No statistically significant differences were observed in the rates of clinical pregnancy, implantation, early abortion, live birth, or malformation at birth among different groups (P > 0.05). CONCLUSION: MNS ≤ 4% affected the total rate of fertilization while MNS ≤ 3% reduced the rate of normal fertilization in IVF. However, even MNS ≤ 1% did not result in fertilization disorder or failure. Therefore, teratozoospermia alone was not an indicator of ICSI and sperm mor- phology assessment had no obvious value for predicting the rates of embryo quality, clinical pregnancy, and live birth in IVF.

Cloning and gene expression of signal transducers and activators of transcription (STAT) homologue provide new insights into the immune response and nucleus graft of the pearl oyster Pinctada fucata.

The signal transducers and activators of the transcription (STAT) family play an important role in regulatory and cellular functions by regulating the expression of a variety of genes, including cytokines and growth factors. In the present study, a Pinctada fucata STAT protein, termed PfSTAT, was described. The deduced amino acid sequence of PfSTAT contains the conserved STAT_bind domain and the SH2 domain, and the additional Bin/Amphiphysin/Rvs (BAR) domain, but does not have STAT_alpha and STAT_int domains. Multiple sequence alignments revealed that PfSTAT showed relatively low identity with vertebrate and other invertebrate STATs, and phylogenetic analysis indicated that the evolution of STAT may have been more complex and ancient. Gene expression analysis revealed that PfSTAT is involved in the immune response to polyinosinic-polycytidylic acid (poly I:C) stimulation and in the nucleus insertion operation. This study contributes to a better understanding of PfSTAT in protecting the pearl oyster from disease or injury caused by grafting.

Nuclear factor of activated T cells (NFAT) in pearl oyster Pinctada fucata: molecular cloning and functional characterization.

Nuclear factor of activated T cells (NFAT) plays an important role in nonimmune cells and also in T cells and many other cells of the immune system, by regulating the expression of a variety of genes involved in the immune response, organ development, developmental apoptosis and angiogenesis. In the present study, the NFAT homology gene, PfNFAT, from the pearl oyster Pinctada fucata was cloned and its genomic structure and promoter were analyzed. PfNFAT encodes a putative protein of 1226 amino acids, and contains a highly conserved Rel homology region (RHR) with DNA-binding specificity, and a regulatory domain (NFAT homology region, NHR) containing a potent transactivation domain (TAD). The PfNFAT gene consists of 12 exons and 11 introns, and its promoter contains potential binding sites for transcription factors such as NF-κB (Nuclear factor κB), STATx (signal transducer and activator of transcription), AP-1 (activator protein-1) and Sox-5/9 (SRY type HMG box-5/9), MyoD (Myogenic Differentiation Antigen) and IRF (Interferon regulatory factor). Comparison and phylogenetic analysis revealed that PfNFAT shows high identity with other invertebrate NFAT, and clusters with the NFAT5 subgroup. Furthermore, gene expression analysis revealed that PfNFAT is involved in the immune response to lipopolysaccharide (LPS) and Polyinosinic-polycytidylic acid (poly I:C) stimulation and in the nucleus inserting operation. The study of PfNFAT may increase understanding of molluscan innate immunity.

Beryllium fluoride exchange rate accelerated by Mg²âº as discovered by ¹9F NMR.

Beryllium fluoride is widely used as a phosphoryl analogue in macromolecular studies, which are not only fluoride-sensitive but also magnesium-dependent. The beryllium fluorides are a mixture of different species including BeF3(-) and BeF4(2-) exchanging under thermodynamic equilibrium in neutral aqueous solutions. In the cases of mimicking phosphate group transfer, both beryllium fluoride and the magnesium ion are generally needed. However, the impact of magnesium on the bioactivity of beryllium fluoride is not clear. We have found by (19)F NMR spectroscopy that Mg(2+) can severely affect the chemical exchange kinetics between BeF3(-) and BeF4(2-). When the F(-) concentration is relatively low, the presence of 10.0 mM Mg(2+) can accelerate the exchange rate 3-4 fold. However, when the F(-) concentration is relatively high, the Mg(2+) effect on the chemical exchange vanishes. On the basis of these findings, we proposed a possible mechanism that BeF4(2-) and Mg(2+) form an ion pair that affects the distribution of beryllium fluoride species and thus the activity in the solution.

Involvement of substance p/neurokinin-1 receptor in the analgesic and anticancer activities of minimally toxic fraction from the traditional Chinese medicine Liu-Shen-Wan in vitro.

Liu-Shen-Wan (LSW), an ancient preparation used to treat localized infection with pain, was recently reported to possess anticancer activity. The mechanism responsible for LSW's analgesic and anticancer activity is unclear. In the present study, we obtained a LSW supernatant (LSWS) fraction from ultrasound-assisted ethanol extraction (yield 15.9%) which proved to be safer than LSW in terms of hepatotoxicity. The LSWS (1 and 10 µg/mL) exhibited a potent inhibitory effect on the bradykinin-evoked rapid release of substance P from dorsal root ganglion (DRG) cells. At concentrations of 0.1 µg/mL and higher, the LSWS resulted in a concentration-related growth inhibitory effect on HepG2, a representative cancer cell lines. The LSWS significantly down-regulated the neurokinin-1 (NK-1) receptor expression in both HepG2 and bradykinin-treated DRG cells. In addition to the NK-1 receptor-dependent growth inhibition in HepG2 cells (0.1-100 µg/mL), the LSWS induced mitochondria-mediated apoptosis at a higher concentration (1-100 µg/mL). In conclusion, we recently isolated a safer LSW fraction which maintained its analgesic and anticancer activity, and found that the substance P/NK-1 receptor system was partly responsible for these effects. Our findings will be useful for developing more effective and less toxic LSW preparations.

Foliar water uptake of Tamarix ramosissima from an atmosphere of high humidity.

Many species have been found to be capable of foliar water uptake, but little research has focused on this in desert plants. Tamarix ramosissima was investigated to determine whether its leaves can directly absorb water from high humidity atmosphere and, if they can, to understand the magnitude and importance of foliar water uptake. Various techniques were adopted to demonstrate foliar water uptake under submergence or high atmospheric humidity. The mean increase in leaf water content after submergence was 29.38% and 20.93% for mature and tender leaves, respectively. In the chamber experiment, obvious reverse sap flow occurred when relative humidity (RH) was persistently above 90%. Reverse flow was recorded first in twigs, then in branches and stems. For the stem, the percentage of negative sap flow rate accounting for the maximum value of sap flow reached 10.71%, and its amount accounted for 7.54% of diurnal sap flow. Small rainfall can not only compensate water loss of plant by foliar uptake, but also suppress transpiration. Foliar uptake can appear in the daytime under certain rainfall events. High atmospheric humidity is beneficial for enhancing the water status of plants. Foliar uptake should be an important strategy of water acquisition for desert plants.

Source identification of microplastics in highly urbanized river environments and its implications for watershed management.

The extensive use of plastic products has resulted in a significant influx of microplastics into aquatic ecosystems, particularly in highly urbanized areas and their associated river environments. However, the specific pathways and quantities through which these microplastics enter the river environment are still unclear, which poses a challenge in developing effective measures to mitigate their sources. In this paper, the spatiotemporal variations of microplastics from different sources in highly urbanized rivers within the Shenzhen Bay watershed were investigated through field sampling, experimental and statistical analysis, and the measures of microplastic reduction were discussed. The observation results exhibited a negative logarithmic correlation between the abundance of microplastics in river water and monthly rainfall (R = 0.994, MSE = 0.051, p < 0.05). When the monthly rainfall was <6 mm, the abundance of microplastics was absolutely dependent on point sources. While the rainfall exceeded 470 mm, the abundance was absolutely predominantly influenced by nonpoint source microplastics. The annual load of microplastics from the watershed was 5.39 × 1012 items, of which 61.6 % originated from point sources. Among the microplastics from point sources, 92.1 % were derived from fibers generated by textile washing. Fragmented microplastics (41.9 %) were the most common type of microplastics from nonpoint sources, primarily originating from the disintegration and weathering of disposable plastics. In the future, there is an expectation to reduce the microplastic load in the watershed to 15.9 % of the total by improving sewage treatment processes and infrastructure. This study can provide scientific guidance for environmental planning and serve as a warning regarding the impact of microplastics on ecosystems in urbanized areas.

A novel method of identifying estuary high-nutrient zones for water quality management.

Coastal shallow waters are highly vulnerable to pollution, often leading to the development of intricate eutrophication zones. However, accurately determining these areas poses a significant challenge due to the complex interplay of estuarine hydrodynamics and nutrient transformation. To address such issue, a novel method was proposed to identify high-nutrient zones through calculating the continuous zonation of released tracers when their instantaneous concentrations declined to 1/e of their initial values. The method was well tested using idealized estuary models with varying shape parameters, water depths and river discharges. The results consistently revealed that the boundaries of high-nutrient zones fell within the mixed zone, characterized by salinity levels of 10- 20 psu. In Shenzhen Bay, a typical shallow bay, distinct differences were observed in the concentrations of dissolved inorganic nitrogen (DIN) and PO43-. Both the 20 psu isohaline and the proposed method effectively identified the partition boundary of high DIN and PO43- in 2001-2010, but only the newly proposed method demonstrated accuracy in delineating the actual high-nutrient zone during the continuous nutrient reduction period from 2010 to 2020. This study provides a practical and feasible approach that can serve as an auxiliary decision-making tool for managing estuarine water environments, and it has potential to facilitate the implementation of timely and effective measures for pollution control.