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Enzyme allocation (or synthesis) is a crucial microbial trait that mediates soil biogeochemical cycles and their responses to climate change. However, few microbial ecological models address this trait, particularly concerning multiple enzyme functional groups that regulate complex biogeochemical processes. Here, we aim to fill this gap by developing a COmpetitive Dynamic Enzyme ALlocation (CODEAL) scheme for six enzyme groups that act as indicators of inorganic nitrogen (N) transformations in the Microbial-ENzyme Decomposition (MEND) model. This allocation scheme employs time-variant allocation coefficients for each enzyme group, fostering mutual competition among the multiple groups. We show that the principle of enzyme cost minimization is achieved by using the substrate's saturation level as the factor for enzyme allocation, resulting in an enzyme-efficient pathway with minimal enzyme cost per unit metabolic flux. It suggests that the relative substrate availability affects the trade-off between enzyme production and metabolic flux. Our research has the potential to give insights into the nuanced dynamics of the N cycle and inspire the evolving landscape of enzyme-mediated biogeochemical processes in microbial ecological modeling, which is gaining increasing attention. [ABSTRACT FROM AUTHOR]

In the Qaidam Basin, meteorological stations are sparsely distributed, and the observational precipitation data are therefore not comprehensive, which significantly hampers the accurate assessment and optimal allocation of regional water resources. This study aims to evaluate the accuracy of three precipitation products (MSWEP V2, GPM IMERG V6, and TRMM 3B43) against gauged-based precipitation data from nine meteorological stations and 12 hydrologic stations in the Qaidam Basin from 2001 to 2016. The results reveal the following: (1) At the annual and monthly scales, the MSWEP product has the highest accuracy, followed by the GPM product. However, the TRMM product only reveals a correlation at the monthly scale; (2) the MSWEP product performs better in the wet season than the dry season, and the TRMM product has an abnormally high value of precipitation in the wet season. Moreover, it was shown that the accuracy of the GPM product is superior to that of the TRMM product; however, it has a low detection capability in some mountainous areas; and (3) the average error of each precipitation product at the meteorological stations is smaller than that at the hydrological stations. [ABSTRACT FROM AUTHOR]

The molecular mechanisms underlying allelopathy and their role in the interactions between invasive weeds and native species remain unclear. In this study, we aimed to explore the physiological and molecular response of plant roots of a native species to allelopathy from an invasive weed. We examined the growth and development of roots of native Arabidopsis thaliana for a 2-week period after being treated with aqueous extracts at different concentrations from invasive Conyza canadensis. Extracts with higher concentration in the Murashige and Skoog (MS) media (i.e., 4 mg of extract/mL of MS) significantly affected the root growth of A. thaliana. Roots of A. thaliana displayed weakened root tip activity and an accumulation of reactive oxygen species (ROS) in response to extracts from C. canadensis. The transcriptome analysis of A. thaliana roots exposed to phytotoxicity revealed differentially expressed genes (DEGs) involved in cell wall formation, abiotic stress, transporter genes and signal transduction. We found that genes associated with nutrient transport, such as major facilitator superfamily (MFS) and amino acid permease (AAP3) transporters as well as genes involved in stress response, including leucine-rich repeat receptor-like protein kinases (LRR-RLKs) were down-regulated. In addition, we found that many transcription factors associated with plant stress (such as APETALA2/ethylene response factors) were up-regulated while others (e.g., zinc-finger proteins) were down-regulated. Allelochemicals from C. canadensis also induced the up-regulation of detoxification (DTX) genes, ROS related genes, calcineurin B-like interacting protein kinases (CIPKs) and calmodulin. Overall, our findings provided insights into allelopathy in C. canadensis at the molecular level, and contributes to our understanding of invasion mechanisms of alien plant species. Clinical trials registration: This study does not contain any studies with clinical trials performed by any of the authors. [ABSTRACT FROM AUTHOR]

Diabetic osteoporosis (DOP) is a complication of diabetes, with the characteristics of bone mineral density (BMD) reduction and bone structure destruction. Zinc was reported has a benefit effect on postmenopausal osteoporosise, it was also has hypoglycemic effect, whether zinc was beneficial on diabetes-induced osteoporosis has not been reported. So in the present study, we established a diabetic rat model by streptozotocin injection (60 mg/kg), and administered zinc sulfate by oral gavage to investigate the protective effects of zinc on DOP and the underline possible mechanism. Thirty six Sprague Dawley rats were divided into T1DM group (diabetic rats), control group (vehicle treatment), and T1DM-Zinc group (diabetic rats administered zinc sulfate 0.25 mg/kg by oral gavage). The bone histomorphological parameters, serum bone metabolism markers (including ALP, OPG, RUNX 2, and RANKL), BMD, and bone marrow adipocyte numbers were detected after eight weeks of zinc sulfate treatment. The results showed zinc sulfate administration (0.25 mg/kg/d) decreased blood glucose, increased the BMD, decreased serum ALP, and RANKL, increased serum OPG and RUNX 2 levels, as well as OPG/RANKL ratio of T1DM rats. Meanwhile, the bone histomorphological parameters, bone marrow adipocytes numbers were returned to be normal. The RUNX 2, and OPG mRNA expression levels in bone tissues of T1DM-Zinc group rats were increased after zinc sulfate treatment compared with the diabetic rats (P < 0.05). Those indicating that zinc sulfate can prevent DOP, the protective mechanism were mainly related to its hypoglycemic effect, bone marrow lipogenesis inhibition effect, OPG/RANKL ratio and RUNX 2 up-regulation effect. [ABSTRACT FROM AUTHOR]

Lead has heavy metal toxicity which endangers human and animal health. Salidroside (SDS) is a natural antioxidant that has extensive pharmacological usage. However, its protective effects on lead-induced oxidative stress and hepatotoxicity has not been reported. In this study, we established an animal model to evaluate the protective effects of SDS on chronic lead exposure induced oxidative stress and hepatotoxicity. Forty healthy Sprague-Dawley (SD) rats were assigned to control group (control, animals were provided with distilled water, n = 10); lead acetate-exposed group (PbAc, animals received lead acetate solution of 500 ppm for 60 days, n = 10); low dosage of SDS-treated group (PbAc-SDS-L, lead acetate exposed animals were given intragastric SDS 150 mg/kg body weight for 60 days, n = 10); and high dosage of SDS-treated group (PbAc-SDS-H, lead acetate exposed animals were given intragastric SDS 300 mg/kg body weight for 60 days, n = 10). The results showed that lead exposure caused a significant increase in serum ALP, AST, ALT, and TB (P < 0.01), and these were reversed after treatment with salidroside for 60 days. Compared to the control, the liver GSH, SOD, and GSH-Px were decreased significantly after lead acetate exposure (P < 0.01). However, after treatment with SDS for 60 days, those were dose-dependently reversed. Similarly, MDA was significantly increased in the PbAc group (P < 0.01), and it was significantly decreased in SDS treatment group. Moreover, SDS ameliorated lead-induced congestion and necrosis of hepatocytes. In addition, the RT-PCR and immunohistochemistry results revealed that the PbAc group showed a significant increase in the protein and mRNA of cytochrome P450 2E1 (CYP2E1) and NADPH oxidase 2 (NOX2) in rat liver. Treatment with SDS significantly reversed CYP2E1 and NOX2 expressions in the liver of lead-exposed rats. The results above indicated that SDS has obvious antioxidant activity; it can cure liver injury caused by lead acetate by inhibiting oxidative stress and increasing the antioxidant stress activity, thus improving the liver tissue structure. [ABSTRACT FROM AUTHOR]

We have reported that genistein (Gen) and silicon (Si) have synergistic effects on ovariectomy-induced bone loss in rat; however, the potential mechanisms behind this effect were not fully clarified yet. This study was performed to evaluate the bone protective mechanisms of concomitant intake of genistein and silicon in ovariectomized rat by OPG/RANKL axis. Three-month-old Sprague-Dawley female rats were subjected to ovariectomy (OVX) or sham surgery; after surgery, the OVX rats were randomly divided into five groups: OVX-Gen, OVX-Si, OVX-Gen-Si, OVX-E, and OVX. Genistein, silicon, and 17β-estradiol supplementation were started after ovariectomy and continued for 10 weeks. The results showed that genistein and silicon treatment increased the bone mineral density (BMD) of ovariectomized rats. In addition, the BMD of the tibia and femur were highest in the OVX-Gen-Si group compared with OVX-Gen and OVX-Si group (p < 0.05). After 10 weeks treatment with genistein and silicon, the bone structure of ovariectomized rats was recovered, there was no difference of bone histomorphometric parameters between OVX-Gen-Si, OVX-E, and SHAM group (p > 0.05), and there was no difference in the concentration of serum ALP, Ca, P, OPG, and RANKL between OVX-Gen-Si, SHAM, and OVX-E groups (p > 0.05). RT-PCR showed that genistein and silicon treatment could effectively increase the OPG mRNA expression and decreased the RANKL mRNA expression compared to that of the OVX group (p < 0.05), the OPG/RANKL mRNA ratios were significantly decreased in the OVX group (p < 0.05), and it was nearly to normal in the OVX-Gen-Si group. Immunohistochemical staining results showed that genistein and silicon supplementation could effectively increase the protein expression of OPG and decrease the protein expression of RANKL in bone tissues; there were no significant differences in OPG and RANKL positive expression areas between OVX-Gen-Si, SHAM, and OVX-E group (p > 0.05). The results above indicate that genistein and silicon supplementation can effectively reduce RANKL, increase OPG levels, and OPG/RANKL ratios in the serum and bone tissue of ovariectomized rats; this is the main mechanism by which genistein and silicon play a bone protective role in ovariectomized rats. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the protective effect of Du-Zhong cortex extract (DZCE) on lead acetate-induced bone loss in rats. Forty female Sprague-Dawley rats were randomly divided into four groups: group I (control) was provided with distilled water. Group II (PbAc) received 500 ppm lead acetate in drinking water for 60 days. Group III (PbAc+DZCE) received 500 ppm lead acetate in drinking water, and given intragastric DZCE (100 mg/kg body weight) for 60 days. Group IV (DZCE) was given intragastric DZCE (100 mg/kg body weight) for 60 days. The bone mineral density, serum biochemical markers, bone histomorphology, and bone marrow adipocyte parameters were analyzed using dual-energy X-ray absorptiometry, biochemistry, histomorphometry, and histopathology, respectively. The results showed that the lumbar spine and femur bone mineral density was significantly decreased in PbAc group compared with the control (P < 0.05); however, this decrease was inhibited by the intake of Du-Zhong cortex extract (P < 0.05, vs. PbAc group; P > 0.05, vs. control and DZCE group). Serum calcium and serum phosphorus in the PbAc+DZCE group were greater than that in the PbAc group (P < 0.05). The PbAc group had higher ALP, osteocalcin, and RANKL than the control group (P < 0.01), and they were significantly lower in the PbAc+DZCE group compared with the PbAc group. There were no significant differences of ALP, osteocalcin, and RANKL among the PbAc+DZCE, control, and DZCE groups (P > 0.05). Serum OPG and OPG/RANKL ration were significantly higher in the PbAc+DZCE group than that in the PbAc group (P < 0.05). The bone histomorphometric analyses showed that bone volume and trabecular thickness in the femoral trabecular bone were significantly lower in the PbAc group than that in the control group, but those were restored in the PbAc+DZCE groups. The bone marrow adipocyte number, percent adipocyte volume per tissue volume (AV/TV), and mean adipocyte diameter were significantly increased in the PbAc group compared to the control (P < 0.01), and those were restored in the PbAc+DZCE group. The differences of those parameters between PbAc+DZCE, DZCE, and the control group were not significant. The results above indicate that the Du-Zhong cortex extract has protective effects on both stimulation of bone formation and suppression of bone resorption in lead-exposed rats, therefore, Du-Zhong cortex extract has the potential to prevent or treat osteoporosis resulting from lead expose. [ABSTRACT FROM AUTHOR]

The topic of constructing a typology of the cultural tourists visiting a particular destination has interested the professionals since early 1990s. A number of typologies, often quite similar to each other, have been proposed and occasionally evaluated at various destinations. While most of the literature is purely conceptual, some works use typological frameworks to empirically categorize cultural tourists at a particular destination sourcing from survey results, typically by administrating a questionnaire to inbound and outbound travelers. This work, to the contrary, constructs an empirical typology of international cultural tourists who have visited Macau based on their reviews on TripAdvisor. The aim of this work is to discover visitation patterns to the nucleus of Macau's culture by analyzing user-generated content data using text analysis approaches. This model can automatically indicate the probability of a visitor being one particular culture tourist type. The results of this work will offer insights into local tourism authorities and industries for better resource allocation and cultural tourism promotion. [ABSTRACT FROM AUTHOR]

In this study, we evaluated the synergistic effects of genistein and zinc on bone metabolism, bone mineral density, and the femoral metaphyseal histomorphology in the ovariectomized rats. Sixty female Sprague-Dawley rats, aged 13 weeks, were divided into sham-operated group (SHAM), ovariectomized group (OVX), genistein-treated group (OVX-Gen), zinc-treated group (OVX-Zn), genistein combined zinc-treated group (OVX-Gen-Zn), and 17β-estradiol-treated group (OVX-E) (n = 10). Genistein, zinc, and 17β-estradiol injections were started immediately after OVX and continued for 10 weeks. The OVX-Gen group was subcutaneous injections of genistein (5 mg/kg once every day). The OVX-Zn group was given intragastric ZnSO4 (0.25 mg/kg once every day) after bilateral ovariectomy. The OVX-Gen-Zn group was subcutaneous injections of genistein (5 mg/kg), at the same time intragastric ZnSO4 (0.25 mg/kg once every day). OVX-E group were intraperitoneally injected with 17β-estradiol (10 μg/kg) once every other day. The results showed that genistein and zinc did not alter body weight in OVX rats. The soluble ZnSO4 had no effect to uterus weight loss. Genistein and zinc supplementation significantly increased the BMD of the femur and lumbar spine in OVX rats (P < 0.05, vs. OVX control group). The BMD of the lumbar spine and femur in the OVX-Gen-Zn group is higher than that in the OVX-Gen and OVX-Zn groups (P < 0.05), and there were no differences of BMD among the OVX-Gen-Zn, OVX-E, and SHAM groups (P > 0.05). The femoral metaphyseal morphology and bone histomorphometric parameters revealed that the trabecular volume and thickness in the OVX-Gen-Zn and OVX-E groups were similar to that of SHAM group, and the OVX-Gen-Zn group had more trabecular volume than the OVX-Gen and OVX-Zn groups. Serum zinc was found to be significantly reduced in the OVX group when compared with SHAM. Serum zinc levels were enhanced in the OVX-Zn, OVX-Gen-Zn, and OVX-E groups and restored to normal levels. Serum calcium and serum phosphorus in the OVX-Gen-Zn group was greater than that in the OVX-Gen and OVX-Zn groups (P < 0.05); the serum calcium, phosphorus, and ALP in the OVX-Gen-Zn group were similar to that of SHAM and OVX-E groups (P > 0.05). The OVX group had higher osteocalcin, CTX, and RANKL than the SHAM group (P < 0.01). They were lower in the OVX-Gen and OVX-Zn groups (P < 0.05), and they were significantly lower in the OVX-Gen-Zn and OVX-E groups, than in the OVX group. There were no significant differences of osteocalcin, CTX, and RANKL among the OVX-Gen-Zn, OVX-E, and SHAM groups (P > 0.05). OPG and OPG/RANKL ratios were significantly higher in the OVX-Gen and OVX-Zn groups than that in the OVX group (P < 0.05). The OPG and OPG/RANKL ratio in the OVX-Gen-Zn group is higher than that in the OVX-Gen and OVX-Zn groups (P < 0.05, vs. OVX-Gen group; P < 0.01, vs. OVX-Zn group). The differences of the OPG and OPG/RANKL ratios between the OVX-Gen-Zn, OVX-E, and the SHAM groups were not significant (P > 0.05). The results above indicate that the genistein and zinc have synergistic effects on both stimulation of bone formation and suppression of bone resorption in ovariectomized rats, thereby increasing bone mass. [ABSTRACT FROM AUTHOR]

The endangered Vatica mangachapoi, a long-lived, tropical tree with economic and ecological importance found in Hainan, China, was used to assess the hypothesis that historical human activities in Hainan’s tropical rain forest could have negative effects on the genetic diversity of V. mangachapoi. Three hundred and twenty individuals from 11 natural populations—which were classified into three groups according to levels of disturbance—were sampled and analyzed with ISSR markers. Although genetic diversity of V. mangachapoi is high at the species level, it is relatively low within populations. A significant genetic differentiation occurs among different disturbance levels. Significant isolation-by-distance indicated relevant historical anthropogenic changes. Our findings showed that historical human disturbances significantly increase the genetic differentiation and slightly decrease the genetic diversity of long-lived tree V. mangachapoi. Relevant targeting conservation actions were recommended. [ABSTRACT FROM AUTHOR]

This study was performed to evaluate the effect of concomitant supplementation of genistein and silicon on bone mineral density and bone metabolism-related markers in ovariectomized rat. Three-month-old Sprague Dawley female rats were subjected to bilateral ovariectomy (OVX) or sham surgery, and then the OVX rats were randomly divided into four groups: OVX-GEN, OVX-Si, OVX-GEN-Si, and OVX. Genistein and silicon supplementation was started immediately after OVX and continued for 10 weeks. In the OVX-GEN group, 5 mg genistein per gram body weight was injected subcutaneously. The OVX-Si group was given soluble silicon daily in demineralized water (Si 20 mg/kg body weight/day). The OVX-GEN-Si group was given subcutaneous injections of 5 mg genistein per gram body weight, at the same time, given soluble silicon daily (Si 20 mg/kg body weight/day). The results showed that the genistein supplementation in the OVX rats significantly prevented the loss of uterus weight; however, the silicon supplementation showed no effect on the uterus weight loss. The lumbar spine and femur bone mineral density was significantly decreased after OVX surgery; however, this decrease was inhibited by the genistein and/or silicon, and the BMD of the lumbar spine and femur was the highest in the OVX-GEN-Si-treated group. Histomorphometric analyses showed that the supplementation of genistein and/or silicon restored bone volume and trabecular thickness of femoral trabecular bone in the OVX group. Besides, the treatment with genistein and silicon for 10 weeks increased the serum levels of calcium and phosphorus in the OVX rats; serum calcium and serum phosphorus in the OVX-GEN-Si group were higher than those in the OVX-GEN and OVX-Si group ( P < 0.05). At the same time, the treatment with genistein and/or silicon decreased serum alkaline phosphatase (ALP) and osteocalcin, which were increased by ovariectomy; serum ALP and osteocalcin in the OVX-GEN-Si group were lower than those in the OVX-GEN and OVX-Si groups ( P < 0.05). The results above indicate that genistein and silicon have synergistic effects on bone formation in ovariectomized rats. [ABSTRACT FROM AUTHOR]

The aim of this study was to reveal a potential key gene network associated with seasonal allergic rhinitis (SAR). The microarray data GSE50101 downloaded from Gene Expression Omnibus were used to screen differentially expressed genes (DEGs) between SAR patients and healthy controls. Then, functional enrichment analysis was conducted using Database for Annotation, Visualization, and Integrated Discovery. Afterwards, the protein-protein interactions (PPIs) of DEGs were obtained from STRING, and the PPI network was constructed. In addition, the PPI network module was analyzed. In total, 98 up-regulated and 63 down-regulated DEGs were identified from the SAR samples, comparing the healthy controls. The up-regulated DEGs were mainly enriched in the Gene Ontology terms about cell death (e.g., DUSP1 and JUN) and pathways related to immune (e.g., FOS and JUN). The down-regulated DEGs were mainly enriched in regulation of transcription (e.g., CEBPD and SCML1). In the PPI network, a set of genes was predicted to interact with each other, such as FOS, JUN, and CEBPD. Furthermore, genes in the network module (e.g., FOS, JUN and CEBPD) was mainly enriched in regulation of transcription, and pathways about immune, such as mitogen-activated protein kinase signaling pathway, B cell receptor signaling pathway, and toll-like receptor signaling pathway. Several genes related to immunity and regulation of transcription, such as FOS, JUN, and CEBPD, may play crucial roles during the process of SAR through the interactions with each other. [ABSTRACT FROM AUTHOR]

Background: Stent placement for middle cerebral artery (MCA) stenosis remains a technical and clinical challenge. Our purpose was to assess the safety and feasibility of balloon-expandable stent (BES) for patients with symptomatic M1 stenosis of MCA, and to introduce our experience during the procedure. Methods: In the study, we analyzed retrospectively 37 patients with M1 stenosis of the MCA ranged from 70 to 90 % in diameter reduction and refractory to medical therapy between January 2012 and January 2015. All the patients underwent angioplasty and stenting with BES, and followed up continuously. Results: Thirty-five out of 37 patients were successfully followed up and available until now. The technical successful rate was 100 % for all the lesions. The complication rate was 0 during the procedure. Stroke occurred to one patient at 4th day after the procedure. There were two patients experiencing slight stroke after 8 months. Two patients were found re-stenosis >50 % without any symptom. The stroke rate of 12 months was 8.57 % (3/35). Conclusions: Angioplasty associated with BES appears to be safe and feasible for the patients with symptomatic M1 stenosis of MCA. Our experiences about the BES may be valuable for decreasing the complication. However, further study is needed. [ABSTRACT FROM AUTHOR]