An integrated mycotoxin-mitigating agent can effectively mitigate the combined toxicity of AFB1, DON and OTA on the production performance, liver and oviduct health in broiler breeder hens.

This study was to evaluate the efficacy of an integrated mycotoxin-mitigating agent in reducing the adverse effects of co-occurring dietary aflatoxin B1 deoxynivalenol and ochratoxin A on broiler breeder hens. 360 30-week-old Hubbard Efficiency Plus broiler breeder hens were allocated into four groups and received a basal diet (BD; Control), BD added 0.15 mg/kg aflatoxin B1+1.5 mg/kg deoxynivalenol+0.12 mg/kg ochratoxin A (Toxins), BD plus Toxins with 0.1% TOXO-XL (Toxins + XL1), and BD plus Toxins with 0.2% TOXO-XL (Toxins + XL2), respectively, for 8 weeks, and then received the same BD for another 4 weeks. Compared with control, mycotoxins decreased total egg weigh, egg laying rate, settable eggs rate, hatch of total eggs rate, egg quality, but increased feed/egg ratio and mortality rate, and impaired the liver and oviduct health during weeks 1-8 and(or) 9-12. It also increased PC and MDA concentrations, TUNEL-positive cells and IL-1ß and IL-6 expression, and decreased T-AOC, GPX and CAT activities in liver and/or oviduct. Notably, most of these negative changes were mitigated by both dosages of TOXO-XL. Generally, 0.2% TOXO-XL displayed better mitigation effects than 0.1% TOXO-XL. Conclusively, these findings revealed that TOXO-XL could mitigate the combined mycotoxins-induced toxicity on the performance, liver and oviduct health, through the regulation of redox, immunity, and apoptosis in broiler breeder hens.

Mitigating the adverse effects of Aflatoxin B1 in LMH, IPEC-J2 and 3D4/21 cells by a novel integrated agent.

This study was to evaluate the efficacy of TOXO-XL (XL), an integrated mycotoxin-mitigating agent, on aflatoxin B1 (AFB1)-induced damage in Leghorn male hepatoma (LMH), porcine jejunum epithelial cell line (IPEC-J2) and porcine alveolar macrophages (3D4/21) cells, and to explore its potential mechanisms. The results showed that 30% inhibition concentration (IC30) of AFB1 in LMH, IPEC-J2 and 3D4/21 cells was 0.5, 15.0, and 2.5 mg/L, respectively. Notably, cell viability, ROS, apoptosis and DNA lesion induced by AFB1 (IC30) could be ameliorated by the supplementation with XL at the dosage of 0.025, 0.025 and 0.005%, respectively. Additionally, the migration and phagocytosis abilities impaired by AFB1 were also restored by XL in 3D4/21. Further experiments revealed that XL supplementation markedly attenuated AFB1-induced inflammatory response by decreasing IL-1ß, IL-6 and IL-10 in LMH, IL-6 in IPEC-J2 and IL-1ß in 3D4/21 cells. Meanwhile, XL supplementation reversed the alterations of BAX, BCL-2 and caspase-3 induced by AFB1 in the three cells, suggesting that AFB1-induced apoptosis may be suppressed via the mitochondria-dependent pathway. Furthermore, XL may have a protective effect on the intestinal barrier through the restoration of occludin protein. Conclusively, these findings indicated that XL could alleviate AFB1-induced cytotoxicity in the three cells, potentially through the regulation of cytokines, ROS, apoptotic and DNA damage signaling.

Identification of AKI signatures and classification patterns in ccRCC based on machine learning.

Background: Acute kidney injury can be mitigated if detected early. There are limited biomarkers for predicting acute kidney injury (AKI). In this study, we used public databases with machine learning algorithms to identify novel biomarkers to predict AKI. In addition, the interaction between AKI and clear cell renal cell carcinoma (ccRCC) remain elusive. Methods: Four public AKI datasets (GSE126805, GSE139061, GSE30718, and GSE90861) treated as discovery datasets and one (GSE43974) treated as a validation dataset were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between AKI and normal kidney tissues were identified using the R package limma. Four machine learning algorithms were used to identify the novel AKI biomarkers. The correlations between the seven biomarkers and immune cells or their components were calculated using the R package ggcor. Furthermore, two distinct ccRCC subtypes with different prognoses and immune characteristics were identified and verified using seven novel biomarkers. Results: Seven robust AKI signatures were identified using the four machine learning methods. The immune infiltration analysis revealed that the numbers of activated CD4 T cells, CD56dim natural killer cells, eosinophils, mast cells, memory B cells, natural killer T cells, neutrophils, T follicular helper cells, and type 1 T helper cells were significantly higher in the AKI cluster. The nomogram for prediction of AKI risk demonstrated satisfactory discrimination with an Area Under the Curve (AUC) of 0.919 in the training set and 0.945 in the testing set. In addition, the calibration plot demonstrated few errors between the predicted and actual values. In a separate analysis, the immune components and cellular differences between the two ccRCC subtypes based on their AKI signatures were compared. Patients in the CS1 had better overall survival, progression-free survival, drug sensitivity, and survival probability. Conclusion: Our study identified seven distinct AKI-related biomarkers based on four machine learning methods and proposed a nomogram for stratified AKI risk prediction. We also confirmed that AKI signatures were valuable for predicting ccRCC prognosis. The current work not only sheds light on the early prediction of AKI, but also provides new insights into the correlation between AKI and ccRCC.

Effects of Voids on Thermal Fatigue Reliability of Solder Joints on Inner Rings in Ball Grid Array Packaging by Finite Element Analysis.

Under alternating temperatures, the fatigue failure of solder balls caused by the mismatch of the thermal expansion coefficient is a key problem in a Ball Grid Array (BGA). However, the combined effects of the solder ball location and the size of voids within it can seriously affect the thermal fatigue reliability of BGA solder balls, which can be easily ignored by researchers. Firstly, the thermal fatigue reliability of the board-level solder balls was evaluated by a temperature cycling test of the BGA package at -20 °C-+125 °C. The experimental results showed that the thermal fatigue reliability of the outer ring's solder joint was lower than that of the inner ring. Secondly, the reliability of the solder balls in the BGA package was studied under the same thermal cycling condition based on finite element analysis (FEA). The influences of voids on fatigue life were investigated. Generally, a linear correlation between the void content and the fatigue life of the inner rings' solder balls could be identified with a gradually smoothed relationship for solder balls closer to the center. In addition, when the size of the void exceeded a critical volume, the inner ring's solder ball with the void would fail before the outermost ring. The results of FEA showed that the critical void volume ratio from the second to fifth ring increased from 10.5% to 42.3%. This study provides a valuable reference for the influence of voids on the thermal fatigue reliability of BGA solder balls.

Effects of Moisture Diffusion on a System-in-Package Module by Moisture-Thermal-Mechanical-Coupled Finite Element Modeling.

Epoxy molding compounds (EMCs) are commonly used in electronic products for chip encapsulation, but the moisture absorption of EMC can induce significant reliability challenges. In this study, the effects of hygrothermal conditions and structure parameters on moisture diffusion and the consequent influences (such as moisture content on die surfaces and stress distribution) on a system-in-package module have been systematically investigated by moisture-thermal-mechanical-coupled modeling. Hygroscopic tests were carried out on a new commercial EMC at 60 °C/60% RH and 85 °C/85% RH, followed by evaluations of diffusion coefficients by Fick's law. It was found that the moisture diffusion coefficients and saturation concentrations at 85 °C/85% RH were higher than those at 60 °C/60% RH. From the modeling, it was found that the consequent maximum out-of-plane deformation and stress of the module at 85 °C/85% RH were both higher than those at 60 °C/60% RH. Influences of thicknesses of EMC and PCB on the moisture diffusion behavior have also been studied for design optimization. It was found that the maximum moisture concentration on die surfaces and resultant stress increased notably with thinner PCB, whereas the effects of EMC thickness were limited. This can be attributed to the comparison between the thicknesses of EMC and PCB and the shortest existing diffusion path within the module. These findings can provide helpful insights to the design optimization of electronic modules for hygrothermal conditions.

Long-term safety and efficacy of fecal microbiota transplantation in 74 children: A single-center retrospective study.

Background: Fecal microbiota transplantation (FMT) is an effective treatment for intestinal and extra-intestinal disorders. Nonetheless, long-term safety and efficacy remain major challenges for FMT applications. To date, few long-term follow-up studies have been published on FMT in children. Methods: Retrospective reviewed the medical charts of 74 patients who underwent 508 FMT courses between August 2014 and July 2019 at our medical center. All the FMT procedures followed uniform standards. Baseline characteristics pre-FMT and follow-up data were collected at 1, 3, 6, 12, 36, 60, and 84 months after FMT. All potential influencing factors for adverse events (AEs) were analyzed and assessed using regression analyses. Results: A total of 70 (13.7%) short-term AEs occurred in twenty-six patients (35.1%). Most AEs (88.5%) occurred within 2 days post-FMT. A total of 91.4% of the AEs were self-limiting. Ulcerative colitis (UC) and within four times of FMT were associated with a higher rate of AEs (p = 0.028 and p = 0.021, respectively). The primary clinical remission rate after FMT was as high as 72.9%. Twenty-five children were followed for more than 5 years after FMT. The clinical remission rates gradually decreased over time after FMT. During follow-up, none of the patients developed autoimmune, metabolic, or rheumatologic disorders or tumor-related diseases. However, nine children developed rhinitis, five developed rhinitis, were underweight, and six developed constipation. Conclusions: FMT is a safe and effective treatment for dysbiosis in children. The long-term efficacy of FMT for each disease decreased over time. Moreover, multiple FMTs are recommended 3 months post-FMT for recurrent diseases.

Phosphatidylethanolamine functionalized biomimetic monolith for immobilized artificial membrane chromatography.

In this research, a new phospholipid based monolith was fabricated by in situ co-polymerization of 1-dodecanoyl-2-(11-methacrylamidoundecanoyl)-sn-glycero-3-phosphoethanolamine and ethylene dimethacrylate to mimick bio-membrane environment. Excellent physicochemical properties of this novel monolith that were achieved included column efficiency, stability, and permeability. Moreover, the biomimetic monolith showed outstanding separation capability for a series of intact proteins and small molecules. In particular, it exhibited good potential as an alternative to the commercial immobilized artificial membrane (IAM) column (IAM.PC.DD2) for studying drug-membrane interactions. This study not only enriched the types of IAM stationary phases, but also provided a simple model for the prediction of phosphatidylethanolamine related properties of drug candidates.

Role of cassava CC-type glutaredoxin MeGRXC3 in regulating sensitivity to mannitol-induced osmotic stress dependent on its nuclear activity.

BACKGROUND: We previously identified six drought-inducible CC-type glutaredoxins in cassava cultivars, however, less is known about their potential role in the molecular mechanism by which cassava adapted to abiotic stress. RESULTS: Herein, we investigate one of cassava drought-responsive CC-type glutaredoxins, namely MeGRXC3, that involved in regulation of mannitol-induced inhibition on seed germination and seedling growth in transgenic Arabidopsis. MeGRXC3 overexpression up-regulates several stress-related transcription factor genes, such as PDF1.2, ERF6, ORA59, DREB2A, WRKY40, and WRKY53 in Arabidopsis. Protein interaction assays show that MeGRXC3 interacts with Arabidopsis TGA2 and TGA5 in the nucleus. Eliminated nuclear localization of MeGRXC3 failed to result mannitol-induced inhibition of seed germination and seedling growth in transgenic Arabidopsis. Mutation analysis of MeGRXC3 indicates the importance of conserved motifs for its transactivation activity in yeast. Additionally, these motifs are also indispensable for its functionality in regulating mannitol-induced inhibition of seed germination and enhancement of the stress-related transcription factors in transgenic Arabidopsis. CONCLUSIONS: MeGRXC3 overexpression confers mannitol sensitivity in transgenic Arabidopsis possibly through interaction with TGA2/5 in the nucleus, and nuclear activity of MeGRXC3 is required for its function.

Fabrication and application of zwitterionic phosphorylcholine functionalized monoliths with different hydrophilic crosslinkers in hydrophilic interaction chromatography.

In this study, a series of zwitterionic phosphorylcholine functionalized monolithic columns were fabricated via the thermally initiated co-polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) and different hydrophilic crosslinkers, including 1,4-bis(acryloyl)piperazine (PDA), N,N'-methylenebisacrylamide (MBA) and 2-(methacryloyloxy)ethyl-[N-(2-methacryloyloxy)ethyl]phosphorylcholine (MMPC). The physicochemical and chromatographic properties of these MPC functionalized monoliths, including column morphology, pore size distribution, permeability, column efficiency, retention mechanism and ζ-potential analysis, were systematically compared. Furthermore, the influence of the crosslinker on the chromatographic performance of these MPC functionalized monoliths was evaluated. The chromatographic results indicate that the polarity of MPC functionalized monoliths may be related to the polarity of the crosslinker, which further affects the column selectivity and efficiency. A particularly high column efficiency (88,000 plates/m) was obtained on the novel poly(MPC-co-MMPC) monolith at optimum linear velocity using thiourea as test analyte. Compared to the poly(MPC-co-MBA) and poly(MPC-co-PDA) monoliths, the poly(MPC-co-MMPC) monolith exhibited higher separation selectivity for polar analytes, including nucleobases, nucleosides and benzoic acid derivatives. Moreover, 24 N-glycopeptides could be detected after enrichment with the poly(MPC-co-MMPC) versus 19 and 10 N-glycopeptides with the poly(MPC-co-MBA) and poly(MPC-co-PDA) monoliths, and no N-glycopeptide without enrichment. Therefore, MMPC has a great potential as a new and alternative hydrophilic crosslinker for the development of zwitterionic polymeric monoliths.

New-onset glucose disorders in peritoneal dialysis patients: a meta-analysis and systematic review.

BACKGROUND: Peritoneal dialysis (PD) patients are at high risk of developing glucose metabolism disturbance (GMD). The incidence and prevalence of new-onset GMD, including diabetes mellitus (DM), impaired glucose tolerance (IGT) and impaired fast glucose (IFG), after initiation of PD, as well as their correlated influence factors, varies among studies in different areas and of different sample sizes. Also, the difference compared with hemodialysis (HD) remained unclear. Thus we designed this meta-analysis and systematic review to provide a full landscape of the occurrence of glucose disorders in PD patients. METHODS: We searched the MEDLINE, Embase, Web of Science and Cochrane Library databases for relevant studies through September 2018. Meta-analysis was performed on outcomes using random effects models with subgroup analysis and sensitivity analysis. RESULTS: We identified 1124 records and included 9 studies involving 13 879 PD patients. The pooled incidence of new-onset DM (NODM) was 8% [95% confidence interval (CI) 4-12; I2 = 98%] adjusted by sample sizes in PD patients. Pooled incidence rates of new-onset IGT and IFG were 15% (95% CI 3-31; I2 = 97%) and 32% (95% CI 27-37), respectively. There was no significant difference in NODM risk between PD and HD [risk ratio 0.99 (95% CI 0.69-1.40); P = 0.94; I2 = 92%]. PD patients with NODM were associated with an increased risk of mortality [hazard ratio 1.06 (95% CI 1.01-1.44); P < 0.001; I2 = 92.5%] compared with non-DM PD patients. CONCLUSIONS: Around half of PD patients may develop a glucose disorder, which can affect the prognosis by significantly increasing mortality. The incidence did not differ among different ethnicities or between PD and HD. The risk factor analysis did not draw a definitive conclusion. The glucose tolerance test should be routinely performed in PD patients.

Identification and characterization of drought-responsive CC-type glutaredoxins from cassava cultivars reveals their involvement in ABA signalling.

BACKGROUND: CC-type glutaredoxins (GRXs) are plant-specific glutaredoxin, play regulatory roles in response of biotic and abiotic stress. However, it is not clear whether the CC-type GRXs are involve in drought response in cassava (Manihot esculenta), an important tropical tuber root crop. RESULTS: Herein, genome-wide analysis identified 18 CC-type GRXs in the cassava genome, of which six (namely MeGRXC3, C4, C7, C14, C15, and C18) were induced by drought stress in leaves of two cassava cultivars Argentina 7 (Arg7) and South China 124 (SC124). Exogenous abscisic acid (ABA) application induced the expression of all the six CC-type GRXs in leaves of both Arg7 and SC124 plants. Overexpression of MeGRXC15 in Arabidopsis (Col-0) increases tolerance of ABA on the sealed agar plates, but results in drought hypersensitivity in soil-grown plants. The results of microarray assays show that MeGRXC15 overexpression affected the expression of a set of transcription factors which involve in stress response, ABA, and JA/ET signalling pathway. The results of protein interaction analysis show that MeGRXC15 can interact with TGA5 from Arabidopsis and MeTGA074 from cassava. CONCLUSIONS: CC-type glutaredoxins play regulatory roles in cassava response to drought possibly through ABA signalling pathway.

Comparison of orthodontic tooth movement between adolescents and adults based on implant superimposition.

OBJECTIVE: We compared tooth movement under maximum anchorage control with mini-screw implants in growing and non-growing patients. METHODS: In total, 15 adolescent (G1) and 19 adult (G2) patients with prognathic profiles were selected. All patients underwent first premolar extraction treatment with mini-screw implants for maximum anchorage control. Cone-beam computed tomography (CBCT) data were obtained immediately after implant placement (T1) and at the end of anterior tooth retraction (T2). Tooth movement and root length changes of the maxillary first molar, canine, and incisors were evaluated with three-dimensional models constructed using CBCT data obtained before and after orthodontic retraction through the superimposition of stable implants. RESULTS: Distal movement of the molar crown was observed in G2, but mesial movement was observed in G1. Mesial tipping of the first molar (1.82 ± 6.76°) was seen in G1 and distal tipping (4.44 ± 3.77°) was observed in G2. For the canines, mesial crown tipping (0.33 ± 4.99°) was noted in G1 and distal crown tipping (8.00 ± 5.57°) was observed in G2. In adults, the lingual inclinations of the lateral and central incisors were 11.91 ± 7.01° and 11.47 ± 6.70°, with 0.99 ± 1.22 mm and 1.08 ± 1.20 mm root retraction, respectively. In adolescents, the torque changes were smaller (lateral incisors, 8.25 ± 10.15°; central incisors, 9.82 ± 8.97°) and the root retractions were 0.31 ± 1.81 mm and 0.77 ± 1.59 mm, respectively. Less shortening of the central incisor roots occurred in adolescents than in adults. CONCLUSIONS: Tooth movements, such as anchor molar angular change, the canine tipping pattern, and the amount of incisor retraction, differed between adolescents and adults treated using the same anchorage with mini-screw implants, bracket prescription, and en masse retraction method. Anchorage strength of the first molars, canine movement patterns, and incisor retraction ranges are not determined by the anchorage device alone; growth and alveolar limitations also play roles.

Preparation and evaluation of tert-leucine derivative functionalized polymeric monoliths for micro-liquid chromatography.

In this study, a novel functional monomer N-[1-(α-naphthyl)ethylaminocarbonyl]-D-tert-leucine-[2-(methacryloyloxy)ethyl] amide (NA-D-tert-Leu-MA) was synthesized, and then employed to prepare polymeric monoliths (240 mm × 100 µm id) functionalized with tert-leucine derivative through a single step thermo-initiated co-polymerization approach or a multi-step post-modification approach. The multi-step approach involves the post-modification of a thiol-containing monolith with NA-D-tert-Leu-MA via "thiol-ene"click reaction. The physicochemical properties of the resulting monoliths were characterized by scanning electron microscopy, energy-dispersive X-ray spectrometry and micro-liquid chromatography. Good column stability, permeability, efficiency and reproducibility were obtained for the optimized monoliths. The poly (NA-D-tert-Leu-MA-co-ethylene dimethacrylate) monolith prepared through the single step co-polymerization approach exhibited satisfactory achiral separation performance for various analytes, including phenols, aniline derivatives and intact proteins, while its enantioseparation ability is rather poor. In contrast to that, the monolith prepared through the multi-step post-modification approach showed much higher enantioselectivity for 7-nitro-2,1,3-benzoxadiazole (NBD)-derivatized amino acids. Three NBD-derivatized amino acids (theanine, proline and norleucine) could be baseline enantioseparated.

Genome-wide characterization and expression analysis enables identification of abiotic stress-responsive MYB transcription factors in cassava (Manihot esculenta).

The myeloblastosis (MYB) transcription factor superfamily is the largest transcription factor family in plants, playing different roles during stress response. However, abiotic stress-responsive MYB transcription factors have not been systematically studied in cassava (Manihot esculenta), an important tropical tuber root crop. In this study, we used a genome-wide transcriptome analysis to predict 299 putative MeMYB genes in the cassava genome. Under drought and cold stresses, many MeMYB genes exhibited different expression patterns in cassava leaves, indicating that these genes might play a role in abiotic stress responses. We found that several stress-responsive MeMYB genes responded to abscisic acid (ABA) in cassava leaves. We characterize four MeMYBs, namely MeMYB1, MeMYB2, MeMYB4, and MeMYB9, as R2R3-MYB transcription factors. Furthermore, RNAi-driven repression of MeMYB2 resulted in drought and cold tolerance in transgenic cassava. Gene expression assays in wild-type and MeMYB2-RNAi cassava plants revealed that MeMYB2 may affect other MeMYBs as well as MeWRKYs under drought and cold stress, suggesting crosstalk between MYB and WRKY family genes under stress conditions in cassava.

Fecal microbiota transplantation induces remission of infantile allergic colitis through gut microbiota re-establishment.

AIM: To investigate the impact of fecal microbiota transplantation (FMT) treatment on allergic colitis (AC) and gut microbiota (GM). METHODS: We selected a total of 19 AC infants, who suffered from severe diarrhea/hematochezia, did not relieve completely after routine therapy or cannot adhere to the therapy, and were free from organ congenital malformations and other contraindications for FMT. Qualified donor-derived stools were collected and injected to the AC infants via a rectal tube. Clinical outcomes and follow-up observations were noted. Stools were collected from ten AC infants before and after FMT, and GM composition was assessed for infants and donors using 16S rDNA sequencing analysis. RESULTS: After FMT treatment, AC symptoms in 17 infants were relieved within 2 d, and no relapse was observed in the next 15 mo. Clinical improvement was also detected in the other two AC infants who were lost to follow-up. During follow-up, one AC infant suffered from mild eczema and recovered shortly after hormone therapy. Based on the 16S rDNA analysis in ten AC infants, most of them (n = 6) had greater GM diversity after FMT. As a result, Proteobacteria decreased (n = 6) and Firmicutes increased (n = 10) in post-FMT AC infants. Moreover, Firmicutes accounted for the greatest proportion of GM in the patients. At the genus level, Bacteroides (n = 6), Escherichia (n = 8), and Lactobacillus (n = 4) were enriched in some AC infants after FMT treatment, but the relative abundances of Clostridium (n = 5), Veillonella (n = 7), Streptococcus (n = 6), and Klebsiella (n = 8) decreased dramatically. CONCLUSION: FMT is a safe and effective method for treating pediatric patients with AC and restoring GM balance.

Chiral separation of acidic compounds using an O-9-(tert-butylcarbamoyl)quinidine functionalized monolith in micro-liquid chromatography.

An O-9-(tert-butylcarbamoyl) quinidine (t-BuCQD) functionalized polymeric monolithic capillary column was prepared by the in situ copolymerization method. The physicochemical properties of the optimized monolithic column were characterized by scanning electron microscopy and micro-LC. Satisfactory column permeability, efficiency, stability and reproducibility were obtained for this monolithic column. The chiral recognition ability of the resulting monolith was also evaluated using 47 N-derivatized amino acids, eight N-derivatized dipeptides, and two herbicides. Under the selected conditions, the enantiomers of all chiral analytes were baseline separated with exceptionally high selectivity and resolution using micro-LC. It is worth noting that this chiral stationary phase (CSP) containing quinidine with a tert-butyl carbamate residue as chiral selector exhibits much higher enantioselectivity and diastereoselectivity than the previously developed O-9-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine (MQD) based CSP for N-derivatized amino acids and dipeptides. These results indicate that this novel quinidine-based polymeric monolith can be used as an effective tool for the enantioseparation of chiral acidic compounds.

Enantioseparation of N-derivatized amino acids by micro-liquid chromatography/laser induced fluorescence detection using quinidine-based monolithic columns.

A novel carbamoylated quinidine based monolith, namely poly(O-9-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine-co-ethylene dimethacrylate (poly(MQD-co-EDMA)), was prepared for the micro-LC enantioseparation of N-derivatized amino acids. The influence of the mobile phase composition, including the organic modifier proportion, the apparent pH and the buffer concentration, on the enantioresolution of N-derivatized amino acids was systematically investigated. Satisfactory column performance in terms of permeability, efficiency and reproducibility was obtained in most cases. The majority of the enantiomers of the tested N-protected amino acids, including 3,5-DNB, 3,5-DClB, FMOC, 3,5-DMB, p-NB, m-ClB, p-ClB and B derivatives, could be baseline separated on the poly(MQD-co-EDMA) monolithic column within 25min. A self-assembled laser induced fluorescence (LIF) detector was employed to improve sensitivity when analyzing 7-nitro-2,1,3-benzoxadiazole (NBD) derivatives of amino acids. Ten NBD-derivatized amino acids, including arginine and histidine whose enantioseparation on quinidine carbamate based CSPs has not been reported so far, were enantioresolved on the poly(MQD-co-EDMA) monolith column. It is worth noting that the d-enantiomers of NBD-derivatized amino acids eluted first, except in the case of glutamic acid. The LOD values obtained with the LIF detector were comparable to those reported using conventional LC-FL methods. The prepared poly(MQD-co-EDMA) monolithic column coupled with the LIF detector opens up interesting perspectives to the determination of trace D-amino acids in biological samples.

Transcriptome analysis reveals crosstalk of responsive genes to multiple abiotic stresses in cotton (Gossypium hirsutum L.).

Abiotic stress is a major environmental factor that limits cotton growth and yield, moreover, this problem has become more and more serious recently, as multiple stresses often occur simultaneously due to the global climate change and environmental pollution. In this study, we sought to identify genes involved in diverse stresses including abscisic acid (ABA), cold, drought, salinity and alkalinity by comparative microarray analysis. Our result showed that 5790, 3067, 5608, 778 and 6148 transcripts, were differentially expressed in cotton seedlings under treatment of ABA (1 µM ABA), cold (4°C), drought (200 mM mannitol), salinity (200 mM NaCl) and alkalinity (pH=11) respectively. Among the induced or suppressed genes, 126 transcripts were shared by all of the five kinds of abiotic stresses, with 64 up-regulated and 62 down-regulated. These common members are grouped as stress signal transduction, transcription factors (TFs), stress response/defense proteins, metabolism, transport facilitation, as well as cell wall/structure, according to the function annotation. We also noticed that large proportion of significant differentially expressed genes specifically regulated in response to different stress. Nine of the common transcripts of multiple stresses were selected for further validation with quantitative real time RT-PCR (qRT-PCR). Furthermore, several well characterized TF families, for example, WRKY, MYB, NAC, AP2/ERF and zinc finger were shown to be involved in different stresses. As an original report using comparative microarray to analyze transcriptome of cotton under five abiotic stresses, valuable information about functional genes and related pathways of anti-stress, and/or stress tolerance in cotton seedlings was unveiled in our result. Besides this, some important common factors were focused for detailed identification and characterization. According to our analysis, it suggested that there was crosstalk of responsive genes or pathways to multiple abiotic or even biotic stresses, in cotton. These candidate genes will be worthy of functional study under diverse stresses.

Isolation of AtNUDT5 gene promoter and characterization of its activity in transgenic Arabidopsis thaliana.

AtNUDT5 is a cytosol Nudix that catalyzes the hydrolysis of a variety of substrates. In this report, a 1,387-bp 5'-flanking region of the AtNUDT5 gene was isolated from Arabidopsis thaliana. The tissue-specific activity of the 5'-flanking region was investigated by using the GUS gene as a reporter in transgenic A. thaliana plants. Weak GUS activity appeared in vascular tissues of young plants, strong GUS activity appeared in the axial roots, but no GUS activity was observed in the root cap, lateral roots, rosette leaf, mature silique and reproductive tissues such as stamen, pistil, and petal. Furthermore, by using these transgenic A. thaliana plants, results of the histochemical staining and fluorometric assays of GUS activity showed that the AtNUDT5 promoter can be activated by both avirulent Pst avrRpm1 and virulent Pst strains at 5 h post-infiltration and that the activity of AtNUDT5 promoter increased significantly at 24 h post-infiltration. Taken together, our results demonstrated that the AtNUDT5 promoter is pathogen-responsive. The promoter may be used to develop transgenic plants with an increased tolerance to pathogenic stresses.