Genomic insights into the modifications of spike morphology traits during wheat breeding.

Over the past century, environmental changes have significantly impacted wheat spike morphology, crucial for adaptation and grain yield. However, the changes in wheat spike modifications during this period remain largely unknown. This study examines 16 spike morphology traits in 830 accessions released from 1900 to 2020. It finds that spike weight, grain number per spike (GN), and thousand kernel weight have significantly increased, while spike length has no significant change. The increase in fertile spikelets is due to fewer degenerated spikelets, resulting in a higher GN. Genome-wide association studies identified 49,994 significant SNPs, grouped into 293 genomic regions. The accumulation of favorable alleles in these genomic regions indicates the genetic basis for modification in spike morphology traits. Genetic network analysis of these genomic regions reveals the genetic basis for phenotypic correlations among spike morphology traits. The haplotypes of the identified genomic regions display obvious geographical differentiation in global accessions and environmental adaptation over the past 120 years. In summary, we reveal the genetic basis of adaptive evolution and the interactions of spike morphology, offering valuable resources for the genetic improvement of spike morphology to enhance environmental adaptation.

Targeted long-term noninvasive treatment of choroidal neovascularization by biodegradable nanoparticles.

Choroidal neovascularization (CNV) is the main cause of vision loss in patients with wet age-related macular degeneration (AMD). Currently, treatment of these conditions requires repeated intravitreal injections, which may lead to complications such as infection and hemorrhage. So, we have developed a noninvasive method for treating CNV with nanoparticles, namely, Angiopoietin1-anti CD105-PLGA nanoparticles (AAP NPs), which targets the CNV to enhance drug accumulation at the site. These nanoparticles, with PLGA as a carrier, can slowly release encapsulated Angiopoietin 1 (Ang 1) and target the choroidal neovascularization marker CD105 to enhance drug accumulation, increases vascular endothelial cadherin (VE-cadherin) expression between vascular endothelial cells, effectively reduce neovascularization leakage and inhibit Angiopoietin 2(Ang 2) secretion by endothelial cells. In a rat model of laser-induced CNV, intravenous injection of AAP NPs exerted a good therapeutic effect in reducing CNV leakage and area. In short, these synthetic AAP NPs provide an effective alternative treatment for AMD and meet the urgent need for noninvasive treatment in neovascular ophthalmopathy. STATEMENT OF SIGNIFICANCE: This work describes the synthesis, injection-mediated delivery, in vitro and in vivo efficacy of targeted nanoparticles with encapsulated Ang1; via these nanoparticles, the drug can be targeted to choroidal neovascularization lesions for continuous treatment. The release of Ang1 can effectively reduce neovascularization leakage, maintain vascular stability, and inhibit Ang2 secretion and inflammation. This study provides a new approach for the treatment of wet age-related macular degeneration.

5Apal, Taql, Fokl, and Bsml polymorphisms and the susceptibility of Behcet's disease: an updated meta-analysis.

OBJECTIVE: The aim of this study was to investigate whether the gene polymorphisms of vitamin D receptor (VDR) had a genetic effect on the susceptibility of Behcet's disease (BD). MATERIAL AND METHODS: We conducted a meta-analysis emphasizing the association between the VDR gene polymorphisms and the risk of BD. The strength of the association in five genetic models was assessed by pooled odds ratios (OR) with a corresponding 95%confidence interval (CI). RESULTS: A total of seven independent comparisons with 478 cases and 666 healthy controls were included in this meta-analysis. The overall results suggested that a significant association between ApaI polymorphism and BD risk was found in allele comparison, recessive model, and homozygote model among total populations. Subgroup analysis indicated that a significant association of ApaI polymorphism in the development of BD existed under the allelic model among Africans, while for Caucasians, a similar link was identified in the recessive model and homozygote model. Regarding Bsml polymorphism, an obvious relationship was detected to be significant in allele comparison and recessive model in the Caucasian population. Interestingly, the Fokl variant decreased the risk of BD in Africans under five genetic models, while it increased the risk in Caucasians across the recessive model and homozygote model. CONCLUSION: The results of this meta-analysis provide evidence of the link between the four widely studied polymorphisms in the VDR gene and BD, indicating a robust estimate of the genetic risk.

Two-Week Central Macular Thickness Reduction Rate >37% Predicts the Long-Term Efficacy of Anti-vascular Endothelial Growth Factor Treatment for Macular Edema Secondary to Retinal Vein Occlusion.

Objective: To determine if the early response assessments can predict the long-term efficacy of anti-vascular endothelial growth factor (VEGF) treatment for macular edema secondary to retinal vein occlusion (RVO-ME). Methods: A retrospective study of patients with diagnosis of RVO-ME and intravitreal anti-VEGF treatment was conducted. Clinical characteristics including age, gender, disease subtype and disease duration were recorded at baseline. The best corrected visual acuity (BCVA and logMAR), intraocular pressure (IOP), and central macular thickness (CMT) were recorded at baseline, 2 weeks, and every month (months 1-6) after injection. Further, we compared the early response assessments between the cured group (6-month CMT ≤ 250 µm) and the uncured group (6-month CMT > 250 µm). Results: A total of 164 eyes in 164 patients (77 male and 87 female) were included. At each post-injection time point, both BCVA and CMT are significantly decreased from baseline (all P < 0.001). Spearman's test showed that 2-week CMT reduction rate after the first injection was negatively correlated with BCVA at 6 months (r = -0.359, P < 0.001). Compared with the uncured group (47 cases), the cured group (117 cases) was younger (59.53 ± 11.68 vs. 65.19 ± 13.10 years old, P < 0.01), had more BRVO patients (76.1% vs. 44.7%, P < 0.01), a shorter disease duration (1.92 ± 2.43 vs. 5.05 ± 4.32 months, P < 0.01), lower baseline CMT (527.09 ± 154.95 vs. 768.96 ± 287.75 µm, P < 0.01), and lower baseline BCVA (0.86 ± 0.44 vs. 1.31 ± 0.51, P < 0.01). At each post-injection time point, the cured group had lower CMT and BCVA values when compared to the uncured group (all P < 0.01), and the 2-week CMT reduction rate was identified as the earliest response time to predict the long-term treatment efficacy. Moreover, ROC curve analysis indicated that a 2-week CMT reduction rate >37% yielded the best cut-off point for predicting the long-term cure of anti-VEGF treatment at 6 months (P < 0.001). Multivariable logistic regression confirmed that the 2-week CMT reduction rate >37% was independently associated with the 6-month cured rate (OR = 9.639, 95% Cl = 1.030-90.227, P = 0.047). Conclusion: Age, disease duration, baseline CMT, and baseline BCVA are associated with visual outcomes at 6-month of anti-VEGF treatment for RVO-ME. The "2-week CMT reduction rate >37%" after the first injection is an independent factor to predict better long-term outcomes.

Case report: An intraretinal macrocyst with crystalline content and retinal detachment.

Introduction: An intraretinal macrocyst is a cavity located in the outer plexiform layer of the retina. It is commonly filled with liquid or blood. To date, few case reports of intraretinal macrocysts with crystalline content and retinal detachment have been published. Case presentation: A 44-year-old woman with no history of other diseases complained of decreased vision in her right eye that had persisted for 20 days. The best corrected visual acuity of the right eye was hand motion. Comprehensive ophthalmic examinations were performed, including a vision test, slit lamp fundus examination, ocular B-scan ultrasound, and orbital magnetic resonance imaging. We performed vitrectomy and retinotomy to sufficiently remove the macrocyst and relieve retinal traction. We then reattached the retina and filled it with silicone oil. During the surgery, we found that the cyst had crystalline content, which has not been previously reported, to the best of our knowledge. Finally, the pathological results confirmed a final diagnosis of intraretinal macrocyst. Six months later, we performed a second operation to remove the silicone oil and implant an intraocular lens. After both surgeries, the best corrected visual acuity of the patient's right eye was restored to 20/200, and the retina had repositioned. Conclusion: Intraretinal macrocysts are very rare. Both orbital magnetic resonance imaging and ocular B-scan ultrasound are essential for their diagnosis. Our results indicated that vitrectomy was the best way to remove the cyst and reattach the retina.

rs10490924 surrounding HTRA1/ARMS2 regulates the susceptibility of age-related macular degeneration.

Multiple studies have assessed the contribution of rs10490924 on chromosome 10q26 surrounding HTRA1/ARMS2 gene to age-related macular degeneration (AMD) risk. However, the causal allele at this locus is still inconclusive. In this meta-analysis, we systematically characterized the potential association between rs10490924 polymorphism and AMD risk. Data available from 12 case-control studies, including a total of 5244 cases and 2755 controls in three different ethnic populations, were used to evaluate the correlation between rs10490924 G/T polymorphism (Ala69Ser) and AMD risk. In overall populations, the results indicated the Ala69Ser polymorphism was significantly associated with AMD under allelic (OR = 0.35, 95% CI = 0.30-0.40), homozygous (OR = 0.12, 95%CI = 0.09-0.17), dominant (OR = 0.18, 95%CI = 0.14-0.24), recessive (OR = 0.33, 95%CI = 0.28-0.39), and heterozygous genetic models (OR = 0.26, 95% CI = 0.21-0.33). Similar results were observed in subgroup analysis. This meta-analysis suggests that rs10490924 (Ala69Ser) polymorphism was significantly associated with the susceptibility of AMD in all ethnicities, Ala69 carriers are resistant to AMD risk.

Xianglian Pill ameliorates antibiotic-associated diarrhea by restoring intestinal microbiota and attenuating mucosal damage.

ETHNOPHARMACOLOGICAL RELEVANCE: Xianglian Pill (XLP), a traditional Chinese pharmaceutical preparation for the treatment of gastrointestinal disease, possessing anti-inflammatory, anti-microbial and analgesic activities, may represent a promising candidate for the treatment of antibiotic-associated diarrhea (AAD). AIM OF THE STUDY: This study aimed to unravel the underlying mechanism of XLP on the amelioration of AAD. MATERIALS AND METHODS: AAD was induced by intragastric administration of a mixture of cefuroxime and levofoxacin (300 mg/kg. bw + 200 mg/kg. bw) for five consecutive days. Then AAD mice were treated with XLP at the dose of 500, 1000 and 2000 mg/kg. bw, respectively for 5 days. The physical manifestations, diarrhea status were monitored during the drug delivery. Histopathology of colon, intestinal microbiota, inflammatory cytokines, tight junction protein and short chain fat acids (SCFAs) were determined. RESULTS: Mice received cefuroxime and levofoxacin for 5 days developed medium to severe diarrhea. XLP treatment, however, mitigated the diarrhea status. Further evaluation revealed that XLP promoted the recovery of mucosa, maintained the integrity of tight junction, attenuated the inflammatory disorders, restored intestinal microbiota and increased SCFAs level in feces. CONCLUSION: XLP ameliorates AAD by restoring intestinal microbiota and attenuating mucosal damage.

The prevalence and causes of visual impairment among ethnic Tujia adults in a rural community in China.

We aimed to investigate the prevalence and causes of visual impairment (VI) in an elderly Tujia ethnic rural population in Southwest China.From June 1 to December 31, 2018, a random cluster sampling survey was conducted among Tujia individuals aged 50 years or older in the rural areas of Qianjiang District County in Chongqing. The sampling design used village-based clusters of approximately equal size (1000 people). The sampling frame was composed of 110 clusters including 26,527 adults aged 50 years or older; 10 clusters (2556 adults) were randomly selected, and 2122 subjects were examined. Ophthalmologic examinations and questionnaires were administered to all the participants. Low vision and blindness were defined using best-corrected visual acuity (BCVA) and presenting visual acuity, according to The World Health Organization standard. The prevalence of VI was estimated, and causes of VI were identified.The participation rate was 83.0%. The prevalence of VI was 15.2% (BCVA 8.0%). In the study population, the prevalence of low vision and blindness increased with age (P < .05) and was higher among those with a low education level (P < .01). The majority of VI was attributed to cataracts (50.0%) and uncorrected refractive error (35.7%). With BCVA, cataract (79.3%) was the most common cause of VI, followed by age-related macular degeneration (10.7%).The main causes of VI in Tujia ethnic were cataracts and refractive errors. Both cataracts and refractive errors are curable eye diseases; thus, local health institutions need to adopt a more active eye care project as a strategy to prevent blindness.

Inhibitory Effect of Slit2-N on VEGF165-induced proliferation of vascular endothelia via Slit2-N-Robo4-Akt pathway in choroidal neovascularization.

Researches have been focusing on the role of Slit2 in angiogenesis, specifically in cell migration and vessel permeability. Nevertheless, the role of Slit2-N, the bioactive fragment of Slit2, in the proliferation of vascular endothelia in choroidal neovascularization and some related mechanisms have not been studied yet. Thus, our study aimed to explore the role of Slit2-N in proliferation of vascular endothelia and the related mechanisms in choroidal neovascularization. Fluorescein isothiocyanate perfusion and HE staining were performed to evaluate volumes of choroidal neovascularization lesions. The effect of Slit2-N on VEGF165-induced cell proliferation and some related mechanisms were detected by CCK8 assay, flow cytometry, siRNA transfection, and western blotting. We found that Slit2-N reduced volumes of laser-induced choroidal neovascularization networks in vivo. Results of the in vitro study showed Slit2-N reduced VEGF165-induced cell proliferation of both human umbilical vascular endothelial cells and human microvascular endothelial cells possibly via activation of AKT rather than that of ERK1/2. Additionally, Robo4, one of the receptors binding to Slit2-N, was involved in the inhibitory effect of Slit2-N. Generally, our findings revealed the inhibitory role of Slit2-N in proliferation of vascular endothelia and some related mechanisms, and presented some potential targets, molecules along Slit2-N-Robo4-AKT axis, to choroidal neovascularization therapy.

Chitosan inhibits inflammation and adipogenesis of orbital fibroblasts in Graves ophthalmopathy.

Purpose: The aim of this study was to investigate the roles of chitosan in inflammation and adipogenesis of primary cultured orbital fibroblasts in Graves ophthalmopathy (GO). Methods: Cell viability, apoptosis, and cell cycle were determined with the Cell Counting Kit-8 (CCK-8), the Annexin V-FITC/PI kit, and flow cytometry, respectively. Inflammation of orbital fibroblasts was stimulated by interleukin-1 beta (IL-1ß). The levels of IL-6 and prostaglandin E-2 (PGE-2) were measured using an enzyme-linked immunosorbent assay (ELISA). The expression of cyclooxygenase-2 (COX-2) was measured with real-time PCR and western blot assay. Phosphorylation of c-Jun N-terminal kinase (JNK) was evaluated with western blot assay. An inhibitor of JNK was used to investigate the signal transduction pathway of cytokine production. Orbital fibroblasts differentiated to adipose cells in differentiation medium. Adipose cells were dyed with Oil Red O. FABP4, adiponectin, C/EBPα, PPAR-γ, and phosphorylation of AKT were evaluated with western blot assay. Results: The results showed that IL-1ß statistically significantly increased the expression of IL-6, PGE-2, and COX-2 in orbital fibroblasts. Phosphorylation of JNK was promoted by IL-1ß. IL-6 and PGE-2 were modulated by the JNK signaling pathway as determined with the inhibition experiments. Chitosan downregulated expression of IL-1ß-stimulated IL-6, COX-2, and PGE-2 and downregulated phosphorylation of JNK. Chitosan inhibited the production of adipose cells dyed by Oil Red O. Chitosan statistically significantly decreased the protein levels of FABP4, adiponectin, C/EBPα, and PPAR-γ with downregulation of AKT phosphorylation during adipocyte differentiation. Conclusions: Chitosan statistically significantly inhibits inflammation and adipogenesis, as well as related signaling pathways, of orbital fibroblasts in GO. This indicates a possible therapeutic effect of chitosan on Graves ophthalmopathy.

Inhibiting adhesion events by Panax notoginseng saponins and Ginsenoside Rb1 protecting arteries via activation of Nrf2 and suppression of p38 - VCAM-1 signal pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Asian countries, such as China, Japan, and Korea, have witnessed a history of more than 1000 years of Panax notoginseng (Burk.) F.H. Chen's application as a famous traditional medicine for cardiovascular diseases (Zhou et al., 2004). The use of Panax notoginseng (Sanqi) was first recorded in "Bencao Gangmu", which was written by Li Shizhen, a Chinese pharmacologist of the MING dynasty, in 1578. It is included in "The Plant List" as one species of genus Panax (family Araliaceae). Panax notoginseng saponins (PNS) are the major active ingredients extracted from Panax notoginseng. AIM OF THE STUDY: This study investigated whether PNS and the active constituent Ginsenoside Rb1 inhibits adhesion events by regulating the NF-E2-related factor 2 (Nrf2) - p38 - vascular cell adhesion molecule (VCAM)-1 pathway. MATERIALS AND METHODS: The AS model rats were treated once daily with PNS (100mg/kg, i.p.) or Rb1 (40mg/kg, i.p.), and pathological changes in the aortas were observed by electron microscopy and Sudan IV staining. The serum levels of NO, superoxide dismutase (SOD) and TNF-α were measured. Upon treatment with H2O2 to induce oxidative stress, cell viability and LDH levels were measured after cells were cultured with PNS or Rb1. oxidized low density lipoprotein (oxLDL)-induced VCAM-1 and p38 protein expression and THP1 cell adhesion to ECs were assessed after treatment with PNS or Rb1. Nuclear translocation of Nrf2 and expression of its target protein heme oxygenase (HO)-1 were observed in the respective presence of PNS or Rb1. RESULTS: Upon treatment with PNS or Rb1, pathological changes observed in the aortas of AS model rats were alleviated, and an increase in serum levels of NO and SOD and a decrease in TNF-α levels were observed. In vitro treatment with PNS or Rb1 protected endothelial cells (ECs) from H2O2-mediated cytotoxicity, suppressed oxLDL-induced p38 and VCAM-1 protein expression and inhibited THP1 cell adhesion to ECs. Finally, PNS and Rb1 treatment functionally activated Nrf2 in ECs. CONCLUSIONS: Nrf2, an EC protective system, suppresses monocyte adhesion events via the inhibition of the ROS - TNF-α - p38 - VCAM-1 pathway following treatment with PNS, with Rb1 specifically playing an important role among PNS active components.

MicroRNA-29 regulates high-glucose-induced apoptosis in human retinal pigment epithelial cells through PTEN.

Hyperglycemia or high-glucose (HG)-induced apoptosis in human retinal pigment epithelial (RPE) cells is a characteristic process in diabetic retinopathy. In our study, we examined whether microRNA-29 (miR-29) may regulate HG-induced RPE cell apoptosis. Human RPE cell line, ARPE-19 cells, was treated with various high concentration of glucose in vitro. HG-induced RPE cell apoptosis was examined by terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL) assay and miR-29 gene expression by quantitative RT-PCR (qRT-PCR). miR-29 was then downregulated in RPE cells, and its effect on HG-induced apoptosis was examined by TUNEL assay and western blot assay on caspase-7 protein. Association of miR-29 on its downstream target, PTEN, in HG-induced RPE cell apoptosis was evaluated by dual-luciferase assay and qRT-PCR. PTEN was silenced in RPE cells. The effects of PTEN downregulation on miR-29-mediated HG-induced RPE cell apoptosis were also examined by TUNEL and western blot assays. HG induced significant apoptosis in RPE cells in a dose-dependent manner. miR-29 was upregulated by HG in RPE cells. miR-29 downregulation protected HG-induced apoptosis and reduced the production of caspase-7 protein in RPE cells. PTEN was shown to be directly downregulated by HG and then upregulated by miR-29 downregulation in RPE cells. Small interfering RNA (siRNA)-mediated PTEN downregulation reversed the protective effect of miR-29 downregulation on HG-induced RPE cell apoptosis. This study demonstrates that miR-29, through inverse association of PTEN, plays an important role in the process of HG-induced apoptosis in RPE cells.

Panax notoginseng saponins attenuate atherosclerosis via reciprocal regulation of lipid metabolism and inflammation by inducing liver X receptor alpha expression.

ETHNOPHARMACOLOGICAL RELEVANCE: Panax notoginseng (Burk.) F.H. Chen has been used as a health product and natural remedy in traditional medicine for cardiovascular diseases for more than 1000 years in Asia, including China, Japan, and Korea. Panax notoginseng saponins (PNS) are the major effective ingredients extracted from Panax notoginseng. AIM OF THE STUDY: The purpose of this study was to investigate whether Panax notoginseng saponins (PNS) attenuated atherosclerosis by inducing liver X receptor alpha (LXRα) expression and to elucidate the mechanisms responsible for the effects. MATERIALS AND METHODS: The AS rats were treated once daily with PNS (100 mg/kg, i.p.), and pathological changes in the aorta were observed using Sudan IV staining. The expression of LXRα in the aortic wall was measured by Western blot analysis. THP-1 macrophages were cultured with PNS in the presence or absence of geranylgeranyl pyrophosphate ammonium salt (GGPP), an LXRα antagonist. The expression of LXRα and its target genes ATP-binding cassette A1 and G1 (ABCA1, ABCG1) were determined by qRT-PCR. The transcriptional activation of the LXRα gene promoter was analyzed by a reporter assay. The NF-κB DNA binding activity and the expression of interleukin (IL)-6, monocyte chemotactic protein-1 (MCP-1) was evaluated respectively by Trans-AM NF-κB ELISA and ELISA in THP-1 macrophages that were stimulated with LPS after treatment with PNS and GGPP. RESULTS: PNS treatment alleviated the typical pathological changes associated with atherosclerosis in rats. The expression of LXRα was increased in rat aortas after treatment with PNS. In vitro, PNS increased LXRα mRNA levels in THP-1 macrophages. The reporter assays showed that PNS enhanced transcriptional activation of the LXRα gene promoter and led to the upregulation of ABCA1 and ABCG1 expression. This upregulation could be reversed by treatment with GGPP. Additionally, PNS inhibited NF-κB DNA binding activity and reduced secretion of IL-6 and MCP-1 in LPS-stimulated THP-1 macrophages. These effects could be reversed by GGPP. CONCLUSIONS: The results indicated that the PNS-mediated attenuation of AS may, at least partly, due to LXRα uprergulation. The mechanisms of action included enhancement transcriptional activation of the LXRα gene promoter by PNS and subsequent upregulation of ABCA1 and ABCG1 and inhibition of NF-κB DNA binding activity.

Characterization of tyrosine kinase and screening enzyme inhibitor by capillary electrophoresis with laser-induced fluoresce detector.

An effective, rapid and reliable capillary electrophoresis-laser induced fluorescence (CE-LIF) procedure was built to study the characterization of tyrosine kinase (TK), which was a target for drug screening. In this procedure, CE separated the sample of the TK reaction and LIF selectively detected the fluorescence-labeled polypeptide substrate and product. The precise TK activity was quantitated by introducing the transformation ratio of the substrate (T%) to avoid the deviation resulted from the detection sensitivity and the injection amounts in different runs and different capillaries. By measuring the T%, the effects of various reaction conditions were optimized. Meanwhile, the progression of the enzyme reaction was monitored. The K(m) and V(max) were calculated for TK under the optimized experimental conditions. In addition, the inhibition effectiveness of two model inhibitors, Staurosporine and SU6656 were evaluated. The results indicated that the screening platform based on electrophoresis was suitable for TK analysis and laid a foundation for the HTS of TK inhibitors.

Zone electrophoresis in an inner-cooling wide-bore electrophoresis system with UV detection.

A novel, high-performance wide-bore electrophoresis (WE) system with inner-cooling has been developed. By introducing the mode of a shell and tube heat exchanger into this system to remove Joule heat generated during electrophoresis, it is feasible to extend electrophoresis from the conventional capillary (i.d. <100 microm) to a wide-bore tube (i.d. >1000 microm). The wide tube allows the loading of over 1.0 microL of the sample with an LOD of 3.0 x 10(-4) mg/mL (signal-to-noise ratio, 3:1). Satisfactory separations of model compounds have been achieved on the WE system.

Capillary electrophoresis with laser-induced fluorescence detection as a tool for enzyme characterization and inhibitor screening.

An effective, rapid and economical CE/LIF (capillary electrophoresis/laser-induced fluorescence) method was developed and applied to the characterization of signal peptidase (SPase) enzyme, which is a target for the screening of new drug candidates. In this method, CE separates the product from the substrate and LIF selectively detects the fluorescence-labeled product and substrate. By measuring the increase of the product as a function of time, one can monitor the progression of the enzyme reaction. The progression curves were also used for screening inhibitors for this enzyme. The effects of various reaction conditions were also studied and discussed. In addition, this CE/LIF method was applied to the determination of the enzyme activity, the quality control of the substrate and/or enzymes, and the cross-reactivity of inhibitors to the enzyme. It can be concluded that this method is suitable for high throughput screening (HTS) assays because it can deliver fast, sensitive, quantitative, and reliable results.

Separation of aromatic acids by wide-bore electrophoresis with nanoparticles prepared by electrospray as pseudostationary phase.

A model mixture of six aromatic acids has been separated using a laboratory-made wide-bore electrophoretic device with aminopropyl-modified nanoparticles used as pseudostationary phase. Optimization of preparation of nanoparticles by an electrospray (ES) method is described. With the optimized electrophoretic method, 30 mmol/L acetate running buffer, pH 4.5, containing 1.0 mg/mL of nanoparticles as an additive was used, and 3.0 kV applied potential, improved resolution was achieved. The average theoretical plate number obtained was above 5.0 x 10(4) theoretical plates per meter with the highest value achieved in certain runs exceeding 1.0 x 10(5) theoretical plates per meter, which was better than previously reported results (approximately 6.7 x 10(4) theoretical plates per meter). Furthermore, repeatabilities of 2, 6.5, and 6% were obtained for the migration time, peak areas, and peak height, respectively. Additionally, sample capacity and sensitivity were improved by hundredfold using the novel wide-bore electrophoresis system compared to traditional CE.

Wide-bore monolithic column for electrochromatography.

A new wide-bore electrophoresis (WE) system adopting an inner cooling device was set up to perform electrochromatography. In this system, a quartz tube of 1.2 mm inner diameter was used as the separation channel. The Joule heat generated during electrophoresis was removed timely through the outer surface of the quartz tube and a cooling capillary inserted into the quartz tube. A proper coolant passed through the cooling capillary to further improve the cooling efficiency. In the primary research, a polyacrylamide monolithic column was successfully prepared in this quartz tube. Then it was evaluated in the electrochromatographic mode. An electric field strength as high as 625 V/cm can be applied to this system without obvious deviation of the current from the linear curve of the Ohm plot. Sample volume as high as 1 microL was injected into the WE system and reasonable efficiency was obtained for separation of the test compounds.