Activation of Pyroptosis Using AIEgen-Based sp2 Carbon-Linked Covalent Organic Frameworks.

Covalent organic frameworks (COFs) have emerged as a promising class of crystalline porous materials for cancer phototherapy, due to their exceptional characteristics, including light absorption, biocompatibility, and photostability. However, the aggregation-caused quenching effect and apoptosis resistance often limit their therapeutic efficacy. Herein, we demonstrated for the first time that linking luminogens with aggregation-induced emission effect (AIEgens) into COF networks via vinyl linkages was an effective strategy to construct nonmetallic pyroptosis inducers for boosting antitumor immunity. Mechanistic investigations revealed that the formation of the vinyl linkage in the AIE COF endowed it with not only high brightness but also strong light absorption ability, long lifetime, and high quantum yield to favor the generation of reactive oxygen species for eliciting pyroptosis. In addition, the synergized system of the AIE COF and αPD-1 not only effectively eradicated primary and distant tumors but also inhibited tumor recurrence and metastasis in a bilateral 4T1 tumor model.

Paeoniflorin-6'-O-benzene sulfonate protected the intestinal epithelial barrier by restoring the inhibitory effect of GRK2 and ß-arrestin 2 on ERK1/2-NF-κB.

Peoniflorin-6'-O-benzene sulfonate (CP-25) inhibited the activity of GRK2 to exert anti-inflammatory and immunomodulatory effects. This study aimed to investigate the effect of CP-25 the intestinal epithelial barrier and the mechanism. CaCO-2 cell monolayer and dextran sulfate salt (DSS)-induced colitis mouse model was used to evaluate intestinal epithelial barrier function in vitro and in vivo, respectively. Results showed that CP-25 prevented dysfunction of the intestinal epithelial barrier and inhibited NF-κB p65 activation in TNF-α-induced CaCO-2 cells. The colon structure destroyed in DSS-induced colitis mice was improved by CP-25. CP-25 has a role in inhibition membrane translocation of GRK2-ß-arrestin 2 complex, stabilization of the binding of GRK2 and ß-arrestin 2 to ERK1/2 in cytoplasm. Subsequently down-regulated the nuclear transcription and transactivation of NF-κB p65 via inhibiting its phosphorylation of Ser536, and Ser276, respectively and restored the epithelial barrier function. In conclusion, CP-25 inhibited ERK1/2-NF-κB activation and thereby protected the intestinal epithelial barrier, which was associated with restoring the inhibition of GRK2 and ß-arrestin 2 on ERK1/2.

Comparative analysis of the main medicinal substances and applications of Echium vulgare L. and Echium plantagineum L.: A review.

ETHNOPHARMACOLOGICAL RELEVANCE: Echium vulgare L. and Echium plantagineum L. originated in the Mediterranean, and were later domesticated in Africa, America, Asia, Europe and Oceania, where they were widely used to treat many diseases including cough, urinary tract infection, fever, inflammation and muscle strain. AIM OF THE STUDY: The purpose of this review is to provide scientific literature on the traditional uses, bioactive chemical components and pharmacological activities of two species of Echium, and to critically analyze the information provided, so as to understand the current work on these two species and explore the possible prospect of this plant in pharmaceutical research. METHODS: Systematic review and meta-analysis were conducted according to Prisma guidelines, and the related literatures searched on Google Academic, Science Direct, Baidu Scholars and China National Knowledge Infrastructure (CNKI) up to June 2021 were reviewed. The key words used are: Echium, E.vulgare, E.plantagineum, plant components, chemical components, pharmacological activities, pharmaceutical products and applications. Thereafter all eligible studies are analyzed and summarized in this review. The selection of manuscripts is based on the following inclusion criteria: the article has years of research or publication, is published in English, Portuguese or Spanish and Chinese, and there are keywords in the title, abstract, keywords or full text of the article. For the selection of manuscripts, first, select articles according to titles, then summarize them, and finally, analyze the full text of the publication. Elimination criteria: 1. Duplicate reports; 2. There are research design defects and poor quality; 3. Incomplete data and unclear ending effect; 4. The statistical method is wrong and cannot be corrected. RESULTS: The pharmacological characteristics of E.vulgare and E.plantagineum can basically support their traditional use, but the medicinal substances contained in them are quite different in composition and content, and the development and application of corresponding products are also different. CONCLUSIONS: At present, there is little clinical data about drugs related to the two species, and more research is needed in the future, especially human experiments and clinical trials, to evaluate the cellular and molecular mechanisms based on pharmacological, biological activity and safety studies, and to provide more powerful scientific basis for their traditional medicinal properties. In addition, the further application and development of the medicinal products of E.vulgare and E.plantagineum still need to be precise and identified, so as to give full play to their medicinal potential.

Immediate Effect of Dry Needling at Myofascial Trigger Point on Hand Spasticity in Chronic Post-stroke Patients: A Multicenter Randomized Controlled Trial.

Background: Hand spasticity after stroke influences the rehabilitation of hand function. Immediate and effective relief of spasticity potentially creates conditions for later rehabilitation training, which has far-reaching significance in the smooth transition of patients to the recovery period. Objective: To evaluate the immediate effect of dry needling (DN) at myofascial trigger point on hand spasticity in stroke patients. Methods: This was a prospective, evaluator blind, multicenter, randomized controlled study. A total of 210 participants were randomly divided into DN group (DN, N = 70), sham dry needling group (SDN, N = 70), and control group (N = 70). Participants in the DN group were treated with DN at myofascial trigger point five times (30 min each time) every week for 4 weeks. Subjects in the SDN group were manipulated the same way as in the DN group, except that the acupuncture site was located in the area adjacent to the myofascial trigger point, which constituted a SDN. Routine rehabilitation treatment was performed for participants in the two groups and in the control group. The primary evaluation index was the immediate effect of hand spasticity relief. Secondary evaluation indicators included the cumulative effect of hand spasticity relief from baseline to week 4, and the changes in flexion angles of the wrist, thumb, and fingers 2-5 in the rest position before, immediately after, and 4 weeks after intervention. Results: The immediate effective rate of spasticity relief (thumb, fingers 2-5, and wrist) of patients with different degrees of spasticity in the DN group was higher than that in the control and SDN groups (thumb, χ2 = 55.833, P < 0.001; fingers 2-5, χ2 = 68.096, P < 0.001; wrist, χ2 = 49.180, P < 0.001) (P < 0.05). The effective rate of spasticity relief from baseline to 4 weeks in the DN group exceeded that in the control group and SDN groups (thumb, χ2 = 8.806, P = 0.012; fingers 2-5, χ2 = 8.087, P = 0.018; and wrist, χ2 = 8.653, P = 0.013) (P < 0.05). No difference in immediate and cumulative effect was found between the control group and SDN group. The change of joints flexion angles in resting position before and after each treatment in the DN group was higher than that in the control and SDN groups (P < 0.05), but it was not significantly different between the control group and SDN group. At 4 weeks, although the change in the DN group was higher than that in the control group and SDN group, this difference was not statistically significant (P > 0.05). Conclusion: Dry needling can relieve varying degrees of hand spasticity instantly in post-stroke. Trial Registration: www.chictr.org.cn, ChiCTR1900022379.

Effects of organic acids on the chemotaxis profiles and biocontrol traits of antagonistic bacterial endophytes against root-rot disease in Panax notoginseng.

Understanding the role of chemotaxis in ecological interactions between plants and microbes in the rhizosphere is necessary to optimize biocontrol strategies targeting plant soil-borne diseases. Therefore, we examined and profiled the antagonistic endophytic bacteria (AEB) population with chemotaxis potential in the medicinal plant Panax notoginseng using a cheA gene-based approach coupled with 16S rRNA sequencing. Phylogenetic analysis of the chemotactic AEB (CAEB) community in P. notoginseng enabled the identification of 56 CAEB strains affiliated with 30 species of Actinobacteria, Firmicutes, and Proteobacteria; Firmicutes, especially Bacillus, were predominant. We then systematically quantified the chemotactic response profiles of CAEB toward five organic acid (OA) attractants: citric acid, fumaric acid (FA), malic acid, oxalic acid, and succinic acid. Further hierarchical cluster analysis revealed that the chemotaxis of CAEB to the same attractant exhibited different patterns among not only genera but also species and even strains of the same species. Following chemotaxis and hierarchical analysis, we selected the strongest chemoattractant, fumaric acid (FA), as the target for evaluating the effects of OAs on the representative CAEB strain Bacillus amyloliquefaciens subsp. plantarum YP1. Application of FA significantly stimulated the chemotaxis ability and growth of YP1, and increased the transcript levels of cheA and biocontrol-related genes in YP1. This is the first study to characterise the diversity of chemotaxis profiles toward OAs in natural bacterial assemblages of P. notoginseng and to highlight how FA promotes the biocontrol-related traits of P. notoginseng-associated CAEB.

Effect of the transcription factor YY1 on the development of pancreatic endocrine and exocrine tumors: a narrative review.

Pancreatic tumors are classified into endocrine and exocrine types, and the clinical manifestations in patients are nonspecific. Most patients, especially those with pancreatic ductal adenocarcinoma (PDAC), have lost the opportunity to receive for the best treatment at the time of diagnosis. Although chemotherapy and radiotherapy have shown good therapeutic results in other tumors, their therapeutic effects on pancreatic tumors are minimal. A multifunctional transcription factor, Yin-Yang 1 (YY1) regulates the transcription of a variety of important genes and plays a significant role in diverse tumors. Studies have shown that targeting YY1 can improve the survival time of patients with tumors. In this review, we focused on the mechanism by which YY1 affects the occurrence and development of pancreatic tumors. We found that a YY1 mutation is specific for insulinomas and has a role in driving the degree of malignancy. In addition, changes in the circadian network are a key causative factor of PDAC. YY1 promotes pancreatic clock progression and induces malignant changes, but YY1 seems to act as a tumor suppressor in PDAC and affects many biological behaviors, such as proliferation, migration, apoptosis and metastasis. Our review summarizes the progress in understanding the role of YY1 in pancreatic endocrine and exocrine tumors and provides a reasonable assessment of the potential for therapeutic targeting of YY1 in pancreatic tumors.

Improved 1D convolutional neural network adapted to near-infrared spectroscopy for rapid discrimination of Anoectochilus roxburghii and its counterfeits.

Anoectochilus roxburghii (Wall.) Lindl. (Orchidaceae) is a rare traditional Chinese medicine. For seeking high profit, some traditional Chinese medicine sellers usually adulterated A. roxburghii with Goodyera Schlechtendaliana and Ludisia discolor or directly fake A. roxburghii using Anoectochilus formosanus. These counterfeits with similar appearance greatly influence the prescription efficacy. Therefore, there is an urgent need for an effective and fast authentication method to identify A. roxburghii and its counterfeits. In this paper, the near-infrared spectroscopy (NIRS) data of A. roxburghii and its counterfeits are mearsured. Then, an improved inception architecture based 1-dimensional convolutional neural network (Improved 1D-Inception-CNN) is designed for processing the NIRS data and identifying A. roxburghii and its counterfeits. The Improved 1D-Inception-CNN has less parameters and high calculation efficiency which makes the identification model more practical. The experimental results show that compared with traditional structured CNN models, the complexity of the Improved 1D-Inception-CNN is reduced by 40 %, the parameters are reduced by 50 % and the performances are improved by 1.01 %. Therefore, the Improved 1D-Inception-CNN model based on NIRS technology can effectively and quickly identify A. roxburghii and its counterfeits.

Hemin from porcine blood effectively stabilized color appearance and odor of prepared pork chops upon repeated freeze-thaw cycles.

This study was designed to evaluate changes in color following pork chop supplementation with porcine hemin, astaxanthin and paprika red in response to repeated freeze-thaw processes. Surface color analyses revealed that hemin significantly enhanced the appearance of the pork chops (P < 0.05), and the coloring efficiency of 0.10% hemin was similar to that of 0.20% astaxanthin and 0.08% paprika red. Sensory evaluations conducted on both raw and fried chops showed that hemin and astaxanthin significantly enhanced the overall acceptability of the chops before and after cooking. The color stability of the pork chops was also evaluated, and the results suggested that the hemin-colored chops were the most stable among the three, upon repeated freeze-thaw cycles. The electronic nose showed that the odor of the hemin-colored samples after 0, 3, and 7 freeze-thaw cycles was better than that of the other two groups. In conclusion, hemin may be a superior supplement for the large scale preparation of prepared pork chop.

Long-Term Follow-Up of Spinal Stenosis Inpatients Treated with Integrative Korean Medicine Treatment.

The present prospective observational study aimed to analyze the outcomes of inpatients who received integrative Korean medicine treatment in order to provide evidence on its effects on lumbar spinal stenosis (LSS). Patients with LSS who received inpatient treatment at four Korean medicine hospitals from January 2015 to December 2018 were followed up. Outcomes measured included the numeric rating scale (NRS) scores for back and leg pain, and Oswestry Disability Index (ODI). Changes in outcomes at admission, discharge, and follow-up, as well as associated predictors that could account for the improvement in outcomes were analyzed. The NRS score for back pain, NRS score for leg pain, and ODI decreased by 2.20 points (95% confidence interval (CI), -2.41 to -1.99), 2.28 points (95% CI, -2.59 to -1.96), and 17.31 points (95% CI, -19.6 to -15.02), respectively, at long-term follow-up compared with at admission. Patients with LSS who received inpatient integrative Korean medicine treatment exhibited an improvement in pain and functional disability. Further studies are required to determine the effects of integrative Korean medicine treatment.

Self-Amplified Apoptosis Targeting Nanoplatform for Synergistic Magnetic-Thermal/Chemo Therapy In Vivo.

The low efficiency homing of nanomaterials in tumors remains a major challenge in nanomedicine. Inspired by the apoptosis targeting properties of phosphatidylserine (PS), a self-amplified apoptosis targeting nanoplatform (MNPs-ZnDPA/ß-Lap) is fabricated combining Zn0.4 Co0.6 Fe2 O4 @Zn0.4 Mn0.6 Fe2 O4 nanoparticles (MNPs) with an excellent magnetic hyperthermia effect, a chemotherapeutic drug of ß-lapachone (ß-Lap) with the promotion of cell apoptosis, and the good apoptosis targeting moiety of Zn(II)-bis(dipicolylamine) (bis-ZnDPA) for PS. In an apoptotic 4T1 xenograft model, MNPs-ZnDPA/ß-Lap can first accumulate in tumors by the EPR effect. The released ß-Lap triggers the apoptosis of cancer cells in the tumor and increases the apoptotic target, which results in amplifying their apoptosis targeting properties. This self-amplified apoptosis targeting efficiency of MNPs-ZnDPA/ß-Lap almost inhibits the growth of tumors with the synergistic magnetic-thermal/chemo therapy, which can offer a significant promise for targeting cancer theranostics.

Acupuncture of fascia points to relieve hand spasm after stroke: a study protocol for a multicenter randomized controlled trial.

BACKGROUND: The loss of functional ability of patients after stroke is mostly caused by dysfunction of the upper limbs, especially the hands. Hand functional exercise is the premise of alleviating hand dysfunction, and the relief of hand spasm is the basis of timely and effective hand functional exercise. Previous clinical observation have shown that fascial-point needling can effectively alleviate hand spasm immediately after stroke, but further evidence from large-sample studies is needed. The overall objective of this trial is to further evaluate the clinical efficacy of fascial-point acupuncture on hand spasm after stroke. METHODS/DESIGN: This multicenter randomized controlled trial will compare the efficacy of fascial-point acupuncture versus sham acupuncture and routine rehabilitation therapy in stroke patients with hand spasm. Patients will be randomized to undergo either the fascial-point acupuncture, the sham acupuncture or the control (routine rehabilitation therapy). We will recruit 210 stroke inpatients who meet the trial criteria and observe the remission of hand spasm and improvement of limb function after 4 weeks of intervention. The first evaluation indices are the remission of hand spasm and the duration of spasm remission. The second evaluation indices are the hand function of the affected limbs and the activities of daily living. When the accumulative total number of cases included reaches 120, a mid-term analysis will be conducted to determine any evidence that experimental intervention does have an advantage. DISCUSSION: Our aim is to evaluate the efficacy of fascial-point acupuncture in relieving hand spasm after stroke. The results should provide more evidence for the clinical application of this therapy in the future. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR), ID: ChiCTR1900022379. Registered on 9 April 2019.

[Quantitative analysis method of Shengxuebao Mixture by HPLC-UV-MS based on quality by design concept].

In this study, the HPLC-UV-MS method for the simultaneous determination of eight active ingredients of Shengxuebao Mixture were developed based on the concept of quality by design（QbD）with a stepwise optimization approach. After the analytical target profile（ATP）had been defined, albiflorin, paeoniflorin, 2, 3, 5, 4'-tetra-hydroxy-stilbene-2-O-ß-D-glucopyranoside, specnuezhenide, ecliptasaponin D, emodin, calycosin-7-glucoside, and astragaloside Ⅳ were identified as the indicator components. The resolution and the signal-to-noise ratio of indicator components were then selected as critical method attributes (CMA) for the first step optimization. According to the results collected from fractional factorial design, critical method parameters (CMP) were determined with a multiple linear regression method, which included the amount of acid addition in the mobile phase, temperature, gradient, and wavelength. After that, the amount of acid addition and the wavelength were optimized to improve the resolution and the signal-to-noise ratio of the indicator components. The peak symmetry factors of specnuezhenide and emodin were then set as CMA for the second step optimization. The Box-Behnken designed experiments were conducted. The temperature and gradient were optimized after modelling. The design space were calculated and verified. The optimized analytical method was validated, and the results showed a good precision, accuracy and stability, which means that it can be used for the quantification of the indicator components in Shengxuebao Mixture.

Salinomycin-loaded lipid-polymer nanoparticles with anti-CD20 aptamers selectively suppress human CD20+ melanoma stem cells.

Melanoma is the deadliest type of skin cancer. CD20+ melanoma stem cells (CSCs) are pivotal for metastasis and initiation of melanoma. Therefore, selective elimination of CD20+ melanoma CSCs represents an effective treatment to eradicate melanoma. Salinomycin has emerged as an effective drug toward various CSCs. Due to its poor solubility, its therapeutic efficacy against melanoma CSCs has never been evaluated. In order to target CD20+ melanoma CSCs, we designed salinomycin-loaded lipid-polymer nanoparticles with anti-CD20 aptamers (CD20-SA-NPs). Using a single-step nanoprecipitation method, salinomycin-loaded lipid-polymer nanoparticles (SA-NPs) were prepared, then CD20-SA-NPs were obtained through conjugation of thiolated anti-CD20 aptamers to SA-NPs via a maleimide-thiol reaction. CD20-SA-NPs displayed a small size of 96.3 nm, encapsulation efficiency higher than 60% and sustained drug release ability. The uptake of CD20-SA-NPs by CD20+ melanoma CSCs was significantly higher than that of SA-NPs and salinomycin, leading to greatly enhanced cytotoxic effects in vitro, thus the IC50 values of CD20-SA-NPs were reduced to 5.7 and 2.6 µg/mL in A375 CD+20 cells and WM266-4 CD+ cells, respectively. CD20-SA-NPs showed a selective cytotoxicity toward CD20+ melanoma CSCs, as evidenced by the best therapeutic efficacy in suppressing the formation of tumor spheres and the proportion of CD20+ cells in melanoma cell lines. In mice bearing melanoma xenografts, administration of CD20-SA-NPs (salinomycin 5 mg·kg-1·d-1, iv, for 60 d) showed a superior efficacy in inhibition of melanoma growth compared with SA-NPs and salinomycin. In conclusion, CD20 is a superior target for delivering drugs to melanoma CSCs. CD20-SA-NPs display effective delivery of salinomycin to CD20+ melanoma CSCs and represent a promising treatment for melanoma.

Enhancement of Schizochytrium DHA synthesis by plasma mutagenesis aided with malonic acid and zeocin screening.

Schizochytrium sp. accumulates valuable polyunsaturated fatty acid (PUFA), such as docosahexaenoic acid (DHA). In order to increase DHA synthesis in this microorganism, physical or chemical mutagenesis aided with powerful screening methods are still preferable, as its DHA synthetic pathway has not yet been clearly defined for gene manipulation. To breed this agglomerate microorganism of thick cell wall and rather large genome for increasing lipid content and DHA percentage, a novel strategy of atmospheric and room temperature plasma (ARTP) mutagenesis coupled with stepped malonic acid (MA) and zeocin resistance screening was developed. The final resulted mutant strain mz-17 was selected with 1.8-fold increased DHA production. Accompanied with supplementation of Fe2+ in shake flask cultivation, DHA production of 14.0 g/L on average was achieved. This work suggests that ARTP mutation combined with stepped MA and zeocin resistance screening is an efficient method of breeding Schizochytrium sp. of high DHA production, and might be applied on other microorganisms for obtaining higher desired PUFA products.

Effect of asiaticoside on endothelial cells in hypoxia­induced pulmonary hypertension.

Pulmonary hypertension (PH) is a chronic progre-ssive disease with limited treatment options. The exact etiology and pathogenesis of PH remain to be elucidated, however there is novel evidence that implicates abnormal endothelial cells (ECs) apoptosis and dysfunction of ECs to be involved in the initiation of PH. Asiaticoside (AS) is a saponin monomer extracted from a medicinal plant called Centella asiatica, which had a preventing effect of hypoxia­induced pulmonary hypertension (hypoxic PH) by blocking transforming growth factor­ß1/SMAD family member 2/3 signaling in our previous study. The present study demonstrated that AS can prevent the development of hypoxic PH and reverse the established hypoxic PH. AS may activate the nitric oxide (NO)­mediated signals by enhancing the phosphorylation of serine/threonine­specific protein kinase/eNOS, thus promoting NO production, and prevent ECs from hypoxia­induced apoptosis. All these findings imply that AS may be a potential therapeutic option for hypoxic PH patients due to its effect on the vitality and function of endothelial cells.

Dosing-time contributes to chronotoxicity of clofarabine in mice via means other than pharmacokinetics.

To evaluate the time- and dose-dependent toxicity of clofarabine in mice and to further define the chronotherapy strategy of it in leukemia, we compared the mortality rates, LD50s, biochemical parameters, histological changes and organ indexes of mice treated with clofarabine at various doses and time points. Plasma clofarabine levels and pharmacokinetic parameters were monitored continuously for up to 8 hours after the single intravenous administration of 20 mg/kg at 12:00 noon and 12:00 midnight by high performance liquid chromatography (HPLC)-UV method. Clofarabine toxicity in all groups fluctuated in accordance with circadian rhythms in vivo. The toxicity of clofarabine in mice in the rest phase was more severe than the active one, indicated by more severe liver damage, immunodepression, higher mortality rate, and lower LD50. No significant pharmacokinetic parameter changes were observed between the night and daytime treatment groups. These findings suggest the dosing-time dependent toxicity of clofarabine synchronizes with the circadian rhythm of mice, which might provide new therapeutic strategies in further clinical application.

The potential of asiaticoside for TGF-ß1/Smad signaling inhibition in prevention and progression of hypoxia-induced pulmonary hypertension.

AIMS: Asiaticoside (AS) is a saponin monomer extracted from the medicinal plant Centella asiatica, which has a variety of biological effects. We intended to investigate the effects of asiaticoside on a hypoxia-induced pulmonary hypertension (HPH) rat model and examine the possible effects of asiaticoside on TGF-ß1/Smad signaling in vivo and in vitro. MAIN METHODS: The rat HPH model was established by hypoxic exposure and asiaticoside was administered for four weeks. Parameters including the mean pulmonary artery pressure (mPAP), the right ventricular hypertrophy (RVH) and the percentage of medial wall thickness were used to evaluate the development of HPH. TGF-ß1, TGF-ß receptor, Smad2/3 and phospho-Smad2/3 expressions were detected and the proliferation, migration and apoptosis of pulmonary arterial smooth muscle cells (PASMCs) adjusted by asiaticoside under the hypoxic condition were evaluated. KEY FINDINGS: Our data indicate that asiaticoside attenuated pulmonary hypertension, pulmonary vascular remodeling and RV hypertrophy in HPH rats, which was probably mediated by restraining the hypoxia-induced overactive TGF-ß1/Smad2/3 signaling and inhibiting the proliferation by inducing apoptosis of the PASMCs. SIGNIFICANCE: Given the preventative potential in animal models and in vitro, we propose asiaticoside as a promising protective treatment in HPH.

Novel integration strategy for enhancing chalcopyrite bioleaching by Acidithiobacillus sp. in a 7-L fermenter.

An integrated strategy (additional energy substrate-three stage pH control-fed batch) was firstly proposed for efficiently improving chalcopyrite bioleaching by Acidithiobacillus sp. in a 7-L fermenter. The strain adaptive-growing phase was greatly shortened from 8days into 4days with the supplement of additional 2g/L Fe(2+)+2g/L S(0). Jarosite passivation was effectively weakened basing on higher biomass via the three-stage pH-stat control (pH 1.3-1.0-0.7). The mineral substrate inhibition was attenuated by fed-batch fermentation. With the integrated strategy, the biochemical reaction was promoted and achieved a better balance. Meanwhile, the domination course of A. thiooxidans in the microbial community was shortened from 14days to 8days. As the results of integrated strategy, the final copper ion and productivity reached 89.1mg/L and 2.23mg/(Ld), respectively, which was improved by 52.8% compared to the uncontrolled batch bioleaching. The integrated strategy could be further exploited for industrial chalcopyrite bioleaching.

Iron and zinc binding activity of Escherichia coli topoisomerase I homolog YrdD.

YrdD, a homolog of the C-terminal zinc-binding region of Escherichia coli topoisomerase I, is highly conserved among proteobacteria and enterobacteria. However, the function of YrdD remains elusive. Here we report that YrdD purified from E. coli cells grown in LB media contains both zinc and iron. Supplement of exogenous zinc in the medium abolishes the iron binding of YrdD in E. coli cells, indicating that iron and zinc may compete for the same metal binding sites in the protein. While the zinc-bound YrdD is able to bind single-stranded (ss) DNA and protect ssDNA from the DNase I digestion in vitro, the iron-bound YrdD has very little or no binding activity for ssDNA, suggesting that the zinc-bound YrdD may have an important role in DNA repair by interacting with ssDNA in cells.

[Contents of total anthocyanins and total saponins as well as composition of saponin monomers of Purple and Green Notoginseng Radix et Rhizoma].

OBJECTIVE: The contents of total anthocyanins and total saponins as well as the composition of saponin monomers of Purple and Green Notoginseng Radix et Rhizoma were studied to compare the medicinal quality and commercial values. METHODS: Three-year-old Notoginseng Radix et Rhizoma was selected as the research materials. The contents of total anthocyanins and total saponins were determined by spectrophotometry. The compositions of saponin monomers were monitored by HPLC. The significance of content differences was determined by variance analysis. RESULTS: The contents of total anthocyanins and total saponins of Purple Notoginseng Radix et Rhizomawere about 204.85% and 33.86% higher than those of Green Notoginseng Radix et Rhizoma respectively. The Purple and Green Notoginseng Radix et Rhizoma both contained five saponin monomers whose contents were as follows: ginsenoside Rg1 > ginsenoside Rb1 > notoginsenoside R1 > ginsenoside Rd > ginsenoside Re. The contents of notoginsenoside R1, ginsenoside Rd and ginsenoside Re of Purple Notoginseng Radix et Rhizoma were about 16.03%, 10.83% and 5.39% higher than those of Green Notoginseng Radix et Rhizoma respectively. However, the contents of ginsenoside Rg1 and ginsenoside Rb1 of Green Notoginseng Radix et Rhizoma were about 0.93% and 3.33% higher than those of Purple Notoginseng Radix et Rhizoma respectively. With respect to Green Notoginseng Radix et Rhizoma, the increase of the total anthocyanins in Purple Notoginseng Radix et Rhizoma reached a significant level, but the increases of total saponins, notoginsenoside R1, ginsenoside Rd and ginsenoside Re and the decreases of ginsenoside Rg1 and ginsenoside Rb1 did not. CONCLUSION: The total anthocyanins accumulation in Notoginseng Radix et Rhizoma implies the content increases of the total saponins, notoginsenoside R1, ginsenoside Rd and ginsenoside Re, and the slight decreases of ginsenoside Rg1 and ginsenoside Rb1 contents; but the type and relative contents of saponin monomers remain unchanged. The medicinal quality and commercial value of Purple Notoginseng Radix et Rhizoma are higher than those of Green Notoginseng Radix et Rhizoma.