Black blooms-induced adaptive responses of sulfate reduction bacteria in a shallow freshwater lake.

Decomposing cyanobacterial bloom-induced black blooms been seen as an issue in the management of freshwater ecosystems, but its effect on sulfate-reducing bacteria (SRB) in shallow freshwater lakes is not clear. The objective of this study is to present an in-depth investigation of black bloom effects on the activities and composition of SRB, as well as the interactions between SRB and other bacteria. Water and surface sediments samples were collected from a shallow freshwater lake during black and non-black blooms. Sulfate reduction rates (SRRs) in the water column were determined from the linear regression of sulfate depletion with time. Quantitative real-time polymerase chain reactions (qPCRs), targeting the dsrA gene and Illumina sequencing of 16S rDNA, were used to estimate the SRB population and SRB community structures, respectively. Our data indicate that although a higher abundance of SRB was responsible for the higher SRR in the bottom water (34.09 ±â€¯2.37 nmol mL-1 day-1) than in the surface water (14.57 ±â€¯2.91 nmol mL-1 day-1) during black blooms, cell-specific sulfate reduction rates (csSRRs) in the distinct water layers were not significantly different (P = 0.95), with the value of approximately 0.017 fmol cell-1 day-1. Additionally, Desulfomicrobium and Desulfovibrio were the two main genera of SRB in the water column during black bloom season, while Desulfobulbus, Desulfobacca and Desulfatiglans genera were identified in the sediments of both the black and non-black blooms in genera pools. Each SRB genus preferentially associated with bacteria for specific functions in the bacterial co-occurrence network, regardless of whether black booms occurred or not. These results extend our knowledge on the importance of SRB during black blooms and the adaptation of SRB to environmental changes in freshwater lakes.

[Clinical observation of pre-suture ligation and suture knot positioning in single-operator circumcision with the stapler for children].

OBJECTIVE: To observe the clinical effects of pre-suture ligation and suture knot positioning in single-operator circumcision with the stapler. METHODS: Totally 120 six to fourteen years old children with phimosis or redundant prepuce were equally and randomly assigned to receive traditional single-operator circumcision with the stapler (group 1), single-operator circumcision with double suture knots for positioning the cutting plane with the stapler (group 2), or pre-suture ligation plus single-operator suture knot positioning circumcision with the stapler (group 3). We recorded and comparatively analyzed the operation time, intraoperative blood loss and hematoma, the number of residual suture knots, the patients' satisfaction with foreskin reservation, sutured frenulum and incision aesthetics, and the rates of surgical conversion, severe postoperative dysuria, severe wound exudation and perioperative anxiety of the parents and surgeon. RESULTS: Statistically significant differences were observed among the three groups in the operation time, intraoperative blood loss, incidence of intraoperative hematoma, number of residual suture knots, the patients' satisfaction with foreskin reservation, sutured frenulum and incision aesthetics, and the rates of surgical conversion, severe postoperative dysuria, severe wound exudation and perioperative anxiety of the parents and surgeon (P < 0.05). Compared with group 1, group 3 showed obviously less operation time and intraoperative blood loss and lower incidence of intraoperative hematoma, number of residual suture knots and rates of surgical conversion and perioperative anxiety of the parents and surgeons, and higher rates of patients' satisfaction with foreskin reservation, sutured frenulum and incision aesthetics. The intraoperative blood loss, incidence of intraoperative hematoma, and the rates of severe postoperative dysuria, severe wound exudation and perioperative anxiety of the parents and surgeon were lower in group 3 than in group 2. CONCLUSION: Pre-suture ligation plus single-operator suture knot positioning circumcision with the stapler helps reduce the operation time, intraoperative blood loss, incidence of intraoperative hematoma, number of residual suture knots and rates of surgical conversion and perioperative anxiety of the parents and surgeon, and increase the patients' satisfaction with foreskin reservation, sutured frenulum and incision aesthetics.

[Single- versus double-suture knot for positioning the cutting plane in circumcision with a stapler].

OBJECTIVE: To observe the clinical effect of single-suture versus that of double-suture knot in positioning the cutting plane in circumcision with a stapler. METHODS: We randomly assigned 120 patients with redundant prepuce or phimosis into three groups of an equal number to receive traditional circumcision without suture knot (group 1), circumcision with single-suture knot (group 2), and circumcision with double-suture knot (group 3) for positioning of the cutting plane. We recorded and compared the operation time, intraoperative blood loss, the rates of frenulum sewing, non-frenulum sewing, poor frenulum sewing and surgical conversion, intraoperative anxiety of the doctors, postoperative ecchymosis, and satisfaction with the retained ventral and dorsal prepuce and postoperative penile appearance among the three groups. RESULTS: There were statistically significant differences among the three groups in the surgery time, intraoperative blood loss, the rates of frenulum sewing, non-frenulum sewing, poor frenulum sewing and surgical conversion, intraoperative anxiety of the doctors, and satisfaction with the retained ventral and dorsal prepuce and postoperative penile appearance, (P < 0.05), but not in postoperative ecchymosis (P = 0.849). The rate of satisfaction with the retained dorsal prepuce was remarkably higher in group 3 than in group 2 (P = 0.003), and the intraoperative anxiety rate of the doctors was lower in the former than in the latter group (P = 0.003). CONCLUSIONS: Both single- and double-suture knots for positioning the cutting plane in circumcision with a stapler can help reduce the operation time, intraoperative blood loss, the rates of frenulum sewing, non-frenulum sewing, poor frenulum sewing and surgical conversion, intraoperative anxiety of the doctors, and satisfaction with the retained ventral and dorsal prepuce and postoperative penile appearance, and double-suture knot positioning has an even higher application value in decreasing the intraoperative anxiety of the doctors and increasing the satisfaction with the retained dorsal prepuce.

[Modified urethral reconstruction with lingual mucosa for complicated anterior urethral stricture].

OBJECTIVE: To investigate the efficiency and complications of modified urethral reconstruction with lingual mucosa in the treatment of complicated anterior urethral stricture (CAUS). METHODS: We retrospectively studied the clinical data on 10 cases of CAUS treated by modified urethral reconstruction with lingual mucosa from December 2017 to June 2019 concerning the age of the patients and the causes, location and length of urethral stricture. We statistically analyzed the pre- and post-operative maximum urine flow rate (Qmax), scores on Mental Status Scale in Non-psychiatric Settings (MSSNS) and quality of life (QOL) scores and observed post-operative complications such as abnormal taste, tongue numbness, urinary tract infection, urethral diverticulum, and urethral stricture. RESULTS: Compared with the baseline, Qmax was significantly improved and the MSSNS and QOL scores dramatically decreased at 3, 6 and 12 months after surgery (P < 0.01). Paraurethral infection developed in 1 case postoperatively, which was cured after dressing change, external urethral orifice stenosis occurred in another, which was improved after regular urethral orifice expansion, and mild tongue numbness was found in 2 cases at 1 month but gradually restored to abnormal. Urethrography showed no urethral diverticulum before catheter removal. CONCLUSIONS: Lingual mucosa is an ideal alternative material for urethral reconstruction in the treatment of CAUS, and lateral lingual mucosa can be easily obtained. Modified urethral reconstruction by embedding lingual mucosa in the dorsal base of the urethra, with the advantages of definite effectiveness and few postoperative complications, is worthy of clinical application.

[Prostatic artery embolization for high-risk patients with benign prostatic hyperplasia: A clinical effect observation].

OBJECTIVE: To observe the clinical effect of prostatic artery embolization (PAE) in the treatment of high-risk patients with BPH. METHODS: Nine high-risk patients with BPH underwent PAE in the Third Affiliated Hospital of Anhui Medical University from January 2016 to June 2018. We followed up the patients and obtained their IPSS, quality of life score (QOL), postvoid residual urine volume (PVR), maximum urinary flow rate (Qmax), prostate volume (PV), hours of undisturbed sleep (HUS), Self-Rating Anxiety Scale score (SAS) and incidence of postoperative complications before and at 6, 12 and 24 months or longer after surgery, followed by comparative analysis of the parameters. RESULTS: Compared with baseline, IPSS, QOL, PVR, Qmax, PV, HUS and SAS were all significantly improved in the patients at 6, 12 and ≥24 months after PAE (P < 0.05). Only 1 case complained of mild numbness in the buttocks, which was gradually relieved after acupuncture therapy. CONCLUSIONS: Prostatic artery embolization is definitely effective for the treatment of high-risk patients with BPH with the bladder volume ≥200 ml, with few postoperative complications, and can be used as an effective therapeutic supplementary for improving the urination symptoms of the patients.

Heparin-binding protein measurement improves the prediction of myocardial injury-related cardiogenic shock.

BACKGROUND: Heparin-binding protein (HBP), a potent inducer of increased vascular permeability, is a potentially useful biomarker for predicting outcomes in patients with postoperative myocardial injury-related cardiogenic shock (MIRCS). We aimed to evaluate and validate HBP as a prognostic biomarker for postoperative MIRCS. METHODS: We performed a case-control study in 792 patients undergoing cardiac surgery from January 1, 2016, to August 1, 2019, including 172 patients with postoperative MIRCS and 620 age- and sex-matched controls. The association between HBP and MIRCS was determined by multivariate logistic regression analysis. Receiver operating characteristic curves (ROCs) with area under the curve (AUC) were performed to calculate the cut-off value, sensitivity and specificity. The association between HBP and cardiac troponin T (cTnT) was determined by multivariable linear regression analysis. Blood samples were drawn from the coronary sinus and arterial line of the cardiopulmonary bypass (CPB) before aortic cross-clamping (time point 1) and 5 min after aortic declamping (time point 2). RESULTS: Before aortic cross-clamping, coronary sinus HBP (HBPCS1) showed no differences between the two groups. However, after declamping, the MIRCS group had a significantly higher sinus HBP level (HBPCS2) than did the control group. HBPCS2 predicted MIRCS with an AUC of 0.85 (95% CI: 0.81-0.89, cut-off: 220 ng/ml, sensitivity: 92% and specificity: 70%). After adjusting for confounding factors, we found that HBP was an independent risk factor for MIRCS (OR: 7.65, 95% CI: 4.86-12.06, P < 0.01) and was positively associated with cTnT (ß > 0, P < 0.01). CONCLUSIONS: Elevated levels of coronary sinus HBP were useful biomarkers for predicting MIRCS after cardiac surgery.

The effects of imidacloprid combined with endosulfan on IgE-mediated mouse bone marrow-derived mast cell degranulation and anaphylaxis.

Low levels of endosulfan are known to stimulate mast cells to release allergic mediators, while imidacloprid can inhibit IgE-mediated mast cell degranulation. However, little information about the effects of both pesticides together on mast cell degranulation is available. To measure the effects, IgE-activated mouse bone marrow-derived mast cells (BMMCs) were treated with imidacloprid and endosulfan, individually, and simultaneously at equi-molar concentrations in tenfold steps ranging from 10-4 to 10-11 M, followed by measuring several allergy-related parameters expressed in BMMCs: the mediator production and influx of Ca2+, the phosphorylation content of NF-κB in the FcεRI signaling pathway. Then, the effects of the mixtures on IgE-induced passive systemic anaphylaxis (PSA) of BALB/c was detectded. This study clearly showed that the application of equi-molar mixtures of both pesticides with 10-4-10-5 M significantly inhibited the IgE-mediated mouse bone marrow-derived mast cells degranulation in vitro and 10-4 M of them decreased IgE-mediated PSA in vivo, as the application of imidacloprid at the same concentration alone did. Morever endosulfan alone had no remarkable stimulatory effects on any of the factors measured. In conclusion, simultaneous application of equi-molar concentrations of both pesticides generally showed highly similar responses compared to the responses to imidacloprid alone, suggesting that the effects of the mixture could be solely attributed to the effects of imidacloprid.

Tracking the behavior of Maillard browning in lysine/arginine-sugar model systems under high hydrostatic pressure.

BACKGROUND: High-pressure processing is gaining popularity in the food industry. However, its effect on the Maillard reaction during high-pressure-assisted pasteurization and sterilization is not well documented. This study aimed to investigate the effects of high hydrostatic pressure on the Maillard reaction during these processes using amino acid (lysine or arginine)-sugar (glucose or fructose) solution models. RESULTS: High pressure retarded the intermediate and final stages of the Maillard reaction in the lysine-sugar model. For the lysine-glucose model, the degradation rate of Amadori compounds was decelerated, while acceleration was observed in the arginine-sugar model. Increased temperature not only accelerated the Maillard reaction over time but also formed fluorescent compounds with different emission wavelengths. Lysine reacted with the sugars more readily than arginine under the same conditions. In addition, it was easier for lysine to react with glucose, whereas arginine reacted more readily with fructose under high pressure. CONCLUSION: High pressure exerts different effects on lysine-sugar and arginine-sugar models. © 2017 Society of Chemical Industry.

Investigation of microRNA-155 as a serum diagnostic and prognostic biomarker for colorectal cancer.

The aim of the present study was to explore serum microRNA-155 (miR-155) expression in patients with colorectal cancer (CRC) and examined the potential usefulness of this molecule as a biomarker for diagnosis and prognosis in CRC. Serum samples were obtained between May 2007 and March 2013 from 146 CRC patients and 60 healthy controls. Serum miR-155 expression levels were measured by quantitative real time reverse transcription-polymerase chain reaction (qRT-PCR). Survival curves were obtained using the Kaplan-Meier method and assessed by the log-rank test. The receiver operating characteristic (ROC) curve was used for the prediction of cut-off values of the markers. Serum miR-155 expression level on average was upregulated in CRC patients compared with the matched healthy controls (P < 0.001). ROC curve analysis showed that miR-155 was a useful marker for discriminating cases from healthy controls, with an area under the ROC curve (AUC) of 0.776 (95% confidence interval (CI) 0.714 to 0.837, P < 0.001). Kaplan-Meier analysis with the log-rank test indicated that high serum miR-155 expression had a significant impact on overall survival (38.2 vs. 69.9%; P < 0.001) and progression-free survival (34.8 vs. 66.0%; P < 0.001). In conclusion, the detection of miR-155 levels in the serum might serve as a new tumor biomarker in the diagnosis and assessment of prognosis of CRC.

Efficacy and toxicity of adding cetuximab to chemotherapy in the treatment of metastatic colorectal cancer: a meta-analysis from 12 randomized controlled trials.

Cetuxiamb, a monoclonal antibody against epidermal growth factor receptor (EGFR), has been used in combination with chemotherapy for patients with metastatic colorectal cancer (mCRC). However, the efficacy of combined therapies of cetuximab and different chemotherapy regimens remains controversial. Therefore, we conducted a meta-analysis to evaluate the efficacy and toxicity of adding cetuximab to oxaliplatin-based or irinotecan-based chemotherapeutic regimens for the treatment of patients with mCRC with wild-type/mutated KRAS tumors. Randomized controlled trials (RCTs), published in Pubmed and Embase were systematically reviewed to assess the survival benefits and toxicity profile mCRC patients treated with cetuximab plus chemotherapy. Outcomes included overall survival (OS), progression-free survival (PFS), overall response rate (ORR), and toxicities. Results were expressed as the hazard ratio (HR) with 95 % confidence intervals (CI). Pooled estimates were generated by using a fixed-effects model or a randomized-effects model, depending on the heterogeneity among studies. A total of 12 trials involving 6,297 patients met the inclusion criteria and were included in this meta-analysis. All patients were administered oxaliplatin-based or irinotecan-based chemotherapy with or without cetuximab. Pooled results showed that the addition of cetuximab did not significantly improve the OS (HR = 0.99, 95 % CI = 0.89-1.09; Z = 0.28, P = 0.78) or PFS (HR = 0.94, 95 % CI = 0.81-1.10; Z = 0.76, P = 0.49), but did improve ORR (RR = 1.34, 95 % CI = 1.08-1.65; Z = 2.72, P = 0.00), when compared with chemotherapy alone. Subgroup analysis showed the highest PFS benefit in patients with wild-type KRAS tumors (HR = 0.80, 95 % CI = 0.65-0.99; Z = 2.1, P = 0.04) or wild-type KRAS/BRAF tumors (HR = 0.64, 95 % CI = 0.52-0.79; Z = 4.15, P = 0.00). When combined with cetuximab, irinotecan-based chemotherapy was significantly associated with prolonged PFS (HR = 0.79, 95 % CI = 0.66-0.96; Z = 2.36, P = 0.02) for all patients with differing gene-status. The incidence of grade 3/4 adverse events, including skin toxicity, diarrhea, hypertension, anorexia, and mucositis/stomatitis, was slightly higher in the combined therapy group than in the chemotherapy-only group. Based on the current evidence, the addition of cetuximab to chemotherapy significantly improves the PFS in patients with wild-type KRAS or wild-type KRAS/BRAF tumors as well as the ORR in all patients. In addition, irinotecan-based combination therapy showed a beneficial effect on the PFS in all patients. These findings confirm the use of cetuximab in combination with chemotherapy for the treatment of patients with mCRC with wild-type KRAS tumors. Further multi-center RCTs are needed to indentify these findings.

Combined effect of glycation and sodium carbonate-bicarbonate buffer concentration on IgG binding, IgE binding and conformation of ovalbumin.

BACKGROUND: Ovalbumin (OVA) is a major allergen in hen egg. During thermal processing, reducing sugars contained in the hen egg white might easily undergo glycation with OVA, but few studies have been conducted on its corresponding immunoreactivity changes. The aim of the present study was to assess changes of the antigenicity, potential allergenicity and conformation of OVA after glycation in a wet-thermal processing system under different concentrations of sodium carbonate-bicarbonate buffer. RESULTS: IgE binding of the glycated OVA was increased after glycation, and the higher the sodium carbonate-bicarbonate buffer concentration, the higher the IgE binding capacity. The increase in IgE binding of OVA corresponded well with the disruption of the disulfide bond, which exposed the epitopes initially buried. Antigenicity of the glycated OVA was increased, and the amount of the increase varied among samples treated under different buffer concentrations. CONCLUSION: Glycation increased the allergenic potential for OVA, with the amount of increase varying with different sodium carbonate-bicarbonate buffer concentrations.

[A case of hemophagocytic lymphohistiocytosis syndrome caused by severe tuberculosis and literature review].

OBJECTIVE: To investigate the clinical features of a case of hemophagocytic lymphohistiocytosis syndrome (abbreviated as hemophagocytic syndrome, HPS) caused by severe tuberculosis and therefore to improve early diagnosis of this condition. METHODS: The clinical features and process of diagnosis and treatment of a case with HPS caused by severe tuberculosis in July 2011 were analyzed, and the reported literatures of the disease were reviewed. RESULTS: The patient was a 16-year-old male. The primary manifestations were fever, cough, abdominal distention and edema. Laboratory analysis indicated pancytopenia (WBC 3.0×10(9)/L, Hb 98 g/L, PLT 34×10(9)/L), liver dysfunction (ALT 51.5 U/L, AST 211 U/L, TBIL 20 µmol/L, DBIL 17.6 µmol/L), coagulation abnormalities (extension of TT and APTT, FIB 0.56 g/L), high level of ferritin (662 µg/L), and hemophagocytosis in bone marrow. Sputum smear was positive for tubercule bacillus. After 2 months of antituberculous therapy with ethambutol, streptomycin and sodium aminosalicylate, along with administration of prednisolone, human immunoglobulin, and thymic peptide α(1), the patient's body temperature, function of coagulation and liver abnormalities all returned to normal, and repeated sputum smears became negative. CONCLUSIONS: Tuberculosis is a cause of reactive hemophagocytic syndrome. Patients with hemophagocytic symptom should be rigorously screened for tuberculosis, and antituberculous therapy should be initiated early to improve prognosis.

Solution-Processed Organic Photodetectors with Renewable Materials.

An organic photodetector prepared by a simple solution method based on renewable citrus pectin with an optimized concentration of aluminum nitrate (AlC05) is introduced herein. The effects of different concentrations of aluminum nitrate on the morphology and optical properties were investigated through various characterization methods. An AlC concentration of 0.5 mg/mL was found to provide the highest on/off ratio and acceptable rise and decay times. Also, the optimized device (Al/AlC0.5/ITO) exhibited good stability and repeatability at a 0.1 V bias under 440 nm visible light. Based on these results, citrus pectin materials were successfully used to fabricate an organic photodetector with a simple and cost-efficient fabrication process, while taking into account environmental commitments.

Experimental and Theoretical Study of Gamma Radiolysis and Dose Rate Effect of o-Cresol Formaldehyde Epoxy Composites.

Gamma radiolysis behaviors and mechanisms of silica-filled o-cresol formaldehyde epoxy are studied at 2.20 × 10-5 to 1.95 × 10-1 Gy/s. The radiolysis-induced changes in chemical structures do not severely affect its thermostability. The slightly deteriorated mechanical strength at temperature exceeding 100 °C is accompanied by the declining glass transition temperature (from 185.9 to 172.2 °C) and enhanced damping ability. The gas yields of hydrogen, methane, and carbon dioxide manifest a remarkable dose rate effect. Based on the Schwarzschild law, their yields at an extremely low dose rate are accurately predicted by the established master curves. Besides, the latent radiolysis of gas products and postradiation effect are found with caution. The radiation-caused residual spin species are proved to be composed of silica defects and a phenoxy-type free radical with a tert-butyl group, according to the experimental results, theoretical calculations, and spectra simulations. The lower vertical ionization potential (7.6 eV) and adiabatic ionization potential (7.1 eV) are primarily due to the ionization of the benzene ring moiety with the tert-butyl group, which is likely to suffer from radiolysis. The calculated bond dissociation energy (260.8-563.5 kJ/mol) of the typical chemical bonds of epoxy is consistent with its radiolytic vulnerability and degradation mechanisms.

[Effects of ZnO nanoparticles on proliferation and apoptosis of human lung epithelial BEAS-2B cells].

OBJECTIVE: To investigate the effects of ZnO nanoparticles (ZnO NPs) on proliferation and apoptosis of human lung epithelial cells BEAS-2B and its molecular mechanisms. METHODS: BEAS-2B cells were treated with ZnO NPs at concentrations of 3, 6 and 12 µg/ml for 12 h and 24 h, the control group was not treated with ZnO NPs, each with 3 replicate wells. Cell viability was detected by CCK-8 method, and the half lethal concentration (IC50) was analyzed. Then, the BEAS-2B cells were treated with ZnO NPs at selected concentrations of 3 and 6 µg/ml for 24 h respectively,each group was set with 3 replicate. Cell morphology was observed under inverted microscope. The morphology of cell nuclei was observed by Hochest33342 staining. The morphology of apoptosis was observed by AO staining and scanning electron microscopy. Cell cycle progression, cell apoptosis rate and the level of reactive oxygen species(ROS)were detected by flow cytometry. Western blot was used to detect the expression levels of Bcl-2 and Bax protein. RESULTS: Compared with the control group, the cell viability of cells treated with ZnO NPs were decreased significantly(P＜0.01), and the IC50 was 6.13 µg/ml at 24 h of drug treatment. After the cells were treated with ZnO NPs for 24 h, the levels of ROS were increased significantly(P＜0.05, P＜0.01)in 3 µg/ml, 6 µg/ml groups. The cell cycle was arrested at G2/M phase, chromatin condensation and apoptotic bodies were induced, apoptosis rate was increased significantly(P＜0.01) in 6 µg/ml group. The expression of Bcl-2 was decreased(P＜0.05), and the expression of Bax was increased (P＜0.05) in cells treated with 6 µg/ml ZnO NPs for 24 h. CONCLUSION: ZnO NPs induced ROS accumulation, blocked progress of cell cycle and induced cell apoptosis in BEAS-2B cells.

Morphology and interference color in spherulite of poly(trimethylene terephthalate) copolyester with bulky linking pendent group.

A novel phosphorus-containing copolyester (PTTP), poly(trimethylene terephthalate) (PTT) copolyester with a bulky linking pendent group of 9,10-dihydro-10-[2,3-di(hydroxycarbonyl) propyl]-10-phosphaphenanthrene-10-oxide (DDP) was prepared, and its crystallization, crystal morphology and interference color were investigated in this article for the first time. Differential scanning calorimeter (DSC) results showed that with the increase of DDP content, the melting point (T(m)) and crystallization ability of PTTP decreased. WAXD results suggests that the three samples share one crystal structure, however the crystallinity decreases with increasing DDP content. Polarized optical microscope (POM) observation indicated that the samples showed non-banded spherulites at a lower and higher temperature, and banded spherulites at the middle temperature range. From the micrographs obtained from scanning electronic microscopy (SEM) and atomic force microscopy (AFM), ringed patterns with many defects could be found for samples with higher DDP contents, which crystallized at a lower temperature, and a transformation from square-shaped spherulites to circular spherulites was noted for samples with higher DDP contents, which crystallized at a higher temperature. The interference color of the spherulites was also studied and it was shown that with the increase of film thickness or decrease of DDP content, the spherulites became more colorful under POM observation, indicating that the hindering effect and randomness caused by incorporating the DDP monomer with a bulky pendent group into the PTT molecular chain exhibited a negative influence on the molecular mobility and crystallization ability of the copolyester, and led to the formation of the defective band morphology and the less colorful interference color of the PTTP spherulites.

High-pressure microfluidisation-induced changes in the antigenicity and conformation of allergen Ara h 2 purified from Chinese peanut.

BACKGROUND: Peanut allergy is one of the most serious food allergies, and Ara h 2 is one of the most important peanut allergens as it is recognised by serum immunoglobulin E from more than 90% of peanut-allergic individuals. Dynamic high-pressure microfluidisation has been widely used in food processing as a new technology. The aim of this study was to investigate the effect of high-pressure microfluidisation on the antigenicity and structure of Ara h 2. Extracted peanut allergen Ara h 2 was treated under a continuous pressure array of 60, 90, 120, 150 and 180 MPa. Immunoreactivity was measured by indirect enzyme-linked immunosorbent assay with rabbit polyclonal antibodies. Secondary structure was analysed by circular dichroism. Surface hydrophobicity and sulfhydryl groups were assessed via fluorescence and UV absorption spectra respectively. RESULTS: High-pressure microfluidisation treatment decreased the antigenicity of peanut allergen Ara h 2, changed its secondary structure and increased its UV absorption intensity and surface hydrophobicity. CONCLUSION: The change in conformation contributed to the decrease in antigenicity of Ara h 2, and the spatial conformation of peanut allergen Ara h 2 plays a critical role in its antigenicity.

[Growth of codoped CdWO4 crystals by Bridgman method and their optical spectra].

The CdWO4 crystals with good quality in the size of Phi25 mm x 120 mm, doped with Co in 0.5% molar fraction in the raw composition, were grown by the Bridgman method by taking -70 degrees C x cm(-1) of solid-liquid interface and -0.50 mm x h(-1) growth rate. The crystal presents transparence and deep blue. The X-ray diffraction (XRD) was used to characterize the crystals. Three absorption peaks at 518, 564 and 655 nm respectively, which are attributed to the overlapping of 4 T1 (4F) --> 4A2 (4F) and 4 T1 (4F) --> 4 T1 (4P) of Co2+ octahedrons, and a wide band centered at 1 863 nm, which is attributed to 4Ti (4F) --> 4 T2 (4F), was observed. The absorption results indicated that the Co ions presented +2 valence in crystal and located within the distorted oxygen octahedrons. The crystal-field parameter D(q) and the Racah parameter B were estimated to be 990 and 726.3 cm(-1) respectively based on the absorption spectra. A fluorescence emission at 778 nm (4T1 (4P) --> 4 T1 (4F)) for codoped CdWO4 crystals was observed under excitation by 520 nm light. It can be deduced from the changes in absorption and emission intensity of different parts of crystal that the concentration of Co2+ ion in crystal increased along growing direction and the effective distribution coefficient of Co2+ ion in CdWO4 crystal is less than 1.

Gamma Radiation Chemistry of Polydimethylsiloxane Foam in Radiation-Thermal Environments: Experiments and Simulations.

The γ radiolysis behavior of polydimethylsiloxane (PDMS) in the radiation-thermal environments (dose rate, 0.2 Gy/s) is studied to pinpoint the basic knowledge of the temperature (20-70 °C) effects. The non-monotonous temperature effects on the formation of gas products, paramagnetic species in silica, and cross-linking density are proposed to correlate with the complex chemical reaction mechanisms. Besides, molecular dynamics simulation and theoretical calculation are first performed simultaneously based on the radical chemistry and intricate material composition, making it easier to comprehend and further harness the radiolysis mechanisms and structure deterioration of PDMS. The γ radiation-induced primary gas products and dominant cross-linking phenomena are reproduced by the molecular dynamics simulations with a reactive force field, and the reaction mechanisms and physicochemical interactions among PDMS chains, gas products, reactive radicals, and silica fillers are thoroughly studied at the atomic scale. The thermochemistry of the barrierless radical coupling reactions and reactions with explicit high-barrier transition states is calculated at the M06-2X theoretical level with the 6-311g(d, p) basis set. The barrierless reactions are all exothermal with the heat release of 321-618 kJ/mol, while the potential barriers for reactions with explicit transition states vary between 37 and 229 kJ/mol. The results show that γ radiation-induced radicals are crucial for the ensuing gas formation and cross-linking reactions, especially for the radical coupling reactions. The radical chemistry involved in the radiolytic PDMS is the key to understand and simulate its radiolysis behavior, according to the experimental and simulated results.

[Effect of heat treatment on the antigenicity and conformation of peanut allergen Ara h 2].

Peanut allergen Ara h 2 was extracted from peanuts and was identified by SDS-PAGE and MALDI-TOF-MS. Effect of heat treatment on the antigenicity and structure of Ara h 2 was measured by indirect ELISA, CD, fluorescence and UV absorption spectra. The results showed that the antigenicity of Ara h 2 had a slight increase after being heated at 55 or 70 degrees C, while above 85 degrees C the antigenicity decreased significantly, and the antigeicity of Ara h 2 decreased with increasing temperature. The CD showed that the secondary structure of Ara h 2 was changed after heat treatment. The ANS fluorescence probe emission spectra analysis demonstrated that the heat treatment induced an increase in surface hydrophobicity of Ara h 2. The UV absorption spectra showed that the absorption maximum wavelength was increased when Ara h 2 was heated except the sample heating at 50 degrees C for 30 min. So the changes in conformation of Ara h 2 lead to the antigenicity degression.