Antioxidant potential evaluation of polysaccharides from Camellia oleifera Abel in vitro and in vivo

The extraction process, structural characterization and free radical scavenging ability of polysaccharides from Camellia oleifera have already been widely studied. However, the antioxidant activities are still lack of systematic experiments. In this study, we used Hep G2 cells and Caenorhabditis elegans to evaluate the antioxidant potential of polysaccharides that from C. oleifera flowers (P-CF), leaves (P-CL), seed cakes (P-CC) and fruit shells (P-CS). The results showed all these polysaccharides could protect cells from oxidative damage induced by t-BHP. The highest cell viabilities were 66.46 ± 1.36 % (P-CF), 55.2 ± 2.93 % (P-CL), 54.49 ± 1.29 % (P-CC) and 61.45 ± 1.67 % (P-CS), respectively. Studies have shown that four polysaccharides may protect cells from apoptosis by reducing ROS levels and maintaining MMP balance. Moreover, P-CF, P-CL, P-CC and P-CS increased the survival rate of C. elegans under thermal stress, which reduced the production of ROS by 56.1 ± 0.67 %, 59.37 ± 1.79 %, 16.63 ± 2.51 % and 27.55 ± 2.62 %, respectively. P-CF and P-CL showed stronger protective effects on C. elegans by increasing the nuclear entry rate of DAF-16 and stimulating the expression of SOD-3. Our study suggested that C. oleifera polysaccharides have the potential to develop into a natural supplement agent.

Enabling Oxygen-Sulfur Exchange Reaction to Produce Semicrystalline Copolymers from Carbon Disulfide and Ethylene Oxide

This work describes the first example of semicrystalline poly(thiocarbonate)s from carbon disulfide (CS₂ ) and ethylene oxide (EO), two mass producible low-cost monomers. Lewis acid/base pairs (LPs) exhibit high activity (EO conversion up to >99%, 8 h) in catalyzing the copolymerization under low Lewis pair/monomer ratio of 1:1500. Oxygen-sulfur exchange reaction (O-S ER) during the copolymerization of CS₂ and EO, the generation and mutual copolymerization with COS, CO₂ , and episulfide, is harnessed to introduce crystallizable segments [SC(O)O and SC(S)S] in the copolymer. The type of Lewis base is found to have a great impact on the chain microstructure and the crystalline properties. The formed copolymers with melting point from 117.7 to 245.3 °C are obtained. The maximum crystallinity is estimated to be 78% based on the powder wide-angle X-ray diffraction pattern. This work provides a general method to prepare semicrystalline sulfur-containing polymers.

[Prevalence of deep venous thrombosis in chronic refractory wounds and its influencing factors]

Objective: To investigate the incidence and risk factors of lower extremities deep venous thrombosis (DVT) in patients with chronic refractory wounds (chronic wounds). Methods: A retrospective analysis of 722 cases of chronic wounds admitted to the First People's Hospital of Zhengzhou from January 1, 2015 to December 31, 2018 was carried out, and clinical data such as gender, age, wound involves the lower extremities, wound type, duration of wound, D-dimer level and complicated diabetes, hypertension, coronary heart disease, cerebral infarction, pneumonia and sepsis/septic shock were collected. The patients were divided into DVT group and non-DVT group according to the color ultrasound test. Multivariate binary logistic regression analysis was used to screen the independent risk factors of DVT in patients with chronic wounds. Results: There were 55 (7.6%) patients in DVT group, of which 44(80.0%) were diagnosed as chronic DVT by conventional lower extremities venous color ultrasound screening at admission, and the remaining 11(20.0%) were newly diagnosed during hospitalization. There were no significant differences in gender, wound involves the lower extremities, duration of wound, complicated diabetes and hypertension between DVT group and non-DVT group (all P>0.05); and the differences were statistically significant in age, wound type, D-dimer level, complicated coronary heart disease, cerebral infarction, pneumonia and sepsis/septic shock (all P<0.05). Multivariate binary logistic regression analysis showed age [OR=2.260 (95%CI: 1.584-3.224)], D-dimer level [OR=14.201 (95%CI: 6.101-33.055)], complicated coronary heart disease [OR=2.731 (95%CI: 1.210-6.162)] and sepsis/septic shock [OR=3.170 (95%CI: 1.115-9.016)] were independent risk factors for DVT (all P<0.05). Conclusion: Chronic wounds patients have a higher incidence of DVT, most of which are chronic DVT, and age, D-dimer level, complicated coronary heart disease and sepsis/septic shock are independent risk factors for DVT in chronic wounds.

Repurposing poly(monothiocarbonate)s to poly(thioether)s with organic bases

This work reports a unique one-pot/one-step route to rapidly produce poly(thioether)s from poly(monothiocarbonate) (PMTC), a sulfur-containing polymer, using commercially available organic bases.

Triethyl borane-regulated selective production of polycarbonates and cyclic carbonates for the coupling reaction of CO2 with epoxides

The copolymerization of CO₂ and epoxides bearing phenyl group is achieved by the combination of Lewis bases and excess triethyl borane that decides the selectivity.

Highly Efficient One-Pot Synthesis of COS-Based Block Copolymers by Using Organic Lewis Pairs

A one-pot synthesis of block copolymer with regioregular poly(monothiocarbonate) block is described via metal-free catalysis. Lewis bases such as guanidine, quaternary onium salts, and Lewis acid triethyl borane (TEB) were equivalently combined and used as the catalysts. By using polyethylene glycol (PEG) as the macromolecular chain transfer agent (CTA), narrow polydispersity block copolymers were obtained from the copolymerization of carbonyl sulfide (COS) and propylene oxide (PO). The block copolymers had a poly(monothiocarbonate) block with perfect alternating degree and regioregularity. Unexpectedly, the addition of CTA to COS/PO copolymerization system could dramatically improve the turnover frequency (TOF) of PO (up to 240 h-1), higher than that of the copolymerization without CTA. In addition, the conversion of CTA could be up to 100% in most cases, as revealed by ¹H NMR spectra. Of consequence, the number-average molecular weights (Mns) of the resultant block copolymers could be regulated by varying the feed ratio of CTA to PO. Oxygen-sulfur exchange reaction (O/S ER), which can generate randomly distributed thiocarbonate and carbonate units, was effectively suppressed in all of the cases in the presence of CTA, even at 80 °C. This work presents a versatile method for synthesizing sulfur-containing block copolymers through a metal-free route, providing an array of new block copolymers.

Active immunization with GnRH-tandem-dimer peptide in young male rats reduces serum reproductive hormone concentrations, testicular development and spermatogenesis

GnRH sterilization vaccines have been developed for various practical and clinical reasons. However, conjugation of GnRH peptide to carrier protein has many drawbacks, hampering the further commercialization of GnRH vaccines. In this study, a new nonconjugated GnRH vaccine, D-Lys6-GnRH-tandem-dimer peptide (TDK), emulsified in Specol adjuvant was investigated for its immunocastration efficacy in young male rats. Prepubertal male rats were randomly allocated into three groups (n = 12): control (no treatment), surgically castrated or immunized against 100 μg TDK in Specol adjuvant at 6 weeks of age (with a booster 8 weeks later). Blood samples (for antibody titers and hormone concentrations) were collected at 2-week intervals until rats were killed (18 weeks of age). Compared to intact controls, active immunization against TDK reduced (P < 0.05) serum concentrations of testosterone, inhibin B, LH and FSH, prevented the onset of spermatogenesis at puberty. Furthermore, mRNA expressions of GnRH receptor, LH-β and FSH-β in the pituitary, LH receptor, FSH receptor, inhibin α, βA and βB subunit in the testes were decreased in immunocastrated rats compared to intact controls (P < 0.05). These results demonstrate for the first time that GnRH-tandem-dimer peptide emulsified in Specol is a promising veterinary sterilization medicine.

Effect of developmental stage of embryos at freezing on live birth outcomes after frozen embryo transfer

　　Purpose Our objective was to evaluate the birth outcomes of FET from different developmental stage of embryo at freezing (Day 3, Day 5 and Day 6). Methods All vitrified-warmed day 3 (D3) and day 5/6 (D5, D6) embryo transfers during the time period from January 2013 until December 2015 were included in the study. The Birthweight, Low birthweight (LBW), sexual distinction, gestation and for singleton births and twins conceived by FET were compared retrospectively between three cryopreservation strategies utilizing either D3, D5 or D6 embryo freezing. All embryos were vitrified by Dimethylsulfoxide (DMSO), Ethylene glycol (EG) and Sucrose used as Cryoprotectants and using Cryoleaf as the receptacles. Results A total of 993 infants from 771 women. The length of embryos storage was 3-38 months, with a median of 8 months. For singleton, birthweight from D5 and D6 blastocysts transfers were significantly heavier than for D3 cleavage-stage embryos transfers (P =0.0065 P =0.0006). For twins, birthweight from D6 blastocysts transfers were significantly heavier than for D5 blastocysts transfers (P =0.0044), and children born after D3 were at a signigicantly increased risk of being born a LBW. Conclusions Birthweights from FET are influenced by developmental stage of embryos at freezing, which were lower for cleavage-stage embryos transfer than blastocysts transfer after FET in singletons. The birth rate of LBW infants was higher in the twins. The study was small so there may be other factors than cryopreservation which affected outcomes. A higher sample size or a multi-centre prospective randomized design could be used in future studies to corroborate the current findings.

Direct high-precision measurement of the effective optical path length of multi-pass cell with optical frequency domain reflectometer

Multi-pass cells (MPCs) are commonly used in trace-gas detection and weak spectrum measurement. It is essential to accomplish a high-precision measurement of MPCs' effective optical path length (EOPL). A direct high-precision measuring method of MPCs' EOPL with optical frequency domain reflectometer (OFDR) was reported and demonstrated in this paper. Several important parameters of a MPC, such as EOPL and base length, were derived with high-precision by identifying the complicated signal of OFDR. The MPC's EOPL was also verified with the prevailing absorbance method. The results showed that the MPC's EOPL measured by each of these two methods is highly consistent. However, the relative uncertainty with the OFDR dramatically decreased 2 orders of magnitude (about 0.0085%) than that with the absorbance method. It demonstrated that the OFDR method with fewer measurement links is more conducive to a direct measurement. The performances of beam spread and stray light in the White-cell were also evaluated with the method.

Initiation of active immunization against testosterone during early puberty alters negative feedback regulation of the hypothalamic-pituitary-testicular axis in rabbits

To investigate the effects of antitestosterone immunization, initiated during early puberty, on hypothalamic-pituitary-testicular feedback in rabbits, 16 early pubertal male rabbits were randomly allocated into 2 groups (n = 8), control or immunized against testosterone-3(O-carboxymethyl)oxime-BSA in Freund adjuvant at 4 mo of age (with a booster immunization 4 wk later). Blood samples (for antibody titers and hormone concentrations) were collected at 2- or 4-wk intervals after immunization. Compared with controls, antitestosterone immunization triggered: a substantial and sustained antibody response (P < 0.01); increases in serum concentrations of luteinizing hormone (LH) and testosterone and testis weight and volume (P < 0.05); hyperplasia of testicular interstitial tissue with clustered and hypertrophic Leydig cells; and greater (P < 0.05) enzyme protein and messenger RNA (mRNA) expression levels for testicular cholesterol side-chain cleavage cytochrome P-450, 17α-hydroxylase cytochrome P-450, and 3β-dydroxysteroid dehydrogenase. Furthermore, immunoneutralization of testosterone upregulated mRNA expressions for genes in sex steroid negative feedback loops, including androgen receptor (AR), estrogen receptor alpha (ER-α), kisspeptin encoded gene (kiss-1) and kisspeptin receptor (G-coupled receptor 54) and gonadotropin-releasing hormone (GnRH) in the hypothalamic arcuate nucleus, GnRH receptor and LH-β in pituitary, and AR, inhibin-α and βA subunits in testes (P < 0.05). However, immunization did not affect mRNA expressions for follicle-stimulating hormone β, AR, and ER-α in pituitary, or ER-α in testes. We concluded that antitestosterone immunization in male rabbits, initiated during early puberty, increased GnRH mRNA expression, and in turn LH synthesis by reducing testicular feedback signaling. Reduction of direct steroidal effects on the testis may also have increased testosterone secretion. Consequently, there was an accelerated testicular development during puberty and enhanced testicular function after puberty, which likely conferred prolonged reproductive advantages.

Degradation of nitenpyram pesticide in aqueous solution by low-temperature plasma

In order to study the new technique of plasma wastewater treatment, the degradation behaviour ofnitenpyram (NTP) pesticide was investigated in a low-temperature plasma formed during a dielectric barrier discharge process. The reactor was a radial flow sedimentation tank centred around the water inlet. We studied the effect of pesticide concentration and input power of the dielectric barrier discharge, together with the effect of external factors on the degradation of nitenpyram pesticide wastewater such as conductivity and the use of various of catalysts, and the reaction products were analyzed by high-performance liquid chromatography mass spectrometry (HPLC-MS). The results showed that NTP could be effectively removed from aqueous solution by low-temperature plasma. Increasing the input power could improve the efficiency of degradation, conforming to a first-order kinetic model. Use of a suitable catalyst clearly improved the degradation process, as also did low conductivity. The pH of NTP was reduced with discharge time.

[Determination of puerarin in xinmaitong oral liquid by HPLC]

OBJECTIVE

To develop a method to determine the content of puerarin in Xinmaitong oral liquid.

METHODS

HPLC method was used. The separation was performed on Suntek kromasil C18 column with methanol-water containing 0.5% acetic acid (25:75) as a mobile phase and the wavelength of UV detector was 250 nm.

RESULTS

The linearity of puerarin was good and average recovery was 97.8%.

CONCLUSION

The method is simple, reliable and sensitive. It also shows good resolation. It can be used in quality control of Xinmaitong oral liquid.

Race-specific HIV-1 disease-modifying effects associated with CCR5 haplotypes

Genetic variation in CC chemokine receptor 5 (CCR5), the major HIV-1 coreceptor, has been shown to influence HIV-1 transmission and disease progression. However, it is generally assumed that the same CCR5 genotype (or haplotype) has similar phenotypic effects in different populations. To test this assumption, we used an evolutionary-based classification of CCR5 haplotypes to determine their associated HIV-1 disease-modifying effects in a large well-characterized racially mixed cohort of HIV-1-seropositive individuals. We demonstrate that the spectrum of CCR5 haplotypes associated with disease acceleration or retardation differs between African Americans and Caucasians. Also, we show that there is a strong interactive effect between CCR5 haplotypes with different evolutionary histories. The striking population-specific phenotypic effects associated with CCR5 haplotypes emphasize the importance of understanding the evolutionary context in which disease susceptibility genes are expressed.

Selective total vascular occlusion for major hepatic resection

Selective total vascular occlusion for the resection of large tumors on the right lobe of the liver or central hepatic tumors was described. The occlusion of the portal triad, infrahepatic vena cava and the total hepatic circulation was selectively used in combination to control bleeding in the process of hepatectomy. Within a year, major resection was successfully performed with this technique on 10 patients (extended right lobectomy 4 patients, right lobectomy 4, central segmentectomy 2). The mean duration of total vascular exclusion was 19.35 +/- 19.32 minutes and mean blood transfusion requirement was 7 +/- 4.5 units during surgery.

[Determination of neuropeptide Y concentration in the cerebrospinal fluid in patients with cerebrovascular diseases and its significance]

Concentration of neuropeptide Y (NPY) in the cerebrospinal fluid (CSF) of patients with cerebrovascular diseases was measured by using radioimmunoassay. The results showed that NPY concentration in CSF in patients with hemorrhagic cerebrovascular diseases (HCVD) was 4148 +/- 397.2 pg/ml, being significantly higher than the control level of 1083.7 +/- 245.8 pg/ml. While the NPY concentration in CSF of patients with ischemic cerebrovascular diseases (ICVD) was 2214 +/- 289.2 pg/ml, being not significantly different from the level in the control group. The effect of NPY in vasospasm after HCVD was preliminarily discussed.

[Modified normothermic avascular hepatic resection]

The conventional Heaney's avascular hepatic resection was modified based on an experimental study on normothermic total hepatic vascular exclusion in dog. The modification was cancellation of simultaneous exclusion of the abdominal aorta and proper prolongation of total hepatic vascular exclusion time. The method was successfully used in 3 patients, 2 with primary hepatocellular carcinoma involving the second porta hepatis and 1 with a huge hepatic cavernous hemangioma in segments VII and VIII. The clinical application of this method is presented and discussed. The modified Heaney's technique, being simpler and safer than the conventional one, may increase the resection rate for central hepatic tumors (segments I, IV, V and VIII according to Couinaud's classification).

Experimental research on utilization of bioluminescent technique to substitute the current viability count for BCG vaccine

The possibility of using the bioluminescent (BL) technique to substitute the traditional viability count of colony forming units (CFU) of BCG vaccine was investigated. The results showed there is a significant dose-dependent correlation between the concentration of standard adenosine triphosphate (ATP) and ATP BL value. The ultrasonic-chloroform method designed by us yielded the best results. The correlation coefficient values (r) of BL of the liquid and lyophilized vaccine were found to be 0.8 155 and 0.8 484 respectively (P less than 0.05). The coefficient of variation (CV) between the BL value of different lots of ATP obtained was 3.2-4.4%, much lower than that of CFU (CV = 10.4-11.2%). The presence of bacterial clumps within the vaccine had great influence on the bacterial ATP value and on the CFU viability count. 2.8 fg of ATP was found in each CFU formed in the vaccine with clumps, while it was only 0.94 fg in the vaccine without clumps, indicating the superiority of the BL method. The BL method has shown a high sensitivity, good reproducibility and simplicity in handling with quick results and high accuracy. Therefore, we consider that the BL method can be used to substitute the CFU method.