Ethyl carbamate in Chinese liquor (Baijiu): presence, analysis, formation, and control.

Ethyl carbamate (EC) is a genotoxic and carcinogenic compound that is also a by-product of fermented foods (bread, sour milk, soy cheese, etc.) and alcoholic beverages (wine, sake, distilled liquor, etc.). Studies have showed that ethyl carbamate is ingested by humans primarily through the consumption of alcoholic beverages. Many countries have thus established EC limits for alcoholic beverages. Chinese liquor (Baijiu) is a traditional and unique distilled liquor, which has a huge consumption in China due to its excellent color, flavor, and taste. Therefore, the control of EC in Chinese liquor is of great significance. This review summarized for the first time the progress in presence level, analysis method, formation mechanism, and elimination strategy of EC of Chinese liquor in recent decades. KEY POINTS: • GC-MS and HPLC are the main methods to quantify EC in Chinese liquor. • EC is formed in the fermentation, distillation, and storage stage. • EC content can be reduced from raw material, microorganism, and production process.

Nuclear transformation of Chlamydomonas reinhardtii: A review.

Chlamydomonas reinhardtii is a model organism with three sequenced genomes capable of genetic transformation. C. reinhardtii has the advantages of being low cost, non-toxic, and having a post-translational modification system that ensures the recombinant proteins have the same activity as natural proteins, thus making it a great platform for application in molecular biology and other fields. In this review, we summarize the existing methods for nuclear transformation of C. reinhardtii, genes for selection, examples of foreign protein expression, and factors affecting transformation efficiency, to provide insights into effective strategies for the nuclear transformation of C. reinhardtii.

Allyl methyl trisulfide protected against acetaminophen (paracetamol)-induced hepatotoxicity by suppressing CYP2E1 and activating Nrf2 in mouse liver.

In order to investigate the protective effects of allyl methyl trisulfide (AMTS) on acetaminophen (APAP)-induced hepatotoxicity, 75 KM mice were randomized into 5 groups, i.e. a control group, an APAP group, and three AMTS/APAP groups. The mice in the AMTS/APAP groups and APAP group were gavaged with 25-100 mg kg-1 AMTS or corn oil for 7 d followed by intraperitoneal injection of 300 mg kg-1 APAP, while mice in the control group were treated with a vehicle. We found that AMTS significantly attenuated APAP-induced hepatotoxicity shown by reduced mortality, decreased serum aminotransferase activities, and improved liver histological morphology. APAP overdose resulted in a significant increase of hepatic malondialdehyde (MDA) level and a decrease of the protein levels of NQO-1, γ-GCS, HO-1, and SOD, which was suppressed by AMTS pretreatment. Furthermore, AMTS inhibited the APAP-induced elevation of hepatic p62 and LC3II protein levels. Interestingly, AMTS attenuated the APAP-induced decline of hepatic CYP2E1 protein levels, but AMTS alone led to the decrease of CYP2E1 protein expression in mouse liver. Collectively, these data suggest that AMTS could attenuate APAP-induced hepatotoxicity by suppressing CYP2E1 and activating Nrf2.

[Tissue culture and plant regeneration of Ixeridium sonchifolium].

OBJECTIVE: To study the callus induction and plant regeneration of Ixeridium sonchifolium. METHOD: By using the orthogonal experiment design, the medium for callus induction and plant regeneration was optimized. RESULT: The optimal medium for callus induction was MS + 2, 4-D 1.5 mg x L(-1) +6-BA 1.5 mg x L(-1) +NAA 1.0 mg x L(-1) + IBA 1.5 mg x L(-1) + KT1.5 mg x L(-1), the optimal medium for inducing adventitious bud was MS +2, 4-D 0.2 mg x L(-1) +6-BA 0.5 mg x L(-1) + NAA 0.5 mg x L(-1) + IBA 0.5 mg x L(-1) + KT 0.5 mg x L(-1). Plantlets were rooted on 1/4MS medium supplemented with different concentrations of IBA, and high rooting and survival was achieved when the IBA concentration was 0.1 mg L(-1). CONCLUSION: An efficient system for plant regeneration of I. sonchifolium was established.

[Determination methods of bromine in air of workplace].

OBJECTIVE: To establish a spectrophotometric determination method of bromine in the air of workplace. METHODS: Bromine in the air of workplace was absorbed by methyl orange solution, then determined by spectrophotometry. RESULTS: The range of the determination was 0.2 to 2.8 microg/ml, the linear equation was Y=0.0427X-0.0092, r=0.9996. The detection limit was 0.2 microg/ml. The minimum detectable concentration was 0.27 mg/m(3) for 7.5 L air sample. The relative standard deviations covered the range of 1.1% approximately 3.7%. The recovery rate was in the range of 93.6% to 97.2%. The sampling efficiency ranged from 93.5% to 100.0%. CONCLUSION: The method is available for the determination of bromine in the air of workplace.

[Treatment effects of the maxillary protraction in correction of maxillary deficiency: a comparative study between RPE group and no RPE group.].

PURPOSE: To compare the clinical effects of rapid palatal expansions combined with maxillary protractions to that of maxillary protractions of the maxillary deficiency alone. METHODS: Twenty patients aging from 9 to 11 years were divided into two groups , each group had 10 patients. All patients were diagnosed as having deficient maxillas with anterior crossbite. Group A were treated with rapid palatal expansion before maxillary protraction.Group B were treated with maxillary protraction alone. Lateral cephalometric films were taken at the beginning and the end of the treatment, and analyzed with McNamara analysis (Co-A,Co-Gn,ANS-Me) and traditional analysis. RESULTS: (1) After maxillary protraction,the maxilla and upper dentitions were protracted in both groups,the anterior crossbite had been corrected and obvious profile changes can be observed. (2) The mandible moved backward and downward in the RPE group and more obvious profile changes can be achieved compared with no RPE group. CONCLUSION: (1) It's an effective method to manage the maxillary deficiency with maxillary protraction in the mixed dentition. (2) Applying maxillary protraction combined with RPE is more adaptable to low angle cases.

[An investigation on dental bio-tribological characteristics of prosthesis made of titanium material].

OBJECTIVE: This study aimed at investigating bio-tribological property of titanium opposite to teeth as a base of clinical application. METHODS: Under a modified fretting machine, wear tests on human natural teeth were carried out in artificial saliva conditions against to pure titanium. The dynamic frictional process and wear mechanisms were investigated by means of Nene-2, MVK-H12, TALYSURF6, OM, LSM, SEM, EDX. RESULTS: The coefficient of friction exhibited a variation pattern of longs. The wear mechanism of natural tooth was detected as micro-cut and denaturation of dental texture and the wear depth of Ti/teeth was 20.33 + 2.86 microm, the wear depth of Ti/Ti being 38.00 + 5.88 microm (P < 0.05). CONCLUSIONS: The natural tooth has a good tribological behavior, matching the friction behavior of pure titanium. Over occlusal force during masticate process and para-function should be avoided. When we chose dental materials, wear resistance should be taken into account.

[A study on biomarkers of styrene].

OBJECTIVE: To study the biomarkers of styrene and to provide theoretical basis for bio-monitoring of styrene. METHODS: Urinary mandalic acid (MA), phenylglyoxalic acid (PGA) and mercapturic acid (MUA) of styrene were examined by high performance liquid chromatography (HPLC). RESULTS: The correlation regression equations between exposure dose and MA, PGA and MUA level in morning urinary samples were: y = 2.58x + 70.82; y = 1.66x + 37.42; y = 0.05x + 0.55 respectively. The correlation regression equations between exposure dose and MA, PGA and MUA level in post-shift urinary samples were: y = 1.85x + 89.02; y = 1.33x + 4.32; y = 0.04x + 0.68 respectively. All showed close dose-response relationship. CONCLUSIONS: The level of MA, PGA and MUA in morning or post-shift urinary samples may be used as bio-monitoring indexes of styrene.