The low mass cutoff ( LMCO) is the main weakness of ion trap when it performs tandem mass analysis by collision induced dissociation (CID). LMCO means that some daughter ions of m/ z are less than about 1 / 3 of the m/ z of parent ion could not be detected during the tandem mass spectrometry processing. A new method which can significantly improve the effect of low mass cutoff was proposed and investigated. By simply changing the scan method of digital potential frequency, some low mass ions can be effectively observed during the tandem mass spectrometric experiment. In the experiment, the frequency of the digital ion trapping power and ion activation power were scanned from lower value to higher value, and some lower mass product ions could be detected during CID process. For example, some lower mass ions were observed during the CID of reserpine precursor ion when the frequency of its digital trapping power was scanned from 500 kHz to 560 kHz. The tandem mass spectra of Reserpine ion showed that the experimental results both from this work and the triple quadrupole mass spectrometer were exactly the same.

To understand the status of testing skills and quality management in drug testing laboratories. Methods:The items, pass rate and type of participating laboratories of measurement audit were analyzed during 2011-2014. Results:The number of application items was increased year by year, more than half of which focused on the content determination, and the overall pass rate was over 80%. Conclusion:The measurement audit is important for laboratories, which should be further strengthened and standard-ized.

Objective To observe the Pin1 expression pattern in skin and to establish an inducible skin specific Pin1 overexpression mouse model. Methods The mouse Pin1 gene was cloned into modified vector pTRE2 with C?terminal Myc tag. The linearized pTRE2?Pin1 DNA was micro?injected into one?cell embryos followed by implantation into foster mice to produce TRE?Pin1 transgenic mice. Results TRE?Pin1 transgenic founder mice were successfully created. These mice were crossed with transgenic tool mice K14?rtTA to create epithelial specific double transgenic progenies. Pin1 gene was induced by incorporating doxycycline into drinking water of the mice. Pin1 protein overexpression in the skin was con?firmed by Western blot and immunohistochemistry. The endogenous Pin1 protein was predominantly expressed in epidermal cells in the skin. Conclusions The inducible skin specific Pin1 overexpression mouse model is successfully established which may serve as a useful model for further study of Pin1 functions in the skin.

AIM:To look for a way of produ cing mild therapeutic hypothermia through regulating transient re-ceptor potential cation channel subfamily V member 1 (TRPV1) pathway by dihydrocapsaicin (DHC).METHODS:Mice were subcutaneously injected with DHC at different doses (2 mg/kg, 3 mg/kg and 4 mg/kg) in order to find the best dose for reaching the target temperature (32~34℃).20%DMSO dissolved in normal saline was used as control group .After a single subcutaneous injection of DHC at an optimal dose was given , awaken CD1 mice were continuously infused with DHC at dose of 1 mg? kg-1? h-1 for providing a more rapid and stable temperature drop and duration of therapeutic mild hypothermia.The adult mice (9~10 weeks) and aged mice (24~27 months) were subcutaneously injected with DHC at the same dose, and the changes of the body temperature were monitored .RESULTS:DHC at 2 mg/kg resulted in a de-crease in the core temperature within the target therapeutic range (32~34 °C).After a bolus dose (2 mg/kg) was deliv-ered at 0 min followed by continuous infusion (1 mg? kg-1? h-1 ) beginning at 30 min, a rapid drop of body temperature to 34 ℃was achieved and the body temperature was maintained within the ranges of 32 to 34℃for the duration of the 6 h continuous infusion .DHC-mediated hypothermia did not lose its effectiveness in the adult and aged models .CONCLU-SION:DHC-induced activation of TRPV1 pathway produces mild therapeutic hypothermia .Besides, this method achieves stronger and longer center hypothermia and is suitable for the animals at different ages .

OBJECTIVEThe skeletal Class III malocclusion often occurs in ethnic Asia population, and it is difficult to obtain an ideal results if only treated with protraction headgear (PH). However, the combined rapid palatal expansion (RPE), Edgewise Technique and PH can reach it, so the authors investigated the methods and characteristics of combined RPE, Edgewise Technique and PH in the treatment of skeletal Class III malocclusion.

METHODSFifteen patients, aged 8.5-12 years, including six males and 9 females, with skeletal Class III malocclusion and maxillary retrusion were selected for this study. Radiographs of left hand and wrist showed that all patients were at the pre-pubertal stage. The duration of treatment was nine months on average.

RESULTSThe SNA and A-ptm increased with a mean of cephalometric analysis, which showed significant difference (P < 0.05).

CONCLUSIONObvious skeletal and profile changes can be achieved with combined RPE, Edgewise Technique and PH in the treatment of early skeletal Class III malocclusion.

Child ; Extraoral Traction Appliances ; Female ; Humans ; Male ; Malocclusion, Angle Class III ; therapy ; Orthodontics, Corrective ; instrumentation ; methods ; Palatal Expansion Technique

Objective Toinvestigatetheeffectsofpyrrolidinedithiocarbamate(PDTC)onexpressionofNF-κB,MMP-2andleft ventricular collagen remodeling following acute myocardial infarction in rats .Methods The myocardial infarction model in rat was induced by ligation of left anterior descending coronary artery .12 adult Sprague-Dawley rats survived 24 for h after acute myocardial infarction were randomly divided into the myocardial infarction (MI) group and the PDTC-treated(PD) group .Six rats were desig-nated as sham-operated group(SH group) .The PD group was intraperitoneally injected with PDTC (80 mg · kg -1 · d-1 ) for 28 d , the MI group and SH group were given normal saline as control .On 28 d ,the cardiac function of left ventricle was measured by ech-ocardiography .The infarct size was evaluated .The total collgen ,typeⅠcollgen ,typeⅢcollgen ,and Ⅰ /Ⅲ collgen ratio were quanti-fied histomorphometry .The mRNA and protein levels of NF-kappaBp65 and MMP-2 were determined by reverse transcription-poly-merase chain reaction(RT-PCR) and by Western blot ,respectively .Results Compared with the SH group ,the values of the total collgen ,typeⅠcollgen ,typeⅢcollgen ,and Ⅰ /Ⅲ collgen ratio in the MI group and the PD group were significantly increased ,the differen had statistical significance (P<0 .01) .The values of the total collgen ,typeⅠcollgen ,typeⅢcollgen ,and Ⅰ /Ⅲ collgen ratio in the PD group were notably decreased than those in the MI group(P<0 .01) .Moreover ,the mRNA and protein levels of NF-kap-paBp65 and MMP-2 in the PD group were lower than those in the MI group ,the difference had statistical significance(P<0 .01) . Conclusion Left ventricular collagen remodeling following acute myocardial infarction could be improved by PDTC to some extent , which mechanism could be related with inhibiting NF-kappaB activation and down -regulating the expression of MMP-2 in rats .

Objective:To evaluate the capacity and level of melting point determination of chemical drugs in the laboratories par-ticipating in the proficiency testing. Methods:Two test samples were prepared, and the labs volunteered to participate in the proficien-cy testing program ( PTP) . The melting point determination was performed according to the general principle 0612 in part four of Chi-nese Pharmacopoeia (2015 edition), and the results were analyzed by robust statistics and the determination proficiency of the laborato-ries were evaluated by Z-score. Results:The analysis showed that two test samples were homogeneous and stable, which met the re-quirements of the PTP. Totally 31 laboratories had satisfactory results, which accounted for 83. 8%. Conclusion:The majority of the participant laboratories can accurately determine the melting points of test samples, and the information is very helpful to the next profi-ciency testing program.

High grade gliomas are always the research focus in the field of neurosurgery due to their poor prognosis despite the current standard therapeutic regimen of surgical resection followed by radiation therapy and chemotherapy. Alkylating agent temozolomide has been established as the standard chemotherapy while its resistance inevitable during treatment. This phenomenon seriously influences the prognosis of patients suffering from high grade gliomas. This review aims to elucidate temozolomide chemoresistance mechanisms through three chapters including O6-methylguanine-DNA methyltransferase (MGMT) methylation, mismatch repair mutation and epigenetic regulation consisting of p21, chromatin and histone, Y-box binding protein-1 and microRNAs.

Objective: To design the proficiency testing (PT) project (No. NIFDC-PT-183) for assays of bismuth potassium citrate capsules and organize to assess the proficiency of complexometric titration in laboratories, and provide some technical analyses and advices.
Methods: Two groups of samples with different concentration were prepared. The uniformity was evaluated with one-way analysis of variance and the stability was confirmed with t-test, whose results all conformed the requirements. The samples with three combinations were randomly distributed to 279 laboratories. The determination was performed according to the assays of bismuth potassium citrate capsules in Volume Ⅱ of the Chinese Pharmacopoeia 2015. The median value and normalized interquartile range (NIQR) of robust statistical analysis was adopted and Z-scores were used to evaluate the results from each of laboratories.
Results: Among 279 laboratories, 240 laboratories results were satisfactory, 23 were questionable, and the other 16 were unsatisfied. The satisfaction rate was 86.0%.
Conclusion: The overall capacity of national laboratories for assays of bismuth potassium citrate capsules is good while a portion of participants require further improvement.

Adenoma ; pathology ; Colonic Neoplasms ; pathology ; Humans ; Intestinal Mucosa ; pathology