Resin composition: An indicator of oil maturity as revealed by fourier transform ion cyclotron resonance mass spectrometry

A pyrolysis experiment was carried out on a Dongying Depression kerogen sample to separate the resin from the oil. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with a positive-ion detector was used to detect the relative proportional changes in the compounds of the resin. During the whole pyrolysis experiment, the relative ratio of resin exceed 10% of the soluble component at each temperature point. Five compounds were detected from the resin: N1, N1O1, N1O_(2), O1, and O_(2). To research the changes in the proportions of the compounds during pyrolysis clearly, these five compounds were divided into three classes: N1, N1Ox, and Ox. The N1 class has the largest proportion in resin at the beginning of the pyrolysis, while Ox class has the least proportion. And the relationship between the number and the molecular mass of three classes compound was researched. With increasing maturity, the proportion of N1 and the N1Ox class decreased rapidly, while the Ox class increased slowly. Through researching these resin compounds, it was found that an inversion in the proportions of above three compounds appeared at the end of the oil window. At the same time, we found that the DBE and carbon number of resin compounds have changed obviously during the pyrolysis: the DBE increased, while the carbon number decreased significantly. And the details of the change of each compound have been researched. This research extends our knowledge of judging the maturity of crude oil during the pyrolysis through the characteristics of compounds in resin and provides the new index based on resin for the evaluation of thermal evolution stage and hydrocarbon generation capacity of source rocks.

快速瞬态质量传递规律的实验与理论研究

建立了液-固及液-液快速阶跃式接触质量传递实验装置与实验测量系统,并分别进行了相应的实验研究.通过实验及理论分析,揭示了液体与固体多孔介质及液体与液体突然接触时不同于经典传质理论所描述的物理机制,研究了各种因素对快速瞬态质量传递规律的影响.结果表明,修正Fick定律表达式的计算结果与实验结果吻合良好,能更好地描述两种介质突然接触时质量传递的阶跃函数特性与规律,表明质量松弛时间、质扩散系数、边界质量扰动强度等对快速瞬态质量传涕规律有一定的影响.

Effects of microtubule-associated protein tau expression on neural stem cell migration after spinal cord injury

Our preliminary proteomics analysis suggested that expression of microtubule-associated protein tau is elevated in the spinal cord after injury. Therefore, the first aim of the present study was to examine tau expression in the injured spinal cord. The second aim was to determine whether tau can regulate neural stem cell migration, a critical factor in the successful treatment of spinal cord injury. We established rat models of spinal cord injury and injected them with mouse hippocampal neural stem cells through the tail vein. We used immunohistochemistry to show that the expression of tau protein and the number of migrated neural stem cells were markedly increased in the injured spinal cord. Furthermore, using a Transwell assay, we showed that neural stem cell migration was not affected by an elevated tau concentration in the outer chamber, but it was decreased by changes in intracellular tau phosphorylation state. These results demonstrate that neural stem cells have targeted migration capability at the site of injury, and that although tau is not a chemokine for targeted migration of neural stem cells, intracellular tau phosphorylation/dephosphorylation can inhibit cell migration.

Direct interaction between Rab5a and Rab4a enhanced epidermal growth factor-stimulated proliferation of gastric cancer cells

BACKGROUND Gastric cancer(GC)is one of the leading causes of cancer-related death worldwide.Although targeted therapies such as antibodies against human epidermal growth factor receptor 2 or vascular endothelial growth factor receptor 2 have been widely used in the treatment of metastatic cancer,the overall outcomes are poor.Therefore,elucidation of the mechanism underlying cancer progression is important to improve prognosis.Overexpression of the Rab5a gene has been confirmed to correlate with tumorigenesis of many cancers,but the mechanism underling,especially of GC,is still unclear.AIM To investigate the effects of Rab5a overexpression on the tumorigenesis of GC.METHODS First,the expression levels of Rab5a and Rab4a in primary tumorous tissues of GC patients diagnosed between 2015 and 2018 were analyzed.Then we constructed HGC-27 cell lines overexpressing green fluorescent protein-Rab5a or red fluorescent protein-Rab4a and investigated the interaction between Rab5a or Rab4a using Western blotting,co-immunoprecipitation,confocal microscopy,and colocalization analysis.Finally,epidermal growth factor-stimulated proliferation of these cell lines was analyzed using cell counting kit-8 cell viability assay.RESULTS Compared with normal gastric tissues,the expression levels of Rab5a and Rab4a increased progressively both in paracancerous tissues and in advanced cancerous tissues.Epidermal growth factor could promote the proliferation of HGC-27 cells,especially Rab5a-overexpressing HGC-27 cells.Notably,Rab5a and Rab4a cooverexpression promoted the proliferation of HGC-27 cells to the greatest extent.Further analysis identified a direct interaction between Rab5a and Rab4a in HGC-27 cells.CONCLUSION Co-overexpression of Rab5a and Rab4a in GC may promote the endosomal recycling of epidermal growth factor receptor,which in turn contributes to poor prognosis and tumor progression in GC patients.Inhibition of Rab5a or Rab4a expression might be a promising therapy for refractory GC.

Hot-embossing fabrication of chalcogenide glasses rib waveguide for mid-infrared molecular sensing

Chalcogenide glasses have shown promise in fabricating mid infrared（MIR） photonic sensing devices due to their excellent optical properties in MIR. In addition, the glass transition temperature of chalcogenide glasses are generally low,making them ideal to create the high-throughput patterns of micro-scale structures based on hot embossing that is alternative to the standard lithographic technology. In this paper, we outline the research progress in the chalcogenide waveguide based on the hot embossing method, and discuss the problems remaining to be solved and the possible solutions.

Influence of stuck-needle technique on joint function and related inflammatory markers in patients with knee osteoarthritis:A randomized controlled trial

Objective:To observe the differences of clinical effect and influence on joint function and inflammatory markers in joint fluid between stuck-needle technique and regular acupuncture in patients with knee osteoarthritis.Methods:Seventy-two patients with knee osteoarthritis were randomly divided into a stuck-needle technique group and a regular acupuncture group,with 36 cases in each one.The selection of acupoints,retaining time of needles,and treatment course were all the same in both groups.The visual analog scale(VAS)score,Lequesne index score,and the content of related inflammatory indexes in joint fluid before and after treatment were observed,and the therapeutic effect were evaluated.Results:After treatment,the VAS scores,Lequesne index scores,interleukin-1 beta(IL-1β),and the tumor necrosis factor a(TNF-α)of the two groups were all lower than those before treatment(all P<0.05).After treatment,the VAS scores,Lequesne index scores,IL-1β,and TNF-αof the stuck-needle technique group were all lower than those of the regular acupuncture group(all P<0.05).The total effective rate of the stuck-needle technique group was 96.97%(32/33),higher than 93.75%(30/32)of the regular acupuncture group(P<0.05).Conclusion:Stuck-needle technique can effectively relieve the pain and improve the joint functions,being more effective than regular acupuncture for the treatment of knee osteoarthritis.

Critical process parameter identification of manufacturing processes of Astragali Radix extract with a weighted determination coeffcient method

Objective:Critical process parameters(CPPs)identification is an important step of the implementation of quality by design(Qb D)concept.There are many CPP identification methods,such as risk analysis method,sensitivity analysis method,multiple linear regression method,standard partial regression coefficient(SPRC)method,and so on.The SPRC method can consider multiple process critical quality attributes(CQAs)simultaneously,but the determination of CPP number is subjective.Therefore,new CPP identification method is still required.Methods:The manufacturing process of Astragali Radix extract,which contained water reflux extraction,concentration,and ethanol precipitation,was used as an example.First,the multiple process CQAs were determined to be the yield of pigment,dry matter,sugars,and active ingredients.Second,the potential CPPs were determined by a knowledge organization method.Plackett-Burman designed experiments were then performed.A weighted determination coefficient(R2 w)method was presented to identify CPPs.In this method,the importance of different CQAs was considered.Process parameters were removed one-by-one according to their importance index.The decrease in R2 wwas used to characterize the importance of the removed parameter.If the decrease of R2 wwas less than a preset threshold,the removed parameter was not a CPP.Results:During the manufacturing process of Astragali Radix extract,the potential CPPs determined by the knowledge organization method were water consumption,reflux extraction time,extraction frequency,ethanol content,ethanol consumption,and concentration endpoint.Reflux extraction time,the first ethanol consumption,the second ethanol consumption,and the second ethanol precipitation refrigeration temperature were found to be CPPs using the weighted determination coefficient method with the threshold of 10%.Conclusion:Using the weighted determination coefficient method,CPPs can be determined with all the CQAs considered based on their importance.The determination of CPP number is more objective compared with the SPRC method.

Disseminated intravascular coagulation as an unusual feature of hypereosinophilic syndrome

To the Editor:A 66-year-old man complaining abdominal pain and bloating for 1 month was admitted to the Department of General Surgery of Xuanwu Hospital,Beijing,China.The patient had a normal body temperature and did not have symptoms such as nausea,diarrhea,or bone/joint pain.He had no history of allergies,no particular past medical or family history.He had taken no medications that could cause eosinophilia.No parasites were found in the stool.Abdominal computerized tomography(CT)scan showed thickening of the stomach wall and peristaltic stiffness with the swelling of the surrounding lymph nodes,indicating possibility of gastric cancer[Figure 1A].Biopsy from gastroscopy showed a massive eosinophil infiltration of the stomach wall[Figure 1B].Meanwhile,blood test showed white blood cell(WBC)count was elevated to 11.09×10^9/L,eosinophils were elevated to 2.53×10^9/L,hemoglobin 160 g/L,and platelet 269×10^9/L.A bone marrow biopsy showed normal cellularity with increased eosinophils.breakpoint cluster region/c-abl oncogene 1,non-receptor tyrosine kinase and Fip1-like1 and platelet-derived growth factor receptor alpha fusion genes were not detected.He was diagnosed as hypereosinophilic syndrome(HES)and treated with corticosteroids(prednisone 20 mg,oral,twice per day).The patient’s abdominal pain and bloating symptoms gradually reduced,and the total number of eosinophils was back to normal in 2 weeks.The follow-up gastroscopy performed at 3 and 6 months after treatment showed normal stomach wall[Figure 1C and Figure 1D].The corticosteroid was tapered and stopped after 8 months treatment.