study

摘要： In this article,structural characteristics of amorphous mono-,di-,and tri-substituted esters of cellulose have been studied.These esters were synthesized under homogenous conditions using anhydrides of various aliphatic acids.The specific gravity of the highly substituted samples was measured by a pycnometric method in the aqueous medium.To calculate the molar,Van der Waals,and free volumes,as well as the packing coefficient of amorphous esters the method of additive contributions of partial volumes of atoms and atom groups in the volumes of polymers was used.Based on the molar volume,also specific gravity of cellulose esters was calculated.The coincidence of calculated and experimental characteristics was shown.In addition,the relationship between glass transition temperature and free volume was found for the esters.The theoretical equations were derived,which provide predicting the structural characteristics of cellulose esters with different degrees of substitution.

摘要： Negation is a ubiquitous phenomenon in all languages.In Chinese,there are a good number of such negative expressions as“fēi(非)”,“bu(不)”,“méi(没)”,“mò(莫)”,“bié(别)”,“wèi(未)”,“wú(无)”,“wù(勿)”,“fiào(覅)”,“béng(甭)”,“fǒu(否)”,and“miǎn(免)”as well as phrases with one of them.This paper is intended to explore the application of negation in Chinese in two ways:(1)People express positive meanings with negative words or phrases;(2)People express negative meanings with positive words or phrases.The linguistic data employed in this paper come from real life,microblogs,variety shows,short videos,and some hǎobùexpressions from three of China’s four classic novels.

摘要： As a part of vocabulary learning,the idiom is an important part of language teaching.This study is to investigate whether conceptual metaphor can promote idioms’teaching and learning or not.In the course of study,we make use of a combination of qualitative and quantitative analysis,collecting data through the questionnaire survey and do experiments in teaching and learning idioms.We get the conclusion:the T value of the experimental group and the control group is p<0.05,the pre-test and post-test values is p<0.05.It is feasible to apply the conceptual metaphor in idiom teaching and learning.

摘要： A verb plays an vital role in a sentence, therefore the study of this perspective attracts numerous scholars. Particularly, corpus-based study has increasing attention in recent years. The present study chooses the THROW verbs in both English and Chi?nese as the subject. The author applies"collocated"function or"pattern query"in two corpus, then analyzes the distinctions of the semantic collocation of the THROW verbs. The findings show that although these verbs belong to the same categorization in a limit?ed range of the specific histories and cultures, there is no one-to-one corresponding relation of these THROW verbs in translation across the two languages.

摘要： BACKGROUND Lifestyle factors such as body mass index(BMI),alcohol drinking,and cigarette smoking,are likely to impact the prognosis of gastric cancer,but the evidence has been inconsistent.AIM To investigate the association of lifestyle factors and long-term prognosis of gastric cancer patients in the China National Cancer Center.METHODS Patients with gastric cancer were identified from the China National Cancer Center Gastric Cancer Database 1998-2018.Survival analysis was performed via Kaplan-Meier estimates and Cox proportional hazards models.RESULTS In this study,we reviewed 18441 cases of gastric cancer.Individuals who were overweight or obese were associated with a positive smoking and drinking history(P=0.002 and P10%groups)but not BMI at diagnosis was related to survival outcomes.With regard to other factors,smoking history of more than 30 years conferred a worse prognosis only in patients who underwent gastrectomy.Extensive efforts are needed to elucidate mechanisms targeting the complex effects of lifestyle factors.

摘要： BACKGROUND Primary tumor location is a prognostic factor for metastatic colorectal cancer(m CRC).Post hoc analyses of m CRC clinical trials,including FIRE-3,CALGB/SWOG 80405,suggest that primary tumor location is also predictive of survival benefit with cetuximab or bevacizumab in combination with 5-fluorouracil-based chemotherapy.AIM Evaluate prognostic/predictive roles of primary tumor location in real-world m CRC patients treated with cetuximab or bevacizumab plus 5-fluorouracil-based chemotherapy.METHODS This retrospective cohort study selected patients with KRAS wild-type m CRC who initiated first-line therapy with cetuximab or bevacizumab in combination with 5-fluorouracil/leucovorin/irinotecan(FOLFIRI)or 5-fluorouracil/leucovorin/oxaliplatin(FOLFOX)between January 2013 and April 2017 from the Flatiron Health electronic health record-derived database of de-identified patientlevel data in the United States.Primary tumor location was abstracted from patients’charts.Left-sided primary tumor location(LPTL)was defined as tumors that originated in the splenic flexure,descending colon,sigmoid colon,or rectum;right-sided primary tumor location(RPTL)was defined as tumors that originated from the appendix,cecum,ascending colon,hepatic flexure,or transverse colon.Propensity score matching was used to balance the baseline demographic and clinical characteristics between patients treated with cetuximab and patientstreated with bevacizumab.Kaplan-Meier and Cox regression methods were used for survival analyses.RESULTS A total of 1312 patients met the selection criteria.Of 248 cetuximab plus FOLFIRI or FOLFOX patients,164 had LPTL and 84 had RPTL;of 1064 bevacizumab plus FOLFIRI or FOLFOX patients,679 had LPTL and 385 had RPTL.Cetuximab LPTL and RPTL patients were more likely to receive FOLFIRI vs bevacizumab patients(LPTL:64.0%vs 24.3%;RPTL:76.2%vs 24.9%,P<0.001).Stage at initial diagnosis was different between cetuximab RPTL vs bevacizumab RPTL patients(P<0.001);cetuximab RPTL patients were more likely to have stage III disease(44.0%vs 22.6%),while bevacizumab RPTL patients were more likely to have stage IV disease(65.7%vs 48.8%).Cetuximab RPTL patients were more likely to have a documented history of adjuvant chemotherapy vs bevacizumab RPTL patients(47.6%vs 22.3%,P<0.001).In the propensity score-matched sample,median overall survival(OS)was 29.7 mo(95%CI:26.9-35.2)for LPTL patients vs 18.3 mo(95%CI:15.8-21.3)for RPTL patients(P<0.001).Median OS was 29.7 mo(95%CI:27.4-NA)for cetuximab LPTL patients vs 29.1 mo(95%CI:26.6-35.6)for bevacizumab LPTL patients(HR=0.87;95%CI:0.63-1.19;P=0.378)and 17.0 mo(95%CI:12.0-32.6)for cetuximab RPTL patients vs 18.8 mo(95%CI:15.8-22.3)for bevacizumab RPTL patients(HR=1.00;95%CI:0.68-1.46;P=0.996).The interaction of treatment and primary tumor location was not significant in the Cox regression.CONCLUSION In this real-world m CRC cohort,the prognostic role of primary tumor location was substantiated,but not the predictive role for treatment with cetuximab vs bevacizumab in combination with 5-fluorouracil-based chemotherapy.

摘要： BACKGROUND Biliary diseases are common digestive system disorders which may combine with biliary tract infection such as cholecystitis or cholangitis.Thus,rapid identification of the bacteria and their antibiotic susceptibility profiles are crucial for reducing the mortality of patients with biliary tract infection.AIM To identify bacterial species and antibiotic susceptibility for antibacterial therapy and analyze bile cultivation risk factors for increasing detection rates.METHODS This retrospective study was conducted from July 2008 to July 2017.In total,1339 bile samples which were collected during therapeutic endoscopic retrograde cholangiopan-creatography or percutaneous transhepatic cholangiodrainage or other biliary surgeries or biliary drainage were obtained to characterize pathogen spectra,antibiotic susceptibility,and clinical features.Clinical data including age,sex,comorbidities,clinical symptoms,protopathies,and history of biliary tract diseases and surgeries were collated from hospital medical records.Species identification and initial drug susceptibility were further identified by biochemical characterization using the VITEK 2 Compact test.RESULTS Positive microbiological findings were observed in 738 samples.The most frequently encountered strains were gram-negative bacteria(74.94%),including Escherichia coli(37.78%),Pseudomonas aeruginosa(8.96%),and Klebsiella pneumoniae(10.29%).Bile bacteria were largely sensitive to carbapenems,piperacillin/tazobactam,and gentamicin.Gram-negative strains had low susceptibility to ceftriaxone,quinolones and ampicillin.Almost the same microorganisms were present in patients with malignant and benign diseases.The number of samples with Klebsiella pneumoniae in the bile culture were significantly different between patients with malignant and benign diseases(55 vs 30;P=0.019).Age(P<0.001),fever(P<0.001),history of biliary tract diseases and surgeries(both P<0.001),benign disease(P=0.002),and the comorbidity chronic renal insufficiency(P=0.007)affected the positive rates of the bile samples.CONCLUSION Gram-negative bacteria were the most commonly isolated biliary bacteria.We determined the major factors associated with positive detection rates.Microbiological analysis of bile samples allowed accurate antibiotic treatments.

摘要： Tai Chi Martial Arts College in Jiaozuo University is the first college entering high-degree education in our country. To some degree, its development indicates whether Tai Chi can leap from "civilian" to"high-taste, high-level". Therefore, the author takes Tai Chi Martial Arts College in Jiaozuo University as anexample, and proposes his advice on healthy development of Tai Chi high-degree education, providing high-level references for decisive management.

摘要： Tai Chi Martial Arts College in Jiaozuo University is the first college entering high-degree education in our country. To some degree, its development indicates whether Tai Chi can leap from "civilian" to"high-taste, high-level". Therefore, the author takes Tai Chi Martial Arts College in Jiaozuo University as anexample, and proposes his advice on healthy development of Tai Chi high-degree education, providing high-level references for decisive management.

摘要： Tai Chi Martial Arts College in Jiaozuo University is the first college entering high-degree education in our country. To some degree, its development indicates whether Tai Chi can leap from "civilian" to"high-taste, high-level". Therefore, the author takes Tai Chi Martial Arts College in Jiaozuo University as anexample, and proposes his advice on healthy development of Tai Chi high-degree education, providing high-level references for decisive management.