AIM： To discuss the efficacy of endoscopic mass screening for gastric cancer.METHODS： The data used in this study were the results of mass screening programs for gastric cancer in Niigata City from 2002 to 2004. The...AIM： To discuss the efficacy of endoscopic mass screening for gastric cancer.METHODS： The data used in this study were the results of mass screening programs for gastric cancer in Niigata City from 2002 to 2004. The number of participants was 35089 in 2002, 34557 in 2003 and 36600 in 2004. The finding ratio referred to the final diagnosis of gastric cancer after a double check of endoscopic files and histological findings. The costs of identifying one case of gastric cancer were calculated based on the total expense for each screening program and additional close examinations. RESULTS： From the analysis of individual screening program with endoscopy, individual screening program with X-ray （ISX） and mass screening program with photofluorography （MSP） in reference to the finding ratio of gastric cancer, endoscopic examination was the best for detecting early gastric cancer, the finding ratio was 0.87% in 2004, approximately 2.7 and 4.6 times higher than those of the ISX and MSP groups. In addition, this novel method was the cheapest means regarding the cost of identifying one case of gastric cancer, which was estimated to be 1608000 Japanese yen in 2004. CONCLUSION： Endoscopic mass screening is a promising method and can be effectively applied if a sufficient number of skilled endoscopists become available to staff the system and if city offices support it.展开更多
Aim:To investigate the pathological features of the prostate biopsy through mass screening for prostate cancer in a Chinese cohort and their association with serum prostate specific antigen (PSA).Methods:A total of 12...Aim:To investigate the pathological features of the prostate biopsy through mass screening for prostate cancer in a Chinese cohort and their association with serum prostate specific antigen (PSA).Methods:A total of 12 027 Chinese men in Changchun were screened for prostate cancer by means of the serum total prostate specific antigen (tPSA) test (by Elisa assay).Transrectal ultrasound-guided systematic six-sextant biopsies were performed on those whose serum tPSA value was >4.0 ng/mL and those who had obstructive symptoms (despite their tPSA value) and were subject to subse- quent pathological analysis with the aid of the statistic software SPSS 10.0 (SPSS.Inc.,Chicago.USA).Results:Of the 12 027 cases,158 (including 137 patients whose serum tPSA values were >4.0 ng/mL and 21 patients [serum tPSA <4. 0 ng/mL] who had obstructive symptoms) undertook prostate biopsy.Of the 158 biopsies,41 cases of prostatic carci- noma were found (25.9 %,41/158).The moderately differentiated carcinoma and poorly differentiated carcinoma ac- counted for 61% and 34 %,respectively.A significant linear positive correlation between the serum tPSA and the Gleason scores in the 41 cases of prostatic carcinoma (r=0.312,P<0.01) was established.A significant linear positive correlation between the serum tPSA value of the 41 prostatic carcinoma and the positive counts of carcinoma in sextant biopsies was established (r=0.406,P<0.01),indicating a significant linear relationship between serum tPSA and the size of tumor. Condusion:This study was the first to conduct mass screening for prostate cancer by testing for serum tPSA values and the first to investigate the pathological features of prostate cancer in a cohort of Chinese men.Our results reveal that the moderately differentiated carcinoma is the most common type of prostate cancer.This study also has shown that the serum tPSA value in prostate cancer is associated with the Gleason score and the size of tumor.展开更多
Background The incidence of prostate carcinoma (Pca) has been increasing in China. We detected Pca in elderly men in Changchun,north China and the significance of prostate specific antigen (PSA) in mass screening an...Background The incidence of prostate carcinoma (Pca) has been increasing in China. We detected Pca in elderly men in Changchun,north China and the significance of prostate specific antigen (PSA) in mass screening and clinical staging of Pca. Methods Serum PSA from 12 027 men over 50 years old from Changchun was analyzed. In case of serum PSA greater than 4.0 ng/ml,the patient was suspected of potentially suffering from Pca,and transrectal six-point puncture prostate biopsies were performed under ultrasound guidance. Pathological examinations were performed on the biopsy tissue,and ABCD and TNM clinical stagings were used in accordance with international standards. Correlations between serum PSA level and clinical stage were analyzed. Results PSA was greater than 4.0 ng/ml in 813 patients (6.8% of the 12 027 men). Transrectal six-point prostate puncture biopsies guided by ultrasound were performed in 273 patients (33.6% of the 813 patients who were tested positive in the initial mass screening). Of these 273 patients,69 cases of Pca (25.3% of 273) were confirmed by biopsy in the second screening,with an overall detection rate for Pca of 0.57% (69/12 027). The total number of patients in stages A,B,T1,or T2 was 57.9%,and over 20% of them suffered from late stage Pca with lymph node and bone metastasis. An obvious positive correlation was observed between ABCD staging,TNM staging,and serum PSA level. Conclusions Serum PSA level is not only the golden standard for mass screening of Pca,but also the predictor for clinical stage of Pca. PSA testing revealed asymptomatic Pca cases in early,middle,and later stages in the elderly,suggesting that mass screening is of paramount importance.展开更多
Breast cancer is a global health concern with a significant impact on the well-being of women. Worldwide, the past several decades have witnessed changes in the incidence and mortality of breast cancer. Additionally,e...Breast cancer is a global health concern with a significant impact on the well-being of women. Worldwide, the past several decades have witnessed changes in the incidence and mortality of breast cancer. Additionally,epidemiological data reveal distinct geographic and demographic disparities globally. A range of modifiable and non-modifiable risk factors are established as being associated with an increased risk of developing breast cancer.This review discusses genetic, hormonal, behavioral, environmental, and breast-related risk factors. Screening plays a critical role in the effective management of breast cancer. Various screening modalities, including mammography,ultrasound, magnetic resonance imaging(MRI), and physical examination, have different applications, and a combination of these modalities is applied in practice. Current screening recommendations are based on factors including age and risk, with a significant emphasis on minimizing potential harms to achieve an optimal benefits-to-harms ratio. This review provides a comprehensive insight into the epidemiology, risk factors, and screening of breast cancer. Understanding these elements is crucial for improving breast cancer management and reducing its burden on affected individuals and healthcare systems.展开更多
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had highly transmissible and pathogenic, which caused serious economic loss and hazard topublic health. Different countries have developed strategiest...The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had highly transmissible and pathogenic, which caused serious economic loss and hazard topublic health. Different countries have developed strategiesto deal with the COVID-19 pandemic that fit their epidemiological situations, capacities, and values. Mass screeningcombined with control measures rapidly reduced thetransmission of the SARS-CoV-2 infection. The COVID-19pandemic has dramatically highlighted the essential role ofdiagnostics capacity in the control of communicable diseases. Mass screening has been increasingly used to detectsuspected COVID-19 cases and their close contacts, asymptomatic case, patients attending fever clinics, high-riskpopulations, employees, even all population to identifyinfectious individuals. Mass screening is a key component tofight against SARS-CoV-2 and return to normalcy. Here wedescribe the history of mass screening, define the scope ofmass screening, describe its application scenarios, anddiscuss the impact and challenges of using this approach tocontrol COVID-19. We conclude that through a comprehension screening program and strong testing capabilities, massscreening could help us return to normalcy more quickly.展开更多
AIM: To improve the prevention and treatment of senile patients with colorectal cancer by evaluating the importance of colonoscopy in clinical screening and follow-up. METHODS: Clinical screening of colonoscopy was pe...AIM: To improve the prevention and treatment of senile patients with colorectal cancer by evaluating the importance of colonoscopy in clinical screening and follow-up. METHODS: Clinical screening of colonoscopy was performed for 2196 patients aged 60-90 years old according to the protocol,and 1740 of them (79.2%) were followed-up. RESULTS: Colorectal cancer was found in 52 patients, and the detectable rate was 2.4%. Among them, 19 were diagnosed as early colorectal cancer, accounting for 36.5% of the detected colorectal cancer. Among the followed-up patients, early colorectal cancer was found in 9, accounting for 45.0% of the detected colorectal cancer. The resectable rate and 5 years survival rate of colorectal cancer were 97.7% and 80.9% respectively. The incidence of complication was 0.05%, and the successful rate of cecum intubation was 98.9%. CONCLUSION: Colonoscopic screening and follow-up of the elderly for colorectal cancer and pre-cancerous lesion (adenomatoid polyp) can increase the detectable rate of early colorectal cancer and improve its prevention and treatment.展开更多
AIM:To examine how the introduction of endoscopy to gastric cancer screening affected survival prognosis in a regional population. METHODS: The subjects comprised 4261 residents of Kamigoto,Nagasaki Prefecture,who und...AIM:To examine how the introduction of endoscopy to gastric cancer screening affected survival prognosis in a regional population. METHODS: The subjects comprised 4261 residents of Kamigoto,Nagasaki Prefecture,who underwent gastric X-ray examination for gastric cancer screening from 1991 to 1995,and all 7178 residents who underwent endoscopic examination for the same purpose from 1996 to 2003. The analysis evaluated trends in age-adjusted gastric cancer mortality rates and standard mortality ratios (SMRs) among the Kamigoto residents. RESULTS: According to demographic statistics,the 1995 and 2000 age-adjusted gastric cancer mortality rates in Nagasaki Prefecture (per 100 000 population) were 42.6 and 37.3 for males and 18.6 and 16.0 for females,while the corresponding rates in Kamigoto before and after the introduction of endoscopic screening were respectively 51.9 and 28.0,and 26.6 and 6.9. The data obtained in this study were divided into those for two periods,1990-1996 and 1997-2006,and SMRs were calculated separately for males and females. For the first period,the SMR was 1.04 (95% CI 0.50-1.58) for males and 1.54 (95% CI 0.71-2.38) for females,while for the second period the SMR was 0.71 (95% CI 0.33-1.10) for males and 0.62 (95% CI 0.19-1.05) for females. CONCLUSION: Following the introduction of endoscopic examination,gastric cancer death rates decreased in Kamigoto.展开更多
AIM:To explore the problems in the screening of colorecta carcinoma in the elderly. METHODS:Three models of colorectal cancer prevention were examined:standard screening,active check-up of suspected cases and summons ...AIM:To explore the problems in the screening of colorecta carcinoma in the elderly. METHODS:Three models of colorectal cancer prevention were examined:standard screening,active check-up of suspected cases and summons to have endoscopic check- up for previously diagnosed colorectal polyps.The study was performed among three groups of elderly individuals: Group 1 (167 cases),hospitalized asymptomatic individuals without symptoms in large intestines.Group 2 (612 cases): old individuals at home for the aged,out of which 32 showed symptoms of colon disorders;Group 3 (44 cases):elderly people with diagnosed polyps.As a result of 1788 rectosigmoidoscopies,we identified 61 individuals with polyps,out of which 44 patients were over 65 years old. However,only 9 of these 44 individuals agreed to have the endoscopy performed again. RESULTS:One cancer and 13 polyps were detected in Group 1,and two polyps in Group 2.However,it should be noted that only eleven individuals from Group 2 agreed to have the endoscopy.In Group 3,there were no relapses of the polyps among the nine individuals who came back for the endoscopy. CONCLUSION:Poor understanding of the screening procedures is one of the greatest problems in early detection of the cancer in the aged.Paradoxically,the cooperation is better with hospitalized patients,than with 'successfully old' persons.展开更多
Colorectal cancer(CRC)is the third most diagnosed form of cancer and second most deadly cancer worldwide.Introduction of better screening has improved both incidence and mortality.However,as the coronavirus disease 20...Colorectal cancer(CRC)is the third most diagnosed form of cancer and second most deadly cancer worldwide.Introduction of better screening has improved both incidence and mortality.However,as the coronavirus disease 2019(COVID-19)pandemic began,healthcare resources were shunted away from cancer screening services resulting in a sharp decrease in CRC screening and a backlog of patients awaiting screening tests.This may have significant effects on CRC cancer mortality,as delayed screening may lead to advanced cancer at diagnosis.Strategies to overcome COVID-19 related disruption include utilizing stool-based cancer tests,developing screening protocols based on individual risk factors,expanding telehealth,and increasing open access colonoscopies.In this review,we will summarize the effects of COVID-19 on CRC screening,the potential longoutcomes,and ways to adapt CRC screening during this global pandemic.展开更多
BACKGROUND The Korea National Cancer Screening Program currently provides screening for colorectal cancer(CRC)for adults older than 50 years with no upper age limit.In general,people are likely to only pay attention t...BACKGROUND The Korea National Cancer Screening Program currently provides screening for colorectal cancer(CRC)for adults older than 50 years with no upper age limit.In general,people are likely to only pay attention to the benefits of cancer screening and to neglect its risks.Most consider the benefits of cancer screening as being far greater than the risks and are unaware that any potential benefits and harms can vary with age.AIM To report acceptance of an upper age limit for CRC screening and factors associated therewith among cancer-free individuals in Korea.METHODS The present study analyzed data from the Korea National Cancer Screening Survey 2017,a nationally representative random sample of 4500 Korean individuals targeted for screening for the five most common types of cancer.A total of 1922 participants were included in the final analysis.The baseline characteristics of the study population are presented as unweighted numbers and weighted proportions.Both univariate and multivariate logistic regression models were developed to examine factors related with acceptance of an upper age limit for CRC screening;subgroup analysis was also applied.RESULTS About 80%(1554/1922)of the respondents agreed that CRC screening should not be offered for individuals older than 80 years.Specifically,those who had never been screened for CRC had the highest acceptance rate(91%).Overall,screening history for CRC[screened by both fecal occult blood test and colonoscopy,adjusted odds ratio(aOR)=0.33,95%CI:0.22-0.50]and other cancers(aOR=0.55,95%CI:0.34-0.87),as well as a family history of cancer(aOR=0.66,95%CI:0.50-0.87),were negatively associated with acceptance of an upper age limit for CRC screening.In contrast,metropolitan residents(aOR=1.86,95%CI:1.29-2.68)and people who exercised regularly(aOR=1.42,95%CI:1.07-1.89)were more likely to accept an upper age limit.After subgrouping,we found gender,marital status,and lifetime smoking history among never-screened individuals and residential region,family history of cancer,and physical activity among never-screened individuals to be associated with acceptance of an upper age limit.CONCLUSION This study describes acceptance of an upper age limit for CRC screening and factors associated with it,and provides perspectives that should be considered,in addition to scientific evidence,when developing population-based cancer screening policies and programs.展开更多
AIM: To set up a mathematic model for gastric cancer screening and to evaluate its function in mass screening for gastric cancer.METHODS: A case control study was carried on in 66patients and 198 normal people, then t...AIM: To set up a mathematic model for gastric cancer screening and to evaluate its function in mass screening for gastric cancer.METHODS: A case control study was carried on in 66patients and 198 normal people, then the risk and protective factors of gastric cancer were determined, including heavy manual work, foods such as small yellow-fin tuna, dried small shrimps, squills, crabs, mothers suffering from gastric diseases, spouse alive, use of refrigerators and hot food,etc. According to some principles and methods of probability and fuzzy mathematics, a quantitative assessment model was established as follows: first, we selected some factors significant in statistics, and calculated weight coefficient for each one by two different methods; second, population space was divided into gastric cancer fuzzy subset and non gastric cancer fuzzy subset, then a mathematic model for each subset was established, we got a mathematic expression of attribute degree (AD).RESULTS: Based on the data of 63 patients and 693 normal people, AD of each subject was calculated. Considering the sensitivity and specificity, the thresholds of AD values calculated were configured with 0.20 and 0.17, respectively.According to these thresholds, the sensitivity and specificity of the quantitative model were about 69% and 63%.Moreover, statistical test showed that the identification outcomes of these two different calculation methods were identical (P＞0.05).CONCLUSION: The validity of this method is satisfactory.It is convenient, feasible, economic and can be used to determine individual and population risks of gastric cancer.展开更多
Background:The effectiveness of lung cancer screening with low-dose computed tomography(LDCT)has been established.The current study evaluates the cost-effectiveness of lung cancer screening with LDCT in a general popu...Background:The effectiveness of lung cancer screening with low-dose computed tomography(LDCT)has been established.The current study evaluates the cost-effectiveness of lung cancer screening with LDCT in a general population in China.Methods:A previously validated micro-simulation model was used to simulate a cohort of men and women on a lifetime horizon in the presence and absence of LDCT screening.The modeling data were collected from numerous national and international sources.Simulated screening scenarios included different combinations of screening intervals and start and stop ages.Additional costs(valued in Chinese Yuan,CNY;1 USD=6.8976 CNY,1 EUR=7.8755 CNY in 2020),life-years gained(LYG)and mortality reduction due to screening were also determined.The costs and life-years were discounted by 3%.All results were scaled to 1,000 individuals.The average cost-effectiveness ratio(ACER)was calculated.A willingness-to-pay threshold of CNY 217.3k/LYG was considered.A healthcare system perspective was adopted.Results:Compared to no screening,lung cancer screening by LDCT in a general Chinese population yielded 21.0-36.7 LYG in men and 9.2-16.6 LYG in women across the scenarios.For men,biennial LDCT screening yielded an ACER of CNY 171.4k-306.3k/LYG relative to no screening.Biennial screening performed between 55 and 75 years of age was optimal at the defined threshold;it resulted in CNY 174.6k/LYG and a lung cancer mortality reduction of 9.1%,and this scenario had a 75%probability of being cost-effective.For women,the ACER ranged from CNY 364.2k to 1193.3k/LYG.Conclusions:In China,lung cancer screening with LDCT in the general population including never smokers could be cost-effective for men with 75%probability,but not for women.The optimal strategy for men would be performing biennial screening between 55 and 75 years of age.展开更多
Colorectal cancer(CRC)is a very heterogeneous disease that is caused by the interaction of genetic and environmental factors.CRC develops through a gradual accumulation of genetic and epigenetic changes,leading to the...Colorectal cancer(CRC)is a very heterogeneous disease that is caused by the interaction of genetic and environmental factors.CRC develops through a gradual accumulation of genetic and epigenetic changes,leading to the transformation of normal colonic mucosa into invasive cancer.CRC is one of the most prevalent and incident cancers worldwide,as well as one of the most deadly.Approximately 1235108 people are diagnosed annually with CRC,and 609051 die from CRC annually.The World Health Organization estimates an increase of77%in the number of newly diagnosed cases of CRCand an increase of 80%in deaths from CRC by 2030.The incidence of CRC can benefit from different strategies depending on its stage:health promotion through health education campaigns(when the disease is not yet present),the implementation of screening programs(for detection of the disease in its early stages),and the development of nearly personalized treatments according to both patient characteristics(age,sex)and the cancer itself(gene expression).Although there are different strategies for screening and although the number of such strategies is increasing due to the potential of emerging technologies in molecular marker application,not all strategies meet the criteria required for screening tests in population programs;the three most accepted tests are the fecal occult blood test(FOBT),colonoscopy and sigmoidoscopy.FOBT is the most used method for CRC screening worldwide and is also the primary choice in most population-based screening programs in Europe.Due to its non-invasive nature and low cost,it is one of the most accepted techniques by population.CRC is a very heterogeneous disease,and with a few exceptions(APC,p53,KRAS),most of the genes involved in CRC are observed in a small percentage of cases.The design of genetic and epigenetic marker panels that are able to provide maximum coverage in the diagnosis of colorectal neoplasia seems a reasonable strategy.In recent years,the use of DNA,RNA and protein markers in different biological samples has been explored as strategies for CRC diagnosis.Although there is not yet sufficient evidence to recommend the analysis of biomarkers such as DNA,RNA or proteins in the blood or stool,it is likely that given the quick progression of technology tools in molecular biology,increasingly sensitive and less expensive,these tools will gradually be employed in clinical practice and will likely be developed in mass.展开更多
AIM: To assess the possibility of non-invasive screening of atrophic chronic gastritis for preventing further development of gastric cancer.METHODS: One hundred and seventy-eight consecutive Helicobacter pylori ( H py...AIM: To assess the possibility of non-invasive screening of atrophic chronic gastritis for preventing further development of gastric cancer.METHODS: One hundred and seventy-eight consecutive Helicobacter pylori ( H pylori)-positive dyspeptic patients after detection of serum levels of pepsinogen-1 (PG-1) and gastrin-17 (G-17) by enzyme immunoassay were proposed for endoscopy and histology. The serologic and morphologic results were compared with estimating the sensitivity, specificity and prognostic values of the tests.RESULTS: There was statistically significant reverse dependence between the grade of stomach mucosal antral or corpus atrophy and the proper decreasing of serum G17 or PG1 levels. The serologic method was quite sensitive in the diagnosis of non-atrophic and severe antral and corpus gastritis. Also, it was characterized by the high positive and negative prognostic values.CONCLUSION: Detection of serum G-17 and PG1 levels can be offered as the screening tool for atrophic gastritis. The positive serologic results require further chromoendoscopy with mucosal biopsy, for revealing probable progressing of atrophic process with development of intestinal metaplasia, dysplasia or gastric cancer.展开更多
AIM:To compare the cost and accuracy of upper gastrointestinal(GI)X-ray and upper endoscopy for diagnosis of gastric cancer using data from the 2002-2004 Korean National Cancer Screening Program(NCSP). METHODS:The stu...AIM:To compare the cost and accuracy of upper gastrointestinal(GI)X-ray and upper endoscopy for diagnosis of gastric cancer using data from the 2002-2004 Korean National Cancer Screening Program(NCSP). METHODS:The study population included 1 503 646 participants in the 2002-2004 stomach cancer screening program who underwent upper GI X-ray or endoscopy.The accuracy of screening was defined as the probability of detecting gastric cancer.We calculated the probability by merging data from the NCSP and the Korea Central Cancer Registry.We estimated the direct costs of the medical examination and the tests for up- per GI X-ray,upper endoscopy,and biopsy. RESULTS:The probability of detecting gastric cancervia upper endoscopy was 2.9-fold higher than via upper GI X-ray.The unit costs of screening using upper GI X-ray and upper endoscopy were$32.67 and$34.89, respectively.In 2008,the estimated cost of identifying one case of gastric cancer was$53094.64 using upper GI X-ray and$16 900.43 using upper endoscopy.The cost to detect one case of gastric cancer was the same for upper GI X-ray and upper endoscopy at a cost ratio of 1:3.7. CONCLUSION:Upper endoscopy is slightly more costly to perform,but the cost to detect one case of gastric cancer is lower.展开更多
The incidence of Barretts metaplasia (BM) as well as Barrett' s adenocarcinoma (BA) has been increasing in western populations. The prognosis of BA is worse because individuals present at a late stage. Attempts ha...The incidence of Barretts metaplasia (BM) as well as Barrett' s adenocarcinoma (BA) has been increasing in western populations. The prognosis of BA is worse because individuals present at a late stage. Attempts have been made to intervene at early stage using surveillance programmes, although proof of efficacy of endoscopic surveillance is lacking, particularly outside the specialist centres. The management of BM needs to be evidencebased as there is a lack clarity about how best to treat this condition. The role of proton pump inhibitors and antireflux surgery to control reflux symptoms is justified.Whether adequate control of gastroesophageal reflux early in the disease alters the natural history of Barrett' s change once it has developed and or prevents it in patients with gastroesophageal reflux disease but with no Barrett' s change remains unanswered. There is much to be learned about BM. Thus there is great need for carefully designed large randomised controlled trials to address these issues in order to determine how best to manage patients with BM.展开更多
Based on the statics theory, a novel and feasible twice-suspended-mass method(TSMM) was proposed to deal with the seldom-studied issue of fault diagnosis for damping springs of large vibrating screen(LVS). With the st...Based on the statics theory, a novel and feasible twice-suspended-mass method(TSMM) was proposed to deal with the seldom-studied issue of fault diagnosis for damping springs of large vibrating screen(LVS). With the static balance characteristic of the screen body/surface as well as the deformation compatibility relation of springs considered, static model of the screen surface under a certain load was established to calculate compression deformation of each spring. Accuracy of the model was validated by both an experiment based on the suspended mass method and the properties of the 3D deformation space in a numerical simulation. Furthermore, by adopting the Taylor formula and the control variate method, quantitative relationship between the change of damping spring deformation and the change of spring stiffness, defined as the deformation sensitive coefficient(DSC), was derived mathematically, from which principle of the TSMM for spring fault diagnosis is clarified. In the end, an experiment was carried out and results show that the TSMM is applicable for diagnosing the fault of single spring in a LVS.展开更多
Pancreatic cancer,as a highly malignant cancer and the fourth cause of cancer-related death in world,is characterized by dismal prognosis,due to rapid disease progression,highly invasive tumour phenotype,and resistanc...Pancreatic cancer,as a highly malignant cancer and the fourth cause of cancer-related death in world,is characterized by dismal prognosis,due to rapid disease progression,highly invasive tumour phenotype,and resistance to chemotherapy.Despite significant advances in treatment of the disease during the past decade,the survival rate is little improved.A contributory factor to the poor outcome is the lack of appropriate sensitive and specific biomarkers for early diagnosis.Furthermore,biomarkers for targeting,directing and assessing therapeutic intervention,as well as for detection of residual or recurrent cancer are also needed.Thus,the identification of adequate biomarkers in pancreatic cancer is of extreme importance.Recently,accompanying the development of proteomic technology and devices,more and more potential biomarkers have appeared and are being reported.In this review,we provide an overview of the role of proteome-based biomarkers in pancreatic cancer,including tissue,serum,juice,urine and cell lines.We also discuss the possible mechanism and prospects in the future.That information hopefully might be helpful for further research in the field.展开更多
According to Wick＇s theorem, the second order self-energy corrections of hadrons in the hot and dense nuclear matter are calculated. Furthermore, the Feynman rules are summarized, and an effective formulation on quan...According to Wick＇s theorem, the second order self-energy corrections of hadrons in the hot and dense nuclear matter are calculated. Furthermore, the Feynman rules are summarized, and an effective formulation on quantum hadrodynamics at finite temperatures and densities is evauated. As the strong couplings between nucleons are considered, the self-consistency of this method is discussed in the framework of relativistic mean-field approximation. Debye screening masses of the scalar and vector mesons in the hot and dense nuclear matter are calculated with this method in the relativistic mean-field approximation. The results are different from those of thermofield dynamics and Brown-Rho conjecture. Moreover, the effective masses of the photon and the nucleon in the hot and dense nuclear matter are discussed.展开更多
文摘AIM： To discuss the efficacy of endoscopic mass screening for gastric cancer.METHODS： The data used in this study were the results of mass screening programs for gastric cancer in Niigata City from 2002 to 2004. The number of participants was 35089 in 2002, 34557 in 2003 and 36600 in 2004. The finding ratio referred to the final diagnosis of gastric cancer after a double check of endoscopic files and histological findings. The costs of identifying one case of gastric cancer were calculated based on the total expense for each screening program and additional close examinations. RESULTS： From the analysis of individual screening program with endoscopy, individual screening program with X-ray （ISX） and mass screening program with photofluorography （MSP） in reference to the finding ratio of gastric cancer, endoscopic examination was the best for detecting early gastric cancer, the finding ratio was 0.87% in 2004, approximately 2.7 and 4.6 times higher than those of the ISX and MSP groups. In addition, this novel method was the cheapest means regarding the cost of identifying one case of gastric cancer, which was estimated to be 1608000 Japanese yen in 2004. CONCLUSION： Endoscopic mass screening is a promising method and can be effectively applied if a sufficient number of skilled endoscopists become available to staff the system and if city offices support it.
文摘Aim:To investigate the pathological features of the prostate biopsy through mass screening for prostate cancer in a Chinese cohort and their association with serum prostate specific antigen (PSA).Methods:A total of 12 027 Chinese men in Changchun were screened for prostate cancer by means of the serum total prostate specific antigen (tPSA) test (by Elisa assay).Transrectal ultrasound-guided systematic six-sextant biopsies were performed on those whose serum tPSA value was >4.0 ng/mL and those who had obstructive symptoms (despite their tPSA value) and were subject to subse- quent pathological analysis with the aid of the statistic software SPSS 10.0 (SPSS.Inc.,Chicago.USA).Results:Of the 12 027 cases,158 (including 137 patients whose serum tPSA values were >4.0 ng/mL and 21 patients [serum tPSA <4. 0 ng/mL] who had obstructive symptoms) undertook prostate biopsy.Of the 158 biopsies,41 cases of prostatic carci- noma were found (25.9 %,41/158).The moderately differentiated carcinoma and poorly differentiated carcinoma ac- counted for 61% and 34 %,respectively.A significant linear positive correlation between the serum tPSA and the Gleason scores in the 41 cases of prostatic carcinoma (r=0.312,P<0.01) was established.A significant linear positive correlation between the serum tPSA value of the 41 prostatic carcinoma and the positive counts of carcinoma in sextant biopsies was established (r=0.406,P<0.01),indicating a significant linear relationship between serum tPSA and the size of tumor. Condusion:This study was the first to conduct mass screening for prostate cancer by testing for serum tPSA values and the first to investigate the pathological features of prostate cancer in a cohort of Chinese men.Our results reveal that the moderately differentiated carcinoma is the most common type of prostate cancer.This study also has shown that the serum tPSA value in prostate cancer is associated with the Gleason score and the size of tumor.
基金ThisstudywasaprojectoftheJapan ChinaInternationalSpecialTechnicalCooperation (No 5 9) ,andwassupportedbytheJapanInternationalCooperationAgency (JICA)
文摘Background The incidence of prostate carcinoma (Pca) has been increasing in China. We detected Pca in elderly men in Changchun,north China and the significance of prostate specific antigen (PSA) in mass screening and clinical staging of Pca. Methods Serum PSA from 12 027 men over 50 years old from Changchun was analyzed. In case of serum PSA greater than 4.0 ng/ml,the patient was suspected of potentially suffering from Pca,and transrectal six-point puncture prostate biopsies were performed under ultrasound guidance. Pathological examinations were performed on the biopsy tissue,and ABCD and TNM clinical stagings were used in accordance with international standards. Correlations between serum PSA level and clinical stage were analyzed. Results PSA was greater than 4.0 ng/ml in 813 patients (6.8% of the 12 027 men). Transrectal six-point prostate puncture biopsies guided by ultrasound were performed in 273 patients (33.6% of the 813 patients who were tested positive in the initial mass screening). Of these 273 patients,69 cases of Pca (25.3% of 273) were confirmed by biopsy in the second screening,with an overall detection rate for Pca of 0.57% (69/12 027). The total number of patients in stages A,B,T1,or T2 was 57.9%,and over 20% of them suffered from late stage Pca with lymph node and bone metastasis. An obvious positive correlation was observed between ABCD staging,TNM staging,and serum PSA level. Conclusions Serum PSA level is not only the golden standard for mass screening of Pca,but also the predictor for clinical stage of Pca. PSA testing revealed asymptomatic Pca cases in early,middle,and later stages in the elderly,suggesting that mass screening is of paramount importance.
基金supported by the CAMS Innovation Fund for Medical Sciences (No. 2021-I2M-1-014 and No. 2022-I2M-2-002)。
文摘Breast cancer is a global health concern with a significant impact on the well-being of women. Worldwide, the past several decades have witnessed changes in the incidence and mortality of breast cancer. Additionally,epidemiological data reveal distinct geographic and demographic disparities globally. A range of modifiable and non-modifiable risk factors are established as being associated with an increased risk of developing breast cancer.This review discusses genetic, hormonal, behavioral, environmental, and breast-related risk factors. Screening plays a critical role in the effective management of breast cancer. Various screening modalities, including mammography,ultrasound, magnetic resonance imaging(MRI), and physical examination, have different applications, and a combination of these modalities is applied in practice. Current screening recommendations are based on factors including age and risk, with a significant emphasis on minimizing potential harms to achieve an optimal benefits-to-harms ratio. This review provides a comprehensive insight into the epidemiology, risk factors, and screening of breast cancer. Understanding these elements is crucial for improving breast cancer management and reducing its burden on affected individuals and healthcare systems.
基金This study was supported by National Key R&D Program of China 2021ZD0114103 to QY W.
文摘The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had highly transmissible and pathogenic, which caused serious economic loss and hazard topublic health. Different countries have developed strategiesto deal with the COVID-19 pandemic that fit their epidemiological situations, capacities, and values. Mass screeningcombined with control measures rapidly reduced thetransmission of the SARS-CoV-2 infection. The COVID-19pandemic has dramatically highlighted the essential role ofdiagnostics capacity in the control of communicable diseases. Mass screening has been increasingly used to detectsuspected COVID-19 cases and their close contacts, asymptomatic case, patients attending fever clinics, high-riskpopulations, employees, even all population to identifyinfectious individuals. Mass screening is a key component tofight against SARS-CoV-2 and return to normalcy. Here wedescribe the history of mass screening, define the scope ofmass screening, describe its application scenarios, anddiscuss the impact and challenges of using this approach tocontrol COVID-19. We conclude that through a comprehension screening program and strong testing capabilities, massscreening could help us return to normalcy more quickly.
文摘AIM: To improve the prevention and treatment of senile patients with colorectal cancer by evaluating the importance of colonoscopy in clinical screening and follow-up. METHODS: Clinical screening of colonoscopy was performed for 2196 patients aged 60-90 years old according to the protocol,and 1740 of them (79.2%) were followed-up. RESULTS: Colorectal cancer was found in 52 patients, and the detectable rate was 2.4%. Among them, 19 were diagnosed as early colorectal cancer, accounting for 36.5% of the detected colorectal cancer. Among the followed-up patients, early colorectal cancer was found in 9, accounting for 45.0% of the detected colorectal cancer. The resectable rate and 5 years survival rate of colorectal cancer were 97.7% and 80.9% respectively. The incidence of complication was 0.05%, and the successful rate of cecum intubation was 98.9%. CONCLUSION: Colonoscopic screening and follow-up of the elderly for colorectal cancer and pre-cancerous lesion (adenomatoid polyp) can increase the detectable rate of early colorectal cancer and improve its prevention and treatment.
文摘AIM:To examine how the introduction of endoscopy to gastric cancer screening affected survival prognosis in a regional population. METHODS: The subjects comprised 4261 residents of Kamigoto,Nagasaki Prefecture,who underwent gastric X-ray examination for gastric cancer screening from 1991 to 1995,and all 7178 residents who underwent endoscopic examination for the same purpose from 1996 to 2003. The analysis evaluated trends in age-adjusted gastric cancer mortality rates and standard mortality ratios (SMRs) among the Kamigoto residents. RESULTS: According to demographic statistics,the 1995 and 2000 age-adjusted gastric cancer mortality rates in Nagasaki Prefecture (per 100 000 population) were 42.6 and 37.3 for males and 18.6 and 16.0 for females,while the corresponding rates in Kamigoto before and after the introduction of endoscopic screening were respectively 51.9 and 28.0,and 26.6 and 6.9. The data obtained in this study were divided into those for two periods,1990-1996 and 1997-2006,and SMRs were calculated separately for males and females. For the first period,the SMR was 1.04 (95% CI 0.50-1.58) for males and 1.54 (95% CI 0.71-2.38) for females,while for the second period the SMR was 0.71 (95% CI 0.33-1.10) for males and 0.62 (95% CI 0.19-1.05) for females. CONCLUSION: Following the introduction of endoscopic examination,gastric cancer death rates decreased in Kamigoto.
文摘AIM:To explore the problems in the screening of colorecta carcinoma in the elderly. METHODS:Three models of colorectal cancer prevention were examined:standard screening,active check-up of suspected cases and summons to have endoscopic check- up for previously diagnosed colorectal polyps.The study was performed among three groups of elderly individuals: Group 1 (167 cases),hospitalized asymptomatic individuals without symptoms in large intestines.Group 2 (612 cases): old individuals at home for the aged,out of which 32 showed symptoms of colon disorders;Group 3 (44 cases):elderly people with diagnosed polyps.As a result of 1788 rectosigmoidoscopies,we identified 61 individuals with polyps,out of which 44 patients were over 65 years old. However,only 9 of these 44 individuals agreed to have the endoscopy performed again. RESULTS:One cancer and 13 polyps were detected in Group 1,and two polyps in Group 2.However,it should be noted that only eleven individuals from Group 2 agreed to have the endoscopy.In Group 3,there were no relapses of the polyps among the nine individuals who came back for the endoscopy. CONCLUSION:Poor understanding of the screening procedures is one of the greatest problems in early detection of the cancer in the aged.Paradoxically,the cooperation is better with hospitalized patients,than with 'successfully old' persons.
文摘Colorectal cancer(CRC)is the third most diagnosed form of cancer and second most deadly cancer worldwide.Introduction of better screening has improved both incidence and mortality.However,as the coronavirus disease 2019(COVID-19)pandemic began,healthcare resources were shunted away from cancer screening services resulting in a sharp decrease in CRC screening and a backlog of patients awaiting screening tests.This may have significant effects on CRC cancer mortality,as delayed screening may lead to advanced cancer at diagnosis.Strategies to overcome COVID-19 related disruption include utilizing stool-based cancer tests,developing screening protocols based on individual risk factors,expanding telehealth,and increasing open access colonoscopies.In this review,we will summarize the effects of COVID-19 on CRC screening,the potential longoutcomes,and ways to adapt CRC screening during this global pandemic.
基金Grant-in-Aid for Cancer Research and Control from the National Cancer Center of Korea,No.#1910231-2.
文摘BACKGROUND The Korea National Cancer Screening Program currently provides screening for colorectal cancer(CRC)for adults older than 50 years with no upper age limit.In general,people are likely to only pay attention to the benefits of cancer screening and to neglect its risks.Most consider the benefits of cancer screening as being far greater than the risks and are unaware that any potential benefits and harms can vary with age.AIM To report acceptance of an upper age limit for CRC screening and factors associated therewith among cancer-free individuals in Korea.METHODS The present study analyzed data from the Korea National Cancer Screening Survey 2017,a nationally representative random sample of 4500 Korean individuals targeted for screening for the five most common types of cancer.A total of 1922 participants were included in the final analysis.The baseline characteristics of the study population are presented as unweighted numbers and weighted proportions.Both univariate and multivariate logistic regression models were developed to examine factors related with acceptance of an upper age limit for CRC screening;subgroup analysis was also applied.RESULTS About 80%(1554/1922)of the respondents agreed that CRC screening should not be offered for individuals older than 80 years.Specifically,those who had never been screened for CRC had the highest acceptance rate(91%).Overall,screening history for CRC[screened by both fecal occult blood test and colonoscopy,adjusted odds ratio(aOR)=0.33,95%CI:0.22-0.50]and other cancers(aOR=0.55,95%CI:0.34-0.87),as well as a family history of cancer(aOR=0.66,95%CI:0.50-0.87),were negatively associated with acceptance of an upper age limit for CRC screening.In contrast,metropolitan residents(aOR=1.86,95%CI:1.29-2.68)and people who exercised regularly(aOR=1.42,95%CI:1.07-1.89)were more likely to accept an upper age limit.After subgrouping,we found gender,marital status,and lifetime smoking history among never-screened individuals and residential region,family history of cancer,and physical activity among never-screened individuals to be associated with acceptance of an upper age limit.CONCLUSION This study describes acceptance of an upper age limit for CRC screening and factors associated with it,and provides perspectives that should be considered,in addition to scientific evidence,when developing population-based cancer screening policies and programs.
基金Supported by National Nature Science Foundation of China, No.30170828
文摘AIM: To set up a mathematic model for gastric cancer screening and to evaluate its function in mass screening for gastric cancer.METHODS: A case control study was carried on in 66patients and 198 normal people, then the risk and protective factors of gastric cancer were determined, including heavy manual work, foods such as small yellow-fin tuna, dried small shrimps, squills, crabs, mothers suffering from gastric diseases, spouse alive, use of refrigerators and hot food,etc. According to some principles and methods of probability and fuzzy mathematics, a quantitative assessment model was established as follows: first, we selected some factors significant in statistics, and calculated weight coefficient for each one by two different methods; second, population space was divided into gastric cancer fuzzy subset and non gastric cancer fuzzy subset, then a mathematic model for each subset was established, we got a mathematic expression of attribute degree (AD).RESULTS: Based on the data of 63 patients and 693 normal people, AD of each subject was calculated. Considering the sensitivity and specificity, the thresholds of AD values calculated were configured with 0.20 and 0.17, respectively.According to these thresholds, the sensitivity and specificity of the quantitative model were about 69% and 63%.Moreover, statistical test showed that the identification outcomes of these two different calculation methods were identical (P＞0.05).CONCLUSION: The validity of this method is satisfactory.It is convenient, feasible, economic and can be used to determine individual and population risks of gastric cancer.
基金support from China Schol-arship Council(CSC file No.201708340072).
文摘Background:The effectiveness of lung cancer screening with low-dose computed tomography(LDCT)has been established.The current study evaluates the cost-effectiveness of lung cancer screening with LDCT in a general population in China.Methods:A previously validated micro-simulation model was used to simulate a cohort of men and women on a lifetime horizon in the presence and absence of LDCT screening.The modeling data were collected from numerous national and international sources.Simulated screening scenarios included different combinations of screening intervals and start and stop ages.Additional costs(valued in Chinese Yuan,CNY;1 USD=6.8976 CNY,1 EUR=7.8755 CNY in 2020),life-years gained(LYG)and mortality reduction due to screening were also determined.The costs and life-years were discounted by 3%.All results were scaled to 1,000 individuals.The average cost-effectiveness ratio(ACER)was calculated.A willingness-to-pay threshold of CNY 217.3k/LYG was considered.A healthcare system perspective was adopted.Results:Compared to no screening,lung cancer screening by LDCT in a general Chinese population yielded 21.0-36.7 LYG in men and 9.2-16.6 LYG in women across the scenarios.For men,biennial LDCT screening yielded an ACER of CNY 171.4k-306.3k/LYG relative to no screening.Biennial screening performed between 55 and 75 years of age was optimal at the defined threshold;it resulted in CNY 174.6k/LYG and a lung cancer mortality reduction of 9.1%,and this scenario had a 75%probability of being cost-effective.For women,the ACER ranged from CNY 364.2k to 1193.3k/LYG.Conclusions:In China,lung cancer screening with LDCT in the general population including never smokers could be cost-effective for men with 75%probability,but not for women.The optimal strategy for men would be performing biennial screening between 55 and 75 years of age.
基金Supported by Partially funded by the Carlos Ⅲ Health Institute No.PI11/01593
文摘Colorectal cancer(CRC)is a very heterogeneous disease that is caused by the interaction of genetic and environmental factors.CRC develops through a gradual accumulation of genetic and epigenetic changes,leading to the transformation of normal colonic mucosa into invasive cancer.CRC is one of the most prevalent and incident cancers worldwide,as well as one of the most deadly.Approximately 1235108 people are diagnosed annually with CRC,and 609051 die from CRC annually.The World Health Organization estimates an increase of77%in the number of newly diagnosed cases of CRCand an increase of 80%in deaths from CRC by 2030.The incidence of CRC can benefit from different strategies depending on its stage:health promotion through health education campaigns(when the disease is not yet present),the implementation of screening programs(for detection of the disease in its early stages),and the development of nearly personalized treatments according to both patient characteristics(age,sex)and the cancer itself(gene expression).Although there are different strategies for screening and although the number of such strategies is increasing due to the potential of emerging technologies in molecular marker application,not all strategies meet the criteria required for screening tests in population programs;the three most accepted tests are the fecal occult blood test(FOBT),colonoscopy and sigmoidoscopy.FOBT is the most used method for CRC screening worldwide and is also the primary choice in most population-based screening programs in Europe.Due to its non-invasive nature and low cost,it is one of the most accepted techniques by population.CRC is a very heterogeneous disease,and with a few exceptions(APC,p53,KRAS),most of the genes involved in CRC are observed in a small percentage of cases.The design of genetic and epigenetic marker panels that are able to provide maximum coverage in the diagnosis of colorectal neoplasia seems a reasonable strategy.In recent years,the use of DNA,RNA and protein markers in different biological samples has been explored as strategies for CRC diagnosis.Although there is not yet sufficient evidence to recommend the analysis of biomarkers such as DNA,RNA or proteins in the blood or stool,it is likely that given the quick progression of technology tools in molecular biology,increasingly sensitive and less expensive,these tools will gradually be employed in clinical practice and will likely be developed in mass.
文摘AIM: To assess the possibility of non-invasive screening of atrophic chronic gastritis for preventing further development of gastric cancer.METHODS: One hundred and seventy-eight consecutive Helicobacter pylori ( H pylori)-positive dyspeptic patients after detection of serum levels of pepsinogen-1 (PG-1) and gastrin-17 (G-17) by enzyme immunoassay were proposed for endoscopy and histology. The serologic and morphologic results were compared with estimating the sensitivity, specificity and prognostic values of the tests.RESULTS: There was statistically significant reverse dependence between the grade of stomach mucosal antral or corpus atrophy and the proper decreasing of serum G17 or PG1 levels. The serologic method was quite sensitive in the diagnosis of non-atrophic and severe antral and corpus gastritis. Also, it was characterized by the high positive and negative prognostic values.CONCLUSION: Detection of serum G-17 and PG1 levels can be offered as the screening tool for atrophic gastritis. The positive serologic results require further chromoendoscopy with mucosal biopsy, for revealing probable progressing of atrophic process with development of intestinal metaplasia, dysplasia or gastric cancer.
基金Supported by Grant No.0710131 from the National Cancer Center Research Fund
文摘AIM:To compare the cost and accuracy of upper gastrointestinal(GI)X-ray and upper endoscopy for diagnosis of gastric cancer using data from the 2002-2004 Korean National Cancer Screening Program(NCSP). METHODS:The study population included 1 503 646 participants in the 2002-2004 stomach cancer screening program who underwent upper GI X-ray or endoscopy.The accuracy of screening was defined as the probability of detecting gastric cancer.We calculated the probability by merging data from the NCSP and the Korea Central Cancer Registry.We estimated the direct costs of the medical examination and the tests for up- per GI X-ray,upper endoscopy,and biopsy. RESULTS:The probability of detecting gastric cancervia upper endoscopy was 2.9-fold higher than via upper GI X-ray.The unit costs of screening using upper GI X-ray and upper endoscopy were$32.67 and$34.89, respectively.In 2008,the estimated cost of identifying one case of gastric cancer was$53094.64 using upper GI X-ray and$16 900.43 using upper endoscopy.The cost to detect one case of gastric cancer was the same for upper GI X-ray and upper endoscopy at a cost ratio of 1:3.7. CONCLUSION:Upper endoscopy is slightly more costly to perform,but the cost to detect one case of gastric cancer is lower.
基金the Cancer Research Campaign,Imperial Cancer Research Fund and Medical Research Council.
文摘The incidence of Barretts metaplasia (BM) as well as Barrett' s adenocarcinoma (BA) has been increasing in western populations. The prognosis of BA is worse because individuals present at a late stage. Attempts have been made to intervene at early stage using surveillance programmes, although proof of efficacy of endoscopic surveillance is lacking, particularly outside the specialist centres. The management of BM needs to be evidencebased as there is a lack clarity about how best to treat this condition. The role of proton pump inhibitors and antireflux surgery to control reflux symptoms is justified.Whether adequate control of gastroesophageal reflux early in the disease alters the natural history of Barrett' s change once it has developed and or prevents it in patients with gastroesophageal reflux disease but with no Barrett' s change remains unanswered. There is much to be learned about BM. Thus there is great need for carefully designed large randomised controlled trials to address these issues in order to determine how best to manage patients with BM.
基金Project(20120095110001)supported by the PhD Programs Foundation of Ministry of Education of ChinaProject(51134022,51221462)supported by the National Natural Science Foundation of China+1 种基金Project(CXZZ13_0927)supported by Research and Innovation Program for College Graduates of Jiangsu Province,ChinaProject(2013DXS03)supported by the Fundamental Research Funds for Central Universities of China
文摘Based on the statics theory, a novel and feasible twice-suspended-mass method(TSMM) was proposed to deal with the seldom-studied issue of fault diagnosis for damping springs of large vibrating screen(LVS). With the static balance characteristic of the screen body/surface as well as the deformation compatibility relation of springs considered, static model of the screen surface under a certain load was established to calculate compression deformation of each spring. Accuracy of the model was validated by both an experiment based on the suspended mass method and the properties of the 3D deformation space in a numerical simulation. Furthermore, by adopting the Taylor formula and the control variate method, quantitative relationship between the change of damping spring deformation and the change of spring stiffness, defined as the deformation sensitive coefficient(DSC), was derived mathematically, from which principle of the TSMM for spring fault diagnosis is clarified. In the end, an experiment was carried out and results show that the TSMM is applicable for diagnosing the fault of single spring in a LVS.
文摘Pancreatic cancer,as a highly malignant cancer and the fourth cause of cancer-related death in world,is characterized by dismal prognosis,due to rapid disease progression,highly invasive tumour phenotype,and resistance to chemotherapy.Despite significant advances in treatment of the disease during the past decade,the survival rate is little improved.A contributory factor to the poor outcome is the lack of appropriate sensitive and specific biomarkers for early diagnosis.Furthermore,biomarkers for targeting,directing and assessing therapeutic intervention,as well as for detection of residual or recurrent cancer are also needed.Thus,the identification of adequate biomarkers in pancreatic cancer is of extreme importance.Recently,accompanying the development of proteomic technology and devices,more and more potential biomarkers have appeared and are being reported.In this review,we provide an overview of the role of proteome-based biomarkers in pancreatic cancer,including tissue,serum,juice,urine and cell lines.We also discuss the possible mechanism and prospects in the future.That information hopefully might be helpful for further research in the field.
基金The project supported by the Foundations of Beijing University of Technology and Ren-Cai-Qiang-Jiao Foundation of Beijing Municipal Education Commission
文摘According to Wick＇s theorem, the second order self-energy corrections of hadrons in the hot and dense nuclear matter are calculated. Furthermore, the Feynman rules are summarized, and an effective formulation on quantum hadrodynamics at finite temperatures and densities is evauated. As the strong couplings between nucleons are considered, the self-consistency of this method is discussed in the framework of relativistic mean-field approximation. Debye screening masses of the scalar and vector mesons in the hot and dense nuclear matter are calculated with this method in the relativistic mean-field approximation. The results are different from those of thermofield dynamics and Brown-Rho conjecture. Moreover, the effective masses of the photon and the nucleon in the hot and dense nuclear matter are discussed.
