The paper analyzes the conditions of research on the current scientific literature text feature extraction methods,applies the TF-IDF method based on background knowledge in the medical text feature extraction,and conducts experimental comparison in four medical fields.The result indicates that this method can obviously improve the extraction effect when there are few vocabularies to be extracted,and is obviously superior to the IDF based TF-IDF method in the aspects of filtration of commonly-used words in the text set and identification of important feature words.

Multidimensional features ( life cycle features, universal acceptability, authority, innovation and inter-disciplinarity) of frontier knowledge and their measurement methods were determined according to the current scien-tific achievements in order to help scientific workers and decision makers timely discover and accurately recognize frontier knowledge.The framework for studies on frontier knowledge discovery in medical field was proposed with its key problems explained in order to provide reference for its future study.

The paper puts forward the method for evaluation on the scientific influence of institution based on PageRank algorithm,configures the initial weight of each institution based on the problems of dividing equally the webpage weight number in the classical PageRank algorithm and cited frequency of the application chapter,constructs the network matrix cited by institution through the citation situation of medical SCI papers published by partial colleges and universities in 2015,respectively calculates the PageRank values of institution when self-citation is excluded or included,and conducts comparative analysis on the sequence of cited frequency indicators of the institution as well as H index.This method can be used to evaluate scientific influence of institution from two dimensions of quality and quantity.

Objective　To study the relationship between the expression of p16 and nm23-H1 and clinicopathology in the patients with gastric cancer. 　Methods　p16 and nm23-H1 protein in cancer tissue of 65 patients were observed with labelled streptavidin biotin (LSAB) immunohistochemical method.　Results　The total positive rate of p16 and nm23-H1 was 30.8% and 41.5% respectively in gastric cancer tissues. The positive expression rate of p16 was significantly higher in well-differentiated cancer than in poorly-differentiated cancer (P＜0.05). The positive expression rate of p16 and nm23-H1 was higher in patients with lymph node metastasis than in those without lymph node metastasis(P＜0.05，P＜0.01) and in clinical stage Ⅰ,Ⅱ than in stage Ⅲ (P＜0.05，P＜0.01).The 3-year survival rate was higher in positive cases of p16 or nm23-H1 protein expression (45.0%，51.9%）than in negative ones（28.9%、21.1%）(P＜0.05).There was a significants positive correlation between p16 and nm23-H1 protein expression(r=0.041*!5,P＜0.05).　Conclusions　p16 and nm23-H1 may play a role in the development of gastric cancer and be related to partial biological behavior. Expression of p16 and nm23-H1 may serve as a marker for predicting the cancer metastasis and evaluating the prognosis of gastric cancer patients.

Objective　To study the relationship between the expression of p16 and nm23-H1 and clinicopathology in the patients with gastric cancer. 　Methods　p16 and nm23-H1 protein in cancer tissue of 65 patients were observed with labelled streptavidin biotin (LSAB) immunohistochemical method.　Results　The total positive rate of p16 and nm23-H1 was 30.8% and 41.5% respectively in gastric cancer tissues. The positive expression rate of p16 was significantly higher in well-differentiated cancer than in poorly-differentiated cancer (P＜0.05). The positive expression rate of p16 and nm23-H1 was higher in patients with lymph node metastasis than in those without lymph node metastasis(P＜0.05，P＜0.01) and in clinical stage Ⅰ,Ⅱ than in stage Ⅲ (P＜0.05，P＜0.01).The 3-year survival rate was higher in positive cases of p16 or nm23-H1 protein expression (45.0%，51.9%）than in negative ones（28.9%、21.1%）(P＜0.05).There was a significants positive correlation between p16 and nm23-H1 protein expression(r=0.041*!5,P＜0.05).　Conclusions　p16 and nm23-H1 may play a role in the development of gastric cancer and be related to partial biological behavior. Expression of p16 and nm23-H1 may serve as a marker for predicting the cancer metastasis and evaluating the prognosis of gastric cancer patients.

OBJECTIVE To investigate the management situation of cross infection in outpatient service of stomatology in hospital and clinic in Zhanjiang city and conduct effective measure to control hospital infection.METHODS In our investigation,we selected 105 hospitals and private clinics to inspect their management situation of cross (infection) via dental(instrument).RESULTS The management in the hospitals of the city was quite qualified but the some private dental clinics were terrible.The main problems were as follows: no effective disinfection for dental instrument and the bad environment in procedure room,especially the worse sterilization situation of the dental handpieces.Most of the doctors in private clinics were short of knowledge in the sterilization for dental(instruments.) CONCLUSIONS There is no time to delay for the health administration department to normalize the management of the private dental clinics.It is essential to train the medical staffs,and implement measures for dental instrument disinfection management in private dental clinics.

Objective To investigate the relationship among Helicobacter pylori(H.pylori),CD4 positive cells and CD8 positive cells in gastric mucosa of the AIDS patients with gastritis.Methods Fiftyeight AIDS patients with upper abdominal pain were diagnosed with chronic gastritis through gastroscopy.The gastric biopsies from them were used for H.pylori detection with rapid urease test and Giemsa staining,pathology examination with HE staining,and immunohistochemistry analysis for CD4,CD8 positive cells in Gastric mucosa.And the application of flow cytometry was for the detection of peripheral blood CD4 and CD8 lymphocytes from the patients.Results H.pylori was positive in 26 cases,and negative was in 32 cases.CD8 cell expression in gastric mucosa of the AIDS patients with H.pylori positive was significantly higher than H.pylori negative patients(P＜0.05).There is no difference CD4 cell expression in gastric mucosa between the AIDS patients with H.pylori positive and H.pylori negative patients.Moreover,CD8 positive lymphocytes in gastric mucosa of those patients with H.pyloriinfection were significantly stronger than the CD4 positive lymphocytes.However,the peripheral blood CD4 lymphocytes from the patients with H.pylori infection were more than those from H.pylorinegative patients significantly(P＜0.05).Conclusion The expression level of CD8 cells in gastric mucosal tissues of AIDS patients with H.pylori infection were higher than those without H.pylori infection.The CD4 lymphocytes from the peripheral blood of the patients with H.pylori infection were more than those without H.pylori negative patients.

Objective:The research analyzed the current situation and trend of health science and technology innovation in China, developed the national health and health science and technology innovation index to estimate the development of health science and technology innovation in China.Methods:The research discussed the connotation and scope of National Health Science and technology innovation, designed the national health science and technology innovation index, and developed the evaluation index system that covered various aspects including innovation resources, innovation output, innovation environment.Results:The total index and sub-index of national health science and technology innovation index from 2011 to 2017 were calculated. Suppose the base number of 2011 was 100, the value of national health science and technology innovation index in 2017 was 201.73.Conclusions:By using multi-level indicators, the indicators that reflect the basic characteristics of scientific and technological innovation can be transformed into the overall indicators that comprehensively reflect the level of scientific and technological innovation, which can be used to monitor the overall development of health scientific and technological innovation and the situation of each innovation stage.

Objective: To explore the association between hypothyroidism and sleep breathing disorders in patients with coronary heart disease (CHD). Methods: A total of 784 patients with CHD were consecutively enrolled at the Emergency & Critical Care Center of Beijing Anzhen Hospital from June 2015 to May 2017. According to thyroid function test results, patients were divided into hypothyroidism group (79 cases) and non-hypothyroidism group (705 cases). All patients had undergone sleep monitoring. The sleep apnea status was compared between the two groups. Multivariate logistic regression and linear regression models were used to analyze the association between hypothyroidism and sleep breathing disorders in patients with CHD. Results: The proportion of females, mean body weight and body mass index in the hypothyroidism group were higher than those in the non-hypothyroidism group [26.6% vs.16.2%, (78.6±11.6) kg vs. (75.7±12.0) kg, (27.7±3.2) kg/m² vs. (26.6±3.5) kg/m², all P<0.05]. Patients in hypothyroidism group had a decreased average oxygen saturation (SaO₂) compared with patients in non-hypothyroidism group [ (93.2±2.9) % vs. (93.9±2.0) %, P=0.030]. In addition, events of hypoventilation in hypothyroidism group were significantly higher than those in non-hypothyroidism group[92.5 (45.8, 758.3) times vs. 68.0 (33.0, 125.0) times, P=0.013]. There were no significant differences in apnea hypopnea index, diagnosis of obstructive sleep apnea and other sleep breathing parameters between the two groups (P>0.05). A multiple linear regression analysis found that in patients with CHD, the correlation between hypothyroidism and average sleep SaO₂ was significant (β=-0.508, 95%CI -0.989--0.026, P=0.039). Conclusions: CHD patients with hypothyroidism had a lower sleep average SaO₂, and a higher sleep hypopnea events. There is a correlation between hypothyroidism and sleep hypoxia in patients with CHD. Clinical trial registration clinicalTrials.gov, NCT03362385.

Objective: To investigate the impact of moderate/severe obstructive sleep apnea (OSA) on the prognosis of acute myocardial infarction. Methods: We prospectively selected patients with acute myocardial infarction (AMI) who were hospitalized at the Emergency Critical Care Center of Beijing Anzhen Hospital from June 2015 to May 2017. Patients who met the inclusion criteria were examined with portable sleep respiration monitoring. Patients were divided into moderate/severe OSA group (apnea-hypopnea index (AHI)≥15 beats/hour) and no/mild OSA group (AHI<15 beats/hour) according to sleep AHI. The incidence of major adverse cerebrovascular events (MACCE) after discharge was compared between the two groups, and the independent risk factors of MACCE were analyzed. Results: A total of 432 patients were enrolled in this study, including 211 moderate/severe OSA patients (48.8%). Compared with no/mild OSA group,patients with moderate/severe OSA had higher body mass index ((27.17±3.22) kg/m² vs. (25.55±3.44) kg/m², t=-5.033,P<0.001), higher proportion of history of percutaneous coronary intervention (PCI) (18.5%(39/211) vs. 8.6%(19/221), χ²=9.076,P=0.003), and higher proportion of 3-vessel disease (31.3%(66/211) vs. 24.9%(55/221), χ²=10.196,P=0.017). The median follow-up time was 1.0 (0.7, 1.7) years. The incidence of MACCE in the moderate/severe OSA and no/mild group was 19.9%(42/211) and 11.3%(25/221), respectively. Kaplan-Meier analysis showed a higher cumulative risk of MACCE in patients with moderate/severe OSA (log-rank test,χ²=5.467, P=0.019). Multivariate Cox regression analysis showed that moderate/severe OSA (HR=1.915, 95%CI 1.016-3.611, P=0.045) and diabetes mellitus (HR=1.819, 95%CI 1.022-3.238, P=0.042) were independent risk factors for MACCE at 1 year post discharge in patients with AMI. Conclusions: Nearly half of AMI patients are complicated with moderate/severe OSA in this patient cohort. Coronary artery disease is more severe in AMI patients complicating with moderate/severe OSA. Moderate/severe OSA is an independent risk factor for MACCE at 1 year after discharge in patients with AMI. Whether the prognosis of AMI can be improved by intervention of OSA remains to be investigated. Trial Registration Clinical Trial.gov, NCT03362385.