Spatial epidemiological characteristics and exponential smoothing model application of tuberculosis in Qinghai Plateau, China.

The epidemic of tuberculosis has posed a serious burden in Qinghai province, it is necessary to clarify the epidemiological characteristics and spatial-temporal distribution of TB for future prevention and control measures. We used descriptive epidemiological methods and spatial statistical analysis including spatial correlation and spatial-temporal analysis in this study. Furthermore, we applied an exponential smoothing model for TB epidemiological trend forecasting. Of 43 859 TB cases, the sex ratio was 1.27:1 (M:F), and the average annual TB registered incidence was 70.00/100 000 of 2009-2019. More cases were reported in March and April, and the worst TB stricken regions were the prefectures of Golog and Yushu. High TB registered incidences were seen in males, farmers and herdsmen, Tibetans, or elderly people. 7132 cases were intractable, which were recurrent, drug resistant, or co-infected with other infections. Three likely cases clusters with significant high risk were found by spatial-temporal scan on data of 2009-2019. The exponential smoothing winters' additive model was selected as the best-fitting model to forecast monthly TB cases in the future. This research indicated that TB in Qinghai is still a serious threaten to the local residents' health. Multi-departmental collaboration and funds special for TB treatments and control are still needed, and the exponential smoothing model is promising which could be applied for forecasting of TB epidemic trend in this high-altitude province.

[A survey on the current status and related factors of influenza vaccination among health care workers in tertiary hospitals of Xining city during the influenza epidemic season from 2017 to 2018].

Objective: To evaluate the current status and related factors of influenza vaccination among health care workers (HCWs) in tertiary hospitals of Xining city after the implementation of the free influenza vaccination policy. Methods: In August 2018, the cluster sampling method was used to select four medical institutions in Xining that had previously conducted investigations and interventions. All HCWs(excluding logistic staff) in each medical institution were included in the study. A total of 3 260 valid respondents were included. Questionnaires were used to collect the demographic characteristics, influenza and influenza vaccination awareness, implementation of free policy in the influenza epidemic season from 2017 to 2018, influenza vaccination status, awareness of influenza vaccination schedule and free policy. The multivariate logistic regression model was used to analyze related factors of influenza vaccination. Results: The age of respondents was (31.41±5.00) years. The influenza vaccination rate was 6.80% (226/3 260) in 2017-2018 influenza epidemic season. After controlling for related factors, the awareness of the influenza vaccination schedule (OR=17.05, 95%CI: 5.86-49.59), vaccination frequency (OR=8.22, 95%CI: 2.98-22.61) and the free policy (OR=3.15, 95%CI: 1.49-6.67) had higher vaccination rate. Conclusion: The influenza vaccination rate of HCWs in tertiary hospitals of Xining city was low. Increasing the awareness of the vaccination schedule, frequency and free policy may promote the influenza vaccination rate of HCWs.

A new method of radio frequency links by coplanar coils for implantable medical devices.

A new method based on coplanar coils for the design of radio frequency links has been developed, to realize the communication between the programming wand and the implantable medical devices with shielding container simply and reliably. With the analysis of electronic and magnetic field theory, the communication model has been established and simulated, and the circuit has been designed and tested. The experimental results are consistent with the simulation fairly well. The voltage transfer ratio of the typical circuit with present parameters can reach as high as 0.02, which can fulfill the requirements of communication.

[Determination of rate order for degradation of drugs with nonisothermal stability experiment].

By a theoretical investigation of simulated nonisothermal data, the inability to determine the rate order for degradation of drugs with ordinary nonisothermal experiment was discussed. Results indicate that both rate order n and activation energy E can change the curvature of the c-t curve and the change caused by higher n can be compensated by higher E in ordinary nonisothermal experiments. That means a suitable E can always be assessed to fit each of the definite n (0, 1, or 2 in our study) very well. As a result, a same set of c-t data can be well fitted by different combinations of n and E. This is why the rate order cannot be assessed in ordinary nonisothermal experiments. To overcome this deficiency, it is important that there have both temperature rising and lowering parts in one nonisothermal experiment. A new heating model, temperature rising and lowering program, was presented. With this new heating model, the kinetic parameters, including the rate order, can be obtained in one nonisothermal stability experiment. The ability of the new heating model to determine rate order is almost the same as that of isothermal experiments.

[Study on shelf-life prediction of drugs under indoor natural light irradiation].

The photodegradation of drugs under natural light and various lamp light irradiation was studied and the shelf-life of drugs under indoor natural light irradiation was predicted with hydroxyprogesterone caproate injection as an example. The equivalent influences of different light sources on the photostability of the above drug were obtained. Therefore, the natural light photostability and the shelf-life of drugs under indoor natural light irradiation can be studied with lamp light exposure experiment. The photodegradation of hydroxyprogesterone caproate injection obeys zero order kinetics: C = C0-kEt, and its shelf-life under indoor natural light irradiation is about 1.9 years.

[Study on the degradation kinetics of vitamin K3 powder].

The effect of temperature and humidity on the rate of discoloration and degradation of vitamin K3 powder was studied via accelerated test under isothermal, constant humidity and dark conditions. The photodegradation of vitamin K3 powder was studied under room temperature and constant humidity. The changes of color and concentration of vitamin K3 were monitored by diffuse reflectance spectroscopy and high performance liquid chromatography, respectively. At temperatures 50-90 degrees C and relative humidities 50-93%, the rate equation of discoloration is -dR/dt = KRR, that of degradation is d(c(o)-c)/dt = kc (c(o)-c)1/2, and that of photodegradation is -dR/dt = kp (Ro-R)-1, where Ro and R are initial relative reflectance and relative reflectance at time t, respectively, c(o) and c are initial concentration and concentration at time t, respectively, kR, kc and kP are apparent rate constants of discoloration, degradation and photodegradation, respectively. The general equation of the relationship between the apparent rate constant k, absolute temperature T and relative humidity RH is k = k' exp (-Ea/RT) exp (m' RH), where Ea is apparent activation energy, k' and m' are constants. Within the ranges of experimental temperatures and humidities, the average apparent activation energies of discoloration and degradation are 105.51 and 130.72 kJ/mol, respectively.

[A study on the decomposition kinetics of vitamin C tablet].

Under the condition of relative humidity less than the critical relative humidity, the discoloration rate and decomposition rate of vitamin C tablet and the discoloration rate of vitamin C tablet in solution were studied at temperatures 60-90 degrees C and relative humidities 60%-80%. The general equation of the relationship between the apparent rate constant k, absolute temperature T and relative humidity RH is: k = k' exp(-E/RT) exp(mRH), where k' and m are constants, E is apparent activation energy. The values of k', m and E for discoloration, decomposition and discoloration in solution are different.

[A study on the decomposition kinetics of vitamin C powder].

The effect of temperature and humidity on the discoloration and degradation of vitamin C powder was studied via accelerated test under isothermal and constant humidity conditions. The changes of color and concentration of vitamin C were monitored by diffuse reflectance spectroscopy and iodimetry respectively. Under the condition of relative humidity less than the critical relative humidity, the apparent rate constant of discoloration of Kc of vitamin C powder is: kc = 'exp (-Ea/RT) exp (m 'RH), where k' and m' are constants, RH is relative humidity and Ea is activation energy, when RH less than 70%, Ea = 104.33 kJ . mol-1. The degradation curve of vitamin C powder under various temperatures and humidities can be expressed by C = N/(1 + Btn), the rate equation of degradation of vitamin C powder is: -dC/dt = kdC(1 + 1/n) (N-C)(1 - 1/n), where kd is the apparent rate constant of degradation, B and n are constants, N is the initial content of vitamin C and C is the content of vitamin C at time t. When RH are 97, 93, and 79.5%, Ea are 86.87, 88.22 and 202.64 kJ.mol-1, respectively.