Discussion on the Five Basic Syndrome Patterns and Their Corresponding Treating Principles and Prescriptions

Based on the theory of latency system and dominance system and the analytical methods of the four forms and five stages in the development of a disease, this article is to explore the regularity of the five basic patterns of a syndrome to explain the mechanism of its occurrence and development. Different patterns of a syndrome suggest different areas affected and symptoms of a disease. Therefore, different treating principles and prescriptions should be adopted, i.e., 'treating the same syndrome with different methods'.

Elastic and thermodynamic properties of vanadium nitride under pressure and the effect of metallic bonding on its hardness

By the particle-swarm optimization method, it is predicted that tetragonal P42mc, 141md, and orthorhombic Amm2 phases of vanadium nitride （VN） are energetically more stable than NaCl-type structure at 0 K. The enthalpies of the predicted three new VN phases, along with WC, NaC1, AsNi, CsCl type structures, are calculated each as a function of pressure. It is found that VN exhibits the WC-to-CsCl type phase transition at 256 GPa. For the considered seven crystal- lographic VN phases, the structures, elastic constants, bulk moduli, shear moduli, and Debye temperatures are investigated. Our calculated equilibrium structural parameters are in very good agreement with the available experimental results and the previous theoretical results for the NaC1 phase. The Debye temperatures of VN predicted three novel phases, which are all higher than those of the remaining structures. The elastic constants, thermodynamic properties, and elastic anisotropies of VN under pressure are obtained and the mechanical stabilities are analyzed in detail based on the mechanical stability criteria. Moreover, the effect of metallic bonding on the hardness of VN is also investigated, which shows that VNs in P42mc, 141md, and Amm2 phases are potential superhard phases. Further investigation on the experimental level is highly recommended to confirm our calculations presented in this paper.

The biomechanical role of periodontal ligament in bonded and replanted vertically fractured teeth under cyclic biting forces

After teeth are replanted,there are two possible healing responses：periodontal ligament healing or ankylosis with subsequent replacement resorption.The purpose of this study was to compare the fatigue resistance of vertically fractured teeth after bonding the fragments under conditions simulating both healing modes.Thirty-two human premolars were vertically fractured and the fragments were bonded together with Super-Bond C＆B.They were then randomly distributed into four groups（BP,CP,CA,BA）.The BP and CP groups were used to investigate the periodontal ligament healing mode whilst the BA and CA groups simulated ankylosis.All teeth had root canal treatment performed.Metal crowns were constructed for the CP and CA groups.The BP and BA groups only had composite resin restorations in the access cavities.All specimens were subjected to a 260 N load at 4 Hz until failure of the bond or until 2 x 106 cycles had been reached if no fracture occurred.Cracks were detected by stereomicroscope imaging and also assessed via dye penetration tests.Finally,interfaces of the resin luting agent were examined by scanning electron microscope.The results confirmed that the fatigue resistance was higher in the groups with simulated periodontal ligament healing.Periodontal reattachment showed important biomechanical role in bonded and replanted vertically fractured teeth.

Use of low-dose computed tomography to assess pulmonary tuberculosis among healthcare workers in a tuberculosis hospital

Background:According to the World Health Organization,China is one of 22 countries with serious tuberculosis(TB)infections and one of the 27 countries with serious multidrug-resistant TB strains.Despite the decline of tuberculosis in the overall population,healthcare workers(HCWs)are still at a high risk of infection.Compared with high-income countries,the TB prevalence among HCWs is higher in low-and middle-income countries.Low-dose computed tomography(LDCT)is becoming more popular due to its superior sensitivity and lower radiation dose.However,there have been no reports about active pulmonary tuberculosis(PTB)among HCWs as assessed with LDCT.The purposes of this study were to examine PTB statuses in HCWs in hospitals specializing in TB treatment and explore the significance of the application of LDCT to these workers.Methods:This study retrospectively analysed the physical examination data of healthcare workers in the Beijing Chest Hospital from September 2012 to December 2015.Low-dose lung CT examinations were performed in all cases.The comparisons between active and inactive PTB according to the CT findings were made using the Pearson chi-square test or the Fisher’s exact test.Comparisons between the incidences of active PTB in high-risk areas and non-high-risk areas were performed using the Pearson chi-square test.Analyses of active PTB were performed according to different ages,numbers of years on the job,and the risks of the working areas.Active PTB as diagnosed by the LDCT examinations alone was compared with the final comprehensive diagnoses,and the sensitivity and positive predictive value were calculated.Results:A total of 1012 participants were included in this study.During the 4-year period of medical examinations,active PTB was found in 19 cases,and inactive PTB was found in 109 cases.The prevalence of active PTB in the participants was 1.24%,0.67%,0.81%,and 0.53%for years 2012 to 2015.The corresponding incidences of active PTB among the tuberculosis hospital participants were 0.86%,0.41%,0.54%,and 0.26%.Most HCWs with active TB(78.9%,15/19)worked in the high-risk areas of the hospital.There was a significant difference in the incidences of active PTB between the HCWs who worked in the high-risk and non-high-risk areas(odds ratio[OR],14.415;95%confidence interval(CI):4.733-43.896).Comparisons of the CT signs between the active and inactive groups via chi-square tests revealed that the tree-in-bud,cavity,fibrous shadow,and calcification signs exhibited significant differences(P=0.000,0.021,0.001,and 0.024,respectively).Tree-in-bud and cavity opacities suggest active pulmonary tuberculosis,whereas fibrous shadow and calcification opacities are the main features of inactive pulmonary tuberculosis.Comparison with the final comprehensive diagnoses revealed that the sensitivity and positive predictive value of the diagnoses of active PTB based on LDCT alone were 100%and 86.4%,respectively.Conclusions:Healthcare workers in tuberculosis hospitals are a high-risk group for active PTB.Yearly LDCT examinations of such high-risk groups are feasible and necessary.