The Rate of Demineralization in the Teeth Prepared by Bur and Er:YAG Laser

Introduction: The present in vitro study evaluated the recurrence rate of caries following cavity preparations with bur (conventional technique) and irradiation by Erbium:Yttrium–Aluminum–Garnet (Er:YAG) laser through micro hardness test.Methods: A total of 72 human extracted molars were randomly divided into 3 groups and class 5 cavities were prepared on them with 3 different methods: G1) conventional bur, G2) Er:YAG laser irradiation alone and G3) laser irradiation + laser treatment. The specimens were immersed in the artificial caries solution with pH of 2.0 and 5.0 (12 days) and then immersed in re-mineralizing solution with pH of 7.0 (25 days). The specimens were longitudinally sectioned and their Vickers micro hardness was determined. Data were statistically analyzed by means of three-way analysis of variance (ANOVA) and Tukey multiple comparisons tests.Results: The micro hardness of the samples was affected by substrate type (enamel and dentin) and low values were achieved in dentin (P < 0.001). Moreover, no significant difference was observed between preparation methods by bar and laser irradiation alone (P ≤ 0.499). Although laser irradiation + laser treatment decreased micro hardness of enamel compared to other methods. In dentin samples, different methods of preparation showed no significant effect on micro hardness (P ≤ 0.874).Conclusion: Due to the similar values of micro hardness following G1 and G2, it seems that Er:YAG laser alone is as much effective as the conventional bur to prevent recurrence caries. However, because of the high prices of laser instruments, bur preparations can be done commonly

Effect of corn silage particle size and level of soybean oil on ruminal mat composition, distribution and consistency in Zel sheep

To determine the effects of two corn silage particle size (coarse particle with geometric mean of 5.83 ± 2.47 mm and fine particle with geometric mean of 4.74 ± 2.74 mm) and two levels of soybean oil (0 and 4% of DM) on ruminal mat composition, distribution and consistency, four two years fistulated ruminant Zel ewes (BW = 34 ± 1.4 kg), fed with 50:50 roughage-concentrate diet, were allocated to a 4 × 4 change over design. The experiment was carried out in 4 periods of 28-days trial (adaptation, 14 days; collection period , 5 days; chewing activity measurement, 1 day; rumen evacuation, 8 days). Experimental diets were: 1) basal diet + coarse corn silage and 0% oil; 2) basal diet + coarse corn silage and 4% oil; 3) basal diet + fine corn silage and 0% oil and; 4) basal diet + fine corn silage and 4% oil. Based on calendar time, rumens were evacuated manually at 3, 7.5 and 12 h post-feeding of each period and total ruminal contents were separated into mat and liquids phase. Dry matter (DM) and organic matter (OM) intake were less in treatment 4 and neutral detergent fiber (NDF) intake in treatment 2 was higher than in the other diets. Physically, effective NDF intakes were higher in treatments 1 and 2 than in treatments 3 and 4, but DM and OM digestibility was higher in treatments 1 than in the other diets. The NDF digestibility was higher in coarse silage diets, but the NFC digestibilities were higher in fine corn silage diets. Rumen mat was greater in coarse silage diets than in fine silage diets (1.83 and 1.32 versus 1.06 and 0.76 kg) at 3 h after feeding. Non-escapable pool sizes in rumen content were higher in diets that contained coarse silage. At all time in post feeding, ruminal pH was less in fine silage particle size with oil supplement. Rumen particulate passage rates were higher in fine corn silage diets. However, passage rates from the lower gastrointestinal tract were similar. In addition, ruminal mean retention times were significantly greater in diets that contained coarse silage. Rumination time was shorter in fine corn silage with oil supplement diet but rumination time per kg of NDF and peNDF was longer in fine corn silage diets. In addition, although reduction of particle size decreased size of rumen mat and non-escapable fraction, oil supplementation reduced ruminal digestion and mean retention of ruminal particulate. However, it seems that oil supplementation can be helpful in fine corn silage diets for maintaining ruminal mat.Key words: Particle size, soybean oil, ruminal mat, Zel sheep

Frequency and types of workplace violence against emergency medical technicians: a cross-sectional study in Tehran, Iran

Objective: This study was implemented to assess various types of violent incidents involving emergency medical technicians (EMTs) working in Tehran, Iran. Furthermore, the characteristics of violent people and possible causes of their violence were assessed. Methods: In this cross-sectional study, 500 EMTs working in the capital city of Tehran were randomly invited. The participants were asked to fill out a questionnaire of workplace violence. Univariate and multivariate logistic regression were also performed for identifying the possible risk factors of violence. In addition, the distribution and association of violence patterns were also analyzed considering demographic features and characteristics of violent people. Results: In total, 320 EMTs with the mean age of 31.8 ± 6.7 years participated, 315 (98.4%) of whom were men. Overall, 279 (87.2%) out of the 320 participants experienced 654 episodes of violence, mostly bullying, in the last 4 months. The relationship between the level of education and experiencing violent incidents was statistically significant (p=0.035). Also, non-Persian EMTs had experienced significantly more violent behaviors than Persian EMTs [171 (91.0%) vs. 108 (81.8%); p=0.016]. Nonetheless, the prevalence of violent incidents was not significantly correlated with marital status, years of work experience, employment situation, and working hours. The odds of facing violent behavior among EMTs with associate degree was 2.9 times higher than those with technical diploma (p=0.048). Furthermore, the odds of experiencing violence among non-Persian EMTs was 2.2 times higher than Persian EMTs (p=0.039). Conclusion: We found that EMTs had faced numerous episodes of violence in their workplace, especially verbal threats, which were more prevalently committed by patients’ relatives during night shifts

Factors affecting Cardiovascular Patients’ Adherence in the hospitals of Kerman University of Medical Sciences based on the Health Belief Model

Background: Medical adherence is one of the most important behaviors in the care of cardiovascular disease. This study aimed to determine the factors affecting cardiovascular patients’ adherence based on the Health Belief Model in 2016. Methods: In this cross-sectional study, 420 cardiovascular patients admitted to Kerman University of Medical Sciences educating hospitals were chosen via convenience sampling, and data was collected by a researcher made questionnaire based on the Health Belief Model about factors effective on medical adherence. The data were analyzed using Chi-square, ANOVA, and t-test in SPSS software 21. Results: In this study, 40.5% of participants had a low level of adherence. There were significant relations between health belief model constructs together, and between adherence with perceived susceptibility, perceived barriers, and self-efficacy (p<0.001). The Health Belief Model predicted 33.7% of the variance in medical adherence (p<0.001). Conclusion: According to the findings of this study the health belief model can be used in planning and intervening to improve medical adherence in cardiovascular patients. Developing an educational intervention based on the Health Belief Model is suggested for enhancing medical adherence among patients. Keywords: Cardiovascular Patients, Health Belief Model, Adherence, Kerma

Attachment styles and emotional intelligence components: the predictors of health dimensions

Health, as one of the most important sources of comfort in life, is the complete physical, mental and social well-being, while there are dynamic mutual relationships among the three components. This study was aimed to investigate the role of attachment styles and emotional intelligence components in the prediction of health dimensions. The statistical population was consisted 160 parents who participated in the trainees’ health assessment programs in Khalkhal city (Iran). Attachment styles questionnaire, emotional intelligence questionnaire and general health questionnaire were used to collect data. Results of the study indicated that avoidant and ambivalent attachment styles has significant relationship with depression dimension. The relationship between emotional intelligence and dimensions of depression, anxiety, physical symptoms and social performance was also significant. Multivariate regression analysis indicated that dependent and ambivalent attachments are predictors of depression/anxiety; secure attachment is a predictors of depression moreover, stress tolerance, social responsibility, empathy, self-esteem, optimism, self-actualization, interpersonal relations, problem solving, independence and assertiveness are predictors of depression, anxiety, physical symptoms and social performance. This study demonstrated that attachment styles and emotional intelligence components play important role in the prediction of health dimensions. Therefore they are applicable and effective in health related programs

Hydrogel Elasticity and Microarchitecture Regulate Dental-Derived Mesenchymal Stem Cells -Host Immune System Cross-Talk

The host immune system (T-lymphocytes and their pro-inflammatory cytokines) has been shown to compromise bone regeneration ability of mesenchymal stem cells (MSCs). We have recently shown that hydrogel, used as an encapsulating biomaterial affects the cross-talk among host immune cells and MSCs. However, the role of hydrogel elasticity and porosity in regulation of cross-talk between dental-derived MSCs and immune cells is unclear. In this study, we demonstrate that the modulus of elasticity and porosity of the scaffold influence T-lymphocyte-dental MSC interplay by regulating the penetration of inflammatory T cells and their cytokines. Moreover, we demonstrated that alginate hydrogels with different elasticity and microporous structure can regulate the viability and determine the fate of the encapsulated MSCs through modulation of NF-kB pathway. Our in vivo data show that alginate hydrogels with smaller pores and higher elasticity could prevent pro-inflammatory cytokine-induced MSC apoptosis by down-regulating the Caspase-3- and 8-associated proapoptotic cascades, leading to higher amounts of ectopic bone regeneration. Additionally, dental-derived MSCs encapsulated in hydrogel with higher elasticity exhibited lower expression levels of NF-kB p65 and Cox-2 in vivo. Taken together, our findings demonstrate that the mechanical characteristics and microarchitecture of the microenvironment encapsulating MSCs, in addition to presence of T-lymphocytes and their pro-inflammatory cytokines, affect the fate of encapsulated dental-derived MSCs

Enhancing Cell Seeding and Osteogenesis of MSCs on 3D Printed Scaffolds Through Injectable BMP2 Immobilized ECM-Mimetic Gel

Objective Design of bioactive scaffolds with osteogenic capacity is a central challenge in cell-based patient-specific bone tissue engineering. Efficient and spatially uniform seeding of (stem) cells onto such constructs is vital to attain functional tissues. Herein we developed heparin functionalized collagen gels supported by 3D printed bioceramic scaffolds, as bone extracellular matrix (ECM)-mimetic matrices. These matrices were designed to enhance cell seeding efficiency of mesenchymal stem cells (MSCs) as well as improve their osteogenic differentiation through immobilized bone morphogenic protein 2 (BMP2) to be used for personalized bone regeneration. Methods A 3D gel based on heparin-conjugated collagen matrix capable of immobilizing recombinant human bone morphogenic protein 2 (BMP2) was synthesized. Isolated dental pulp Mesenchymal stem cells (MSCs) were then encapsulated into the bone ECM microenvironment to efficiently and uniformly seed a bioactive ceramic-based scaffold fabricated using additive manufacturing technique. The designed 3D cell-laden constructs were comprehensively investigated trough in vitro assays and in vivo study. Results In-depth rheological characterizations of heparin-conjugated collagen gel revealed that elasticity of the matrix is significantly improved compared with freely incorporated heparin. Investigation of the MSCs laden collagen-heparin hydrogels revealed their capability to provide spatiotemporal bioavailability of BMP2 while suppressing the matrix contraction over time. The in vivo histology and real-time polymerase chain reaction (qPCR) analysis showed that the designed construct supported the osteogenic differentiation of MSCs and induced the ectopic bone formation in rat model. Significance The presented hybrid constructs combine bone ECM chemical cues with mechanical function providing an ideal 3D microenvironment for patient-specific bone tissue engineering and cell therapy applications. The implemented methodology in design of ECM-mimetic 3D matrix capable of immobilizing BMP2 to improve seeding efficiency of customized scaffolds can be exploited for other bioactive molecules

Exploring noise effects in chaotic optical networks

We report the experimental evidence coherence and stochastic resonance in a dynamics of fast chaotic spiking of a semiconductor laser with optical feedback using an external nonwhite noise in the pumping current. We characterize both coherence and stochastic resonance in the time and frequency domain. We show that the regularity of the chaotic pulses in the intensity of laser diod increases when adding noise and it is optimal for some intermediate value of the noise intensity. We find that the power spectrum of the signal develops a peak at a finite frequency at intermediate values of the noise. The results show that noise may help in extracting the periodic signal without synchronization in chaotic communication. Then we reported the effect of external noise numerically on a single system by using bifurcation diagram. Finally, we considered Chaos synchronization in a network of 28 distinct chaotic systems with independent initial conditions when a normal Gaussian noise is added. The transition between non-synchronization to synchronization states using a suitable spatio-temporal representation has been reported. The role of coherence has also been considered. Keywords: Coherence resonance, Stochastic resonance, Control, Nois

Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112

Global burden of chronic respiratory diseases and risk factors, 1990–2019: an update from the Global Burden of Disease Study 2019

Background: Updated data on chronic respiratory diseases (CRDs) are vital in their prevention, control, and treatment in the path to achieving the third UN Sustainable Development Goals (SDGs), a one-third reduction in premature mortality from non-communicable diseases by 2030. We provided global, regional, and national estimates of the burden of CRDs and their attributable risks from 1990 to 2019. Methods: Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we estimated mortality, years lived with disability, years of life lost, disability-adjusted life years (DALYs), prevalence, and incidence of CRDs, i.e. chronic obstructive pulmonary disease (COPD), asthma, pneumoconiosis, interstitial lung disease and pulmonary sarcoidosis, and other CRDs, from 1990 to 2019 by sex, age, region, and Socio-demographic Index (SDI) in 204 countries and territories. Deaths and DALYs from CRDs attributable to each risk factor were estimated according to relative risks, risk exposure, and the theoretical minimum risk exposure level input. Findings: In 2019, CRDs were the third leading cause of death responsible for 4.0 million deaths (95% uncertainty interval 3.6–4.3) with a prevalence of 454.6 million cases (417.4–499.1) globally. While the total deaths and prevalence of CRDs have increased by 28.5% and 39.8%, the age-standardised rates have dropped by 41.7% and 16.9% from 1990 to 2019, respectively. COPD, with 212.3 million (200.4–225.1) prevalent cases, was the primary cause of deaths from CRDs, accounting for 3.3 million (2.9–3.6) deaths. With 262.4 million (224.1–309.5) prevalent cases, asthma had the highest prevalence among CRDs. The age-standardised rates of all burden measures of COPD, asthma, and pneumoconiosis have reduced globally from 1990 to 2019. Nevertheless, the age-standardised rates of incidence and prevalence of interstitial lung disease and pulmonary sarcoidosis have increased throughout this period. Low- and low-middle SDI countries had the highest age-standardised death and DALYs rates while the high SDI quintile had the highest prevalence rate of CRDs. The highest deaths and DALYs from CRDs were attributed to smoking globally, followed by air pollution and occupational risks. Non-optimal temperature and high body-mass index were additional risk factors for COPD and asthma, respectively. Interpretation: Albeit the age-standardised prevalence, death, and DALYs rates of CRDs have decreased, they still cause a substantial burden and deaths worldwide. The high death and DALYs rates in low and low-middle SDI countries highlights the urgent need for improved preventive, diagnostic, and therapeutic measures. Global strategies for tobacco control, enhancing air quality, reducing occupational hazards, and fostering clean cooking fuels are crucial steps in reducing the burden of CRDs, especially in low- and lower-middle income countries