[Mitigating metal artifacts from cobalt-chromium alloy crowns in cone-beam CT images through deep learning techniques]

Objective: To develop and evaluate metal artifact removal systems (MARS) based on deep learning to assess their effectiveness in removing artifacts caused by different thicknesses of metals in cone-beam CT (CBCT) images. Methods: A full-mouth standard model (60 mm×75 mm×110 mm) was three-dimensional (3D) printed using photosensitive resin. The model included a removable and replaceable target tooth position where cobalt-chromium alloy crowns with varying thicknesses were inserted to generate matched CBCT images. The artifacts resulting from cobalt-chromium alloys with different thicknesses were evaluated using the structural similarity index measure (SSIM) and peak signal-to-noise ratio (PSNR). CNN-MARS and U-net-MARS were developed using a convolutional neural network and U-net architecture, respectively. The effectiveness of both MARSs were assessed through visualization and by measuring SSIM and PSNR values. The SSIM and PSNR values were statistically analyzed using one-way analysis of variance (α=0.05). Results: Significant differences were observed in the range of artifacts produced by different thicknesses of cobalt-chromium alloys (all P<0.05), with 1 mm resulting in the least artifacts. The SSIM values for specimens with thicknesses of 1.0, 1.5, and 2.0 mm were 0.916±0.019, 0.873±0.010, and 0.833±0.010, respectively (F=447.89, P<0.001). The corresponding PSNR values were 20.834±1.176, 17.002±0.427, and 14.673±0.429, respectively (F=796.51, P<0.001). After applying CNN-MARS and U-net-MARS to artifact removal, the SSIM and PSNR values significantly increased for images with the same thickness of metal (both P<0.05). When using the CNN-MARS for artifact removal, the SSIM values for 1.0, 1.5 and 2.0 mm were 0.938±0.023, 0.930±0.029, and 0.928±0.020 (F=2.22, P=0.112), while the PSNR values were 30.938±1.495, 30.578±2.154 and 30.553±2.355 (F=0.54, P=0.585). When using the U-net-MARS for artifact removal, the SSIM values for 1.0, 1.5 and 2.0 mm were 0.930±0.024, 0.932±0.017 and 0.930±0.012 (F=0.24, P=0.788), and the PSNR values were 30.291±0.934, 30.351±1.002 and 30.271±1.143 (F=0.07, P=0.929). No significant differences were found in SSIM and PSNR values after artifact removal using CNN-MARS and U-net-MARS for different thicknesses of cobalt-chromium alloys (all P>0.05). Visualization demonstrated a high degree of similarity between the images before and after artifact removal using both MARS. However, CNN-MARS displayed clearer metal edges and preserved more tissue details when compared with U-net-MARS. Conclusions: Both the CNN-MARS and U-net-MARS models developed in this study effectively remove the metal artifacts and enhance the image quality. CNN-MARS exhibited an advantage in restoring tissue structure information around the artifacts compared to U-net-MARS.

[Mitigating metal artifacts in cone-beam CT images through deep learning techniques]

Objective: To develop and evaluate metal artifact removal systems (MARSs) based on deep learning to assess their effectiveness in removing artifacts caused by different thicknesses of metals in cone-beam CT (CBCT) images. Methods: A full-mouth standard model (60 mm×75 mm×110 mm) was three-dimensional (3D) printed using photosensitive resin. The model included a removable and replaceable target tooth position where cobalt-chromium alloy crowns with varying thicknesses were inserted to generate matched CBCT images. The artifacts resulting from cobalt-chromium alloys with different thicknesses were evaluated using the structural similarity index measure (SSIM) and peak signal-to-noise ratio (PSNR). CNN-MARS and U-net-MARS were developed using a convolutional neural network and U-net architecture, respectively. The effectiveness of both MARSs were assessed through visualization and by measuring SSIM and PSNR values. The SSIM and PSNR values were statistically analyzed using one-way analysis of variance (α=0.05). Results: Significant differences were observed in the range of artifacts produced by different thicknesses of cobalt-chromium alloys (all P<0.05), with 1 mm resulting in the least artifacts. The SSIM values for specimens with thicknesses of 1.0 mm, 1.5 mm, and 2.0 mm were 0.916±0.019, 0.873±0.010, and 0.833±0.010, respectively (F=447.89, P<0.001). The corresponding PSNR values were 20.834±1.176, 17.002±0.427, and 14.673±0.429, respectively (F=796.51, P<0.001). After applying CNN-MARS and U-net-MARS to artifact removal, the SSIM and PSNR values significantly increased for images with the same thickness of metal (both P<0.05). When using the CNN-MARS for artifact removal, the SSIM values for 1.0, 1.5 and 2.0 mm were 0.938±0.023, 0.930±0.029, and 0.928±0.020 (F=2.22, P=0.112), while the PSNR values were 30.938±1.495, 30.578±2.154 and 30.553±2.355 (F=0.54, P=0.585). When using the U-net-MARS for artifact removal, the SSIM values for 1.0, 1.5 and 2.0 mm were 0.930±0.024, 0.932±0.017 and 0.930±0.012 (F=0.24, P=0.788), and the PSNR values were 30.291±0.934, 30.351±1.002 and 30.271±1.143 (F=0.07, P=0.929). No significant differences were found in SSIM and PSNR values after artifact removal using CNN-MARS and U-net-MARS for different thicknesses of cobalt-chromium alloys (all P>0.05). Visualization demonstrated a high degree of similarity between the images before and after artifact removal using both MARSs. However, CNN-MARS displayed clearer metal edges and preserved more tissue details when compared with U-net-MARS. Conclusions: Both the CNN-MARS and U-net-MARS models developed in this study effectively remove the metal artifacts and enhance the image quality. CNN-MARS exhibited an advantage in restoring tissue structure information around the artifacts compared to U-net-MARS.

Reduced Risk of Sepsis and Related Mortality in Chronic Kidney Disease Patients on Xanthine Oxidase Inhibitors: A National Cohort Study

Background

Advanced chronic kidney disease (CKD) patients are at higher risk of sepsis-related mortality following infection and bacteremia. Interestingly, the urate-lowering febuxostat and allopurinol, both xanthine oxidase inhibitors (XOis), have been suggested to influence the sepsis course in animal studies. In this study, we aim to investigate the relationship between XOis and infection/sepsis risk in pre-dialysis population.

Methods

Pre-dialysis stage 5 CKD patients with gout were identified through the National Health Insurance Research Database (NHIRD) in Taiwan from 2012 to 2016. Outcomes were also compared with national data.

Results

In our nationwide, population-based cohort study, 12,786 eligible pre-dialysis stage 5 CKD patients were enrolled. Compared to non-users, febuxostat users and allopurinol users were associated with reduced sepsis/infection risk [hazard ratio (HR), 0.93; 95% confidence interval (CI), 0.87–0.99; P = 0.0324 vs. HR, 0.92; 95% CI, 0.86–0.99; P = 0.0163]. Significant sepsis/infection-related mortality risk reduction was associated with febuxostat use (HR, 0.68; 95% CI, 0.52–0.87). Subgroup analysis demonstrated preference of febuxostat over allopurinol in sepsis/infection-related mortality among patients younger than 65 years of age, stain users, non-steroidal anti-inflammatory drug non-users, and non-diabetics. There was no significant difference in major adverse cardiac and cerebrovascular event (MACCE) risk between users and non-users while reduced risk of all-cause mortality was observed for XOi users.

Conclusions

Use of XOi in pre-dialysis stage 5 CKD patients may be associated with reduced risk of sepsis/infection and their related mortality without increased MACCE and overall mortality.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

[The impact of ambient temperature exposure on emergency calls-a time series analysis based on data of Xuchang and Zhengzhou]

Objective: To investigate the effect of hourly ambient temperature exposure on emergency calls in Xuchang city and Zhengzhou city. Methods: The hourly meteorological data, air pollution data and emergency calls of Xuchang city and Zhengzhou city were collected from January 1, 2017 to October 31, 2019. A distributed lag non-linear model was used to calculate the excess relative risk (ERR). The lag effect and cumulative effect of extreme temperature exposure on emergency calls were evaluated. Results: The relationship between hourly temperature exposure and emergency calls was a U-shaped curve. In Xuchang city and Zhengzhou city, both low and high temperatures would increase the number of hourly emergency calls. The earliest effect of low temperature occurred at a lag of 22 h and 52 h, with ERR values (95%CI) about 0.20% (0.00%, 0.39%) and 0.11% (0.00%, 0.22%), respectively. The earliest effect of high temperature occurred at a lag of 0 h with ERR values about 1.59% (1.09%, 2.09%) and 1.45% (1.22%, 1.69%), respectively. High temperature had the greatest impact on the number of emergency calls of cardiovascular disease at a lag of 4-8 h. The cumulative ERR values (95%CI) of the two cities were 8.70% (4.98%, 12.75%) and 3.89% (2.61%, 5.22%), respectively. Conclusion: High temperature exposure could increase the number of emergency calls within a few hours, while the effect of low temperature would not occur until 22 hours later.

Facilitating ventilator weaning through rib fixation combined with video-assisted thoracoscopic surgery in severe blunt chest injury with acute respiratory failure

Background

Severe blunt chest injury sometimes induces acute respiratory failure (ARF), requiring ventilator use. We aimed to evaluate the effect of performing rib fixation with the addition of video-assisted thoracoscopic surgery (VATS) on patients with ARF caused by blunt thoracic injury with ventilator dependence.

Methods

This observational study prospectively enrolled patients with multiple bicortical rib fractures with hemothorax caused by severe blunt chest trauma. All patients received positive pressure mechanical ventilation within 24 h after trauma because of ARF. Some patients who received rib fixation with VATS were enrolled as group 1, and the others who received only VATS were designated as group 2. The length of ventilator use was the primary clinical outcome. Rates of pneumonia and length of hospital stay constituted secondary outcomes.

Results

A total of 61 patients were included in this study. The basic demographic characteristics between the two groups exhibited no statistical differences. All patients received operations within 6 days after trauma. The length of ventilator use was shorter in group 1 (3.19 ± 3.37 days vs. 8.05 ± 8.23, P = 0.002). The rate of pneumonia was higher in group 2 (38.1% vs. 75.0%, P = 0.005). The length of hospital stay was much shorter in group 1 (17.76 ± 8.38 days vs. 24.13 ± 9.80, P = 0.011).

Conclusion

Rib fixation combined with VATS could shorten the length of ventilator use and reduce the pneumonia rate in patients with severe chest blunt injury with ARF. Therefore, this operation could shorten the overall length of hospital stay.

Comparative Renoprotective Effect of Febuxostat and Allopurinol in Predialysis Stage 5 Chronic Kidney Disease Patients: A Nationwide Database Analysis

Hyperuricemia has been associated with chronic kidney disease (CKD) progression. The antihyperuricemic febuxostat's potential renoprotective effect has been demonstrated in stage 1–3 CKD. Large‐scale studies comparing the renoprotective potential of febuxostat and allopurinol in advanced CKD are lacking. We exclusively selected 6,057 eligible patients with predialysis stage 5 CKD prescribed either febuxostat or allopurinol using the National Health Insurance Research Database in Taiwan during 2012–2015. There were 69.57% of allopurinol users and 42.01% febuxostat users who required long‐term dialysis (P < 0.0001). The adjusted hazard ratio (HR) of 0.65 (95% confidence interval (CI) 0.60–0.70) indicated near 35% lower hazards of long‐term dialysis with febuxostat use. The renal benefit of febuxostat was consistent across most patient subgroups and/or using the propensity score‐matched cohort. The adjusted HR was 0.66 (95% CI, 0.61–0.70) for long‐term dialysis or death. In conclusion, lower risk of progression to dialysis was observed in predialysis stage 5 CKD febuxostat users without compromising survival.

[Association between low handgrip strength and air pollution among people aged 50 years and over]

Objective: To examine the association between long-term exposure to ambient PM(2.5) combined with indoor air pollution and handgrip strength among people aged 50 and over. Methods: Data were from the first wave of World Health Organization Study on global AGEing and adult health in China. Ambient annual concentration of PM(2.5) was estimated by using the satellite data we also investigated the use of fuels and chimneys as indoor air pollution. A two-level (individual level and community level) linear model was applied to examine the association between long-term exposure to ambient PM(2.5) combined with indoor air pollution and the handgrip strength. Results: A total of 13 175 individuals aged 50 years and over were included for analysis. The handgrip strength was (26.67±0.54) kg. Ambient PM(2.5) was found to be significantly associated with the risk of decreased handgrip strength. Outdoor PM(2.5) concentration was negatively correlated with handgrip strength (β=-0.23, 95%CI: -0.31 - -0.14) decrease in handgrip strength after adjusting for gender, age, residence, education, household assets, intake of vegetables and fruits, smoking and drinking, physical activity. In rural area, compared to those who used solid fuel, use of clean fuel increased (β=1.41, 95%CI: 0.36-2.46) handgrip strength. But in urban area, we did not find any statistically significant association between the use of clean fuel and handgrip strength (β=0.19, 95%CI: -0.95-1.32). Conclusion: This study found that long-term exposure to ambient PM(2.5) combined with indoor air pollution was significantly associated with low handgrip strength among people aged 50 years and over, this suggested that ambient PM(2.5) might serve as one of the risk factors for low physical function seen in the people aged 50 years and over.

Silica-based colloid centrifugation enhances sperm quality in cockerel semen

1. Percoll^TM is one of the most widely used colloid for animal sperm preparation. The aim of this study was to evaluate whether Percoll^TM colloid centrifugation could be practical to improve cockerel sperm quality, and to compare the effects of Percoll^TM single layer centrifugation (SLC) and density gradient centrifugation (DGC) in order to obtain the most optimal protocol for cockerel semen.2. In the experiment with Percoll^TM SLC for fresh semen, an increase of motile sperm was seen after Percoll^TM 80% SLC and 90% SLC was conducted, at levels of 28.8% and 30.2% respectively (P < 0.01). The increase of progressively motile sperm after Percoll^TM 80% SLC and 90% SLC was 177.2% and 202.4% respectively (P < 0.01). Meanwhile, for semen stored at 4°C for 24 h, the increase of motile sperm after Percoll^TM 70% SLC and 80% SLC was 41.2% and 44.0% (P < 0.01), and the increase of progressive sperm after Percoll^TM 70% SLC and 80% SLC was 71.3% and 83.1% respectively (P < 0.01). Both the percentage of motile sperm and progressive sperm of the fresh and stored cockerel semen after appropriate Percoll^TM SLC was significantly enhanced.3. Sperm membrane integrity did not show any decrease after Percoll^TM centrifugation compared with non-centrifuged semen, which suggested that the Percoll^TM centrifugation treatment in this study did not cause damage to cockerel sperm membranes.4. In the experiment regarding the comparison of Percoll^TM SLC and DGC with fresh semen, the increase of motile sperm after Percoll^TM 80% SLC, 90% SLC and 40%/80% DGC was 29.5%, 36.4%, and 25.0% respectively; and the increase of progressive sperm was 44.7%, 58.5%, and 54.7%, respectively. For semen stored at 4°C for 24 h, the increase of motile sperm after Percoll^TM 70% SLC, 80% SLC and 35%/70% DGC were 41.2%, 44.0%, and 26.4%; and the increase of progressive sperm was 71.3%, 83.1%, and 43.7%, respectively. There were no significant differences between the increase of sperm motility after Percoll^TM 80%, 90% SLC or Percoll^TM 40%/80% DGC in fresh cockerel semen. There was no significant difference between Percoll^TM 70%, 80% SLC and Percoll^TM 35%/70% in stored cockerel semen. There was a tendency for sperm recovery rates with Percoll^TM SLC to be higher than Percoll^TM DGC, although this did not reach statistical significance in this study.5. It was concluded that Percoll^TM SLC was more suitable for cockerel sperm separation than Percoll^TM DGC. The results suggested that Percoll^TM 80% SLC was the most optimal procedure to separate fresh cockerel sperm and Percoll^TM 70% SLC was the most optimal procedure to separate stored cockerel sperm. Percoll^TM SLC is more simple, user-friendly and economical and less time-consuming than DGC for cockerel semen processing.

The advantages of adding rib fixations during VATS for retained hemothorax in serious blunt chest trauma - A prospective cohort study

BACKGROUND

Serious blunt chest trauma usually induces hemothorax, pneumothorax, and rib fracture. Early video-assisted thoracoscopic surgery (VATS) to evacuate retained hemothorax is one commonly used treatment. In this study, a new strategy was implemented to combine VATS with fractured rib fixation simultaneously.

METHODS

This prospective observational study was performed from January 2013 to April 2018. All patients were aged 18 years or older and had blunt chest trauma with displaced fractures in more than three ribs. No patients had acute respiratory failure within 24 h after trauma. Patients with retained hemothorax who received VATS constituted the study cohort. Subsequently, patients who received rib fixation during VATS procedures were compared with those who did not. Clinical outcomes such as dose of analgesics, and length of hospital stay were recorded.

RESULTS

During the study period, 128 patients were enrolled. Available demographic characteristics of the 2 groups were compared, and no statistical differences were observed. The rates of shorter temporary ventilator dependence after operations were lower in the rib fixation group (0% vs. 24.7%, P = 0.017). Persistent air leakage more than 5 days after operations were also lower in the rib fixation group (0% vs. 10.4%, P = 0.001). The length of stay in overall hospital stay were longer for patients who received VATS without rib fixation (9.29 ± 2.51 days vs. 12.39 ± 4.65, P = 0.001). Furthermore, the rib fixation group were administered much lower doses of opiates during their hospital stays (52.45 ± 15.67 mg vs. 77.24 ± 50.42 mg, P = 0.001).

CONCLUSION

Adding rib fixation during VATS in the management of retained hemothorax can contribute to shorten whole treatment courses. Rib fixation can also reduce pain, thus reducing dependence on analgesics.

Permissive hypotensive resuscitation in patients with traumatic hemorrhagic shock

We read the article “Risks and benefits of hypotensive resuscitation in patients with traumatic hemorrhagic shock: a meta-analysis” by Natthida Owattanapanich et al. with great interest and found it to be insightful. In our commentary, we propose possible reasons why mortality was lower in the permissive hypotension group and how the need for blood transfusion decreased in this group. No significant difference in acute kidney injury (AKI) was evident among patient groups, possibly because all these patients might have AKI. However, we do agree that permissive hypotension is of considerable benefit to trauma patients and worth further study.

Evaluation of cockerel spermatozoa viability and motility by a novel enzyme based cell viability assay

1. The results of spermatozoa assessment by the WST-8 (2-[2-methoxy-4-nitrophenyl]-3-[4-nitrophenyl]-5-[2,4-disulfophenyl]-2H-tetrazolium, monosodium salt) assay, flow cytometry (FC) or computer-assisted sperm analysis (CASA) were compared. 2. Different live/killed ratios of cockerel semen were serially diluted to 120, 60, and 30 × 10⁶ cells/ml, and each sample was analysed by (1) WST-8 assay at 0, 10, 20, 30, 40, 50, 60 min, (2) viability with FC, and (3) motility with CASA. 3. The WST-8 reduction rate was closely correlated with spermatozoa viability and motility. The optimal semen concentration for the WST-8 assay was 120 × 10⁶ cells/ml, and the standard curves for spermatozoa viability and motility predictions, respectively, were y_viability60 = 162.8x + 104.96 (R² = 0.9594) after 60 min of incubation and y_motility40 = 225.09x + 96.299 (R² = 0.8475) after 40 min of incubation. 4. It was concluded that the WST-8 assay is useful for the practical evaluation of cockerel spermatozoa viability and motility. Compared to FC and CASA, the WST-8 assay does not require expensive and complex instrumentation in the lab. Furthermore, one well of the WST-8 reaction can be used to predict spermatozoa viability and motility at the same time, which all lead it to be efficient and economical for semen quality assessment.

[Study on the difference of binocular accommodative response between atients with intermittent exotropia under different viewing condition]

Objective: To evaluate the accommodative response of patients with intermittent exotropia (IXT) objectively, and study the changes of accommodative response of intermittent exotropia patients when maintaining binocular fusion. Methods: The prospective cohort study was used in this study. Twenty-four patients diagnosed with basic intermittent exotropia who visited the eye hospital of Wenzhou Medical University during October 2016 through January 2017 together with 24 normal volunteers were included, the 48 participants aged from 10 to 27 years old. The participants were divided into the case group and the control group. There were 11 males and 13 females in the case group, and 7 males and 17 females in the control group. The Open-filed autorefractor WAM-5500 (Grand Seiko, Japan) was used to measure the accommodative response of each eye under binocular and monocular viewing conditions at 5 m and 40 cm respectively. During the measurement, patients wore full correction spectacles to achieve distant best-corrected visual acuity of both eyes. The accommodative responses of each eye under binocular and monocular viewing conditions at distance or near between fellow eyes and groups were compared. Results: Under near fixation (40cm) binocular viewing conditions, the accommodative response of the fixating eye (-1.915±0.301)D was different from the deviating eye -1.649(-2.020, -0.304)D in the case group (Z=-3.714, P<0.001). Under near fixation monocular viewing conditions, the accommodative response of the fixating eye (-1.653±0.271)D was also different from the deviating eye -1.565 (-2.031, -0.667)D in the case group (Z=-2.971, P=0.003). During binocular viewing, the asymmetric value of the accommodative response between both eyes of the case group was 0.389(0.102, 1.458)D which was more significant than the normal controls' 0.155(0.009, 0.573)D (Z=-3.505, P<0.001), but during monocular viewing, there was no significant difference between the groups (Z=-1.908, P=0.056). Under near viewing conditions, the variation value of the fixating eyes of the case group was -0.228(-0.796, 0.382)D, which was greater than the variation value -0.086(-0.606, 0.628)D of the right eye of the normal controls, such difference is of statistical significance (Z=-2.279, P=0.023). Under distance viewing conditions, there was no significant difference in the accommodative response between fixating eyes and deviating eyes in case group neither during monocular viewing nor binocular viewing (t=-1.525, -1.729, P>0.05). Besides, the asymmetric values of accommodative response between groups were not significantly different (Z=-1.433, P=0.152. Z=-0.938, P=0.348). Under distance viewing conditions, the changes in accommodative response of each eye during both monocular viewing and binocular viewing were not significantly different between case group and normal controls (Z=-0.041, P=0.967. Z=-1.433, P=0.152). Conclusions: The accommodative responses of the fixating eye and deviating eye of patients with intermittent exotropia were asymmetric under near fixation binocular viewing conditions, and the accommodative response of the deviating eye tends to decrease. Besides, the change of accommodative response of the patients with intermittent exotropia when maintaining binocular fusion is more significant than that of the normal controls. (Chin J Ophthalmol, 2018, 54: 55-61).

[Commuting mode specific exposure to PM(2.5) in urban area of Guangzhou]

Objective: To find the differences in PM(2.5) exposure level in the context of four commuting modes (by walk, bicycle, bus and subway) in Guangzhou. Methods: The PM(2.5) exposure assessment was carried out from January to December 2015 in Guangzhou. PM(2.5) was measured by using SidePak individual dust meter (AM510, TSI Inc. USA) with time interval of 1 minute. Our measurement was taken on Monday, Wednesday, Friday and Sunday in the second week of each month and the samples were collected in the morning (07:00-09:00), afternoon (11:00-13:00) and evening (17:00-19:00). Results: A total of 284 air samples during walking, 281 air samples during bicycle riding, 278 air samples in bus, and 280 air samples in subway were collected. The median PM(2.5) concentrations exposed during walking, during bicycle riding, in bus and in subway were 38.4, 38.6, 23.3 and 24.1 μg/m(3), respectively, which were positive correlated with exposure concentration in fixed surveillance sites. The exposure level was lowest in summer, and highest in winter. The median of one-way exposure level to PM(2.5) from high to low were as follows: 21.0 μg for bicycle riding, 20.1 μg for walking, 5.1 μg for taking bus and 2.6 μg for taking subway. The season and time specific one-way exposure levels to PM(2.5) of four commuting modes were consistent. Conclusions: The exposure level to PM(2.5) was obviously higher during walking and bicycle riding than that in bus and subway. The exposure level to PM(2.5) during walking was higher than that during bicycle riding, in bus and in subway.

[Lagged effects of diurnal temperature range on mortality in 66 cities in China: a time-series study]

Objective: To estimate the effect of daily diurnal temperature range (DTR) on mortality in different areas in China. Methods: A time series study using the data collected from 66 areas in China was conducted, and Meta-analysis was used to analyze the estimates of associations between DTR and daily mortality. Modifying effects of extremely low and high DTR-mortality relationship by season and socioeconomic status (SES) were also evaluated respectively. Cumulative excess risk (CER) was used as an index to evaluate the effects. Results: The information about 1 260 913 registered deaths were collected between 1 January 2006 and 31 December 2011, we found the relationship between extreme DTR and mortality was non-linear in all regions and the exposure-response curve was J-shaped. In central and south areas of China, the result indicated the obvious acute effect of extremely high DTR, and the mortality effect in central area (CER=5.1%, 95% CI: 2.4%-7.9%) was significant higher than that in south area (CER=4.5%, 95% CI: 1.7%-7.3%). Regarding to the modification of seasons, the cumulative mortality effect of DTR in cold season (CER=5.8%, 95%CI: 2.5%-9.2%) was higher than that in hot season (CER=3.1%, 95%CI: 1.1%-5.1%). Generally, deaths among the elderly (≥75 years) were associated more strongly with extremely high DTR. Conclusions: The mortality effects of extremely DTR in different areas and seasons showed different characteristics, that in central area and in cold season it was significantly stronger. After modified by season and SES, DTRs were the greatest threat to vulnerable population, especially to the elderly (≥75 years). Therefore, more attention should be paid to vulnerable groups and protection measures should be taken according to the local and seasonal conditions.

[Effectiveness of health education about heat wave hazard prevention in the elderly: a mixed effect model analysis]

Objective: To evaluate the effectiveness of health education about prevention of heat wave hazard in the elderly. Methods: A non-randomized controlled trial was conducted during the summer of 2015 among a sample of residents aged ≥60 years in Panyu district, Guangzhou. Eight intervention measures for heat wave hazard prevention were taken in intervention group for 3 months (from August to October) and in control group no intervention measures were taken. The comparison of intervention effects was conducted between the intervention group and control group with mixed effect model after the collection of related information with same questionnaire. Results: After adjusting of family per capita income, family air-condition availability, alcohol use, disease history and time, the average score of risk awareness in the intervention group increased by 1.62, while it was 0.51 in the control group, the difference was significant (t=2.76, P=0.006). A significant effect was observed in the intervention group on the reduction of hospitalizations due to chronic diseases. The hospitalization rate due to chronic diseases in resent 3 months in the intervention group decreased from 32.39% (46/142) before intervention to 28.87% (41/142) after intervention; while in the control group, it increased from 26.28% (41/156) before intervention to 36.53% (57/156) after intervention. There was no significant difference between the two groups in awareness of knowledge on heat wave hazard prevention and the score of adaptation to heat wave. Conclusion: Health education programs could improve the risk awareness on heat waves, and reduce the hospitalizations due to chronic diseases in the elderly.

Hes1 Increases the Invasion Ability of Colorectal Cancer Cells via the STAT3-MMP14 Pathway

The Notch pathway contributes to self-renewal of tumor-initiating cell and inhibition of normal colonic epithelial cell differentiation. Deregulated expression of Notch1 and Jagged1 is observed in colorectal cancer. Hairy/enhancer of split (HES) family, the most characterized targets of Notch, involved in the development of many cancers. In this study, we explored the role of Hes1 in the tumorigenesis of colorectal cancer. Knocking down Hes1 induced CRC cell senescence and decreased the invasion ability, whereas over-expression of Hes1 increased STAT3 phosphorylation activity and up-regulated MMP14 protein level. We further explored the expression of Hes1 in human colorectal cancer and found high Hes1 mRNA expression is associated with poor prognosis in CRC patients. These findings suggest that Hes1 regulates the invasion ability through the STAT3-MMP14 pathway in CRC cells and high Hes1 expression is a predictor of poor prognosis of CRC.

Surgeon commitment to trauma care decreases missed injuries

STUDY OBJECTIVE

Missed injuries sustain an important issue concerning patient safety and quality of care. The purpose of this study is to examine the effect of surgeon commitment to trauma care on missed injuries. We hypothesised that surgeons committed to the trauma service has less missed injuries than surgeons not committed to the trauma service would have.

METHODS

By retrospective analysis of 976 adult patients admitted to the trauma intensive care unit (ICU) at an urban, university-based trauma centre. Missed injuries were compared between two groups; in group 1 the patients were evaluated and treated by the surgeons who were committed to the trauma service and in group 2 the patients were evaluated and treated by surgeons practicing mainly in other specialties.

RESULTS

Patients had significantly lower rates of missed major or life-threatening injuries when treated by group 1 surgeons. Logistic regression model revealed significant factors associated with missed major or life-threatening injuries including ISS and groups in which patients were treated by different group surgeons.

CONCLUSIONS

Physicians will perform better when they are trained and interested in a specific area than those not trained, or even not having any particular interest in that specific area. Surgeons committed to the trauma service had less missed injuries in severely injured patients, and it is vital to improve patient safety and quality of care for trauma patients. Staff training and education for assessing severely injured patients and creating an open culture with detection and reduction of the potential for error are important and effective strategies in decreasing missed injuries and improving patient safety.

Acute pesticide poisoning outcomes: a nationwide study in Taiwan

BACKGROUND

This study presents the findings of a nationwide study of acute pesticide poisoning (APP) outcomes, including outcome predictors such as physician and hospital volume and associated factors.

METHODS

This study of data contained in the Taiwan National Health Insurance Research Database analysed 27 046 patients who had been hospitalised for APP from January 1996 to December 2007. Patient characteristics were then compared among quartiles. The primary outcome measures were length of stay (LOS) and hospital treatment cost. Effect size (ES) was compared among three equally divided periods, and multiple regression models were used to identify outcome predictors.

RESULTS

The overall prevalence of APP per 100 000 patients decreased from 12.43 in 1996 to 6.87 in 2007. The LOS for APP treatment was negatively associated with physician volume during the study period. Both LOS and hospital treatment cost were lowest in the high hospital volume subgroup. Comparisons of LOS and hospital treatment cost among the three periods showed that high-volume hospitals and high-volume physicians had better ESs compared to low-volume hospitals and low-volume physicians. Age and number of co-morbidities had significant positive associations with LOS, while admission year, male gender, hospital level, hospital volume and physician volume had significant negative associations with LOS (p<0.05). Hospital treatment cost and hospital level correlated positively with admission year, number of co-morbidities and LOS but correlated negatively with hospital volume and physician volume (p<0.05).

CONCLUSIONS

In APP patients, treatment by a high-volume physician can reduce LOS and treatment cost.

The role of repairing lung lacerations during video-assisted thoracoscopic surgery evacuations for retained haemothorax caused by blunt chest trauma

OBJECTIVES

Retained haemothorax and pneumothorax are the most common complications after blunt chest traumas. Lung lacerations derived from fractures of the ribs are usually found in these patients. Video-assisted thoracoscopic surgery (VATS) is usually used as a routine procedure in the treatment of retained pleural collections. The objective of this study was to find out if there is any advantage in adding the procedure for repairing lacerated lungs during VATS.

METHODS

Patients who were brought to our hospital with blunt chest trauma were enrolled into this prospective cohort study from January 2004 to December 2011. All enrolled patients had rib fractures with type III lung lacerations diagnosed by CT scans. They sustained retained pleural collections and surgical drainage was indicated. On one group, only evacuation procedure by VATS was performed. On the other group, not only evacuations but also repair of lung injuries were performed. Patients with penetrating injury or blunt injury with massive bleeding, that required emergency thoracotomy, were excluded from the study, in addition to those with cardiovascular or oesophageal injuries.

RESULTS

During the study period, 88 patients who underwent thoracoscopy were enrolled. Among them, 43 patients undergoing the simple thoracoscopic evacuation method were stratified into Group 1. The remaining 45 patients who underwent thoracoscopic evacuation combined with resection of lung lacerations were stratified into Group 2. The rates of post-traumatic infection were higher in Group 1. The durations of chest-tube drainage and ventilator usage were shorter in Group 2, as were the lengths of patient intensive care unit stay and hospital stay.

CONCLUSIONS

When compared with simple thoracoscopic evacuation methods, repair and resection of the injured lungs combined may result in better clinical outcomes in patients who sustained blunt chest injuries.

Folate intake and pancreatic cancer risk: an overall and dose-response meta-analysis

OBJECTIVE

Inconsistent findings of association between supplemental folate consumption and pancreatic cancer risk have been observed in the literature. This study aims to summarize the relationship between folate intake and risk of pancreatic cancer.

STUDY DESIGN

Pertinent studies published before November 2011 were identified by searching PubMed and Embase and by reviewing the reference lists of retrieved articles. The summary relative risks were estimated by the random effects model. A linear regression analysis of the natural logarithm of the relative risk (RR) was carried out to assess a possible dose-response relationship between folate intake and pancreatic cancer risk.

RESULTS

Ten studies on dietary and supplemental folate intake and pancreatic cancer (4 case-control and 6 cohort studies) were included in the meta-analysis. The pooled RRs of pancreatic cancer for the highest vs lowest categories of dietary folate intake and supplemental folate intake were 0.66 (95% CI: 0.49-0.88) and 1.08 (95% CI, 0.82-1.41), respectively. The dose-response meta-analysis indicated that a 100 μg/day increment in dietary folate intake conferred a RR of 0.93 (95% CI: 0.90-0.97). These findings support the hypothesis that dietary folate may play a protective role in carcinogenesis of pancreatic cancer.

Building an ethical environment improves patient privacy and satisfaction in the crowded emergency department: a quasi-experimental study

Background

To evaluate the effectiveness of a multifaceted intervention in improving emergency department (ED) patient privacy and satisfaction in the crowded ED setting.

Methods

A pre- and post-intervention study was conducted. A multifaceted intervention was implemented in a university-affiliated hospital ED. The intervention developed strategies to improve ED patient privacy and satisfaction, including redesigning the ED environment, process management, access control, and staff education and training, and encouraging ethics consultation. The effectiveness of the intervention was evaluated using patient surveys. Eligibility data were collected after the intervention and compared to data collected before the intervention. Differences in patient satisfaction and patient perception of privacy were adjusted for predefined covariates using multivariable ordinal logistic regression.

Results

Structured questionnaires were collected with 313 ED patients before the intervention and 341 ED patients after the intervention. There were no important covariate differences, except for treatment area, between the two groups. Significant improvements were observed in patient perception of “personal information overheard by others”, being “seen by irrelevant persons”, having “unintentionally heard inappropriate conversations from healthcare providers”, and experiencing “providers’ respect for my privacy”. There was significant improvement in patient overall perception of privacy and satisfaction. There were statistically significant correlations between the intervention and patient overall perception of privacy and satisfaction on multivariable analysis.

Conclusions

Significant improvements were achieved with an intervention. Patients perceived significantly more privacy and satisfaction in ED care after the intervention. We believe that these improvements were the result of major philosophical, administrative, and operational changes aimed at respecting both patient privacy and satisfaction.

Less is more? The impact of trauma volume on the positive rate of head computed tomography scans in head trauma patients

Objective. Few studies have assessed the impact of trauma volume on the operational efficiency of emergency departments. Herein, we evaluate the association between trauma volume with the positive rate of head computed tomography scans in head trauma patients in a tertiary care hospital. Methods. This is a retrospective cohort review involving all head trauma patients presenting to a tertiary care hospital. Trauma census, head trauma patient volume, the number of emergent head CT scans, and the number of positive head CT scans were collected on a monthly basis. Comparison was primarily made between the trauma patient volume and the positive rate of head CT scans. Results. 25,549 trauma patients were reviewed. Of these, 5,168 (20.2%) sustained head trauma and 3,336 head CT scans were performed with mean 29.1% positive rate of substantial head injuries. The monthly data were analyzed and a statistically significant correlation between monthly trauma volume and decrease in positive rate of head CT scan was identified (Pearson r = −0.51, P = 0.02). With introducing different cut-point values of trauma volume, we identified the threshold of trauma census as approximately 4.9 and 8.8% higher than mean monthly trauma volume in discriminating significant decrease of positive rate of head CT scans.

Osteoporosis self-assessment tool for Asians as a simple risk index of identifying a poor prognosis in women surgically treated for colorectal cancer

BACKGROUND

Osteoporosis and colorectal cancer (CRC) in older women are considered enormous public health burdens. The effects of osteoporosis on the oncologic outcome of CRC surgery are poorly understood. We evaluated the use of the Osteoporosis Self-assessment Tool for Asians (OSTA) for predicting postoperative outcome in older women after receiving surgical treatment of CRC.

MATERIALS AND METHODS

The present single-institution retrospective study analyzed patients who had undergone surgery for CRC in 2002-2008. To characterize the major population of women with osteoporosis, which consists of postmenopausal women, only patients aged 50 years and older were analyzed. Their OSTA scores were evaluated for correlations with cancer-specific survival after surgery for CRC by performing univariate, multivariate, and survival analyses.

RESULTS

During a 7-year period, 440 women were studied. The cancer-specific mortality and overall mortality rate was 28.4% and 33.4%, respectively. The univariate analyses revealed that significant predictors of cancer-specific mortality after CRC surgery were the International Union Against Cancer (UICC) stage, OSTA category, histologic grading, lymph node metastases, and tumor invasion depth. After risk adjustment, the UICC stage and OSTA risk index were independent predictors of mortality. A comparison of OSTA risk index among patients with different UICC stages showed that the accuracy of the index in predicting cancer-specific survival after CRC surgery was greatest for patients with stage II and III disease.

CONCLUSIONS

The UICC stage and OSTA risk status showed independent positive associations with postoperative mortality in aged female patients with CRC. Moreover, the OSTA index had a particularly strong association with cancer-specific mortality in patients with UICC stage II and III.

Generation of transgenic chicks using an oviduct-specific expression system

We successfully replaced the ovalbumin gene of a magnum region in chickens with a human plasminogen activator. We constructed pL-eGFP, pL-tPAGFP and pL-2.8OVtPAGFP vectors and cultured 293FT chicken embryo fibroblasts, chicken primordial germ cells, Hela C127 cells, and oviduct epithelial cells. All vectors were expressed in the transfected cells, except pL-2.8OVtPAGFP vector, which was only expressed in oviduct epithelial cells. A lentivirus with pL-2.8OVtPAGFP was injected in fertilized eggs; 11 chicks hatched in the G₀ generation, four of them carried the tPAGFP. Two cockerels from the G₀ generation were crossed with four wild-type hens. Three chicks in G₁ carried the tPAGFP. We concluded that by using an oviduct-specific vector for transfection, human recombinant plasminogen activator protein can be expressed in the oviducts of laying hens. This character is inherited and can be reproduced with a need for repeated transfection.

Clinical characteristics and outcomes of patients with extended-spectrum β-lactamase-producing bacteremias in the emergency department

Extended-spectrum β-lactamase (ESBL)-producing bacteria have been spreading from hospitals to communities. Despite this, there are limited emergency department (ED) patient-based studies about these bacteremias. A retrospective matched case-control study with a ratio of 1:3 was conducted at a university hospital. The case group consisted of patients aged >16 years with ESBL-producing bacteremias in the ED. Patients matched for age and sex with non-ESBL-producing bacteremias were sampled as the control group. Finally, 64 episodes of ESBL-producing Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis bacteremias were included in our study. The median age of case patients was 71 years, and 29 (45.3%) were males. The most common type of infection was urinary tract infection (71.9%), followed by intra-abdominal infection (12.5%). Inappropriate empirical antibiotics therapy was prescribed in 87.5% of case patients, which was significantly higher than the control group (13.0%; p < 0.001). Patients with inappropriate empirical antibiotics had a significantly longer hospital stay than those with appropriate empirical antibiotics (p < 0.001). Multivariate analysis showed that hospital-acquired infection, urinary catheterization, and previous antibiotics use were independent risk factors for the acquisition of ESBL-producing bacteremia. The 28-day mortality rate of case patients was 18.8%. Whether they received appropriate empirical antibiotics treatment or not, there was no statistical difference in the mortality of patients with ESBL-producing bacteremias (p = 0.167). To face these emerging multidrug-resistant bacteria and to guide the empirical antibiotics therapy, it is crucial for emergency physicians to recognize the characteristics and risk factors for ESBL-producing organisms.

Characteristics and outcomes of polymicrobial bloodstream infections in the emergency department: A matched case-control study

OBJECTIVES

Polymicrobial bloodstream infection (BSI) is a critical condition and has been increasingly reported; however, the authors were unable to find an emergency department (ED) patient-based study in the literature.

METHODS

A retrospective matched case-control study with a ratio of 1:3 among patients with polymicrobial BSIs in an ED was conducted. The case group was patients aged > 16 years with polymicrobial BSIs. Patients matched for age and sex with monomicrobial BSIs were sampled as the control group. Demographic information, underlying conditions, microbiologic data, and outcomes were collected for further analysis.

RESULTS

From January 2005 to December 2007, a total of 112 episodes of polymicrobial BSIs among 109 patients were included. Two pathogens were isolated among 87 (77.7%) episodes and three were found among 25 (22.3%) episodes. A history of hospitalization within 90 days was an independent risk factor for polymicrobial BSIs (p = 0.003). Intraabdominal infection (p < 0.001) and respiratory tract infection (p = 0.017) were more likely to be associated with polymicrobial BSIs. Gram-negative and Gram-positive bacteria were documented in 95.5 and 46.4% episodes of polymicrobial BSIs, respectively. Inappropriate antimicrobial treatment was observed in 53.6% of polymicrobial BSIs, but only accounted for 23.8% of monomicrobial BSIs (p < 0.001). The overall 30-day mortality rate of the polymicrobial group was significantly higher than those with monomicrobial BSIs (30.3 and 11.6%, respectively; p < 0.001).

CONCLUSIONS

Patients with polymicrobial BSIs had a high mortality rate. Acknowledgment of the clinical and microbiologic characteristics and recognition of patients at risk for polymicrobial BSIs are critical in EDs.

Sphingomonas paucimobilis bacteremia in humans: 16 case reports and a literature review

BACKGROUND/PURPOSE

Sphingomonas paucimobilis is a glucose-nonfermenting Gram-negative bacillus that is widely distributed in both natural environment and hospitals. Various infections in humans have been reported, but most have been limited to sporadic case reports. The aim of this study was to describe the clinical characteristics and manifestations of S. paucimobilis bacteremia. We also reviewed the literature on S. paucimobilis bacteremia.

METHODS

Cases of S. paucimobilis bacteremia were identified retrospectively at a university-affiliated hospital in Taiwan. In addition, relevant case reports were identified through PubMed and reviewed.

RESULTS

From April 2004 to April 2008, 42 cases of S. paucimobilis bacteremia were identified in this study. Among them, 16 cases were identified from E-Da hospital, Kaohsiung, Taiwan and 26 cases from the literature review. The median age of patients was 48.5 years and 57.1% were male. The most common comorbidities included malignancy (57.1%), immunosuppressant use (40.5%), and diabetic mellitus (11.9%). Hospital-acquired bacteremia accounted for 69.0% of infections. Primary bacteremia and catheter-related bloodstream infection were found in 35.7% and 33.3% respectively. The most effective antibiotics were fluoroquinolones, carbapenems, and beta-lactam/beta-lactamase inhibitor combinations. All 42 patients survived the S. paucimobilis bacteremic episodes, but three patients experienced septic shock.

CONCLUSION

S. paucimobilis can cause infections in healthy as well as immunocompromised individuals. Although it is an organism of low clinical virulence, infection caused by S. paucimobilis can lead to septic shock. Further clinical research is required to characterize this infection.

Effects of the Emergency Trauma Training Course on the confidence of final-year medical students dealing with trauma patients

Trauma is an important issue that has been neglected in the training of medical students. This study evaluated the effects of the Emergency Trauma Training Course (ETTC), after completion of standard medical training, on seventh-year medical students. The ETTC was designed in Taiwan by the Taiwan Society of Emergency Medicine to train physicians and registered nurses who care for trauma patients in the emergency department (ED). We implemented the course for our medical students' internship. One hundred and fifty-one participants were divided into three groups: Group A included 36 medical students before they entered their internship in hospital; Group B included 41 medical students who had received 6 months of internship training in hospital; and Group C included 74 ED nurses. Group C was used to test Cronbach's alpha coefficient of the questionnaire. After the training course, the participants had a final examination and filled out a questionnaire about the training course and their levels of self-confidence. There were no differences in scores between the medical students in Groups A and B (p = 0.064). Using repeated measures analysis of variance, we found that confidence before training was low, with no difference between Groups A and B. Confidence improved after training, but there was still no significant difference between the groups (p = 0.875). However, there were significant differences between confidence levels before and after the training course (p < 0.001). Therefore, although inhospital training for 6 months failed to increase confidence, the confidence of final year medical students after completion of their training was improved by the ETTC. This indicates that the ETTC could increase the confidence of participants. This is the first evaluation of the implementation of the ETTC for final-year medical students in Taiwan. Based on our results, we highly recommend that this training course be taught to final-year medical students before they practice in hospital.