1.Analysis of verification results of protective effects of hearing protectors in different industries.
Han Xue SHI ; Shi Biao SU ; Ming LIU ; Rong Zong LI ; Tian Jian WANG ; Bin XIAO
Chinese Journal of Industrial Hygiene and Occupational Diseases 2023;41(5):333-337
Objective: To get insight into the current practice of noise reduction effect of workers as they wore hearing protectors in different domestic enterprises and the possible affected factors. Methods: From October 2020 to April 2021, using a random sampling method, 1197 workers exposed to noise in petrochemical factories, textile factories, and parts manufacturing factories were selected as the study subjects. The noise reduction effect of hearing protectors worn by workers in daily use was tested using a hearing protector suitability testing system. The personal sound attenuation level (PAR) was compared among workers in three enterprises, Targeted intervention and repetitive testing were conducted for workers who did not meet the noise reduction effect required by the enterprise, and the changes in PAR of workers before and after the intervention were compared. The comparison of baseline PARs between two or more groups was performed using the Mann Whitney test, the comparison of baseline PARs with post intervention PARs was performed using the Wilcoxon signed rank sum test, and the comparison of qualitative data between two or more groups was performed using the Chi square test. Results: The median baseline PAR for all workers was 15 dB. Men, age<30 years old, education level at or above college level, working experience of 5 to 15 years, and those who used hearing protectors for 5 to 15 years had higher PARs, with statistically significant differences (P<0.05). The median difference in baseline PAR among workers from three enterprises was statistically significant (H=175.06, P<0.01). The median PAR of subjects who did not pass the baseline increased from 3 dB to 21 dB after intervention (Z=-27.92, P<0.01) . Conclusion: Some workers wearing hearing protectors do not meet the required PAR, and low PARs may be related to incorrect wearing methods and incorrect selection of hearing protectors. As a tool for testing, training, and assisting in selection, the hearing protector suitability testing system is of great significance for worker hearing protection.
Male
;
Humans
;
Adult
;
Hearing Loss, Noise-Induced/prevention & control*
;
Ear Protective Devices
;
Noise, Occupational/prevention & control*
;
Hearing
;
Audiometry
4.Case of the Index Patient Who Caused Tertiary Transmission of COVID-19 Infection in Korea: the Application of Lopinavir/Ritonavir for the Treatment of COVID-19 Infected Pneumonia Monitored by Quantitative RT-PCR
Jaegyun LIM ; Seunghyun JEON ; Hyun Young SHIN ; Moon Jung KIM ; Yu Min SEONG ; Wang Jun LEE ; Kang Won CHOE ; Yu Min KANG ; Baeckseung LEE ; Sang Joon PARK
Journal of Korean Medical Science 2020;35(6):79-
Since mid-December of 2019, coronavirus disease 2019 (COVID-19) infection has been spreading from Wuhan, China. The confirmed COVID-19 patients in South Korea are those who came from or visited China. As secondary transmissions have occurred and the speed of transmission is accelerating, there are rising concerns about community infections. The 54-year old male is the third patient diagnosed with COVID-19 infection in Korea. He is a worker for a clothing business and had mild respiratory symptoms and intermittent fever in the beginning of hospitalization, and pneumonia symptoms on chest computerized tomography scan on day 6 of admission. This patient caused one case of secondary transmission and three cases of tertiary transmission. Hereby, we report the clinical findings of the index patient who was the first to cause tertiary transmission outside China. Interestingly, after lopinavir/ritonavir (Kaletra, AbbVie) was administered, β-coronavirus viral loads significantly decreased and no or little coronavirus titers were observed.
China
;
Clothing
;
Commerce
;
Coronavirus
;
Fever
;
Hospitalization
;
Humans
;
Korea
;
Male
;
Pneumonia
;
Thorax
;
Viral Load
5.Investigation of protective exposure risk events in nurses against corona virus disease 2019 in Wuhan.
Qiu WANG ; Jin Yu GUO ; Hong SUN ; Ling WANG ; Ju Su YING ; Hui Xin LIU
Journal of Peking University(Health Sciences) 2020;52(4):711-714
OBJECTIVE:
To investigate the current situation of virus exposure risk incidents of nurses against corona virus disease 2019 (COVID-19) in Wuhan, and to provide reference evidence for nursing managers to protect nursing staff who were working in the isolation ward.
METHODS:
In the study, 308 nursing staff against COVID-19 working in the isolation ward in Wuhan were conveniently selected to participate in the investigation. The designed questionnaires including 7 kinds of protective exposure risk events were made by the team of researchers on the basis of literature review and interview with the nurses in Wuhan. All the participants recalled their working experience in the status of dressing in personal protective equipment and filled in the questionnaires online by WeChat according to the same instruction.
RESULTS:
The questionnaires were filled in validly by a total of 304 nursing staff, of whom 88.8% received emergency training on the prevention and dealing measurement of exposure risk events. The incidence of shoe cover contamination, falling off or torn was relatively high, about 53.6%. Due to the protection of gloves, the incidence of hand or skin contamination was relatively low, about 14.1%. The most nervousness of protective exposure risk event for nurses was N95 mask contamination, falling off or shifting, with a score of 8.2±2.3, showing a higher psychiatric burden. Single factor analysis found that the number of days in Wuhan was different, the number of the types of protective risk events occurred was different (χ2=14.562, P=0.024), orderly multivariate Logistic regression found that men were the independent protective factor for the number of the types of protective exposure risk events that occurred (P=0.019).
CONCLUSION
Protective exposure risk events may occur in the work of nursing staff working in the isolation ward in Wuhan. It is necessary to guide nurses to prevent the occurrence of protective exposure risk events and effectively deal with them, so as to prevent virus exposure and reduce psycholo-gical burden.
Betacoronavirus
;
COVID-19
;
China
;
Coronavirus Infections/transmission*
;
Ear Protective Devices
;
Humans
;
Male
;
Occupational Exposure/prevention & control*
;
Pandemics/prevention & control*
;
Pneumonia, Viral/transmission*
;
Risk Factors
;
SARS-CoV-2
6.Surface characterization of calcium phosphate coating formed on chitosan and alkali-treaDted titanium metal
Kyung Hee PARK ; Woon Young LEE ; Ho Ju SONG ; Yeong Joon PARK
Korean Journal of Dental Materials 2019;46(1):33-42
The calcium phosphate coating on various pretreated metals was prepared by soaking in modified simulated body fluid (m-SBF) solution. The coating structure and its surface morphologies were determined by x-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The results revealed significant differences in morphology and composition of the calcium phosphate coatings with and without chitosan and NaOH-pretreated commercially pure titanium (cp-Ti) substrate. The calcium phosphates formed on chitosan coated-Ti pretreated with NaOH were ~ 350 nm-sized resulting in strong bonding of the apatite layer with the substrates and a uniform gradient of stress transfer from coating materials to the Ti-substrate. After NaOH pretreatment, the hydroxyl groups bind to Ca²⁺ to attract PO₄³⁻ anions, eventually resulting in a continuous layer of calcium phosphate on chitosan coated-Ti substrate during immersion in m-SBF solution. The chitosan coated-Ti showed hydrophobic surface while NaOH pretreatment resulted in maximum hydrophilicity to the Ti substrate. Due to improved wettability of Ti by NaOH pretreatment before chitosan coating, aggregation of calcium phosphate was prevented and size-controlled composite materials were obtained.
Anions
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Body Fluids
;
Calcium Phosphates
;
Calcium
;
Chitosan
;
Clothing
;
Hydrophobic and Hydrophilic Interactions
;
Immersion
;
Metals
;
Microscopy, Electron, Scanning
;
Spectroscopy, Fourier Transform Infrared
;
Titanium
;
Wettability
;
X-Ray Diffraction
7.Cytopathologic Features of Secretory Carcinoma of Salivary Gland: Report of Two Cases
Young Ah KIM ; Jae Won JOUNG ; Sun Jae LEE ; Hoon Kyu OH ; Chang Ho CHO ; Woo Jung SUNG
Journal of Pathology and Translational Medicine 2019;53(1):70-74
Secretory carcinoma of the salivary gland (SC) is a newly introduced rare salivary gland tumor that shares histological, immunohistochemical, and genetic characteristics with secretory carcinoma of the breast. Here, we report the cytologic features of two cases of SC confirmed by surgical resection. In these two cases, SC was incidentally detected in a 64-year-old female and a 56-yearold male. Fine needle aspiration cytology revealed nests of tumor cells with a papillary or glandular structure floating in mucinous secretions. The tumor cells demonstrated uniform, round, smooth nuclear contours and distinct nucleoli. Multiple characteristic cytoplasmic vacuoles were revealed. Singly scattered tumor cells frequently showed variable sized cytoplasmic vacuoles. The cytopathologic diagnosis of SC should be considered when characteristic cytological findings are revealed. Further immunohistochemistry and gene analyses are helpful to diagnose SC.
Biopsy, Fine-Needle
;
Breast
;
Clothing
;
Cytoplasm
;
Diagnosis
;
Female
;
Humans
;
Immunohistochemistry
;
Male
;
Mammary Analogue Secretory Carcinoma
;
Middle Aged
;
Mucins
;
Salivary Glands
;
Vacuoles
8.Efficiency of Air Bubble Removal in Preparation of Low-Profile Angioplasty Balloon Catheter: Bench-Top Comparison of Six Methods
Joon Ho CHOI ; Seon Moon HWANG ; Deok Hee LEE
Neurointervention 2019;14(1):27-34
PURPOSE: Complete removal of air bubbles from balloons for neurovascular angioplasty is cumbersome. We compared the preparation difficulty, air removal efficiency, and air collection pattern of six different balloon catheter preparation methods to propose a better preparation method for both initial and second balloon uses, especially for small-profile angioplasty balloon catheters. MATERIALS AND METHODS: A total of 18 neurovascular angioplasty balloon catheters with nominal diameters of 2 mm were prepared to test six different preparation methods: the instruction for use method (method A), simplified method using a syringe (method B) and four newly devised preparation methods using inflating devices (methods C–F). Serial radiographs were obtained while the balloons were gradually inflated. We measured the time for each preparation and the bubble number, analyzed their distribution in the balloon, and calculated the contrast filling ratio (contrast filling area/total balloon area) for initial and second ballooning. The whole process was repeated three times. RESULTS: The preparation time varied widely (11.5 seconds [method D] to 73.3 seconds [method A]). On initial inflation, the contrast filling ratio at 8 atm was the highest (100%) with methods A and F. On second inflation, the ratio was again highest with method A (99.5%), followed by method F (99.2%). Initial ballooning tended to show a uniform pattern of single bubble in the distal segment of the balloon; in contrast, second ballooning showed varying patterns in which the bubbles were multiple and randomly distributed. CONCLUSION: None of the six methods were able to completely exclude air bubbles from the balloon catheters including the second ballooning; however, the method of repeating aspiration with high-volume inflating device (method F) could be a practical option considering the simplicity and efficiency of preparation.
Angioplasty
;
Angioplasty, Balloon
;
Catheters
;
Clothing
;
Embolism, Air
;
Equipment Failure
;
Inflation, Economic
;
Intracranial Arteriosclerosis
;
Methods
;
Syringes
9.In vitro evaluation of the wear resistance of provisional resin materials fabricated by different methods
Jong Ju AHN ; Jung Bo HUH ; Jae Won CHOI
The Journal of Korean Academy of Prosthodontics 2019;57(2):110-117
PURPOSE: This study was to evaluate the wear resistance of 3D printed, milled, and conventionally cured provisional resin materials. MATERIALS AND METHODS: Four types of resin materials made with different methods were examined: Stereolithography apparatus (SLA) 3D printed resin (S3P), digital light processing (DLP) 3D printed resin (D3P), milled resin (MIL), conventionally self-cured resin (CON). In the 3D printed resin specimens, the build orientation and layer thickness were set to 0° and 100 µm, respectively. The specimens were tested in a 2-axis chewing simulator with the steatite as the antagonist under thermocycling condition (5 kg, 30,000 cycles, 0.8 Hz, 5℃/55℃). Wear losses of the specimens were calculated using CAD software and scanning electron microscope (SEM) was used to investigate wear surface of the specimens. Statistical significance was determined using One-way ANOVA and Dunnett T3 analysis (α = .05). RESULTS: Wear losses of the S3P, D3P, and MIL groups significantly smaller than those of the CON group (P < .05). There was no significant difference among S3P, D3P, and MIL group (P > .05). In the SEM observations, in the S3P and D3P groups, vertical cracks were observed in the sliding direction of the antagonist. In the MIL group, there was an overall uniform wear surface, whereas in the CON group, a distinct wear track and numerous bubbles were observed. CONCLUSION: Within the limits of this study, provisional resin materials made with 3D printing show adequate wear resistance for applications in dentistry.
Clothing
;
Dentistry
;
In Vitro Techniques
;
Mastication
;
Methods
;
Printing, Three-Dimensional
10.The use of tissue fiducial markers in improving the accuracy of post-prostatectomy radiotherapy
Michael CHAO ; Huong HO ; Daryl Lim JOON ; Yee CHAN ; Sandra SPENCER ; Michael NG ; Jason WASIAK ; Nathan LAWRENTSCHUK ; Kevin MCMILLAN ; Shomik SENGUPTA ; Alwin TAN ; George KOUFOGIANNIS ; Margaret COKELEK ; Farshad FOROUDI ; Tristan Scott KHONG ; Damien BOLTON
Radiation Oncology Journal 2019;37(1):43-50
PURPOSE: The aim of this retrospective study was to investigate the use of a radiopaque tissue fiducial marker (TFM) in the treatment of prostate cancer patients who undergo post-prostatectomy radiotherapy (PPRT). TFM safety, its role and benefit in quantifying the set-up uncertainties in patients undergoing PPRT image-guided radiotherapy were assessed. MATERIALS AND METHODS: A total of 45 consecutive PPRT patients underwent transperineal implantation of TFM at the level of vesicourethral anastomosis in the retrovesical tissue prior to intensity-modulated radiotherapy. Prostate bed motion was calculated by measuring the position of the TFM relative to the pelvic bony anatomy on daily cone-beam computed tomography. The stability and visibility of the TFM were assessed in the initial 10 patients. RESULTS: No postoperative complications were recorded. A total of 3,500 images were analysed. The calculated prostate bed motion for bony landmark matching relative to TFM were 2.25 mm in the left-right, 5.89 mm in the superior-inferior, and 6.59 mm in the anterior-posterior directions. A significant 36% reduction in the mean volume of rectum receiving 70 Gy (rV₇₀) was achieved for a uniform planning target volume (PTV) margin of 7 mm compared with the Australian and New Zealand Faculty of Radiation Oncology Genito-Urinary Group recommended PTV margin of 10 mm. CONCLUSION: The use of TFM was safe and can potentially eliminate set-up errors associated with bony landmark matching, thereby allowing for tighter PTV margins and a consequent favourable reduction in dose delivered to the bladder and rectum, with potential improvements in toxicities.
Clothing
;
Cone-Beam Computed Tomography
;
Fiducial Markers
;
Humans
;
New Zealand
;
Postoperative Complications
;
Prostate
;
Prostatectomy
;
Prostatic Neoplasms
;
Radiation Oncology
;
Radiotherapy
;
Radiotherapy, Image-Guided
;
Radiotherapy, Intensity-Modulated
;
Rectum
;
Retrospective Studies
;
Urinary Bladder

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