• 제목/요약/키워드: non-persistent

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Exploring shrinkage crack propagation in concrete: A comprehensive analysis through theoretical, experimental, and numerical approaches

  • Vahab Sarfarazi;Soheil Abharian;Nima Babanouri
    • Computers and Concrete
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    • 제34권1호
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    • pp.15-31
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    • 2024
  • This study explores the failure mechanisms of 'I' shaped non-persistent cracks under uniaxial loads through a combination of experimental tests and numerical simulations. Concrete specimens measuring 200 mm×200 mm×50 mm were manufactured, featuring 'I' shaped non-persistent joints. The number of these joints varied from one to three, with angles set at 0, 30, 60, and 90 degrees. Twelve configurations, differing in the placement of pre-existing joints, were considered, where larger joints measured 80 mm in length and smaller cracks persisted for 20 mm with a 1 mm crack opening. Numerical models were developed for the 12 specimens, and loading in Y-axis direction was 0.05 mm/min, considering a concrete tensile strength of 5 MPa. Results reveal that crack starting was primarily influenced by the slope of joint that lacks persistence in relation to the loading direction and the number of joints. The compressive strength of the samples exhibited variations based on joint layout and failure mode. The study reveals a correlation between the failure behavior of joints and the number of induced tensile fracture, which increased with higher joint angles. Specimen strength increased with decreasing joint angles and numbers. The strength and failure processes exhibited similarities in both laboratory testing and numerical modeling methods.

Factors Associated with Persistent Sputum Positivity at the End of the Second Month of Tuberculosis Treatment in Lithuania

  • Diktanas, Saulius;Vasiliauskiene, Edita;Polubenko, Katazyna;Danila, Edvardas;Celedinaite, Indre;Boreikaite, Evelina;Misiunas, Kipras
    • Tuberculosis and Respiratory Diseases
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    • 제81권3호
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    • pp.233-240
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    • 2018
  • Background: Non-conversion of sputum smear and culture prolongs the infectivity of the patient and has been associated with unfavorable outcomes. We aimed to evaluate factors associated with persistent sputum positivity at the end of two months of treatment of new case pulmonary tuberculosis (TB). Methods: Data of 87 human immunodeficiency virus-negative patients with culture-positive drug-susceptible pulmonary TB admitted to local university hospital between September 2015 and September 2016 were reviewed. Factors associated with sputum smear and/or culture positivity at the end of the second month of treatment were analyzed. Results: Twenty-two patients (25.3%) remained smear and/or culture-positive. Male sex, lower body mass index (BMI), unemployment, alcohol abuse, higher number of lobes involved and cavities on chest X-rays, shorter time to detection (TTD) on liquid cultures, higher respiratory sample smear grading and colony count in solid cultures, higher C-reactive protein, erythrocyte sedimentation rate, leukocytosis, thrombocytosis, and anemia were all significantly associated with persistent sputum positivity. However, in the logistic regression analysis only male sex, lower BMI, alcohol abuse, higher radiological involvement, cavitation, higher smear grading, higher colony count in solid cultures and shorter TTD were determined as independent factors associated with persistent sputum positivity at the end of 2 months of treatment. Conclusion: In conclusion, higher sputum smear and culture grading at diagnosis, shorter TTD, higher number of lobes involved, cavitation, male sex, alcohol abuse, and lower BMI were independently associated with persistent sputum positivity. These factors should be sought when distinguishing which patients will remain infectious longer and possibly have worse outcomes.

A Stability of P-persistent MAC Scheme for Periodic Safety Messages with a Bayesian Game Model (베이지안 게임모델을 적용한 P-persistent MAC 기반 주기적 안정 메시지 전송 방법)

  • Kwon, YongHo;Rhee, Byung Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • 제38B권7호
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    • pp.543-552
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    • 2013
  • For the safety messages in IEEE 802.11p/WAVE vehicles network environment, strict periodic beacon broadcasting requires status advertisement to assist the driver for safety. In crowded networks where beacon message are broadcasted at a high number of frequencies by many vehicles, which used for beacon sending, will be congested by the wireless medium due to the contention-window based IEEE 802.11p MAC. To resolve the congestion, we consider a MAC scheme based on slotted p-persistent CSMA as a simple non-cooperative Bayesian game which involves payoffs reflecting the attempt probability. Then, we derive Bayesian Nash Equilibrium (BNE) in a closed form. Using the BNE, we propose new congestion control algorithm to improve the performance of the beacon rate under saturation condition in IEEE 802.11p/WAVE vehicular networks. This algorithm explicitly computes packet delivery probability as a function of contention window (CW) size and number of vehicles. The proposed algorithm is validated against numerical simulation results to demonstrate its stability.

Implications for selecting persistent hot spots of schistosomiasis from community- and school-based surveys in Blue Nile, North Kordofan, and Sennar States, Sudan

  • Hassan Ahmed Hassan Ahmed Ismail;Seungman Cha;Yan Jin;Sung-Tae Hong
    • Parasites, Hosts and Diseases
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    • 제61권2호
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    • pp.216-224
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    • 2023
  • In several schistosomiasis-endemic countries, the prevalence has remained high in some areas owing to reinfection despite repeated mass drug administration (MDA) interventions; these areas are referred to as persistent hot spots. Identifying hotspots is critical for interrupting transmission. This study aimed to determine an effective means of identifying persistent hot spots. First, we investigated the differences between Schistosoma haematobium and Schistosoma mansoni prevalence among school-aged children (SAC) estimated by a community-based survey, for which local key informants purposively selected communities, and a randomly sampled school-based survey. A total of 6,225 individuals residing in 60 villages in 8 districts of North Kordofan, Blue Nile, or Sennar States, Sudan participated in a community-based survey in March 2018. Additionally, the data of 3,959 students attending 71 schools in the same 8 districts were extracted from a nationwide school-based survey conducted in January 2017. The community-based survey identified 3 districts wherein the prevalence of S. haematobium or S. mansoni infection among SAC was significantly higher than that determined by the randomly sampled school survey (e.g., S. haematobium in the Sennar district: 10.8% vs. 1.1%, P<0.001). At the state level, the prevalence of schistosomiasis among SAC, as determined by the community-based survey, was consistently significantly higher than that determined by the school-based survey. Purposeful selection of villages or schools based on a history of MDA, latrine coverage, open defecation, and the prevalence of bloody urine improved the ability for identifying persistent hot spots.

Review of advanced oxidation processes (AOPs) for treatment of pharmaceutical wastewater

  • Verma, Manisha;Haritash, A.K.
    • Advances in environmental research
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    • 제9권1호
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    • pp.1-17
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    • 2020
  • Pharmaceutically active compounds (PhACs) have become an environmental havoc in last few decades with reported cases of antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARGs), lethal effects over aquatic organisms, interference in natural decomposition of organic matter, reduced diversity of microbial communities in different environmental compartments, inhibition of growth of microbes resulting in reduced rate of nutrient cycling, hormonal imbalance in exposed organisms etc. Owing to their potential towards bioaccumulation and persistent nature, these compounds have longer residence time and activity in environment. The conventional technologies of wastewater treatment have got poor efficiency towards removal/degradation of PhACs and therefore, modern techniques with efficient, cost-effective and environment-friendly operation need to be explored. Advanced oxidation processes (AOPs) like Photocatalysis, Fenton oxidation, Ozonation etc. are some of the promising, viable and sustainable options for degradation of PhACs. Although energy/chemical or both are essentially required for AOPs, these methods target complete degradation/mineralization of persistent pollutants resulting in no residual toxicity. Considering the high efficiency towards degradation, non-toxic nature, universal viability and acceptability, AOPs have become a promising option for effective treatment of chemicals with persistent nature.

Early-life exposure to endocrine disrupting chemicals associates with childhood obesity

  • Yang, Chunxue;Lee, Hin Kiu;Kong, Alice Pik Shan;Lim, Lee Ling;Cai, Zongwei;Chung, Arthur C.K.
    • Annals of Pediatric Endocrinology and Metabolism
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    • 제23권4호
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    • pp.182-195
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    • 2018
  • Increasing prevalence of childhood obesity poses threats to the global health burden. Because this rising prevalence cannot be fully explained by traditional risk factors such as unhealthy diet and physical inactivity, early-life exposure to endocrine disrupting chemicals (EDCs) is recognized as emerging novel risk factors for childhood obesity. EDCs can disrupt the hormone-mediated metabolic pathways, affect children's growth and mediate the development of childhood obesity. Many organic pollutants are recently classified to be EDCs. In this review, we summarized the epidemiological and laboratory evidence related to EDCs and childhood obesity, and discussed the possible mechanisms underpinning childhood obesity and early-life exposure to non-persistent organic pollutants (phthalates, bisphenol A, triclosan) and persistent organic pollutants (dichlorodip henyltrichloroethane, polychlorinated biphenyls, polybrominated diphenyl ethers, per- and polyfluoroalkyl substances). Understanding the relationship between EDCs and childhood obesity helps to raise public awareness and formulate public health policy to protect the youth from exposure to the harmful effects of EDCs.

LACTATION CURVE OF HOLSTEIN FRIESIAN COWS IN THE KINGDOM OF SAUDI ARABIA

  • Ali, A.K.A.;Al-Jumaah, R.S.;Hayes, E.
    • Asian-Australasian Journal of Animal Sciences
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    • 제9권4호
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    • pp.439-447
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    • 1996
  • Monthly test day production for 12,020 records, were collected from six of the largest specialized dairy farms located in central region of the Kingdom of Saudi Arabia. The records described lactating cows in four parities and two seasons of calving. Monthly test day records were fitted using Wood's model $At{{^b}{_e}}^{-ct}$ with multiple and additive error term. Linear and non-linear regression models were used to find the estimates of the parameters necessary to draw the lactation curves. The shape of the lactation curves of different parities showed that third lactation has the heighest peak (43.08 kg) for linear regression model and (42.08 kg) for non-linear regression model. Fourth lactation has the lowest peak (24.00kg) for linear regression model and (25.64 kg) for non-linear regression models. Cows of second and third lactations reached the peak at 58 day for both linear and non-linear regression models. Cows of first lactation were more persistent and had late peak at 68 and 67 days for both models respectively. While, third lactation cows were lower persistent and had early peak at 58 day for both models. Cows calved at winter months have higher starting values (A), higher ascending slope (b) and higher decending slope (c). Least square means of milk yield of the first four parities and for overall data were 6,653, 7,659, 7,482, 6,988 and 7,614 kg respectively. The corresponding lactation period were 358, 367, 350, 363 and 364 days respectively.

The outcome of epiduroscopy treatment in patients with chronic low back pain and radicular pain, operated or non-operated for lumbar disc herniation: a retrospective study in 88 patients

  • Hazer, Derya Burcu;Acarbas, Arsal;Rosberg, Hans Eric
    • The Korean Journal of Pain
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    • 제31권2호
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    • pp.109-115
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    • 2018
  • Background: Patients with lumbar disc herniation are treated with physiotherapy/medication and some with surgery. However, even after technically successful surgery some develop a failed back syndrome with persistent pain. Our aim was to evaluate the efficacy of epiduroscopy in patients who suffer chronic low back pain and/or radicular pain with or without surgery and the gender difference in outcome. Methods: A total of 88 patients were included with a mean age of 52 years (27-82), 54 women and 34 men. 66 of them were operated previously and 22 were non-operated. They all had persistent chronic back pain and radicular pain despite of medication and physical rehabilitation. Visual Analog Scale (VAS) for pain and Oswestry Disability Index (ODI) were evaluated preoperatively, after one month, six months and one-year after the epiduroscopy. Results: All patients, and also the subgroups (gender and operated/non-operated) improved significantly in pain (VAS) and disability (ODI) at one month. A significant improvement was also seen at one year. No differences were found between men and woman at the different follow-up times. A slight worsening in VAS and ODI was noticed over time except for the non-operated group. Conclusions: Epiduroscopy helps to improve the back and leg pain due to lumbar disc herniation in the early stage. At one year an improvement still exists, and the non-operated group seems to benefit most of the procedure.

Investigation of Transition Types of HPV DNA Test Results over Time in Korean Women

  • Ko, Kiwoong;Kwon, Min-Jung;Woo, Hee-Yeon;Park, Hyosoon
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권8호
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    • pp.3167-3172
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    • 2015
  • Background: Understanding the history of human papilloma virus (HPV) infection is important for interpretation of a positive HPV DNA screening test, future work-up and treatment. We investigated the transition of HPV DNA test results in Korean women, and analyzed the association of cytology result with transition type. Materials and Methods: We retrospectively reviewed annual HPV DNA test results for 5,274 subjects between January 2005 and December 2012. Each subject had a minimum of five annual tests over the eight-year period. Based on the pattern of results, the transition type for each subject was assigned to one of the following: negative, persistent, latent, transient, and unclassifiable. Associations of cytology results with the HPV DNA transition types, number of positive results, and the durations of positive results were also analyzed. Results: The proportion of abnormal cytology findings decreased in the following order of transition patterns: persistent, latent, transient, and negative. Among transient patterns, a duration of three years or more significantly correlated with cytology results of non-high grade squamous intraepithelial lesion (HSIL; p<0.001). In the persistent group, duration of five years or more correlated with both non-HSIL and HSIL (p<0.001). Latent group showed no correlation with duration. Irrespective of patterns, having five or more positive results was significantly associated with HSIL (p<0.001). Conclusions: Our findings may contribute to better understanding of HPV infection, interpretation of HPV DNA screening results, and prediction of prognosis according to transition type.

A Case of Persistent Hiccups of Non-Small Cell Lung Cancer Patient Treated with Korean Medicine (한방 치료로 지속성 딸꾹질이 호전된 비소세포폐암 환자 치험 1례)

  • Ye-Chae, Hwang;Hye-Jin, Lee;Hye-Min, Heo;Gyu-Ri, Jeon;Seung-Yeon, Cho;Seong-Uk, Park;Jung-Mi, Park;Chang-Nam, Ko
    • The Journal of the Society of Stroke on Korean Medicine
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    • 제23권1호
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    • pp.1-12
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    • 2022
  • Persistent hiccups persist for more than 48 hours. Those can often occur in cancer patients after chemotherapy or high dose of corticosteroids. A 52-year-old male patient undergoing Non-small cell lung cancer(NSCLC), recently suffered presistent hiccups and dyspnea. He was treated with herbal medicine for 56days and acupuncture for 9days. No side effects were observed during treatment. The severity of hiccups was measured in every hospital visit and psychometric symptoms were evaluated periodically through the Edmonton Symptom Assessment System(ESAS). The severity of hiccups and psychometric symptoms were alleviated and the effect persisted during the treatment. The patient took no other nervous system drugs in the end of the treatment. In conclusion, Korean medicine like Hyeongbangjihwang-tang and Jeongcheonhwadamgangki-tang can be effective for patients with persistent hiccups and dyspnea who cannot use alternative drugs or treatment because of other complications.