1
|
Nesting chinstrap penguins accrue large quantities of sleep through seconds-long microsleeps. Science 2023; 382:1026-1031. [PMID: 38033080 DOI: 10.1126/science.adh0771] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 10/05/2023] [Indexed: 12/02/2023]
Abstract
Microsleeps, the seconds-long interruptions of wakefulness by eye closure and sleep-related brain activity, are dangerous when driving and might be too short to provide the restorative functions of sleep. If microsleeps do fulfill sleep functions, then animals faced with a continuous need for vigilance might resort to this sleep strategy. We investigated electroencephalographically defined sleep in wild chinstrap penguins, at sea and while nesting in Antarctica, constantly exposed to an egg predator and aggression from other penguins. The penguins nodded off >10,000 times per day, engaging in bouts of bihemispheric and unihemispheric slow-wave sleep lasting on average only 4 seconds, but resulting in the accumulation of >11 hours of sleep for each hemisphere. The investment in microsleeps by successfully breeding penguins suggests that the benefits of sleep can accrue incrementally.
Collapse
|
2
|
Clinical Significance of Arginine Signaling in Patients with Cervical Cancer Receiving Cisplatin Chemoradiation Therapy. Int J Radiat Oncol Biol Phys 2023; 117:e506. [PMID: 37785587 DOI: 10.1016/j.ijrobp.2023.06.1757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Many human malignancies do not produce sustainable amounts of arginine (Arg) because the rate-limiting enzyme, arginosuccinate synthetase 1 (ASS1), in the biosynthesis of Arg has been silenced. We investigated the clinical significance of ASS1 expression on cisplatin chemoradiation therapy for cervical cancer. MATERIALS/METHODS A total of 118 consecutive patients with FIGO stages IB to IVA cervical cancer who had received platinum-based concurrent chemoradiotherapy were identified and their clinical courses were reviewed. Immunohistochemical studies were performed on their formalin-fixed, paraffin-embedded tissues. The prognostic value of ASS1 was investigated by performing univariate and multivariate analyses on factors affecting patient survival. RESULTS Median follow-up for all patients was 5.5 years (range: 1 to 23.5 years). Overexpression of ASS1 was an independent prognostic factor. The 5-year disease-free survival for patients with ASS1-positive tumors was 72.3%, compared with 51.6% for patients with ASS1-negative tumors (P = 0.02). Univariate Cox proportional hazards models showed positive ASS1 immunostaining (hazard ratio [HR]: 0.50, 95% CI: 0.28-0.90), FIGO stage (HR: 0.33, 95% CI: 0.18-0.59) and brachytherapy (HR: 0.22, 95% CI: 0.10-0.48) were significant prognostic factors affecting disease-free survival. In multivariate analyses, positive ASS1 remained an independent significant prognostic factor for DFS (HR = 0.45, 95% CI: 0.25-0.83). CONCLUSION Overexpression of ASS1 is an independent prognostic factor for cervical cancer patients receiving cisplatin concurrent chemoradiotherapy.
Collapse
|
3
|
Local refinement mechanism for improved plant leaf segmentation in cluttered backgrounds. FRONTIERS IN PLANT SCIENCE 2023; 14:1211075. [PMID: 37711291 PMCID: PMC10499048 DOI: 10.3389/fpls.2023.1211075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 08/08/2023] [Indexed: 09/16/2023]
Abstract
Plant phenotyping is a critical field in agriculture, aiming to understand crop growth under specific conditions. Recent research uses images to describe plant characteristics by detecting visual information within organs such as leaves, flowers, stems, and fruits. However, processing data in real field conditions, with challenges such as image blurring and occlusion, requires improvement. This paper proposes a deep learning-based approach for leaf instance segmentation with a local refinement mechanism to enhance performance in cluttered backgrounds. The refinement mechanism employs Gaussian low-pass and High-boost filters to enhance target instances and can be applied to the training or testing dataset. An instance segmentation architecture generates segmented masks and detected areas, facilitating the derivation of phenotypic information, such as leaf count and size. Experimental results on a tomato leaf dataset demonstrate the system's accuracy in segmenting target leaves despite complex backgrounds. The investigation of the refinement mechanism with different kernel sizes reveals that larger kernel sizes benefit the system's ability to generate more leaf instances when using a High-boost filter, while prediction performance decays with larger Gaussian low-pass filter kernel sizes. This research addresses challenges in real greenhouse scenarios and enables automatic recognition of phenotypic data for smart agriculture. The proposed approach has the potential to enhance agricultural practices, ultimately leading to improved crop yields and productivity.
Collapse
|
4
|
Public awareness of preventive measures against COVID-19: an infodemiology study. Hong Kong Med J 2023; 29:214-223. [PMID: 37349138 DOI: 10.12809/hkmj219556] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/24/2023] Open
Abstract
INTRODUCTION The coronavirus disease 2019 (COVID-19) pandemic has led to an increase in global awareness of relevant public health preventive measures. This awareness can be explored using online search trends from major search engines, such as Google Trends. We investigated the relationship between public awareness of preventative measures and progression of the COVID-19 pandemic. METHODS Search data for five queries ('mask', 'hand washing', 'social distancing', 'hand sanitizer', and 'disinfectant') were extracted from Google Trends in the form of relative search volume (RSV). Global incidence data for COVID-19 were obtained from 1 January to 30 June 2020. These data were analysed and illustrated using a global temporal RSV trend diagram, a geographical RSV distribution chart, scatter plots comparing geographical RSV with average number of daily cases, and heat maps comparing temporal trends of RSV with average number of daily cases. RESULTS Global temporal trends revealed multiple increases in RSV, associated with specific COVID-19-related news events. The geographical distribution showed top regions of interest for various preventive measures. For the queries 'mask', 'hand washing', 'hand sanitizer', and 'disinfectant', heat maps demonstrated patterns of early RSV peaks in regions with lower average number of daily cases, when the temporal element was incorporated into the analysis. CONCLUSION Early public awareness of multiple preventive measures was observed in regions with lower average number of daily cases. Our findings indicate optimal public health communication regarding masks, hand washing, hand sanitiser, and disinfectant in the general population during early stages of the COVID-19 pandemic. Early public awareness may facilitate future disease control efforts by public health authorities.
Collapse
|
5
|
Global Forum of Cancer Surgeons: Cancer Surgery During the COVID-19 Pandemic: Impact and Lessons Learned. Ann Surg Oncol 2022; 29:2773-2783. [PMID: 35211857 PMCID: PMC8870071 DOI: 10.1245/s10434-022-11506-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 02/14/2022] [Indexed: 11/18/2022]
Abstract
Background The purpose of this article is to summarize the opinions of the surgical oncology leaders from the Global Forum of Cancer Surgeons (GFCS) about the global impact of COVID-19 pandemic on cancer surgery. Methods A panel session (virtual) was held at the annual Society of Surgical Oncology 2021 International Conference on Surgical Cancer Care to address the impact of COVID-19 on cancer surgery globally. Following the virtual meeting, a questionnaire was sent to all the leaders to gather additional opinions. The input obtained from all the leaders was collated and analyzed to understand how cancer surgeons from across the world adapted in real-time to the impact of COVID-19 pandemic. Results The surgical oncology leaders noted that the COVID-19 pandemic led to severe disruptions in surgical cancer care across all domains of clinical care, education, and research. Several new changes/protocols associated with increased costs were implemented to deliver safe care. Leaders also noted that preexisting disparities in care were exacerbated, and the pandemic had a detrimental effect on well-being and financial status. Conclusions The COVID-19 pandemic has led to severe disruptions in surgical cancer care globally. Leaders of the GFCS opined that new strategies need to be implemented to prepare for any future catastrophic events based on the lessons learned from the current events. The GFCS will embark on developing such a roadmap to ensure that surgical cancer care is preserved in the future regardless of any catastrophic global events.
Collapse
|
6
|
Potential effects of COVID-19 on reproductive systems and fertility; assisted reproductive technology guidelines and considerations: a review. Hong Kong Med J 2021; 27:118-126. [PMID: 33853972 DOI: 10.12809/hkmj209078] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) employs the angiotensin-converting enzyme 2 (ACE2) receptor in the renin-angiotensin system for viral entry. The ACE2 receptor is present in both female and male reproductive systems, and reports of multi-organ involvement have led to uncertainty regarding its effects on the reproductive system and fertility. We review the existing literature regarding the function of ACE2 and the renin-angiotensin system in the female and male reproductive systems to postulate the possible implications of SARS-CoV-2 regarding fertility. Because of the presence of ACE2 in the ovaries, SARS-CoV-2 infection may disrupt ovarian function and hence oocyte quality. Higher expression of ACE2 in the endometrium with age and during the secretory phase raises concern about increased susceptibility to infection during periods of high ACE2 expression. The possibility of vertical transmission and the presence of ACE2 in the placenta and during pregnancy are also discussed. The presence of SARS-CoV-2 RNA in semen is controversial, but impaired semen quality has been found in men with moderate coronavirus disease 2019 infection. Evidence of orchitis and hormonal changes seen in male coronavirus disease 2019 infection may lead to infertility. The implications of these effects on assisted reproductive technology (ART) outcomes are also explored. The ART guidelines from different fertility societies for the management of patients treated with ART are provided. The importance of prioritising 'time-sensitive' patients for ART, counselling patients about the uncertainty and risks of ART, and pregnancy during the pandemic is discussed. Recommendations are also provided for infection control and safe regulation of ART centres and laboratories.
Collapse
|
7
|
Primordial GATA6 macrophages function as extravascular platelets in sterile injury. Science 2021; 371:371/6533/eabe0595. [PMID: 33674464 DOI: 10.1126/science.abe0595] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 01/08/2021] [Indexed: 12/14/2022]
Abstract
Most multicellular organisms have a major body cavity that harbors immune cells. In primordial species such as purple sea urchins, these cells perform phagocytic functions but are also crucial in repairing injuries. In mammals, the peritoneal cavity contains large numbers of resident GATA6+ macrophages, which may function similarly. However, it is unclear how cavity macrophages suspended in the fluid phase (peritoneal fluid) identify and migrate toward injuries. In this study, we used intravital microscopy to show that cavity macrophages in fluid rapidly form thrombus-like structures in response to injury by means of primordial scavenger receptor cysteine-rich domains. Aggregates of cavity macrophages physically sealed injuries and promoted rapid repair of focal lesions. In iatrogenic surgical situations, these cavity macrophages formed extensive aggregates that promoted the growth of intra-abdominal scar tissue known as peritoneal adhesions.
Collapse
|
8
|
Different effects on right ventricular function in different etiology of secondary tricuspid regurgitation. Eur Heart J Cardiovasc Imaging 2021. [DOI: 10.1093/ehjci/jeaa356.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Science and Technology, Excutive Yuan, Taiwan
Background
Tricuspid regurgitation (TR) is traditionally classified as primary or secondary TR. The effects of TR on right ventricular (RV) function were not consistent. We hypothesized that secondary TR is not a unique group, sophisticated sub-grouping can be useful for studying effects of TR on RV function.
Methods
207 consecutive patients identified as significant TR (moderate and severe) by echocardiography were recruited. Standard measurements for right heart were done according to guideline. Lateral tricuspid annulus systolic tissue velocity (S’) and RV fractional area change (FAC) were used for RV function. We classified these patients into primary TR and 6 subgroups of secondary TR according to a new systemic approach.
Results
Mean age of subjects was 71.2 ± 14.7 years, and there were 84 (40.6%) male. There were 29 (14%) primary TR. Secondary TR was further classified into 6 groups included 18 (8.7%) pacemaker related, 81 (39.1 %) left heart diseases, 6 (2.9%) congenital heart diseases, 3 (1.4%) RV myopathy, 27 (13.0%) pulmonary hypertension, and 43 (20.8%) idiopathic TR. Among 4 major groups (congenital heart disease and RV myopathy were not included in analysis due to low numbers) of secondary TR, S’ was significant higher in idiopathic TR and RV FAC were higher in pacemaker related and idiopathic TR. RV dysfunction was defined as FAC < 35%. RV dysfunction presented mostly in pulmonary hypertension related TR and leastly in idiopathic TR (59.3% vs. 14%, p <0.001). Multivariate analysis using idiopathic TR as reference and controlled TR maximal velocity, RV end-diastolic area, right atrial area, and severity of TR, left heart disease related TR had higher risk of RV dysfunction (OR 4.178, 95% CI 1.490-11.703, p = 0.007).
Conclusions
Effects of TR on RV function were different among different subgroups of secondary TR. Left heart disease related TR had highest risk for RV dysfunction. Secondary TR should not be regarded as a single disease.
Collapse
|
9
|
1108 REM Sleep Motor Dysregulation in Narcolepsy. Sleep 2018. [DOI: 10.1093/sleep/zsy063.1107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
10
|
1109 Hypoglossal Nerve Stimulation for Treatment of Patient with Severe Obstructive Sleep Apnea (OSA) Complicated by Severe Bruxism. Sleep 2018. [DOI: 10.1093/sleep/zsy063.1108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
11
|
Tissue-Engineered Acellularized Valve Xenografts: A Comparative Animal Study between Plain Acellularized Xenografts and Autologous Endothelial Cell Seeded Acellularized Xenografts. Int J Artif Organs 2018; 27:501-8. [PMID: 15293356 DOI: 10.1177/039139880402700609] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background Acellularized valve xenografts are considered a promising way of overcoming the inherent limitations of current prosthetic valves. The aim of this study was to compare the biological responses of an autologous endothelial cell seeded acellularized xenograft (AAX) and a plain acellularized xenograft (PAX) implanted in the pulmonary valve leaflet in the same animal. Methods Endothelial cells were isolated and cultured from the jugular vein of goats. Porcine valve leaflets were acellularized with Nacl-SDS, and for AAX, leaflets were then seeded with autologous endothelial cells. A PAX and an AAX were implanted as double pulmonary valve leaflet replacement in the same animal in a goat model (n=6). After sacrifice, the implanted valve leaflet tissues were retrieved and analyzed visually and under a light microscope. Results and Conclusions Six animals were sacrificed as scheduled during the short-term (6 and 24 hours), mid-term (1 week and 1 month) and long-term (3 and 6 months). Gross and ultrasonographic examinations revealed good valve function with no thrombosis but with slight thickening. Microscopic analysis of the leaflets showed abundant cellular ingrowth into the acellularized leaflets over time. The role of endothelial cell seeding remains controversial. This animal experiment demonstrates the practical feasibility of using acellularized valve xenografts.
Collapse
|
12
|
Antibiotic Prescribing for Patients with Upper Respiratory Tract Infections by Emergency Physicians in a Singapore Tertiary Hospital. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490790501200207] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Objective Despite the paucity of supporting evidence, the use of antibiotics in the management of upper respiratory tract infections (URTI) remains a persistent and worrying trend worldwide. This survey study set out to examine the antibiotic prescribing profile of emergency physicians for patients diagnosed with URTI at a local tertiary hospital. Methods Patients seeking treatment for URTI at the emergency department in the year 2001 were identified by their ICD-9 code. The electronic medical records of a random sample of these patients were reviewed. Patients with the following documented findings were excluded: (a) a duration of more than 7 days between disease onset and date of consultation, (b) prior antibiotic usage or medical consultation, (c) presentation of purulent sputum and/or purulent nasal discharge, and (d) existing medical conditions requiring antibiotic treatment/prophylaxis. Chi-square and multivariate analyses were performed to assess the association of patient-related factors with antibiotic prescribing. Results Of a random sample of 488 cases of URTI, inappropriate antibiotic prescribing was observed in 24% of cases (95% CI 20%, 28%). Significant associations were observed between antibiotic prescribing and month of consultation, patients' temperature and symptom of rhinorrhoea. Conclusion A substantial proportion of emergency department patients with URTI received antibiotics despite the lack of evidence supporting the drugs' effectiveness. Appropriate interventions to promote evidence-based prescribing amongst emergency physicians are required to reduce the extent of inappropriate antibiotic prescribing as well as to ensure the longevity of antibiotic effectiveness.
Collapse
|
13
|
Abstract
Study Objectives The object of this study is to audit the care of ankle sprain of different severity and the functional limitations at two weeks and six weeks post injury of patients presenting to the Emergency Department of my hospital. Methods Over a three month period, all patients presenting with acute ankle sprain were recruited at triage (index visit). Exclusion criteria were ankle injuries more than twenty-four hours old or had already received radiological evidence of fractures. A self-administered questionnaire was used to determine the severity and treatment. At second and at sixth week post index visit, three telephone interview attempts were made respectively to ask for the functional limitations and recovery using a standard questionnaire. Results One hundred and thirty-nine candidates were recruited. Of these, 35.3% had mild, 19.6% had moderate and 15.2% had severe ankle sprain. Those with moderately severe ankle sprain have the least medical leave days. Only 48% were given more than 3 days of medical leave compared to 71% (mild group) and 76% (severe group). The treatment is otherwise similar across the three groups. Eighty-one patients (58%) and 70 patients (50%) were captured in the 2nd and 6th week telephone interviews respectively. Those patients with moderate severity fared worse with higher overall percentages in functional limitations and secondary consultations. This was more obvious in the 6th week telephone interview. Conclusion Patients with moderate severity ankle sprain fared worse compared with patients with severe or mild ankle sprain over a six-week recovery period. This may be due to insufficient rest days given to this group of patients at initial presentation.
Collapse
|
14
|
The association between distance to public amenities and cardiovascular risk factors among lower income Singaporeans. Prev Med Rep 2017; 8:116-121. [PMID: 29021948 PMCID: PMC5633842 DOI: 10.1016/j.pmedr.2017.09.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 08/21/2017] [Accepted: 09/09/2017] [Indexed: 01/05/2023] Open
Abstract
Existing evidence on the association between built environment and cardiovascular disease (CVD) risk factors focused on the general population, which may not generalize to higher risk subgroups such as those with lower socio-economic status (SES). We examined the associations between distance to 5 public amenities from residential housing (public polyclinic, subsidized private clinic, healthier eatery, public park and train station) and 12 CVD risk factors (physical inactivity, medical histories and unhealthy dietary habits) among a study sample of low income Singaporeans aged ≥ 40 years (N = 1972). Using data from the Singapore Heart Foundation Health Mapping Exercise 2013–2015, we performed a series of logistic mixed effect regressions, accounting for clustering of respondents in residential blocks and multiple comparisons. Each regression analysis used the minimum distance (in km) between residential housing and each public amenity as an independent continuous variable and a single risk factor as the dependent variable, controlling for demographic characteristics. Increased distance (geographical inaccessibility) to a train station was significantly associated with lower odds of participation in sports whereas greater distance to a subsidized private clinic was associated with lower odds of having high cholesterol diagnosed. Increasing distance to park was positively associated with higher odds of less vegetable and fruits consumption, deep fried food and fast food consumption in the preceding week/month, high BMI at screening and history of diabetes, albeit not achieving statistical significance. Our findings highlighted potential effects of health-promoting amenities on CVD risk factors in urban low-income setting, suggesting gaps for further investigations. We examined associations between access to 5 amenities and 12 CVD risk factors. Only 2/60 associations were statistically significant. Poorer access to train station was associated with lower odds of sports. Poorer access to primary care was associated with lower high cholesterol diagnosis.
Collapse
|
15
|
Missed opportunities for earlier HIV-testing in patients with HIV infection referred to a tertiary hospital, a cross-sectional study. THE MEDICAL JOURNAL OF MALAYSIA 2017; 72:209-214. [PMID: 28889131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
INTRODUCTION In Malaysia, the prevalence of missed opportunities for HIV-testing is unknown. Missed opportunities have been linked to late diagnosis of HIV and poorer outcome for patients. We describe missed opportunities for earlier HIV-testing in newly-HIV-diagnosed patients. METHODS Cross sectional study. Adult patients diagnosed with HIV infection and had at least one medical encounter in a primary healthcare setting during three years prior to diagnosis were included. We collected data on sociodemographic characteristics, patient characteristics at diagnosis, HIV-related conditions and whether they were subjected to risk assessment and offered HIV testing during the three years prior to HIV diagnosis. RESULTS 65 newly HIV-diagnosed patients (male: 92.3%; Malays: 52.4%; single: 66.7%; heterosexual: 41%; homosexual 24.6%; CD4 <350 at diagnosis: 63%). 93.8% were unaware of their HIV status at diagnosis. Up to 56.9% had presented with HIV-related conditions at a primary healthcare facility during the three years prior to diagnosis. Slightly more than half were had risk assessment done and only 33.8% were offered HIV-testing. CONCLUSIONS Missed opportunities for HIV-testing was unacceptably high with insufficient risk assessment and offering of HIV-testing. Risk assessment must be promoted and primary care physicians must be trained to recognize HIV-related conditions that will prompt them to offer HIVtesting.
Collapse
|
16
|
Streptococcus agalactiae outbreaks in cultured golden pomfret, Trachinotus blochii (Lacépède), in Singapore. JOURNAL OF FISH DISEASES 2017; 40:971-974. [PMID: 28000924 DOI: 10.1111/jfd.12570] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 09/19/2016] [Accepted: 09/20/2016] [Indexed: 06/06/2023]
|
17
|
Identification of lactoferrin and glutamate receptor-interacting protein 1 in bovine cervical mucus: A putative marker for oestrous detection. Reprod Domest Anim 2016; 52:16-23. [DOI: 10.1111/rda.12744] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 07/01/2016] [Indexed: 11/28/2022]
|
18
|
BPA and NP removal from municipal wastewater by tropical horizontal subsurface constructed wetlands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 542:93-101. [PMID: 26519570 DOI: 10.1016/j.scitotenv.2015.09.154] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/29/2015] [Accepted: 09/30/2015] [Indexed: 06/05/2023]
Abstract
It has been recognized that numerous synthetic compounds like Bisphenol A (BPA) and nonylphenols (NP) are present in effluents from wastewater treatment plants (WWTP) at levels of parts per billion (μg L(-1)) or even parts per trillion (ng L(-1)) with a high potential to cause endocrine disruption in the aquatic environment. Constructed wetlands (CW) are a cost-effective wastewater treatment alternative with promising performance to treat these afore mentioned compounds. This research was aimed to evaluate the efficacy of CW treatment of WWTP effluent for mitigating the effects endocrine disrupting compounds (EDCs). This research goal was accomplished by (1) quantifying the removal of BPA and NP in CWs; (2) isolating CW fungal strains and testing for laccase production; and (3) performing endocrine disruption (reproduction) bioassays using the fruit fly Drosophila melanogaster. Three pilot scale horizontal subsurface flow constructed wetlands (HSSF-CW) were operated for eight weeks: one planted with Phragmites australis; one planted with Heliconia psitacorum; and one unplanted. The Heliconia CW showed a removal efficiency of 73.3(± 19%) and 62.8(± 20.1%) for BPA and NP, respectively; while the Phragmites CW demonstrated a similar removal for BPA (70.2 ± 27%) and lower removal efficiency for NP 52.1(± 37.1%).The unplanted CW achieved 62.2 (± 33%) removal for BPA and 25.3(± 37%) removal for NP. Four of the eleven fungal strains isolated from the Heliconia-CW showed the capacity to produce laccase. Even though complete removal of EDCs was not achieved by the CWs, the bioassay confirmed a significant improvement (p < 0.05) in fly viability for all CWs, with Heliconia sp. being the most effective at mitigating adverse effects on first and second generational reproduction. This study showed that a CW planted with a native Heliconia sp. CW demonstrated a higher removal of endocrine disrupting compounds and better mitigation of reproductive disruption in the bioassay.
Collapse
|
19
|
Impact of initial management on respiratory complications in emergency department patients requiring mechanical ventilation. Intensive Care Med Exp 2015. [PMCID: PMC4797919 DOI: 10.1186/2197-425x-3-s1-a670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
20
|
Well plate-based perfusion culture device for tissue and tumor microenvironment replication. LAB ON A CHIP 2015; 15:2854-2863. [PMID: 26021852 PMCID: PMC4470735 DOI: 10.1039/c5lc00341e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
There are significant challenges in developing in vitro human tissue and tumor models that can be used to support new drug development and evaluate personalized therapeutics. The challenges include: (1) working with primary cells which are often difficult to maintain ex vivo, (2) mimicking native microenvironments from which primary cells are harvested, and (3) the lack of culture devices that can support these microenvironments to evaluate drug responses in a high-throughput manner. Here we report a versatile well plate-based perfusion culture device that was designed, fabricated and used to: (1) ascertain the role of perfusion in facilitating the expansion of human multiple myeloma cells and evaluate drug response of the cells, (2) preserve the physiological phenotype of primary murine osteocytes by reconstructing the 3D cellular network of osteocytes, and (3) circulate primary murine T cells through a layer of primary murine intestine epithelial cells to recapitulate the interaction of the immune cells with the epithelial cells. Through these diverse case studies, we demonstrate the device's design features to support: (1) the convenient and spatiotemporal placement of cells and biomaterials into the culture wells of the device; (2) the replication of tissues and tumor microenvironments using perfusion, stromal cells, and/or biomaterials; (3) the circulation of non-adherent cells through the culture chambers; and (4) conventional tissue and cell characterization by plate reading, histology, and flow cytometry. Future challenges are identified and discussed from the perspective of manufacturing the device and making its operation for routine and wide use.
Collapse
|
21
|
The adequacy of the distal resection margin after preoperative chemoradiotherapy for rectal cancer. Colorectal Dis 2014; 16:O257-63. [PMID: 24422744 DOI: 10.1111/codi.12554] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 10/20/2013] [Indexed: 02/08/2023]
Abstract
AIM The study aimed to determine the adequacy of the distal margin in patients having preoperative chemoradiotherapy (CRT) followed by restorative surgery for rectal cancer. METHOD A total of 368 patients with locally advanced rectal cancer treated for cure at our institution between July 1999 and March 2009 were included in the study. All underwent preoperative CRT and sphincter-sparing surgery. The distal margin and other factors were examined for their effect on recurrence and survival. The median duration of follow-up was 48 months. RESULTS The length of distal margin ranged from 0 to 9.0 cm (median 1.5 cm). The pelvic control and disease-free survival rates at 5 years for patients with a margin of ≤ 3 mm were no different from those in whom it was > 3 mm (P = 0.6 and 0.8). The 5-year pelvic control rates between the ≤ 3 mm and > 3 mm groups were 66.7 and 86.2% in patients with a ypT3-4 tumour (P = 0.049) and 70.0 and 89.1% in patients who showed no response to CRT (P = 0.039). CONCLUSION The results suggest that a distal margin of < 3 mm in the surgical specimen after preoperative CRT is associated with a lower rate of pelvic tumour control at 5 years in patients with Stage ypT3-4 tumours or in those who do not respond to CRT.
Collapse
|
22
|
Dosimetric advantages and superior treatment delivery efficiency of RapidArc over conventional intensity-modulated radiotherapy in high-risk prostate cancer involving seminal vesicles and pelvic nodes. Clin Oncol (R Coll Radiol) 2013; 25:706-12. [PMID: 23954261 DOI: 10.1016/j.clon.2013.07.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 06/06/2013] [Accepted: 06/10/2013] [Indexed: 11/27/2022]
Abstract
AIMS To compare the dosimetry and treatment delivery efficiency of RapidArc with conventional intensity-modulated radiotherapy (IMRT) in the treatment of high-risk prostate cancer. MATERIALS AND METHODS Fifteen patients with high-risk localised prostate cancer were studied. Sequential treatment was used. The initial planning target volume (PTV-L) included the prostate, seminal vesicles and pelvic lymphatics, whereas the prostate boost PTV (PTV-P) included the prostate and seminal vesicles only. The total prescription dose was 76 Gy (44 Gy to PTV-L, 32 Gy to PTV-P; 2 Gy/fraction). Two separate planning techniques were generated for each patient: seven static-field IMRT versus two-arc RapidArc. Dose-volume parameters for the organs at risk, conformity index and homogeneity index for the PTVs, the calculated monitor units and treatment delivery time for both techniques were compared. RESULTS RapidArc gave more conformal plans than IMRT for both PTVs. RapidArc gave a higher homogeneity index to the PTV-P and a similar homogeneity index to the PTV-L. The two techniques gave similar dosimetric results for the rectum, bladder and femoral heads. The mean dose (Dmean) and the maximum dose (Dmax) of the bowel space were reduced by 3.06 and 2.83%, respectively, with RapidArc. The V20 Gy, V30 Gy and V40 Gy for healthy tissues were reduced by 7.77, 14.25 and 17.55%, respectively, with RapidArc. The calculated treatment delivery time and monitor units were reduced by 74.09%/60.93% and 68.32%/48.06% for the PTV-L/PTV-P, respectively, with RapidArc. CONCLUSION RapidArc is better than conventional IMRT in terms of dosimetry and delivery efficiency for high-risk prostate cancer.
Collapse
|
23
|
Dihydrotanshinone induces p53-independent but ROS-dependent apoptosis in colon cancer cells. Life Sci 2013; 93:344-51. [PMID: 23871989 DOI: 10.1016/j.lfs.2013.07.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 06/26/2013] [Accepted: 07/06/2013] [Indexed: 12/16/2022]
Abstract
AIMS The therapeutic potential of various tanshinones was examined and compared for their anti-cancer activities on colon cancer cells. The role of ROS generation in the pro-apoptotic activity of dihydrotanshinone (DHTS) was further studied. MAIN METHODS Cell viability was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis and poly-ADP-ribose-polymerase (PARP) cleavage were respectively measured by flow cytometer and Western blot. Changes of mitochondrial membrane potential (MMP), mitochondrial ROS (mitoROS) and total ROS were determined by confocal system under an inverted microscope. KEY FINDINGS Among the different tanshinones examined, DHTS produced the most potent anti-cancer effect. DHTS induced a selective cytotoxicity and apoptosis in both HCT116 p53(-/-) and HCT116 p53(+/+) colon cancer cells. A time- and concentration-dependent PARP cleavage further confirmed the apoptotic activity. In this regard, it was found DHTS provoked mitochondrial dysfunction in the early stage by decreasing MMP and mitoROS levels. This was followed by a time-dependent increase in intracellular ROS generation. Pretreatment with N-acetyl-l-cysteine (NAC) or catalase-PEG, the free radical scavengers, reduced apoptotic cell death. From these findings, it seems that leakage of ROS from mitochondria into cytosol by DHTS represents the major contributory factor leading to cell death in colon cancer cells. SIGNIFICANCE We report for the first time that DHTS induces apoptosis in colon cancer cells through a p53-independent pathway. Disturbance of ROS generation at the oxidative phosphorylation (OXPHOS) complex in mitochondria followed by the decrease of MMP and increase of intracellular ROS accumulation are suggested to be involved in the pro-apoptotic activity of DHTS.
Collapse
|
24
|
Characterization of GFRα-1-Positive and GFRα-1-Negative Spermatogonia in Neonatal Pig Testis. Reprod Domest Anim 2013; 48:954-60. [DOI: 10.1111/rda.12193] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Accepted: 05/08/2013] [Indexed: 12/21/2022]
|
25
|
Efficacy and safety of the dipeptidyl peptidase-4 inhibitor gemigliptin compared with sitagliptin added to ongoing metformin therapy in patients with type 2 diabetes inadequately controlled with metformin alone. Diabetes Obes Metab 2013; 15:523-30. [PMID: 23320436 DOI: 10.1111/dom.12060] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2012] [Revised: 12/21/2012] [Accepted: 12/21/2012] [Indexed: 11/28/2022]
Abstract
AIMS This study was designed to assess the efficacy and safety of a dipeptidyl peptidase-4 inhibitor, gemigliptin versus sitagliptin added to metformin in patients with type 2 diabetes. METHODS We conducted a double-blind, randomized, active-controlled trial in 425 Asian patients with inadequately controlled type 2 diabetes being treated with metformin alone. Eligible patients were randomized into three groups: 50 mg gemigliptin qd, 25 mg gemigliptin bid or sitagliptin 100 mg qd added to ongoing metformin treatment for 24 weeks. Haemoglobin A1c (HbA1c) and fasting plasma glucose (FPG) were measured periodically, and oral glucose tolerance tests were performed at baseline and 24 weeks after starting the treatment regimen. RESULTS Twenty-four weeks later, adding gemigliptin (50 mg/day) to ongoing metformin therapy significantly improved glycaemic control. Reduction in HbA1c caused by 50 mg gemigliptin qd (-0.77% ± 0.8) was non-inferior to that caused by 100 mg sitagliptin qd (-0.8% ± 0.85). Proportion of patients achieving HbA1c <7% while taking 25 mg gemigliptin bid (50%) or 50 mg gemigliptin qd (54.07%) was comparable to the results with 100 mg sitagliptin qd (48.87%). There were significant decreases in FPG, postprandial glucose and AUC0-2 h glucose, as well as increases in GLP-1 and β cell sensitivity to glucose (supported by homeostasis model assessment of β-cell function, postprandial 2-h c-peptide and insulinogenic index) in patients receiving gemigliptin treatment with their metformin therapy. There was no increased risk of adverse effects with this dose of gemigliptin compared with sitagliptin 100 mg qd. CONCLUSIONS Addition of gemigliptin 50 mg daily to metformin was shown to be efficacious, well tolerated and non-inferior to sitagliptin in patients with type 2 diabetes mellitus.
Collapse
|
26
|
Efavirenz does not cause false-positive urine cannabis test in HIV-infected patients on Highly Active Anti-Retroviral Therapy. THE MEDICAL JOURNAL OF MALAYSIA 2013; 68:249-252. [PMID: 23749016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Efavirenz is a non-nucleoside reverse transcriptase inhibitor used in combination with other drugs for the treatment of patients with HIV infection. Efavirenz has been reported to cause a positive urine cannabis test reaction which may create problems between HIV-infected patients on Efavirenz and law enforcement agencies. Doctors are at loss whether to issue documents certifying the potential false positive urine cannabis test with Efavirenz to patients. We investigated if the urine of HIV-infected patients on Efavirenz caused a positive urine cannabis test using the AxSYM Cannabinoids Assay®. Urine samples from 51 eligible patients on Efavirenz were tested for cannabis. All tested negative except for one who had used cannabis the day before. Efavirenz does not cause false positive urine cannabis test with the AxSYM Cannabinoids Assay®. Certification documents from doctors are therefore unnecessary.
Collapse
|
27
|
Abstract
In a previous study, we established a collection of appropriate porcine placental extracts using PBS at 80°C (PE-PBS80) as a food supplement to increase immune activities in a mice model. In this study, piglets were treated with 0.1%, 0.3%, and 0.5% PE-PBS80 for 3 wk after weaning. Experiments were performed at 2 separate farms using 2 different pig varieties. Composition of white blood cells, lymphocyte activation, and cytokine concentrations were analyzed to assess the immune modulation effect. In Exp. 1, the number of white blood cells increased significantly in the PE-PBS80 treatment and T- and B-cell activation increased as well (P < 0.01). Interestingly, piglets in all treatments in Exp. 2 were naturally infected by a rotavirus at the third day of the experiment but recovered after d 10. Increased lymphocyte activation was observed in the PE-PBS80 treatment (P < 0.01) regardless of viral infection. Additionally, unlike in Exp. 1, the percentage of granulocytes and concentrations of interferon-γ, IL-1β, and IgG increased in the PE-PBS80 treatment (P < 0.01) and were more active in the 0.3% PE-PBS80 treatment compared with the control and the other treatment. In conclusion, 0.3% PE-PBS80 treatment modulated immune activities in antigen-infected piglets. Therefore, the PE-PBS80 pig placental extract, particularly the 0.3% supplement to the normal diet, could be useful as an alternative feed supplement to modulate immune activity during the early piglet period.
Collapse
|
28
|
Identification of the DDAH2 Protein in Pig Reproductive Tract Mucus: A Putative Oestrus Detection Marker. Reprod Domest Anim 2013; 48:e13-6. [DOI: 10.1111/j.1439-0531.2012.02122.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
29
|
Asian venous thromboembolism guidelines: prevention of venous thromboembolism. INT ANGIOL 2012; 31:501-516. [PMID: 23222928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Venous thromboembolism (VTE) prophylaxis is under-utilized in Asia because of the misconception that its incidence is lower in Asians as compared to the Caucasians. The available data on VTE in Asia is limited due to the lack of well-designed multicenter randomized controlled trials as well as non-standardized research designs, making data comparison difficult. Emerging data indicates that the VTE incidence is not low in Asia, and is comparable to that reported in the Western literature in some instances. There is also a trend towards increasing incidence of VTE, as demonstrated by a number of hospital-based studies in Asia. This could be attributed to lifestyle changes, ageing population, increasing awareness of VTE and wider availability of Duplex ultrasound. The risk of VTE in hospitalized patients remain the same in Asians and Caucasians, even though there may be factors that are inherent to patients in Asia that influence the slight variation in incidence. The utilization rate of VTE prophylaxis remains suboptimal in Asia. The Asian Venous Thrombosis Forum (AVTF) comprises participants from various countries such as China, Hong Kong, India, Indonesia, Korea, Malaysia, Philippines, Singapore, Taiwan, Thailand and experts from Australia and Europe. The forum evaluated the available data on VTE from the Asian region and formulated guidelines tailored to meet the needs of the region. We recommend that serious considerations are given to VTE prophylaxis especially in the at-risk group and a formal hospital policy be established to facilitate the implementation. On admission to the hospital, we recommend assessing the patients for both VTE and bleeding risk. We recommend mechanical prophylaxis for patients at increased risk of bleeding and utilizing it as an adjunctive measure in combination with pharmacological prophylaxis in patients with high risk of VTE. For patients undergoing general or gynecological surgery and with moderate risk for VTE, we recommend prophylaxis with one of the following: low dose unfractionated heparin (LDUH), low molecular weight heparin (LMWH), fondaparinux or intermittent pneumatic compression (IPC). For the same group of patients at high risk of VTE, we recommend pharmacological or combination of pharmacological and mechanical prophylaxis. For patients undergoing major orthopedic surgeries like total hip replacement, total knee replacement and proximal hip fracture surgery, we recommend using one of the following: LMWH, fondaparinux, rivaroxaban, apixaban, edoxaban, dabigatran, warfarin or aspirin with IPC. For patients admitted to the hospital with acute medical illness and has moderate risk of VTE, we recommend prophylaxis with LDUH, LMWH or Fondaparinux. For the same group at high risk of VTE, we recommend combination of pharmacological and mechanical prophylaxis.
Collapse
|
30
|
Endoscopic submucosal dissection or transanal endoscopic microsurgery for nonpolypoid rectal high grade dysplasia and submucosa-invading rectal cancer. Endoscopy 2012; 44:1031-6. [PMID: 23012217 DOI: 10.1055/s-0032-1310015] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND STUDY AIMS Transanal endoscopic microsurgery (TEM) has been shown to be highly effective for early rectal cancer, and endoscopic submucosal dissection (ESD) has been introduced to treat noninvasive colorectal neoplasia. The aim of this study was to compare the outcomes of ESD and TEM for superficial early rectal cancer. PATIENTS AND METHODS We retrospectively analyzed 63 patients with nonpolypoid rectal high grade dysplasia or submucosa-invading cancer who were treated with ESD or TEM, and compared clinical outcomes and safety between the treatment groups. RESULTS 30 patients underwent ESD and 33 underwent TEM. For ESD compared with TEM, en bloc resection rates were 96.7% vs. 100% (P = 0.476) and R0 resection rates were 96.7 % vs. 97.0 % (P = 1.000). There were no cases of local recurrence or distant metastasis in either group. Antibiotics were required in 11 patients (36.7%) in the ESD group and 33 (100%) in the TEM group (P < 0.001). There was no difference in net procedure time although ESD was associated with shorter total procedure time and hospital stay than TEM, with mean (standard deviation [SD]) 84.0 (51.2) vs. 116.4 (58.5) min (P = 0.0023), and 3.6 (1.2) vs. 6.6 (3.5) days (P < 0.001), respectively. There were no significant differences in complications between the two groups. CONCLUSIONS Both ESD and TEM are effective and oncologically safe for treating nonpolypoid rectal high grade dysplasia and submucosa-invading cancers. ESD has the additional advantages of minimal invasiveness and avoidance of anesthesia. Therefore, ESD could be recommended as a treatment option for superficial early rectal cancers.
Collapse
|
31
|
Multifunctional surfaces with biomimetic nanofibres and drug-eluting micro-patterns for infection control and bone tissue formation. Eur Cell Mater 2012; 24:237-48. [PMID: 23007909 DOI: 10.22203/ecm.v024a17] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
For long-term orthopaedic implants, the creation of a surface that is repulsive to bacteria while adhesive to tissue cells represents a promising strategy to control infection. To obtain such multifunctional surfaces, two possible approaches were explored to incorporate a model antibiotic, rifampicin (Rf), into the osteogenic polycaprolactone (PCL)/chitosan (CHS) biomimetic nanofibre meshes by (1) blending Rf into the electrospinning solutions and then electrospinning into nanofibres (i.e., Rf-incorporating fibres), or (2) depositing Rf-containing poly(D,L-lactic-co-glycolic) acid (PLGA) micro-patterns onto the PCL/chitosan nanofibre meshes via ink-jet printing (i.e., Rf-eluting micro-pattern/fibre). Rapid release of Rf from both meshes was measured even though a relatively slower release rate was obtained from the Rf-eluting micro-pattern ones. Antibacterial assay with Staphylococcus epidermidis showed that both mesh surfaces could effectively kill bacteria and prevent biofilm formation. However, only Rf-eluting micro-pattern meshes favoured the attachment, spreading and metabolic activity of preosteoblasts in the cell culture study. Furthermore, the Rf-eluting micro-pattern meshes could better support the osteogenic differentiation of preosteoblasts by up-regulating the gene expression of bone markers (type I collagen and alkaline phosphatase). Clearly, compared to Rf-incorporating nanofibre meshes, Rf-eluting micro-patterns could effectively prevent biofilm formation without sacrificing the osteogenic properties of PCL/chitosan nanofibre surfaces. This finding provides an innovative avenue to design multifunctional surfaces for enhancing bone tissue formation while controlling infection.
Collapse
|
32
|
The Effects of Alcohol Abstinence on BDNF, Ghrelin, and Leptin Secretions in Alcohol-Dependent Patients with Glucose Intolerance. Alcohol Clin Exp Res 2012; 37 Suppl 1:E52-8. [DOI: 10.1111/j.1530-0277.2012.01921.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 07/02/2012] [Indexed: 01/15/2023]
|
33
|
Abstract
Virus evolution should be monitored because frequent reassortment, which contributes to virus diversity, creates the potential for more severe infections. Several severe respiratory virus infections that have emerged during the past decade originated in animals, including bats. In Indonesia, exposure to bats has been associated with increased risk of acquiring orthoreovirus infection. Although orthoreovirus infections are mild and self-limiting, we explored their potential for evolution into a more virulent form. We used conventional virus culture, electron microscopy, and molecular sequencing to isolate and identify orthoreoviruses from 3 patients in whom respiratory tract infection developed after travel to Indonesia. Virus characterization by plaque-reduction neutralization testing showed antigenic similarity, but sequencing of the small segment genes suggested virus reassortment, which could lead to increased virulence. Bats as a reservoir might contribute to virus evolution and genetic diversity, giving orthoreoviruses the potential to become more virulent. Evolution of this virus should be closely monitored so that prevention and control measures can be taken should it become more virulent.
Collapse
|
34
|
Abstract
AIMS To determine whether there is a relationship between 1,5-anhydroglucitol (1,5-AG), a marker of postprandial hyperglycaemia and glycaemic variability, and the presence of diabetic retinopathy and albuminuria in patients with Type 2 diabetes. METHODS Five hundred and sixty-seven patients with Type 2 diabetes (serum creatinine < 133 μmol/l), who were enrolled in the Seoul Metro-City Diabetes Prevention Program (SMC-DPP), were cross-sectionally assessed by multivariate logistic regression analysis. RESULTS After controlling for age, sex, binary HbA(1c) levels, duration of diabetes, triglyceride, systolic blood pressure, smoking status, history of hypertension and dyslipidaemia, and the use of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker medication, the odds ratios (95% CI) of diabetic retinopathy were 2.86 (1.12-7.25) for the first (lowest) quartile of 1,5-anhydroglucitol, 2.87 (1.25-6.61) for the second quartile and 0.88 (0.35-2.22) for the third quartile compared with the fourth quartile (P for trend = 0.010). Conversely, the associations between 1,5-anhydroglucitol and clinical albuminuria were non-significant after adjustment. Subjects with low 1,5-anhydroglucitol (< 10.0 μg/ml) were more likely to experience diabetic retinopathy than those with high 1,5-anhydroglucitol (≥ 10.0 μg/ml) under moderate glucose control (HbA(1c) < 8%, 64 mmol/mol) and there were no significant differences in the prevalence of diabetic retinopathy between the subgroup with HbA(1c) < 8% (64 mmol/mol) and low 1,5-anhydroglucitol and the subgroup with HbA(1c) ≥ 8% (64 mmol/mol). CONCLUSIONS 1,5-Anhydroglucitol levels show close associations with diabetic retinopathy, especially among patients under moderate glucose control, but not with albuminuria. These results suggest that 1,5-anhydroglucitol might be a complementary marker for targeting higher risk group.
Collapse
|
35
|
The impact of image-guided radiotherapy (IGRT) for prostate cancer (PC) on radiotherapy (RT)-related acute toxicities and prostate-specific antigen (PSA) kinetics. J Clin Oncol 2012. [DOI: 10.1200/jco.2012.30.15_suppl.e15110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e15110 Background: IGRT for PC could potentially improve the therapeutic ratio by enhancing accuracy of delivery of radiation to the prostate gland. Our aim is to compare the treatment outcomes in terms of RT-related acute toxicities and PSA kinetics of PC patients (pts) undergoing radical intensity-modulated radiotherapy (IMRT) with or without image-guidance. Methods: A cohort of 21 consecutive pts treated by IGRT (I) from January 2010, when the IGRT system was introduced in our institution, was compared with an immediately precedent cohort of 21 pts receiving IMRT without image-guidance (Non-I). The prescription dose (76Gy in 38 fractions) and the treatment margins were the same between the 2 groups (gps). In the I gp, daily online verification and correction of treatment position was performed with reference to image registration of the daily pre-treatment on-board imaging with the corresponding digitally reconstructed radiographs, based on three-dimensional matching of three intra-prostatic fiducial markers. Androgen deprivation therapy was not used in both gps. Acute toxicities were scored weekly during the course of RT according to the Common Terminology Criteria for Adverse Events Version 4.02. The pre- and the post-RT PSA within 6 months after completion of RT were obtained. The PSA halving time (PSAHT) was calculated by first order kinetics. Results: There was no statistically significant difference regarding the baseline clinical characteristics (age, PSA at diagnosis, Gleason score, T staging) between the gps. No grade 3 or 4 acute genitourinary (GU) or gastrointestinal (GI) toxicities was encountered in either gps. Acute grade 1 or 2 GI toxicities were significantly less frequent in the I gp (23.8% vs 81.0%, p=0.001), and their median duration of such toxicity were also significantly shorter (0.33 week vs 1.38 week, p=0.004).The frequencies of acute grade 1 or 2 GU toxicities were comparable between both gps (66.6% vs 81.0%, p=0.45).The I gp had a shorter median PSAHT than the non-I gp (3.36 week vs 5.49 week, p=0.09). Conclusions: IGRT is effective in reducing acute GI toxicities in treatment of PC, and may have more favorable PSA kinetics.
Collapse
|
36
|
Atypical hereditary spastic paraplegia with thin corpus callosum in a Korean patient with a novel SPG11 mutation. Eur J Neurol 2012; 19:e7-8. [PMID: 22175763 DOI: 10.1111/j.1468-1331.2011.03569.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
37
|
Influence Of Repeated Breath-hold Diving In Cold Water On Heart Rate, Lactate, And Blood Oxygen Saturation. Med Sci Sports Exerc 2011. [DOI: 10.1249/01.mss.0000400918.89312.51] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
38
|
Impact of non-alcoholic fatty liver disease on microalbuminuria in patients with prediabetes and diabetes. Intern Med J 2011; 40:437-42. [PMID: 19460054 DOI: 10.1111/j.1445-5994.2009.01979.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND It is unknown whether microalbuminuria is associated with non-alcoholic fatty liver disease (NAFLD) among patients with prediabetes and type 2 diabetes mellitus (DM). This study investigated the association of NAFLD with microalbuminuria among patients with prediabetes and diabetes. METHODS We evaluated 1361 subjects who had an abnormal oral glucose tolerance test (OGTT) on routine screening. All participants were divided into two groups, prediabetes and newly diagnosed type 2 DM, and the association of NAFLD with metabolic parameters on microalbuminuria was analysed. RESULTS The patients with NAFLD had higher prevalence rates of microalbuminuria (6.3% vs 19%; P = 0.001 in prediabetes, 4.5% vs 32.6%; P < 0.001 in diabetes) and also had a greater albumin-to-creatinine ratio (14.6 +/- 52.0 microg/mg Cr vs 27.7 +/- 63.9 microg/mg Cr; P = 0.051 in prediabetes, 11.4 +/- 21.4 microg/mg Cr vs 44.7 +/- 76.4 microg/mg Cr; P < 0.001 in diabetes) than those without NAFLD. The logistic regression analysis showed that NAFLD was associated with increased rates of microalbuminuria (odds ratio 3.66; 95%confidence interval (CI) 1.31-10.20, P = 0.013 in prediabetes, odds ratio 5.47;95% CI 1.01-29.61, P = 0.048 in diabetes), independently of age, sex, body mass index, waist circumference, liver enzymes, lipid profiles, HbA1c, insulin resistance as estimated by homeostasis model assessment, hypertension,smoking status and the metabolic syndrome. CONCLUSIONS The results of our study revealed a strong relationship between microalbuminuria and NAFLD in the patients with prediabetes and newly diagnosed diabetes. Further studies are required to confirm whether NAFLD is a predictor of the development of microalbuminuria in patients with prediabetes and diabetes.
Collapse
|
39
|
Ovarian hyperstimulation syndrome: an analysis of patient characteristics in the Asian population. Singapore Med J 2011; 52:168-174. [PMID: 21451925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
INTRODUCTION We aimed to identify the variables associated with ovarian hyperstimulation in Asian patients and compare them with western standards. METHODS This is a retrospective case record analysis of 79 patients with ovarian hyperstimulation at a tertiary restructured hospital. RESULTS Gonadotropin doses resulting in hyperstimulation did not vary between long and antagonist cycles in women less than 35 years with polycystic ovaries (PCO). Mean oestradiol levels at hyperstimulation were not different between PCO and non-PCO patients in a long cycle. Hyperstimulation was mostly due to higher starting doses. Total follicle counts of more than 20 on Day 5-7 after stimulation may be predictive of subsequent hyperstimulation. Hyperstimulation tended to be more severe in lean PCO patients, and prophylactic albumin helped to reduce its severity. CONCLUSION Gonadotropin doses at stimulation should start at 150 iu or less in women below 35 years of age, with a step up of 37.5 iu, as necessary. Transfer should be abandoned in the presence of high oestradiol levels (more than 5,000 pg/ml), when the total number of intermediate and large follicle count exceeds 30 on the day of oocyte retrieval, or when more than 19 eggs are retrieved. Variables in the Asian population appear to be similar to those in the western population.
Collapse
|
40
|
Sero-immunity and serologic response to pandemic influenza A (H1N1) 2009 virus in Hong Kong. J Med Virol 2011; 82:1809-15. [PMID: 20872705 DOI: 10.1002/jmv.21895] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
To study the serologic response to the new pandemic influenza A (H1N1) 2009 virus in Hong Kong, the level of immunity was measured before and after the occurrence of the outbreak, and the titer of antibody to the pandemic influenza A (H1N1) 2009 virus in serum samples of laboratory confirmed cases. The presence of pre-outbreak pandemic influenza A (H1N1) 2009 virus antibodies in 37% of individuals older than >65 years suggested previous exposures to heterologous virus strains may have elicited cross-reacting antibody. Following large outbreaks of pandemic influenza A 2009 virus that peaked in September 2009, there is a change in immunity level in various age groups consistent with the attack rates among population in Hong Kong. Among individuals with mild clinical presentation, the antibody response to pandemic influenza A (H1N1) 2009 virus was stronger in those individuals aged ≤ 24 years but took more time to reach a titer of 40 when compared with those aged >24 years; however, the antibody level declined slower among individuals aged ≤ 24 years. Regardless of age, the antibody response rose rapidly and reached much higher titer among individuals with severe clinical presentation. Further study is required to collect additional data on antibody persistence and determine how much protection is conferred by previous exposure to seasonal influenza A (H1N1) viruses.
Collapse
|
41
|
Comparison of laboratory diagnostic methods for measles infection and identification of measles virus genotypes in Hong Kong. J Med Virol 2010; 82:1773-81. [PMID: 20827776 DOI: 10.1002/jmv.21888] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The sensitivities of IgM detection, virus isolation, and RT-PCR for the diagnosis of measles infection were assessed using samples collected from confirmed measles cases from 2006 to 2009. The optimal timing of specimen collection and the preferred specimen type(s) for these tests were also determined. IgM detection showed highest sensitivity when serum samples were collected >or=5 days after rash onset. Virus isolation gave the highest sensitivity when samples were collected <or=3 days after rash onset, with nasopharyngeal aspirate being the best specimen type, followed by urine and throat/combined throat and nasal swab. The highest RT-PCR positive rate (81.0%) was obtained with serum samples collected <or=3 days after rash onset. RT-PCR positive rate of 100% was observed with throat/combined throat and nasal swab, urine and nasopharyngeal aspirate collected <or=16, 4-16, and 4-7 days after rash onset, respectively. The genotype of each measles case was confirmed by sequencing. It was shown that the predominant measles viruses detected in Hong Kong during 2006-2009 belonged to genotype H1 (subtype a) and these strains were related closely to those detected in China.
Collapse
|
42
|
A multicenter, randomized, placebo-controlled, double-blind phase II trial evaluating the optimal dose, efficacy and safety of LC 15-0444 in patients with type 2 diabetes. Diabetes Obes Metab 2010; 12:1113-9. [PMID: 20977584 DOI: 10.1111/j.1463-1326.2010.01303.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM The objective of this study was to evaluate the optimal dose, efficacy and safety of a novel dipeptidyl peptidase-4 (DPP-IV) inhibitor, LC15-0444, in Korean subjects with type 2 diabetes mellitus treated by diet and exercise. METHODS This study was a double-blind, randomized, multicenter and parallel-group, dose-range finding study. We enrolled 145 patients (91 men and 54 women) with a median age of 53 years and a median body mass index of 25.1 kg/m(2) . The median baseline fasting plasma glucose (FPG) was 8.1 mmol/l, the median HbA1c was 7.9% and the median time since the diagnosis of diabetes was 3 years. After 2 weeks of an exercise/diet programme followed by 2 weeks of a placebo period, the subjects were randomized to one of the four following groups for a 12-week active treatment period: placebo and 50, 100 or 200 mg of LC15-0444. RESULTS All three doses of LC15-0444 significantly reduced the HbA1c from baseline compared to the placebo group (-0.06 vs. -0.98, -0.74 and -0.78% in the placebo and 50, 100 and 200 mg groups, respectively), without a significant difference between the doses. Subjects with a higher baseline HbA1c (≥8.5%) had a greater reduction in HbA1c. Insulin secretory function, as assessed using homeostasis model assessment-beta cell, C-peptide and the insulinogenic index, improved significantly with LC15-0444 treatment. Insulin sensitivity, as assessed using homeostasis model assessment-insulin resistance, also improved significantly after 12 weeks of treatment. The 50 and 200 mg groups had significantly reduced total cholesterol and low-density lipoprotein cholesterol levels at 12 weeks compared to the placebo group. No dosage of LC15-0444 affected weight or waist circumference. The incidences of adverse events were similar in all study subjects. CONCLUSIONS LC15-0444 monotherapy (50 mg for 12 weeks) improved the HbA1c, FPG level, oral glucose tolerance test results, β-cell function and insulin sensitivity measures, and was well tolerated in Korean subjects with type 2 diabetes.
Collapse
|
43
|
Abstract
OBJECTIVES Osteoporosis is a disease that increases the fracture rates and it is the major cause of increased mortality and morbidity in the elderly people. To determine which component of body composition is most important to bone health, we analysed the relationship between elements of the body composition and bone mineral density (BMD) in Korean women. DESIGN Cross-sectional clinical study. PATIENTS Totally 1694 women (mean age 51 years) were selected from subjects who participated in a medical check-up program. MEASUREMENTS Body composition analysis was performed by segmental bioelectric impedance method and lean mass, fat mass and per cent body fat measured. Waist: hip ratio (WHR) was assessed as a marker for visceral fat. Lumbar spine (L-spine) BMD was measured by dual X-ray absorptiometry (DEXA). As menopausal status could not be confirmed in all subjects, we divided the subjects into two groups according to the age > 50 years and < 50 years. RESULTS Among the entire population, 599 subjects (35.4%) were osteopaenic and 229 subjects (13.5%) were osteoporotic. The bivariate correlation among the variables showed that weight had the highest correlation with fat mass. Mean lean mass was decreased and the WHR increased as the subjects progressed from normal to osteoporotic status; fat mass was the highest among the osteopaenic subjects. L-spine BMD showed a positive correlation with lean mass, and a negative correlation with WHR by bivariate correlation analysis. However, fat mass had a negative correlation with L-spine BMD only after adjustment for age and weight. Multiple regression analysis with L-spine BMD as the dependent variable showed that age, height, fasting insulin, lean mass and WHR were significant determinants of the L-spine BMD (R(2) = 0.170, P < 0.05). CONCLUSION In this Korean female population, L-spine BMD showed a consistently positive correlation with lean mass and a negative correlation with WHR. Fat mass failed to show any consistent correlation with L-spine BMD in this study population.
Collapse
|
44
|
Energy Expenditure During Varying Intensity Running On A Position Sensitive Automatic Speed Adjusting Treadmill. Med Sci Sports Exerc 2009. [DOI: 10.1249/01.mss.0000355148.18880.50] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
45
|
Metabolic Response During Exercise On A Position Sensitive Automatic Speed Adjusting Treadmill. Med Sci Sports Exerc 2009. [DOI: 10.1249/01.mss.0000355149.18880.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
46
|
The association of serum adipocyte fatty acid-binding protein with coronary artery disease in Korean adults. Eur J Endocrinol 2009; 160:165-72. [PMID: 19001529 DOI: 10.1530/eje-08-0665] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Adipocyte fatty acid-binding protein (A-FABP), also known as aP2 or FABP4, is abundantly expressed in adipocytes and plays a role in glucose homeostasis. We analyzed the relationship between the coronary artery disease and serum FABP4 levels in Korean adults. METHODS In a total of 234 Korean adults, in whom coronary angiograms were performed, anthropometric measurements were done and fasting glucose and lipid profiles were measured. Serum FABP4 levels were measured using ELISA. The presence of metabolic syndrome was diagnosed according to American Heart Association/National Heart, Lung and Blood Institute (AHA/NHBL) criteria with body mass index (BMI) substituted for waist circumference. RESULTS Among the subjects, 31.6% had diabetes, 46.9% had metabolic syndrome, and mean log (FABP4) levels showed significantly higher levels in subjects with diabetes. Among the subjects, 42.4% had normal coronary vessel, 34.6% had 1-vessel disease, 13.7% had 2-vessel disease, and 9.4% had 3-vessel disease. Among the parameters, mean age, fasting glucose, and log (FABP4) levels increased significantly as the numbers of stenotic vessel increased from normal to 3-vessel disease, and for FABP4, these significances showed a consistent trend for difference after adjustment for age, gender, BMI, and fasting glucose (P=0.072). Mean log (FABP4) level showed lower values in subjects taking aspirin, and higher values in subjects taking statin and anti-hypertensive drugs. CONCLUSIONS Serum FABP4 levels increased as the numbers of stenotic coronary artery increased, although these differences were attenuated after adjustment for age and fasting glucose levels. Various anti-atherogenic medications showed different effects on the serum FABP4 levels, which need further investigation.
Collapse
|
47
|
Local recurrence after curative resection in patients with colon and rectal cancers. Int J Colorectal Dis 2008; 23:1081-7. [PMID: 18688621 DOI: 10.1007/s00384-008-0530-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/26/2008] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND AIMS There are a range of rates and a number of prognostic factors associated with the local recurrence of colorectal cancer after curative resection. The aim of this study was to identify the potential prognostic factors of local recurrence in patients with colon and rectal cancers. MATERIALS AND METHODS A retrospective review of 1,838 patients who underwent curative resection of non-metastatic colorectal cancer was conducted. The patients were treated between 1994 and 2004, and had a minimum follow-up of 3 years. RESULTS There were 994 patients with colon cancer and 844 patients with rectal cancer. The median duration of follow-up was 60.9 +/- 24.5 months. With respect to colon cancer, the local recurrence rate was 6.1% (61 patients). With respect to rectal cancer, 95 patients had a local recurrence (11.3%), the rate of which was statistically greater than the local recurrence rate for colon cancer (p < 0.001). The overall recurrence rate was 16.4% (301 patients), and the local recurrence rate, with or without systemic metastases, was 8.5% (156 patients). Local recurrences occurred within 2 and 3 years in 59.9% and 82.4% of the patients, respectively. In patients with colon and rectal cancer, the pathologic T stage (p = 0.044 and p = 0.034, respectively), pathologic N stage (p = 0.001 and p < 0.001, respectively), and lymphovascular invasion (p = 0.013 and p = 0.004, respectively) were adverse risk factors for local recurrence. The level of the anastomosis from the anal verge was an additional prognostic factor (p = 0.007) in patients with rectal cancer. CONCLUSION Compulsive follow-up care of patients with colon and rectal cancers is needed for 3 years after curative resection, especially in patients who have adverse risk factors for local recurrence.
Collapse
|
48
|
Characteristics of early colorectal carcinoma with lymph node metastatic disease. HEPATO-GASTROENTEROLOGY 2008; 55:1293-1297. [PMID: 18795675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
BACKGROUND/AIMS Endoscopic resection may safely and effectively remove early colorectal cancers. However, additional surgical treatment is needed in cases with metastatic lymph nodes for curative treatment. The purpose of this study was to investigate the correlation between lymph node metastasis and various pathological parameters in early colorectal cancers. METHODOLOGY The clinicopathological records of 3,557 colorectal adenocarcinoma patients who underwent surgical resection at the Samsung Medical Center from August 1995 to June 2005 were reviewed. One hundred forty seven tissue samples with early colorectal cancer were used in this study. Various parameters were studied including gender, location, macroscopic appearance, differentiation, lymphatic tumor emboli, and the depth of tumor invasion. RESULTS Twenty five patients (17.0%) had lymph node metastasis. Male gender, left colon, macroscopically depressed lesions, moderately or poorly differentiated carcinoma, depth of tumor invasion (Sm2 or Sm3), and presence of lymphatic tumor emboli were the risk factors for lymph node metastasis. CONCLUSIONS Early colorectal cancers with male gender, location in the left colon, macroscopically depressed lesion, moderate or poor differentiation, depth in Sm2 or Sm3, and the presence of lymphatic tumor emboli have higher risk of lymph node metastasis than those without. The early colorectal cancers with these risk factors should have surgical resection.
Collapse
|
49
|
|
50
|
Kondo effect in magnetic tunnel junctions. PHYSICAL REVIEW LETTERS 2007; 98:107202. [PMID: 17358561 DOI: 10.1103/physrevlett.98.107202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Indexed: 05/14/2023]
Abstract
Tunneling magnetoresistance was found to be suppressed with decreasing temperature for magnetic tunnel junctions (MTJs) oxidized under high plasma power. A strong temperature dependence of the junction resistance was observed, along with zero-bias anomalies of dynamic resistance at low temperatures. Resistance shows a logarithmic dependence on temperature, and resistance versus temperature exhibits a scaling behavior. Our experimental data can be explained in a consistent way by the Kondo effect in the MTJs with the Kondo temperature TK=20-30 K.
Collapse
|