scholarly journals 230 years of AGN monitoring: Frequency of cloud occultation events in AGN & constraints for clumpy torus models

2013 ◽  
Vol 9 (S304) ◽  
pp. 265-265 ◽  
Author(s):  
Mirko Krumpe ◽  
A. Markowitz ◽  
R. Nikutta

AbstractWe systematically search for discrete absorption events in the vast archive of the Rossi X-ray Timing Explorer. This includes dozens of nearby type I and Compton-thin type II AGN and covers timescales from days to over a decade for individual objects. We are sensitive to discrete absorption events due to clouds of full-covering, neutral or mildly-ionized gas with columns 1022−25 cm−2 transiting the line of sight. We detect 13 eclipse events in 8 objects, roughly tripling the number of previously published events from this archive. Despite sensitivity to events with NH up to 1024−25 cm−2, we measured no Compton-thick eclipses in our sample. Peak column densities span 2.5–19 × 1022 cm−2. Event durations span hours to months. We infer the clouds distances from the black hole, assuming Keplerian motion, to span 0.2–80 × 104 Schwarzschild radii. We find no statistically significant difference between the individual cloud properties of type I and II objects. The presence of eclipses in both type Is and IIs argues against sharp-edged cloud distributions. The type II AGN show a level of “base-line” X-ray absorption that is consistent with being constant over timescales from 0.6 to 8.4 yr. This can either be explained by a homogeneous medium, or by X-ray-absorbing clouds that each have NH ≪ 1022 cm−2. Considering the “selection function” of the monitoring, we derive the probability of cloud occultation events. Finally, we derive the first X-ray statistical constraints for clumpy-torus models.

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Ang Gao ◽  
Yongqiang Wang ◽  
Miao Yu ◽  
Xiaoguang Liu

Abstract Background Few studies describe thoracolumbar disc herniation (TLDH) as an isolated category, it is frequently classified as the lower thoracic spine or upper lumbar spine. Thus, less is known about the morphology and aetiology of TLDH compared to lumbar disc herniation (LDH). The aim of study is to investigate sagittal alignment in TLDH and analyze sagittal profile with radiographic parameters. Methods Data from 70 patients diagnosed with TLDH were retrospectively reviewed. The thoracic-lumbar alignment was depicted by description of curvatures (the apex of lumbar curvature, the apex of thoracic curvature, and inflexion point of the two curvatures) and radiographic parameters from complete standing long-cassette spine radiographs. The rank sum test was utilised to compare radiographic parameter values in each subtype. Results We found two subtypes differentiated by the apex of thoracic kyphotic curves. The sagittal profile was similar to that of the normal population in type I, presenting the apex of the thoracic kyphotic curve located in the middle thoracic spine. The well aligned thoracic-lumbar curve was disrupted in type II, presenting the apex of the thoracic kyphotic curve located in the thoracolumbar region in type II patients. Thirty-six patients were classified as type I, and 34 patients were classified as type II. The mean sagittal vertical axis, T1 pelvic angle and L1 pelvic angle were 27.9 ± 24.8°, 8.2 ± 7.3° and 6.2 ± 4.9°, respectively. There was significant difference (p < 0.001) of thoracolumbar angle between type I (14.9 ± 7.9°) and type II patients (29.1 ± 13.7°). Conclusions We presented two distinctive sagittal profiles in TLDH patients, and a regional kyphotic deformity with a balanced spine was validated in both subtypes. In type I patients, disc degeneration was accelerated by regional kyphosis in the thoracolumbar junction and eventually caused disc herniation. In type II patients, excessive mechanical stress was directly loaded at the top of the curve (thoracolumbar apex region) rather than being diverted by an arc as in a normal population or type I patients. Mismatch between shape and sacral slope value was observed, and better agreement was found in Type II patients.


1992 ◽  
Vol 285 (2) ◽  
pp. 577-583 ◽  
Author(s):  
G Sugumaran ◽  
J E Silbert

The effects of the non-ionic detergent Triton X-100 on 6-sulphation of two species of endogenous nascent proteochondroitin by a chick-embryo cartilage microsomal system was examined. Sulphation of the larger (Type I) species with adenosine 3′-phosphate 5′-phosphosulphate was slightly diminished when Triton X-100 was present, whereas sulphation of the smaller (Type II) species was slightly enhanced. An ordered rather than random pattern of sulphation was obtained for the smaller proteoglycan, but with a considerably lower degree of sulphation than that of the larger proteochondroitin. These differences were consistent with other differences between these two species as described previously. Sulphation of exogenous [14C]chondroitin and exogenous proteo[3H]chondroitin by the microsomal system with Triton X-100 present produced ordered rather than random sulphation patterns. When a 100,000 g supernatant fraction was utilized for sulphation of [14C]chondroitin or proteo[3H]chondroitin, Triton X-100 was not needed, and ordered sulphation was still obtained. When hexasaccharide was used, sulphation of multiple N-acetylgalactosamine residues of the individual hexasaccharides resulted. This was relatively independent of Triton X-100 or the concentration of the hexasaccharide acceptors. With soluble enzyme, sulphation of multiple N-acetylgalactosamine residues on the individual hexasaccharide molecules was even greater, so that tri-sulphated products were found. This suggests that ordered rather than random sulphation of chondroitin with these enzyme preparations is due to enzyme-substrate interaction rather than to membrane organization.


2018 ◽  
Vol 31 (Supplement_1) ◽  
pp. 28-28
Author(s):  
Joel Lambert ◽  
Sanya Caratella ◽  
Eloise Lawrence ◽  
Bilal Alkhaffaf

Abstract Background Anastomotic leak after esophagectomy is associated with high levels of morbidity and may impact negatively on oncological outcomes. The aim of this single centre study was to describe our experience in managing these complications Methods From 2007–2017 data was reviewed retrospectively from our prospectively maintained electronic database. All patients underwent either 2 or 3 phase esophagectomy for cancer of the oesophagus or esophago-gastric junction. All histological sub-types and stage of cancer were included in the analysis. Anastomotic leaks were classified according to the Esophagectomy Complications Consensus Group (ECCG) guidelines; type I—conservative management, type II—non-surgical intervention, type III—surgical intervention. Results 224 esophagectomies were included in our analysis (104 (46%) minimally invasive, 120 (54%) open approach). The incidence of all anastomotic leaks was 10% (23/224). Surgical approach did not influence the incidence of anastomotic leak (minimally invasive 10 (43%), open approach 13(57%), P = 0.76). Five patients (22%) had a type I leak, 9 patients (39%) type II and 9 (39%) had a type III leak. There was an increase in the number of leaks managed non-surgically over the last 5 years compared to those in the first five years of our dataset (2012–2017: 11/23 (48%) vs 2007–2012: 4/23 (17%) P = 0.08). The median time for leak diagnosis was 8 days. Most leaks were diagnosed with oral contrast CT 19 (83%). Median hospital stay after anastomotic leak was 58.5 days. Type III leaks were associated with an increased length of stay (median 84 days) compared to type I&II leaks (median (38.5 days) (P = 0.002 95% CI 18.19- 74.41). There was no significant difference in 30-day mortality between type I&II (0 patients) and type III leaks (1 patient) P = 0.260. Conclusion Low mortality rates with anastomotic leak can be achieved. In centres with experienced radiological and endoscopic skills, most anastomotic leaks can be managed non-surgically. Disclosure All authors have declared no conflicts of interest.


2021 ◽  
Vol 71 (4) ◽  
pp. 187-193
Author(s):  
Putu Astawa ◽  
Made Agus Maharjana ◽  
Surya Adisthanaya ◽  
Made Winatra Satya Putra ◽  
Agus Suarjaya Putra ◽  
...  

Introduction: Displaced supracondylar fracture in children is a challenging injury that may result in impaired functional and cosmetic outcome if not well-treated. Utilization of Closed Reduction and Percutaneus Pinning (CRPP) increased for this pathology, some authors believe ORIF results better anatomical reduction and lower rate of loss of reduction. Study aims to compare CRPP and ORIF for pediatric supracondylar humerus fracture. Method: Systematic review was conducted based on PRISMA guideline. Inclusion criteria were age <18 years old, comparing CRPP and ORIF for Supracondylar Humerus Fractures Gartland Type II, II.Studies of one surgical technique, Gartland type I, case reports were excluded. For meta-analysis, 6 studies were included and fixed effect model used to pool the result. In each study, mean difference (MD) with 95% confidence interval (CI) was calculated for dichotomous outcomes using Review Manager. Result: Total of 252 patients aged 0-15 years old were included. CRPP more often performed than ORIF. Satisfactory outcomes measured by Flynn’s criteria were achieved in 87.74% in CRPP and 86.73% in ORIF patient group, indicating significant difference (Heterogeneity, I2 = 23%; WMD, 1.26; 0.58 to 2.73; P =0.56). Conclusion: Current systematic review and meta-analysis suggest that for displaced supracondylar humerus fractures, ORIF offers a comparable functional and cosmetic outcome compared to CRPP.


1981 ◽  
Vol 50 (2) ◽  
pp. 272-278 ◽  
Author(s):  
R. W. Brauer ◽  
R. W. Beaver ◽  
H. W. Gillen

Individual convulsion threshold pressures were determined in mice exposed successively to type I and type II convulsions of the high-pressure neurological syndrome (HPNS), as well as in others exposed, in successive compressions, to type I convulsions under diverse conditions of replication of compression rate. Correlation analyses of the results showed the following degrees of correlation of individual convulsion-threshold pressures: type I with type II-negligible (r2 less than equal to 0.2); type I with type I at the same compression rate-closely correlated (r2 greater than or equal to 0.8); type I with type I at a different compression rate-negligible (r2 less than or equal to 0.2). Individual susceptibility to HPNS (type I) convulsions thus is a stable characteristic of individual seizures vary independently of one another. Likewise, the magnitude of the individual compression rate effect varies independently of intrinsic individual susceptibility to type I HPNS seizures. The results support the view that the HPNS is a composite entity, define constraints on personnel selection, and provide a basis for estimating the efficacy of various selection strategies.


2015 ◽  
Vol 25 (7) ◽  
pp. 1201-1207 ◽  
Author(s):  
Esther Louise Moss ◽  
Tim Evans ◽  
Philippa Pearmain ◽  
Sarah Askew ◽  
Kavita Singh ◽  
...  

IntroductionThe dualistic theory of ovarian carcinogenesis proposes that epithelial “ovarian” cancer is not one entity with several histological subtypes but a collection of different diseases arising from cells of different origin, some of which may not originate in the ovarian surface epithelium.MethodsAll cases referred to the Pan-Birmingham Gynaecological Cancer Centre with an ovarian, tubal, or primary peritoneal cancer between April 2006 and April 2012 were identified from the West Midlands Cancer Registry. Tumors were classified into type I (low-grade endometrioid, clear cell, mucinous, and low-grade serous) and type II (high-grade serous, high-grade endometrioid, carcinosarcoma, and undifferentiated) cancers.ResultsOvarian (83.5%), tubal (4.3%), or primary peritoneal carcinoma (12.2%) were diagnosed in a total of 583 woman. The ovarian tumors were type I in 134 cases (27.5%), type II in 325 cases (66.7%), and contained elements of both type I and type II tumors in 28 cases (5.7%). Most tubal and primary peritoneal cases, however, were type II tumors: 24 (96.0%) and 64 (90.1%), respectively. Only 16 (5.8%) of the ovarian high-grade serous carcinomas were stage I at diagnosis, whereas 240 (86.6%) were stage III+. Overall survival varied between the subtypes when matched for stage. Stage III low-grade serous and high-grade serous carcinomas had a significantly better survival compared to clear cell and mucinous cases,P= 0.0134. There was no significant difference in overall survival between the high-grade serous ovarian, tubal, or peritoneal carcinomas when matched for stage (stage III,P= 0.3758; stage IV,P= 0.4820).ConclusionsType II tumors are more common than type I and account for most tubal and peritoneal cancers. High-grade serous carcinomas, whether classified as ovarian/tubal/peritoneal, seem to behave as one disease entity with no significant difference in survival outcomes, therefore supporting the proposition of a separate classification of “tubo-ovarian serous carcinoma”.


2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
Yufeng Chen ◽  
Huilin Yang ◽  
Lianfang Zhang ◽  
Yue Wang ◽  
Jun Zou

Objective. This study aimed to investigate if the presence of Modic changes (MCs) was correlated with lower back pain (LBP) and LBP-related disability in patients who underwent nonsurgical treatment. Methods. In this study, 129 patients who experienced consecutive LBP and underwent lumbar spine magnetic resonance imaging in our institute were divided into three groups according to the presence or type of MCs. The Oswestry Disability Index (ODI) and visual analog scale (VAS) were used to assess the outcomes of the treatment. Results. Based on the achieved results, there was no significant difference between three groups before treatment (P>0.05). Three months after undergoing nonsurgical treatment, the rates of improved ODI and VAS scores were statistically significantly different (P=0.014,  0.023). After an additional 3 months of treatment, in patients with Modic type I changes, the symptoms significantly improved in comparison with those 3 months prior (P=0.037,  0.026), while that improvement did not occur in patients with Modic type II changes (P>0.05). Conclusions. The existence of MCs affects the outcomes of nonsurgical treatment in patients with LBP. However, symptoms can be improved after an additional round of treatment for Modic type I changes, while this is not confirmed for Modic type II changes.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Kurai Z. Chako ◽  
Heather Phillipo ◽  
Erisi Mafuratidze ◽  
Danai Tavonga Zhou

Diabetics have chronically elevated glucose levels. High levels of glucose result in nonenzymatic formation of glycosylated haemoglobin (HbA1c). Therefore, elevated HbA1c is a good indicator of poorly controlled diabetes. We used the standard HbA1c method to determine glycemic control in diabetics attending a public health facility in Harare, Zimbabwe. Our study sought to assess the prevalence of elevated HbA1c amongst treated diabetics and compare the HbA1c levels by type of diabetes. The cross-sectional study was carried out at one of the main public health centres in Zimbabwe: the Parirenyatwa Group of Hospitals in Harare. Type I and type II diabetics were recruited and had their blood HbA1c levels measured. The standard one tailed proportion z test was used to test the hypothesis at 5% significance level. Combined prevalence of type I and type II diabetics with elevated HbA1c was 27%. There was no significant difference in levels of HbA1c by age and sex. Over half (54%) of Type I diabetics had elevated HbA1c, suggesting poor glycemic control. In contrast only 24% of the Type II diabetics studied had elevated HbA1c. The difference in proportion of Type I and Type II diabetics with elevated HbA1c suggestive of poor glycemic control was significant (P=0.0067).


1975 ◽  
Vol 53 (1) ◽  
pp. 79-91 ◽  
Author(s):  
Chung-Hsi Huang ◽  
Osvald Knop ◽  
David A. Othen ◽  
Frank W. D. Woodhams ◽  
R. Allan Howie

Cubic M4+P2O7 pyrophosphates of Ti, Zr, Hf, Sn, and Pb have been examined by X-ray powder diffractometry and by infrared, Raman, and Mössbauer 119Sn spectroscopy. The tin compound appeared to be of Chaunac's type I (with P2O7 groups oriented at random) and could be converted to type II (with ordered P2O7 groups) by heating to high temperatures. All the other preparations were of Chaunac's type II. Evidence from lattice parameters and intensity features of the Raman spectra suggests that the cubic MP2O7 pyrophosphates fall in two groups, one containing the compounds of the typical elements (Ge, Sn, Pb) and the other, the compounds of the transition elements. No support has been found for the view that the P—O—P groupings of the pyrophosphate anion in these compounds are linear. The 119Sn chemical shift in SnP2O7 is only slightly less negative than the shift in CuSnF6.4H2O, which makes SnP2O7 one of the most ionic compounds of tetravalent tin known. The observed quadrupole splitting in the Mössbauer spectrum of SnP2O7 arises largely from the contribution of the valence term to the electric field gradient at the Sn atom.


2006 ◽  
Vol 30 (4) ◽  
pp. 329-332 ◽  
Author(s):  
Kenshi Maki ◽  
Yasuhiro Sorada ◽  
Toshihiro Ansai ◽  
Takahiro Nishioka ◽  
Raymond Braham ◽  
...  

A review of the dental literature revealed relatively few studies on the expansion of the mandibular dental arch. The present study attempted expansion of the mandibular arch using a Bihelix appliance. The subjects were 16 children, exhibiting crowding, age ranges from 7 to 11 years. The mandible was expanded 2.0 mm every 3 months. Significant expansion, not only of the individual tooth inter-arch dimensions but also of the overall arch length, was obtained during the period of incisor tooth replacement. The mode of expansion was classified as follows: Type I, those, which showed no effect on the apical base; Type II, those which showed no consistency of the measurement lines. In this study, 6 of16 cases were classified as type I and 10 cases as type II. Expansion was continued over a period of 1.5 to 3 years. We concluded that considerable lateral expansion of the mandibular arch is possible using the Bihelix appliance. It is suggested that this might contribute greatly to non-extraction orthodontic treatment. Further studies are recommended.


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