Characterization of the gunshot suicides

The aim of this study is to present the characteristics of gunshot suicides by highlighting the ones with multiple entrance wounds. The criminal investigation reports of suicides (n=318) during the period 1991-2000, in the central judicial district of Eskisehir were investigated. 20.4% of all suicide cases (n=65) used firearms. Firearm suicides were more common in males and their frequency decreased as age increased. The usage of long-barrelled weapons was 47.7%. Among the long-barrelled gunshots, twelve were shotguns and the remaining were military riffles. Forty-five weapons were legal. Thirty-four out of 45 gunshot suicide victims had licensed weapons because of their occupations. In the majority of cases, (72.3%) the shooting distance was contact or near contact. Most of the entrance wounds (75.0%) were located in the head and neck region and the direction of the bullet path was upward and front-to-back. Of all the gunshot suicides, 6.1% (n=4) had multiple entrance and exit wounds. All of the victims were soldiers. In suicide cases using long-barrelled weapons (3/4), military rifles were set on automatic mode. In our study, at least eight of the victims survived for a period. To be able to increase the survival rate of the victims or improve the outcomes, intensive pre- and post-operative care is critical.     

Characterization of the rotating display

The rotating display is a useful method for reviewing single photon emission computed tomography (SPECT) data. This study evaluated the requirements for a subjectively pleasing and useful implementation of this technique. Twelve SPECT data sets were modified and viewed by several observers who recorded the minimum framing rates for apparent smooth rotation, 3D effect, effects of image size, and other parameters. The results showed that a minimum of 16 frames was needed for a useful display. Smaller image sizes and more frames were preferred. The recommended minimal framing rate for a 64-frame study is 16-17 frames per second and for a 32-frame study, 12-13 frames per second. Other enhancements also were useful.     

Characterization of the NIST seaweed Standard Reference Material.

The National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) for seaweed was developed through an interlaboratory comparison with 24 participants from 16 countries. After evaluating different techniques to calculate certified values for the radionuclides, the median method was found to be the most representative technique. The certified values were provided for 13 radionuclides and information values were given for 15 more radionuclides. Results for the natural decay series showed disequilibrium in both the uranium and thorium series.     

Characterization of the heart rate response during biathlon.

Continuous heart rate recordings were obtained on elite American bi-athletes during competitions to provide a better understanding of the physiological demands of biathlon and the strategies used in approaching the shooting range. The findings demonstrate that the average age heart rate during skiing was approximately 90% of maximum heart rate. Heart rates decreased 10-12 bpm over a time period of approximately 50-60 sec during the approach to the firing line. At arrival to the firing line, heart rates were similar for prone and standing shooting averaging 85-87% of maximum heart rate. Mean minimum heart rates while at the firing line dropped to 61-73% of maximum heart rate and averaged approximately 20 bpm lower for prone shooting. The lower minimum heart rates during prone shooting were accounted for by the bi-athletes spending a longer time at the firing line and having a more rapid decrease in heart rate while in the prone position.     

Characterization of haemorrhages at the origin of the sternocleidomastoid muscles in hanging

Haemorrhages at the periostal-clavicular origin of the sternocleidomastoid muscles were found in 52 out of 54 cases of death by hanging. This cervical haemorrhage is most frequently found in death by hanging, but only seldomly seen in other causes of death and can therefore be regarded as being typical for death by hanging. The frequency of this finding on the side of the highest point of the ligature mark is significantly higher, thereby supporting the hypothesis of extension as the causative mechanism. External cardiac massage and assisted breathing have no influence on the occurrence of haemorrhages. Histology shows the haemorrhages to be mainly directly epiperiostal, however, many cases displayed concurrent sub- and intraperiostal extravasations. Artificial post mortem production of these findings is discussed in the light of the literature.     

Characterization of cystic tumors of the pancreas: CT accuracy

PURPOSE: The purpose of this work was to evaluate the capabilities of CT to accurately characterize cystic tumors of the pancreas. METHOD: Two observers retrospectively evaluated the CT exams of 100 cystic masses of the pancreas, with pathological confirmation. The two observers, blinded about clinical information and the final diagnosis, tried to categorize the lesions according to well established morphologic features. Statistical analysis was performed to measure the agreement between each radiologist and the consensus diagnosis and to evaluate the usefulness of certain CT findings in differentiating one type of cystic pancreatic neoplasm from another. RESULTS: Serous cystadenoma was better diagnosed by CT [Youden misclassification index (Ymi) = 0.72] than mucinous cystic tumor (Ymi = 0.44) and solid pseudopapillary tumor (cystic variant) (Ymi = 0.47). CONCLUSION: As patients with previous history of pancreatitis were excluded from the study, CT findings allowed correct characterization of only 60% of cystic pancreatic masses. Among the remaining 40%, 15-20% of the wrong diagnoses could not be corrected by means of CT, given the patterns shown by the tumors. In 20-25% of the cases, a nonspecific diagnosis of cystic mass was made.     

Characterization of in vivo chemistry of cations in the heart

A variety of laboratory procedures can be used to define the chemistry and pharmacokinetics of myocardial cationic imaging agents. These methods are utilized to define the in vivo chemistry of cationic heart agents, in order to understand the kinetics and mechanisms of: tissue and cellular transport, subcellular distribution, and intracellular localization. Transport across cell membranes can be active, passive or facilitated. Studies performed in erythrocytes, heart cells, slices and isolated perfused hearts using methods for separation of metabolites have shown a high degree of myocardial specificity for [99mTc]hexakis alkyl isonitrile by an uptake mechanism different from 201Tl. These studies demonstrate the importance of in vivo chemistry and pharmacokinetics in the development of new radiopharmaceuticals.     

典型居室内氡子体的特性

用瞬时和连续两种方法对澳大利亚一所典型住房室内氡子体的特性进行了初步调查, 两种方法的结果符合得很好。氡予体平衡因子在0.17至0.49之问, 瞬时和连续测量的均值和标准偏差分别为0.28±0.06和0.32±0.39ɑ潜能浓度(PAEC)的未结合态份额(fp)在0至80%之间, 两种方法的均值在白天均为14%, 而用连续方法测得的24小时均值为24%。测量表明, PAEC粒度呈双态分布, 其峰的几何均值分别在0.5至1.2nm和85至200nm之间。根据测量结果用Jarues—Birchall和Jacobi—Eisfeld两个剂量模型计算了有效剂量当量转换因子。     

Characterization of pinhole transmission gratings

Gold pinhole transmission gratings fabricated by Heidenhain GmbH primarily for the purpose of studying the radiation of intense soft x-ray sources have been tested with the synchrotron radiation of BESSY. Typical results for the spectral dependence of the grating efficiency into the various diffraction orders are presented in a wavelength region ranging from 4 to 20 nm. Also the influence of grating irregularities has been studied. With appropriate grating parameters quite good agreement between the experimental results and theoretical Calculations is Obtained.     

Characterization of the Patient Population in a Sports Medicine Facility

In brief: This article presents a statistical portrait of the injuries seen over a five-year period at a large sports medicine facility that serves primarily recreational athletes. About half of the 10,271 injuries treated were caused by overuse. Overuse problems exceeded acute injuries in running, tennis, figure skating, and aerobic dance, while acute injuries were more common in skiing, basketball, football, and soccer. The knee was the anatomic area most often injured in all of the major sports. The prevalence of overuse injuries indicates the importance of instructing patients in prevention methods.     

Characterization of the #Radiology Twitter Conversation During the Global COVID-19 Pandemic

ObjectiveTo assess the #Radiology conversation on Twitter social media platform during the COVID-19 pandemic.Materials and MethodsFrom February 1 to December 31, 2020, all tweets with a #Radiology hashtag were identified using the healthcare social media analytics tool, Symplur Signals. Data collected included number of tweets, retweets, impressions, links, and user characteristics. Data were stratified by the presence of a COVID-19-related keyword, and a social media network analysis was further performed.ResultsOf the 68,172 tweets, 10,093 contained COVID-19 content from 2809 users generating 65,513,669 impressions. More tweets with COVID-19 content contained links than without (P < 0.01). Network analysis demonstrated most users were physicians (48.10%), authoring the most tweets (40.38%), using the most mentions (32.15%), and retweeting the most (51.45%). The most impressions, however, were by healthcare organizations not providing clinical care (20,235,547 impressions, 30.89%). Users came from 80 countries, most from the United States (29.3%) and the United Kingdom (8.69%). During early March, COVID-19 dominated the #Radiology conversation, making up 54.67% of tweets the week of March 14 and 64.74% of impressions the week of March 21 compared to 13.97% of tweets and 16.76% of impressions in the remainder of the study period (P < 0.01).There was an influx of new users to the #Radiology conversation during this time period with more users tweeting about COVID-19 than not (P < 0.01).ConclusionDiscussion of COVID-19 in the #Radiology community increased significantly during the early weeks of the pandemic. Real time sharing and collaboration proved a useful tool when rapid information dissemination was needed to manage an emerging pathogen.     

Characterization of the glow-peak fading properties of six common thermoluminescent materials

The pre-irradiation and post-irradiation fading rates of the thermoluminescent glow peaks of six commonly used thermoluminescent dosimeters under controlled environmental conditions over approximately 30 d are examined. Glow peaks were fit to the first-order kinetics model using a computerized glow curve deconvolution program. Dosimeters studied were LiF:Mg,Ti, CaF₂:Dy, CaF₂:Tm, CaF₂:Mn, LiF:Mg,Cu,P, and CaSO₄:Dy. LiF:Mg,Ti and LiF:Mg,Cu,P experienced significant pre-irradiation fading. All types except CaF₂:Mn experienced post-irradiation fading. Ratios of glow-peak areas were fit to exponential decay functions when possible.     

RR间隔的相关维及最大Lyapunov指数定征

目的 寻找三组对象RR间存在确定性混沌的证据，并定量描述这种混沌现象。方法 提出一种改进的Grassberger-Procaccia(GP)算法并求得10名健康年轻人，10名健康老人，10名房颤病人RR间的相关维，同时计算了其最大Lyapunov指数。结果 健康年轻人的心脏是约7～8维的复杂动力学系统．健康老人约6～6．5维，而房颤病人为4～4．5维。健康年轻人的最大Lyapunov指数为0．19～0．23，健康老人为0．12～0．16，房颤病人为0．083～0．123。结论 研究表明健康年轻人、健康老人及房颤病人的RR间是混沌的。相关维和最大Lyapunov指数从健康年轻人到健康老人再到房颤病人是逐渐减小的，这反映了心脏健康状况下降时其复杂性也减小。因此，相关维和最大Lyapunov指数可能成为新的无损伤检测心脏功能的手段。     

蕨麻素冻干脂质体的制备及理化性质的研究

目的 制备蕨麻素冻干脂质体注射剂并研究其理化性质。方法 采用薄膜超声分散法并冷冻干燥来制备蕨麻素脂质体,用葡聚糖凝胶（Sephadex G-50）微型柱离心法测定包封率。结果 制得的蕨麻素脂质体包封率为56．62％,粒径范围为71．70—166．47nm,透射显微镜下观察脂质体为粒径均匀的球类或近球状小囊泡。结论 蕨麻素脂质体处方和制备工艺稳定可行,重现性好。     

Characterization of the NMR behavior of white matter in bovine brain.

In vitro experiments on 15 white matter samples from five bovine brains were performed on a 1H-NMR spectrometer at 24 degrees C and 37 degrees C. The average myelin water fractions (MWFs) were 10.9% and 11.8% for samples at 24 degrees C and 37 degrees C, respectively. The T1 relaxation time at 37 degrees C was found to be 830 ms, exhibiting monoexponential behavior. A four-pool model including intra/extracellular (IE) water, myelin water, nonmyelin tissue, and myelin tissue was proposed to simulate the NMR behavior of bovine white matter. A cross-relaxation correction was introduced to compensate for shifting of the measured data points and T2 times over the duration of the Carr-Purcell-Meiboom-Gill (CPMG) measurement due to cross relaxation. This correction was found to be slight, providing evidence that MWFs measured using a multiecho technique are near physical values. At 24 degrees C the cross-relaxation times between myelin tissue and myelin water, myelin water and IE water, and IE water and nonmyelin tissue were found to be approximately 227, 2064, and 402 ms, respectively. At 37 degrees C these same cross-relaxation times were 158, 1021, and 170 ms, respectively. The exchange rate between myelin water and myelin was found to be 11.8 s-1 at 37 degrees C, while the exchange rate between IE water and nonmyelin tissue was found to be 6.8 s-1. These exchange rates are of similar magnitude, which indicates that the interaction between IE water and nonmyelin tissue cannot be ignored.