基于拟合法和谱减法的牙釉质电子顺磁共振波谱处理方法对比研究

目的:建立拟合法和谱减法的牙釉质电子顺磁共振(EPR)波谱处理方法,分析对比两种方法处理羊牙釉质EPR波谱的结果.方法:收集自由放养的2～5岁山羊牙齿,根据年龄分为2岁组、3岁组和5岁组,采用物理化学结合的方法获取3组年龄不同的山羊牙釉质样品,测量牙釉质样品的EPR波谱.利用基于矩阵模型的拟合法和谱减法处理EPR波谱,...     

DR实际光野外影像成因的研究

目的:研究DR原始图像光野外的影像成因,减少患者辐射剂量,实现放射防护最优化。方法:分析原始图像光野外影像成因及射线来源,比较指示野与实际射线光野是否一致,外加遮线器以增加遮线器厚度减少漏线,使用自制可调手动遮线器对身体附近射线进行遮挡实验。结果:DR原始图像光野外影像是直射线方向产生的散射线照射到患者后在探测器形成的影像。结论:DR原始图像实际光野外影像是原发射线方向上的散射线照射到患者后,由于探测器(FD)比较灵敏,使患者肢体在探测器实际射线光野外形成的污渍影像,符合散射线"污渍效应"成像。     

纵隔子宫放置两只吉妮IUD2例

目的:观察吉妮致美与吉妮宫内节育器(IUD)使用18月的临床效果.方法:随机分组分别放置吉妮致美IUD517例,吉妮IUD508例,分别于置器后1、3、6、18个月进行随访,记录病史、放置IUD手术时间及术后随访情况,对数据进行生命表分析和Logistic多因素分析.结果:①随访18个月吉妮致美和吉妮IUD的带器妊娠率分别为0.60/100妇女年和0.61/100妇女年(P>0.05);②置器后6月内月经周期缩短、经量增多、月经期延长情况吉妮致美组低于吉妮组(P<0.05),因出血终止使用的吉妮致美组(1.2/100妇女年)明显低于吉妮组(6.69/100妇女年),P<0.05;③两组均无因疼痛所致的终止.④带器妊娠的危险因素为子宫内口至子宫底外缘距离大和子宫后屈;⑤脱落的危险因素则为体力劳动和哺乳期置器者.结论:吉妮和吉妮致美IUD避孕效率高;吉妮致美IUD对减少置器后近期出血及因出血所致终止率有明显效果,为吉妮IUD系列的扩大应用提供了更多的选择.     

放置两种吉妮IUD 18个月临床效果分析

目的:观察吉妮致美与吉妮宫内节育器(IUD)使用18月的临床效果。方法:随机分组分别放置吉妮致美IUD517例,吉妮IUD508例,分别于置器后1、3、6、18个月进行随访,记录病史、放置IUD手术时间及术后随访情况,对数据进行生命表分析和Logistic多因素分析。结果:①随访18个月吉妮致美和吉妮IUD的带器妊娠率分别为0.60/100妇女年和0.61/100妇女年(P>0.05);②置器后6月内月经周期缩短、经量增多、月经期延长情况吉妮致美组低于吉妮组(P<0.05),因出血终止使用的吉妮致美组(1.2/100妇女年)明显低于吉妮组(6.69/100妇女年),P<0.05;③两组均无因疼痛所致的终止。④带器妊娠的危险因素为子宫内口至子宫底外缘距离大和子宫后屈;⑤脱落的危险因素则为体力劳动和哺乳期置器者。结论:吉妮和吉妮致美IUD避孕效率高;吉妮致美IUD对减少置器后近期出血及因出血所致终止率有明显效果,为吉妮IUD系列的扩大应用提供了更多的选择。     

Sysmex SF-3000血细胞分析仪常见故障的分析与处理

SysmexSF - 30 0 0全自动血细胞分析仪是日本东亚公司SF系列产品 ,是一台自动化程度较高 ,可随机任意选择 ,电脑触摸屏幕指令操作的精密仪器。全自动多参数 (五分类 ,2 3项参数 ,4种细胞粒度布图 )分析仪 ,对常见的报警分析如下 :故障一 :自动进样针没有吸到样品 (shortsm ple)原因 :(1 )样品量太少或者样品凝固 ;(2 )样品针太脏或者被堵塞 ;(3)样品针歪斜或样品针弯曲、折断 ,穿破试管胶塞时碰到试管壁或不能穿破试管胶塞。处理 :(1 )样品量太少可改用手动进样 (ManualMode) ,如进样品凝固须重新抽血 ;(2 )用清洁液CELLCLEAN或次氯…     

4种新型宫内节育器使用5年临床效果评价

为较好掌握新型 IUD 的优点和特征,便于医务人员根据不同育龄妇女身体状况选择适当的 IUD 类型,本课题对2400例育龄妇女随机放置 TCu380A、三球头 TCu220C、MLCu375SL 和含药宫铜4种新型 IUD 使用5年间的终止原因进行临床多中心研究分析。结果表明:第二代活性 IUD具有安全、高效、长效的优点,其中尤以 TCu380A 具有较高续用率(78.1/100妇女),其妊娠率(带器妊娠及意外妊娠)为4.9/100妇女,脱落率也最低,为6.9/100妇女(P<0.05);MLCu375SL 城市组使用效果明显优于农村组,其5年续用率分别为80.54/100妇女和66.89/100妇女(P<0.05);农村组脱落率最高,为14.6/100妇女(P<0.05);含药宫铜 IUD 置器后月经量增加的症状明显减少,因症取出率最低,5年末为3.7/100妇女(P<0.01);;三球头 TCu220C 具有低因症取出率和低脱落率的优点,但带器妊娠率最高,为8.4/100妇女(P<0.01)。结果提示:T 铜 IUD 的脱落率相对较低;三球头 TCu220C 的球头和含药宫铜 IUD 所含的消炎痛在减少副反应方面有一定的作用;ML-Cu375SL 适合城市妇女使用。     

基于深度学习的自动分割方法对头颈部危及器官勾画的评价

目的：探讨与评价AccuContour软件基于深度学习的自动分割方法对头颈部危及器官(OAR)自动勾画结果的准确性。方法：选取20例鼻咽癌患者的CT图像资料,应用基于深度学习的机器算法模型AccuContour软件,对图像的19个OARs(脑干、脊髓、双侧眼球、双侧晶体、双侧视神经、垂体、双侧腮腺、口腔、下颌骨、双侧颌下腺、双侧颞颌关节、甲状腺和喉)进行自动勾画,勾画结果定义为深度学习勾画的体积(V_DL),对其进行手动修改后,将修改结果定义为参考勾画(V_ref),采用相似性系数(DSC)、Jaccard系数(JAC)、平均Hausdorff距离(AHD)、体积差异比(ΔV)、最大剂量(D_max)或平均剂量(D_mean)评价勾画结果。结果：除垂体、双侧颞颌关节及双侧视神经外,其他器官的DSC平均值均>0.7,JAC平均值均>0.6;各器官AHD均值最大为1.91 mm,最小为0.23 mm。双侧眼球、双侧晶体、下颌骨、双侧颌下腺、喉和甲状腺在剂量评估中表现优异,以ΔD_max     

一种新型高交联聚乙烯髋臼内衬的体外磨损性能测试

目的：分析一种含多酚的新型高交联聚乙烯(XLPE)髋臼内衬的磨损性能,为新型聚乙烯材料的研发和在人工髋关节置换术(THA)中的临床应用提供依据。方法：按照国际标准化组织(ISO)14242标准规定的方法,使用人工髋关节模拟试验机,按照人体步态生物力学运动参数,对新型XLPE髋臼内衬进行体外磨损试验。试验样品为4组髋关节假体,其中1组样品为对照组,其余3组样品分别为试验1组、试验2组和试验3组;每组样品均包含髋臼外杯、髋臼内衬和球头3个部件。4组样品均经过预浸泡、恒重、固定、磨损、清洗、称重等步骤,计算其髋臼内衬的磨损率。收集磨损500万次后的血清样本,按照ISO 17853标准规定的方法消解稀释血清,通过孔径1.2μm和0.1μm的滤膜过滤。使用扫描电子显微镜在滤膜上随机选取聚乙烯磨屑颗粒图像,分析磨屑的数量、大小和形状,评估其磨损性能。结果：新型XLPE髋臼内衬平均磨损率为(36.49±2.21)mg/million cycles;聚乙烯磨屑当量直径平均值为0.29μm,<0.6μm的磨屑颗粒占98.5%,磨屑的形态指数值<4的占比为99.5%。结论：含多酚的XLPE制成...     

钢针合并镍钛记忆合金环抱器(卡环)治疗锁骨骨折的疗效分析

目的通过应用钢针髓内固定同时合并使用镍钛记忆合金环抱器(卡环)髓外固定治疗锁骨骨折,探讨其临床效果。方法2008年4月~2009年4月对40例锁骨骨折,行切开复位后,采用钢针髓内固定同时合并使用镍钛记忆合金环抱器(卡环)髓外固定治疗,术后随访1~12个月,平均6个月。结果所有骨折均愈合良好,无内固定松动、脱落、骨折畸形愈合等,分别于术后3~5个月取出钢针,术后6~12个月取出环抱器(卡环),27例单纯取出钢针,未取出环抱器(卡环),无不良反应。结论钢针同时合并镍钛记忆合金环抱器(卡环)手术,有操作简便、固定牢固、允许患者早期功能锻炼、并发症低等优点,是治疗锁骨中段和中外1/3处骨折的一种理想的方法。     

广东省置器从业人员置器质量现状调查

目的:评估广东省计划生育系统各级置宫内节育器(IUD)从业人员的置器质量,分析研究置器妇女的社会生物学特征等因素对置器质量的影响。方法:采用分层整群抽样方法,选择9个市(县)计划生育服务中心(站)及11个服务所的全体置器从业人员,每人现场置器10-15例。置器后B超测量IUD上缘至宫底外缘的距离。结果:从业人员所在单位级别(中心、站、所)对置器平均距离无影响;从业人员学历、职称、工作年限对置器质量有明显影响;受术者子宫位置对置器平均距离有影响。结论:置器从业人员距“把节育器置入宫底部位”的要求尚有差距;应把置器质量进行定量,制定相应的指标。     

Tooth enamel EPR dosimetry: optimization of EPR spectra recording parameters and effect of sample mass on spectral sensitivity

In order to improve the accuracy of the tooth enamel EPR dosimetry method, EPR spectra recording conditions were optimized. The uncertainty of dose determination was obtained as the mean square deviation of doses, determined with the use of a spectra deconvolution program, from the nominal doses for ten enamel samples irradiated in the range from 0 to 500 mGy. The spectra were recorded at different microwave powers and accumulation times. It was shown that minimal uncertainty is achieved at the microwave power of about 2 mW for a used spectrometer JEOL JES-FA100. It was found that a limit of the accumulation time exists beyond which uncertainty reduction is ineffective. At an established total time of measurement, reduced uncertainty is obtained by averaging the experimental doses determined from recorded spectra following intermittent sample shaking and sample tube rotation, rather than from one spectrum recorded at longer accumulation time. The effect of sample mass on the spectrometer's sensitivity was investigated in order to find out how to make appropriate corrections.     

Investigation of some parameters influencing the sensitivity of human tooth enamel to gamma radiation using electron paramagnetic resonance

Electron paramagnetic resonance (EPR) has been successfully used as a physical technique for gamma radiation dose reconstruction using calcified tissues. To minimize potential discrepancies between EPR readings in future studies, the effects of cavity response factor, tooth position and donor gender on the estimated gamma radiation dose were studied. It was found that the EPR response per sample mass used for assessment of doses in teeth outside of the 70-100 mg range should be corrected by a factor which is a function of the sample mass. In the EPR measurements, the difference in sensitivity of different tooth positions to gamma-radiation was taken into consideration. It was determined that among all the pre-molars and molars tooth positions, the relative standard deviation of sensitivity was 6.5%, with the wisdom teeth and the first molars having the highest and lowest sensitivity to gamma-radiation, respectively. The current results reveal no effect of the donor gender on the sensitivity to gamma-radiation.     

牙齿发育成熟程度的横向研究

目的：研究儿童牙齿发育的规律及牙龄。方法：观察南京市２３６名青少年儿童的全颌曲面断层片及手腕片，研究牙齿钙化的影像，对儿童的牙齿发育成熟状况进行横向研究。结果：上下颌尖牙的发育钙化速度最为均衡，显示很强的一致性，在儿童青春发育期的加速期、高峰期、减峰期、减速期，牙齿的钙化分布分别为：上颌尖牙Ｆ期８２．３５％、Ｇ期９８．１０％、Ｈ期７８．２６％，下颌尖牙Ｆ期７８．２９％、Ｇ期９２．３８％、Ｈ期９５．     

Incidence of tooth loss among elderly Iowans.

This study investigated the 18-month incidence of tooth loss in a random sample of 451 dentate noninstitutionalized Iowans aged 65 and older residing in two rural counties. They had a mean of 19.0 teeth at baseline and lost an average of 0.4 teeth during the subsequent 18 months. Twenty-one per cent of the population lost at least one tooth. Four people had all their teeth extracted. Of the teeth present at baseline, 1.9 per cent subsequently were extracted. The highest incidence of tooth loss occurred among mandibular molars (3.7 per cent), followed by maxillary premolars and canines (3.1 per cent each). The best predictors of tooth loss were previous coronal and root caries.     

Socio-demographic risk indicators for tooth mortality in rural Sri Lankans

To explore the socio-demographic factors associated with tooth loss in rural inhabitants of Sri Lanka, a random sample of 2178 males aged 20-60 years was selected using multi-stage cluster sampling procedure. The number of missing and present teeth was recorded excluding third molars and the subjects were interviewed to elicit socio-demographic information as well as oral hygiene and tobacco consumption habits. The mean number of teeth lost in the sample was 5.17 +/- 5.43. Tooth loss increased significantly with age. Sinhalese had significantly fewer lost teeth (5.05 +/- 5.38) compared to Tamils (6.54 +/- 6.18) and Muslims (6.02 +/- 5.21) whereas education, income, oral hygiene practices and tobacco use were significantly associated with tooth loss in the bivariate analysis. A forward stepwise multiple regression analysis revealed that age, Muslim ethnicity and quantified tobacco use were positively associated with tooth loss while better socio-economic conditions and good oral hygiene habits were negatively linked with tooth mortality independent of other factors. Age, Muslim ethnicity, quantified tobacco use, income, education, brushing frequency and substance used for cleaning had significantly affected tooth loss. Quantified tobacco use and oral hygiene may be regarded as modifiable socio-demographic risk indicators associated with tooth mortality in Sri Lankans.     

Study of the stability of EPR signals after irradiation OF fingernail samples

Previous studies have suggested that the electron paramagnetic resonance in fingernails can be used for radiation dosimetry purposes. Use of fingernails as an emergency dosimeter has benefits of easy, noninvasive sampling and fast dose measurements (～10 min) potentially in field conditions and almost immediately after an exposure event. This study represents the next step in the development of EPR fingernail dosimetry; e.g., evaluation of the stability of the radiation-induced signal (RIS) at different storage and irradiation conditions. RIS fading during storage in both stressed (untreated) and unstressed (soaked in water) samples (n = 20) was studied at two temperature conditions: freezing (temp ≈ -20°C) and room temperature (20-24°C). Fingernail samples with the same clipping size and number and irradiated to 15 and 20 Gy were measured for over 200 d. Those irradiated to 100 and 200 Gy were measured for 114 d. The other group of samples irradiated to 1, 3, 8, and 20 Gy was followed for 25 mo of storage time. This study demonstrated that all samples that were kept at low freezing temperatures showed a stable RIS with no significant fading. All samples that were kept at room temperatures showed an initial fading of the signal with a slow rise of the EPR signal after irradiation with time to a saturation level. Obtained results allow making recommendations on the appropriate storage conditions of fingernails for EPR dosimetry use.     

红外测温仪测温影响因素分析

目的:分析距离、角度和测量部位等因素对红外测温仪测量结果的影响,提高防疫期间体温监测的准确性。方法:选取北京地区24名健康志愿者作为体温测量的受试者,采用两种常用国产品牌(A型和B型)红外测温仪,分别采集受试者不同测量距离(1~3 cm、3~5 cm和5~7 cm)、不同测量角度(额头正前垂直、向下倾斜45°)和不同测量部位(额头、内关)的体温测量数据,连续测量7 d,排除缺项后共纳入60组体温测量值数据。同时采用水银体温计测量受试者腋温行自身对照,分析比较不同角度、距离和部位的测量数据。结果:不同测温角度中红外测温仪于有效距离内"垂直"和"斜下"方向的额温,A型红外测温仪3~5 cm和B型红外测温仪1~3 cm垂直和斜下测量差异有统计学意义(Z=-2.62,Z=-4.37;P<0.05)。A型红外测温仪和B型红外测温仪垂直测额温距离皮肤1~3 cm、3~5 cm和5~7 cm测温结果比较,差异均有统计学意义(F=24.06,F=26.97;P<0.05)。A型红外测温仪距皮肤1~3 cm和3~5 cm测量内关温与额温比较,差异均有统计学意义(t=-4.99,t=-5.006;P<0.01);B型红外测温仪距皮肤1~3 cm测量内关温与额温比较,差异有统计学意义(t=-5.13,P<0.01)。结论:测温角度的改变会对测量产生影响,尤其在测量距离增加情况下。当超过有效测量距离时随着距离增加,测量数据准确性将会下降。相较于额温,正常体温人群的内关温更接近于腋温。     

Dental knowledge and oral health among middle-aged adults

Objective: Knowledge of oral disease prevention should lead to better oral health outcomes. The aims were to assess the association of dental knowledge and oral health. Methods: A random sample of 45–54 year‐olds from Adelaide, South Australia, was surveyed in 2004/05. Oral examinations provided data on caries. Results: A total of 879 persons returned questionnaires (response=43.8%) with 709 (80.7%) examined. The majority rated ‘seeing a dentist regularly’ (63.0%), ‘regular brushing of teeth’ (92.5%) and ‘using fluoride toothpaste’ (52.2%) as ‘definitely important’ in preventing tooth decay. The percentage of persons who had a high knowledge of tooth decay prevention was 59.9%. Multivariate analysis controlling for sex, place of birth, education and income showed (p<0.05) associations of high dental knowledge of tooth decay prevention with fewer decayed teeth (β=‐0.19) and more filled teeth (β=1.13). Conclusions: Dental knowledge was associated with oral health status. Implications: Conveying of information should be one part of oral health promotion actions to improve oral health.     

The burden of traditional practices, ebino and tea-tea, on child health in Northern Uganda

Traditional medical practices persist today in Northern Uganda; for example, the operations of ebino and tea-tea are frequently performed in childhood. Ebino, or "false teeth", refers to gingival swellings during the eruption of the primary canine teeth in infants, and consists of the extraction of deciduous canine tooth buds. Tea-tea consists of systematic cuts made on the chest wall when the child has difficulty in breathing. The objectives of this study are to describe the morbidity and mortality related to complications arising from the ebino and tea-tea procedures among children admitted to the paediatric ward of St. Mary's Hospital Lacor in 1999, and to estimate the prevalence of ebino and tea-tea among children aged 0-4 years attending, for any cause, the child welfare department (CWD) of the hospital. The prevalence survey consisted of the examination of 1,995 children attending CWD during a four-week period in 1999 to look for missing primary canine teeth (ebino), and for "therapeutic" cuts on the chest wall (tea-tea). In the difficult context of war and social disruption prevailing in Northern Uganda, sustainable methods of data collection and analysis should be utilised to support evidence-based decision-making.     

Eighteen-month incidence of tooth loss among older adults in North Carolina.

This study investigated tooth loss in North Carolina adults 65 years of age or older. A random sample of 335 Blacks and 284 Whites participated in dental examinations and interviews at baseline and again after 18 months. Blacks were more likely than Whites to lose at least one tooth (36% vs 19%), and they lost more teeth on average (1.0 vs 0.4). Several oral disease conditions and symptoms were related to tooth loss, but many other hypothesized factors were not. Risk models were inconclusive in the identification of factors related to risk of tooth loss.