[目的]建立同时检测配合饲料中64种药物的超高效液相色谱-三重四极杆串联质谱(ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry,UHPLC-MS/MS)法,提高非法添加物的检测效率。[方法]采用Waters...[目的]建立同时检测配合饲料中64种药物的超高效液相色谱-三重四极杆串联质谱(ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry,UHPLC-MS/MS)法,提高非法添加物的检测效率。[方法]采用Waters HSS T3型色谱柱(2.1 mm×100 mm,1.8μm)进行分离,流动相A为0.1%甲酸水溶液,流动相B为含0.1%甲酸的乙腈溶液,梯度洗脱,流速为0.40 mL/min,进样量为2μL;采用电喷雾离子源正离子扫描模式进行检测,多反应监测模式进行信号采集。比较4种样品提取溶剂以及2种固相萃取柱处理对目标药物的回收率,确定样品前处理的最佳方法。利用建立的UHPLC-MS/MS法对宁夏回族自治区不同来源的100批次配合饲料样品进行64种药物检测。[结果]配合饲料样品均质后,用含0.2%甲酸的乙腈水溶液(乙腈∶水=8∶2,V/V)提取,利用Oasis PRiME HLB型固相萃取柱对样品净化,多数目标药物的回收率在60%以上。64种药物在浓度为5.0~200.0μg/L的范围内线性关系良好,相关系数(R)均大于0.99;不同药物的定量限在5.0~10.0μg/kg;阳性添加5.0、20.0、50.0μg/kg 3个浓度的平均回收率在41.00%~120.49%,批内相对标准偏差(RSD)在0.54%~15.94%,批间RSD在1.25%~13.64%。在100个批次的配合饲料样品中均未检出目标药物。[结论]建立的UHPLC-MS/MS法线性关系良好、回收率高、精密度好,具有较高的重现性和较好的可操作性,可用于配合饲料中非法添加64种药物的筛查。展开更多
近些年,无线医疗传感器网络(Wireless Medicine Sensor Networks,WMSNs)得到了广泛的应用。WMSNs提高了患者护理质量,但同时也存在许多安全隐患。为了保护患者数据的隐私安全,Yi等人提出了一个基于Paillier密码系统的分布式ElGamal密码...近些年,无线医疗传感器网络(Wireless Medicine Sensor Networks,WMSNs)得到了广泛的应用。WMSNs提高了患者护理质量,但同时也存在许多安全隐患。为了保护患者数据的隐私安全,Yi等人提出了一个基于Paillier密码系统的分布式ElGamal密码系统。然而,Rao分析了他们的方案并展示了一种可行的攻击,该攻击允许攻击者获取密钥。因此,是否可以将具有加法同态性质的密码系统修改为安全的分布式解密系统,以实现更简单的分布式密钥生成和更高效的分布式解密仍然是一个挑战。针对上述挑战,该文提出了一种基于Castagnos和Laguillaumie(CL)加密的改进分布式解密系统,并对未知阶群G上的离散对数关系给出了有效的零知识证明。与其他分布式解密系统相比,基于CL加密的改进分布式系统具有良好的性能、更可靠的设置、更高的安全级别。展开更多
Inherent drawbacks associated with drug-eluting stents have prompted the development of bioresorbable cardiovascular stents.Additive manufacturing(3-dimentional(3D)printing)has been widely applied in medical devices.I...Inherent drawbacks associated with drug-eluting stents have prompted the development of bioresorbable cardiovascular stents.Additive manufacturing(3-dimentional(3D)printing)has been widely applied in medical devices.In this study,we develop a novel screw extrusion-based 3D printing system with a new designed mini-screw extruder to fabricate stents.A stent with a zero Poisson’s ratio(ZPR)structure is designed,and a preliminary monofilament test is conducted to investigate appropriate fabrication parameters.3D-printed stents with different geometric structures are fabricated and analyzed by observation of the surface morphology.An evaluation of the mechanical properties and a preliminary biological evaluation of 3D-printed stents with different parameters are carried out.In conclusion,the screw extrusion-based 3D printing system shows potential for customizable stent fabrication.展开更多
The development of personalized healthcare is rapidly growing thanks to the support of low-power electronics,advanced fabrication processes and secured data transmission protocols.Long-acting drug delivery systems abl...The development of personalized healthcare is rapidly growing thanks to the support of low-power electronics,advanced fabrication processes and secured data transmission protocols.Long-acting drug delivery systems able to sustain the release of therapeutics in a controllable manner can provide several advantages in the treatment of chronic diseases.Various systems under development control drug release from an implantable reservoir via concentration driven diffusion through nanofluidic membranes.Given the high drug concentration in the reservoir,an inward osmotic fluid transport occurs across the membrane,which counters the outward diffusion of drugs.The resulting osmotic pressure buildup may be sufficient to cause the failure of implants with associated risks to patients.Confidently assessing the osmotic pressure buildup requires testing in vivo.Here,using metal and polymer AM(additive manufacturing)processes,we designed and developed implantable drug reservoirs with embedded strain sensors to directly measure the osmotic pressure in drug delivery implants in vitro and in vivo.展开更多
It is difficult to measure the sizes of illegal drug user populations directly by using the survey method because of many “hidden drug addicts” and the difficulty of receiving a true response. Systematic and routine...It is difficult to measure the sizes of illegal drug user populations directly by using the survey method because of many “hidden drug addicts” and the difficulty of receiving a true response. Systematic and routine information on treatment episodes of drug users is adopted to estimate the population size in this study. Mixture models of zero-truncated Poisson distributions using the nonparametric maximum likelihood estimators (NPMLE) by means of capture-recapture repeated count data were used to project the number of drug users. The method was applied to surveillance data of drug users identified by treatment episodes in over 1140 health treatment centers in Thailand from the Bureau of Health Service System Development, Ministry of Public Health. We presented how this mixture model could be utilized to construct the unobserved frequency of drug users with no treatment episode and further estimated the total population size of drug users in the country from 2005 to 2007. The result of simulation was confirmed that mixture model is suitable when population is large. By means of mixture models, the estimations for the number of drug users were fitted with excellent goodness-of-fit values and we were also compared to the conventional Chao estimates. The NPMLE for the total number of drug users in Thailand 2005, 2006, and 2007 were 184,045 (95% CI: 181,297-86,793), 230,665 (95% CI: 226,611-234,719), 299,670 (95% CI: 294,217-305,123), respectively, also 125,265 (95% CI: 123,092-127,142), 166,287 (95% CI: 163,222-169,352), 228,898 (95% CI: 224,766 - 233,030) for the number of methamphetamine (Yaba) users, and 11,559 (95% CI: 10,234-12,884), 11,333 (95% CI: 9276-13,390), 8953 (95% CI: 7878-10,028) for the number of heroin users, respectively. The numbers of marijuana, kratom-plant, opium, and inhalant users were underestimated because their symptoms were mild and not severe enough to remedy in health treatment centers which led to the smaller size of the total number of drug users. The well-estimated sizes of heroin and methamphetamine addicts are high reliable because they are based on clearly evident count with a severe addiction problem to health treatment centers. The estimation by means of mixture models can be recommended to monitor drug demand trend and drug health service routinely;it is easy to calculate via the available programs MIXTP based on request.展开更多
文摘近些年,无线医疗传感器网络(Wireless Medicine Sensor Networks,WMSNs)得到了广泛的应用。WMSNs提高了患者护理质量,但同时也存在许多安全隐患。为了保护患者数据的隐私安全,Yi等人提出了一个基于Paillier密码系统的分布式ElGamal密码系统。然而,Rao分析了他们的方案并展示了一种可行的攻击,该攻击允许攻击者获取密钥。因此,是否可以将具有加法同态性质的密码系统修改为安全的分布式解密系统,以实现更简单的分布式密钥生成和更高效的分布式解密仍然是一个挑战。针对上述挑战,该文提出了一种基于Castagnos和Laguillaumie(CL)加密的改进分布式解密系统,并对未知阶群G上的离散对数关系给出了有效的零知识证明。与其他分布式解密系统相比,基于CL加密的改进分布式系统具有良好的性能、更可靠的设置、更高的安全级别。
基金funding support from the Beijing Municipal Natural Science Foundation,China(Z150001)supported by Beijing Anzhen Hospital.
文摘Inherent drawbacks associated with drug-eluting stents have prompted the development of bioresorbable cardiovascular stents.Additive manufacturing(3-dimentional(3D)printing)has been widely applied in medical devices.In this study,we develop a novel screw extrusion-based 3D printing system with a new designed mini-screw extruder to fabricate stents.A stent with a zero Poisson’s ratio(ZPR)structure is designed,and a preliminary monofilament test is conducted to investigate appropriate fabrication parameters.3D-printed stents with different geometric structures are fabricated and analyzed by observation of the surface morphology.An evaluation of the mechanical properties and a preliminary biological evaluation of 3D-printed stents with different parameters are carried out.In conclusion,the screw extrusion-based 3D printing system shows potential for customizable stent fabrication.
文摘The development of personalized healthcare is rapidly growing thanks to the support of low-power electronics,advanced fabrication processes and secured data transmission protocols.Long-acting drug delivery systems able to sustain the release of therapeutics in a controllable manner can provide several advantages in the treatment of chronic diseases.Various systems under development control drug release from an implantable reservoir via concentration driven diffusion through nanofluidic membranes.Given the high drug concentration in the reservoir,an inward osmotic fluid transport occurs across the membrane,which counters the outward diffusion of drugs.The resulting osmotic pressure buildup may be sufficient to cause the failure of implants with associated risks to patients.Confidently assessing the osmotic pressure buildup requires testing in vivo.Here,using metal and polymer AM(additive manufacturing)processes,we designed and developed implantable drug reservoirs with embedded strain sensors to directly measure the osmotic pressure in drug delivery implants in vitro and in vivo.
文摘It is difficult to measure the sizes of illegal drug user populations directly by using the survey method because of many “hidden drug addicts” and the difficulty of receiving a true response. Systematic and routine information on treatment episodes of drug users is adopted to estimate the population size in this study. Mixture models of zero-truncated Poisson distributions using the nonparametric maximum likelihood estimators (NPMLE) by means of capture-recapture repeated count data were used to project the number of drug users. The method was applied to surveillance data of drug users identified by treatment episodes in over 1140 health treatment centers in Thailand from the Bureau of Health Service System Development, Ministry of Public Health. We presented how this mixture model could be utilized to construct the unobserved frequency of drug users with no treatment episode and further estimated the total population size of drug users in the country from 2005 to 2007. The result of simulation was confirmed that mixture model is suitable when population is large. By means of mixture models, the estimations for the number of drug users were fitted with excellent goodness-of-fit values and we were also compared to the conventional Chao estimates. The NPMLE for the total number of drug users in Thailand 2005, 2006, and 2007 were 184,045 (95% CI: 181,297-86,793), 230,665 (95% CI: 226,611-234,719), 299,670 (95% CI: 294,217-305,123), respectively, also 125,265 (95% CI: 123,092-127,142), 166,287 (95% CI: 163,222-169,352), 228,898 (95% CI: 224,766 - 233,030) for the number of methamphetamine (Yaba) users, and 11,559 (95% CI: 10,234-12,884), 11,333 (95% CI: 9276-13,390), 8953 (95% CI: 7878-10,028) for the number of heroin users, respectively. The numbers of marijuana, kratom-plant, opium, and inhalant users were underestimated because their symptoms were mild and not severe enough to remedy in health treatment centers which led to the smaller size of the total number of drug users. The well-estimated sizes of heroin and methamphetamine addicts are high reliable because they are based on clearly evident count with a severe addiction problem to health treatment centers. The estimation by means of mixture models can be recommended to monitor drug demand trend and drug health service routinely;it is easy to calculate via the available programs MIXTP based on request.
