Ecopharmacology: Deliberated or casual dispersion of pharmaceutical principles, phytosanitary, personal health care and veterinary products in environment needs a multivariate analysis or expert systems for the control, the measure and the remediation

The increasing human and animal use and abuse of drugs as well as of personal health care and gross domestic products, involve disposal and waste problems and, as a consequence, affect the environmental condition. Actually most of the active principles are complex synthesised organic molecules that react, inside human or animal body, by specific biochemical reactions that in no case can reach a 100% yield and produce residues that could be more noxious of the starting compounds. Just reading the indication sheet accompanying any drugs, it is easy to state that no drug can be considered healthy, so, their use constitutes a serious pollution source. The full awareness of this relatively new environmental problem let many researchers to face it from different point of view. Current studies are considering the sources of these substances in the environment, the effects on human health as well as on the flora and fauna species, the recalcitrance and possible degradation methods, analytical techniques able to determine them and their metabolites even at low concentrations and in complex matrices.Literature on the subject continuously increases and a comparison of all data became more and more difficult both for a single drug and for different ones based on the same or different active principles. This is a typical case in which chemometrics can extract a full information in the easier way, so the design of a European database coupled to suitable expert system software should be strongly suggested.     

The effect of signal suppression and mobile phase composition on the simultaneous analysis of multiple classes of acidic/neutral pharmaceuticals and personal care products in surface water by solid-phase extraction and ultra performance liquid chromatography-negative electrospray tandem mass spectrometry

A new multi-residue method for the determination of 25 acidic/neutral pharmaceuticals (antibiotics, anti-inflammatory/analgesics, lipid regulating agents, diuretics, triazides, H2-receptor antagonists, cardiac glicozides and angiotensin II antagonists) and personal care products (sunscreen agents and preservatives) in surface water with the usage of a new technique: ultra performance liquid chromatography–negative electrospray tandem mass spectrometry (UPLC–MS/MS) was developed and validated. The novel UPLC system with 1.7 μm particle-packed column allowed for good resolution of analytes with the application of low mobile phase flow rates (0.05 mL min⁻¹) and short retention times (from 4.7 min to 13.3 min) delivering a fast and cost-effective multi-residue method. SPE with the usage of Oasis MCX strong cation-exchange mixed-mode polymeric sorbent was chosen for sample clean-up and concentration. The influence of mobile-phase composition, matrix assisted ion suppression and SPE recovery on the sensitivity of the method was identified and quantified. The instrumental limits of quantification varied from 0.2 μg L⁻¹ to 30 μg L⁻¹. The method limits of quantification were at low nanogram per litre levels and ranged from 0.3 ng L⁻¹ to 30 ng L⁻¹. The instrumental and method intra-day and inter-day repeatabilities were on average less than 5%. The method was successfully applied for the determination of PPCPs in River Taff. Thirteen compounds were determined in river water at levels ranging from a single to a few hundred nanograms per litre. Among them were ten pharmaceuticals (aspirin, salicylic acid, ketoprofen, naproxen, diclofenac, ibuprofen, mefenamic acid, furosemide, sulfasalazine and valsartan) and three personal care products (methyl- and ethylparaben and 4-benzophenone).     

非水毛细管电泳法同时测定消毒剂、个人护理品及药膏中三氯生、三氯卡班和对氯间二甲苯酚

三氯生（TCS）、三氯卡班（TCC）和对氯间二甲苯酚（PCMX）这3种消毒有效成分因广谱杀菌而广泛应用于消毒剂、个人护理品及药品中。为监督这些产品质量、保障消毒效果,非常有必要建立同时分析这3种消毒有效成分的方法。鉴于此,该文以十二烷基三甲基溴化铵（DTAB）为电渗流反转剂,建立了同时测定上述3种消毒有效成分的非水毛细管电泳-紫外检测新方法,并对分离缓冲体系及浓度、样品介质等条件进行了优化。结果表明,未涂层熔融石英毛细管（20.0 cm×50.0 μm,总长度30.2 cm）为分离毛细管,14 mmol/L硼砂、2 g/L聚乙二醇20000和0.5 mmol/L DTAB的甲醇溶液为分离缓冲溶液,样品介质为含5 g/L聚乙二醇20000的甲醇-乙腈（50∶50, v/v）,在214 nm下进行检测,实现了3种消毒有效成分的同时分离。在1~100 mg/L范围内,3种消毒有效成分的校正峰面积与质量浓度呈良好的线性关系,相关系数（r）均大于0.99。方法的检出限（LOD,信噪比为3）为0.2 mg/L,定量限（LOQ,信噪比为10）为1.0 mg/L;加标回收率在94.5%~104.4%范围内,相对标准偏差均小于4.8%。利用研究建立的新方法测定了消毒液、洗手液、婴儿爽身粉、抑菌乳膏共31件样品,并将结果与国家标准方法GB/T 27947-2020和GB/T 34856-2017中的液相色谱法结果相比较,无统计学显著性差异。与国标方法相比,方法极大地减少了有机溶剂消耗量。该法前处理简单,结果准确,非常适合实验室的常规分析。     

VaR methods for the dynamic impawn rate of steel in inventory financing under autocorrelative return

This paper proposes the way of setting the dynamic impawn rate by dividing the impawn periods into different risk windows. In an efficient financial market, the return is hypothetically independent, while in a pledged inventory market where spot transactions predominate, the return is auto-correlative. Therefore, the key to setting the impawn rate is to predict the long-term risk. In this experiment, using the database of spot steel, we established a model with the formula AR (1)-GARCH (1,1)-GED, forecasting the VaR of steel during the different risk windows in the impawn period through a method of out-of-sample, and got the impawn rate according with the risk exposure of banks. The results of our experiment indicated that the introduction of coefficient K into the model can significantly improve bank risk coverage and reduce its efficiency loss. Besides, the impawn rate obtained by the model correlates positively with the lowest price in the future risk windows.     

Development of a sensitive detection method of cancer biomarkers in human serum (75%) using a quartz crystal microbalance sensor and nanoparticles amplification system

A simple and sensitive sensor method for cancer biomarkers [prostate specific antigen (PSA) and PSA-alpha 1-antichymotrypsin (ACT) complex] analysis was developed, to be applied directly with human serum (75%) by using antibody modified quartz crystal microbalance sensor and nanoparticles amplification system. A QCM sensor chip consisting of two sensing array enabling the measurement of an active and control binding events simultaneously on the sensor surface was used in this work. The performance of the assay and the sensor was first optimised and characterised in pure buffer conditions before applying to serum samples. Extensive interference to the QCM signal was observed upon the analysis of serum. Different buffer systems were then formulated and tested for the reduction of the non-specific binding of sera proteins on the sensor surface. A PBS buffer containing 200 μg mL⁻¹ BSA, 0.5 M NaCl, 500 μg mL⁻¹ dextran and 0.5% Tween 20, was then selected which eliminated the interfering signal by 98% and enabled the biomarker detection assay to be performed in 75% human serum. By using Au nanoparticles to enhance the QCM sensor signal, a limit of detection of 0.29 ng mL⁻¹ PSA and PSA-ACT complex (in 75% serum) with a linear dynamic detection range up to 150 ng mL⁻¹ was obtained. With the achieved detection limit in serum samples, the developed QCM assay shows a promising technology for cancer biomarker analysis in patient samples.     

High purity oxygen production with a polymer electrolyte membrane electrolyser

Oxygen is required for treatment of patients in hospitals and at home, in industrial processes and for fuel combustion. Most commonly oxygen is produced by cryogenic or pressure swing adsorption routes. Other techniques include oxygen-ion conducting ceramic membranes, polymer membranes and chemical processes used mainly in civil aviation to reduce the condition of hypoxia at high altitudes. Water electrolysis is used mainly for the production of hydrogen with oxygen as a by-product. In order to use this system only for oxygen production, hydrogen must be utilised and disposed off safely. This, however, is not practical in many instances where there is no use for hydrogen and it poses an explosion hazard. In this paper, an electrolyser system based on polymer electrolyte membrane is described in which hydrogen produced on one side of the electrochemical cell is consumed by combining it with atmospheric oxygen, through operating the cell in a carefully configured fuel cell mode. This reduces the power consumed in the electrolysis operation by more than 35% and eliminates hydrogen in exit gases. Oxygen generated is of high quality and can be used for human consumption (portable and plug-in home care oxygen therapy devices, in hospitals, defence or aerospace requirements) and for many other industrial applications.     

Long-term equilibrium potential and electrochemical impedance study of Ag/AgCl electrodes used in Harned Cell measurements of pH

A long term study of the voltage and electrochemical impedance characteristics of Ag/AgCl electrodes used in Harned Cell measurement of pH is presented. By all the measures investigated the electrodes are shown to degrade only slowly until approximately 200 days after manufacture, after which time the rate of degradation and critical failure of the electrodes increases. The absolute voltage drift of the electrodes may not be easily measured, so parameters determined directed or indirectly by electrochemical impedance spectroscopy have been assessed as a method to produce an alternative indication of electrode integrity. In this respect, resistance to charge transfer has been shown to be a very sensitive measure of changes in the characteristics of the electrodes, and the most closely related to the observed changes in voltage. Evidence is presented to support the hypothesis that the majority of electrode degradation (excluding critical failure) comes from the increased blocking of the microporous structure of the electrodes.     

Modeling time allocation for prevention in primary care

This paper discusses the problem of allocating time for prevention at the primary care level, focusing on a general practitioner (GP) practice. The basic trade-off is between improved state of the health of the population, which translates into less demand for the GP services, and a decreased capacity for curative services, which translates into increased congestion. The problem of how much time to devote to prevention is modeled as a non-linear optimization problem. As an extension of the problem, selection of preventive activities to perform among recommended alternatives is modeled using a knapsack formulation, and its application is illustrated with a numerical example. The author is supported in part by Türkiye Bilimsel ve Teknik Araştirma Kurumu (TüBİTAK) Career Grant No. 106K260.     

A mathematical model of infectious diseases

In the formulation of models for the spread of communicable diseases which include removal and population dynamics, it is necessary to distinguish between removal through recovery with immunity and removal by death due to disease. This distinction must be made because of the difference in the effect on the population dynamics of the different kinds of removal and because there are significant differences in the behavior of the models. We have formulated a class of models which allow recovery with immunity for a fraction of the infective and permanent removal by death from disease for the remainder. Earlier models of this type have postulated an increased death rate for infective, but such models are restricted to exponentially distributed-infective periods. Because of the differences in behavior between models with recovery and models with permanent removal do not arise when the infective period is exponentially distributed, we have chosen to formulate a different type of model which is sufficiently general to admit qualitative differences.     

Quality [r]evolution in diabetes care

 To implement the St. Vincent Declaration Action Programme, initiatives have been started in the quality development of diabetes care across Europe. The main elements of the quality development cycle implemented in our hospital were realized by the use of the software package ‘CamitPro’ and participation in ‘the DiabCare Q-net NL’ network. From 1997 to 1999, 955, 1468, and 1624 patients with diabetes mellitus type 2 were integrated in the DiabCare Q-net NL network by using ‘CamitPro’ software, respectively. These patients showed substantial improvement in all of the clinical measures monitored. In addition, there was a drop in HbA_1c level. From 1997 to 1999, an HbA_1c interval of 5.1%–8.3% (mean up to mean +4SD) was recorded for 66%, 76% and 81% of the patients, respectively. An extension of the use of the software to a pan-European level should markedly improve diabetes care throughout the community. Received: 10 July 2000 / Accepted: 10 July 2000