Cross-contamination Research Articles

Design of Biomolecule Interaction Detection System Based on Fiber Biosensor

Biolayer interferometry is a non-marker technique which uses an optical interference signal to analyze and detect molecular dynamics. In order to rapidly detect biomolecule interactions and obtain kinetic parameters of biological molecules, this paper presents a molecular interaction detection system based on biofilm light interference and a fiber biosensor. The coupling structure of the self-focusing lens and the quartz fiber greatly improves the coupling efficiency between the light source and the interference light. The system uses a microprocessor as the main controller to realize data acquisition, three-dimensional transmission mechanism control and constant temperature oscillation control. Finally, we design a molecular interaction detection system and compare the results with a Hitachi 7180 biochemical analyzer to detect different concentrations of immunoglobulin IgG and protein A. The binding and dissociation reactions of the human serum immunoglobulin IgG antigen and the antigen molecule protein A biosensor are detected in real time. The experimental results show that the detection limit of the system can reach $10~\mu \text{g}$ /mL, and the repeatability CV value is less than 6%, which is close to the Hitachi 7180. However, the proposed system has the advantages of high automation, low cost and does not cause cross contamination during the detection process, so it can meet the requirements of pharmacokinetics research.

Evaluation of a sanitizing washing step with different chemical disinfectants for the strawberry processing industry

Strawberries are often consumed fresh or only receive minimal processing, inducing a significant health risk to the consumer if contamination occurs anywhere from farm to fork. Outbreaks of foodborne illness associated with strawberries often involve a broad range of microbiological agents, from viruses (human norovirus) to bacteria (Salmonella spp. and Listeria monocytogenes). The addition of sanitizers to water washes is one of the most commonly studied strategies to remove or inactivate pathogens on berries as well as avoid cross contamination due to reuse of process wash water. The risk posed with the safety issues of by-products from chlorine disinfection in the fruit industry has led to a search for alternative sanitizers. We evaluated the applicability of different chemical sanitizers (peracetic acid (PA), hydrogen peroxide (H2O2), citric acid (CA), lactic acid (LA) and acetic acid (AA)) for the inactivation of S. enterica, L. monocytogenes and murine norovirus (MNV-1) on strawberries. A control treatment with chlorine (NaClO) (100 ppm) was included. For each sanitizer, different doses (40, 80 and 120 ppm for PA and 1, 2.5 and 5% for H2O2, LA, AA and CA) and time (2 and 5 min) were studied in order to optimize the decontamination washing step. The best concentrations were 80 ppm for PA, 5% for H2O2 and 2.5% for organic acids (LA, AA and CA) after 2 min treatment. Results indicate that the sanitizers selected may be a feasible alternative to chlorine (100 ppm) for removing selected pathogenic microorganisms (P > 0.05), with reductions about ≥2 log for bacterial strains and ≥ 1.7 log for MNV-1. As the washing water may also increase the microbial counts by cross-contamination, we observed that no pathogenic bacteria were found in wash water after 5% H2O2 and 80 ppm PA after 2 min treatment. On the other hand, we also reported reductions about total aerobic mesophyll (TAM) (0.0–1.4 log CFU/g) and molds and yeasts (M&Y) (0.3–1.8 log CFU/g) with all alternative sanitizers tested. Strawberries treated did not shown significant differences about physio-chemical parameters compared to the untreated samples (initial). For this study, the optimal sanitizer selected was PA, due to the low concentration and cost needed and its microbiocidal effect in wash water and fruit. Notwithstanding the results obtained, the effect of PA in combination with other non-thermal technologies such as water-assisted ultraviolet (UV-C) light should be studied in future research to improve the disinfection of strawberries.

Characterization and selection of functional yeast strains during sourdough fermentation of different cereal wholegrain flours

The increasing demand for healthy baked goods boosted studies on sourdough microbiota with beneficial metabolic traits, to be used as potential functional starters. Here, 139 yeasts isolated from cereal-based fermented foods were in vitro characterized for their phytase and antioxidant activities. The molecular characterization at strain level of the best 39 performing isolates showed that they did not derive from cross contamination by baker’s yeast. Afterwards, the 39 isolates were in vivo analyzed for their leavening ability, phytase activity and polyphenols content using five different wholegrain flours, obtained from conventional and pigmented common wheat, emmer and hull-less barley. Combining these findings, through multivariate permutation analysis, we identified the 2 best performing strains, which resulted diverse for each flour. Doughs singly inoculated with the selected strains were further analyzed for their antioxidant capacity, phenolic acids, xanthophylls and anthocyanins content. All the selected yeasts significantly increased the total antioxidant activity, the soluble, free and conjugated, forms of phenolic acids and anthocyanins of fermented doughs. This study revealed the importance of a specific selection of yeast strains for wholegrain flours obtained from different cereals or cultivars, in order to enhance the pro-technological, nutritional and nutraceutical traits of fermented doughs.

Current Transport Mechanisms in Au-Free Metallizations for CMOS Compatible GaN HEMT Technology

Gallium nitride (GaN) and its AlGaN/GaN heterostructures grown on large area Si substrates are promising systems to fabricate power devices inside the existing Si CMOS lines. For this purpose, however, Au-free metallizations are required to avoid cross contaminations. In this paper, the mechanisms of current transport in Au-free metallization on AlGaN/GaN heterostructures are studied, with a focus on non-recessed Ti/Al/Ti Ohmic contacts. In particular, an Ohmic behavior of Ti/Al/Ti stacks was observed after an annealing at moderate temperature (600°C). The values of the specific contact resistance ρc decreased from 1.6×104 Ω.cm2 to 7×105 Ω.cm2 with increasing the annealing time from 60 to 180s. The temperature dependence of ρc indicated that the current flow is ruled by a thermionic field emission (TFE) mechanism, with barrier height values of 0.58 eV and 0.52 eV, respectively. Finally, preliminary results on the forward and reverse bias characterization of Au-free tungsten carbide (WC) Schottky contacts are presented. This contact exhibited a barrier height value of 0.82 eV.

Reduced Incidence of Healthcare-associated Infections in a Long-term Care Facility by Converting to Automated Touchless Dispensing and Closed-refill Systems

Background Automated touchless dispensing and closed-refill systems minimize touch points that help prevent cross contamination events and reduce dispenser contamination with clinically significant pathogens in healthcare settings. Additionally, most consumers prefer touchless dispensing when using public restrooms. However, many healthcare settings still utilize manual dispensers for soap and sanitizer. Some even have open, bulk, refillable dispensing systems and manual pumps and dispensers. A finding of a clinical in-use study revealed a significant reduction in the incidence of healthcare associated infections (HAIs) following the conversion to automated touchless soap and sanitizer dispensing systems with premeasured dosage amounts in a long-term care (LTC) care facility. Methods A LTC facility was qualified as a testing site for clinical in-use study of hand hygiene (HH) products’ impact on healthcare workers’ (HCWs) hands. The facility replaced all HH manual dispensing systems and locally purchased hygiene products with automated touchless dispensers, closed-refill systems, and quality formulations. In addition to the biophysical measurements of HCWs hands using bioengineering instrumentation, the baseline incidence of HAIs was recorded prior to the intervention and surveillance continued from 2014 to 2018. HAI rates provided by the testing site were compared to the baseline data collected in 2014 with specific emphasis on the infection outbreak season from October to December in each year. Results Descriptive data analysis of HAI incidence rates revealed significant and sustained reduction in HAI rates from 6.7% in October through December of 2014 to 1.6 % the same period in 2015, 2.8 % in 2016 and 2.4 % in 2017. Conclusions Converting the HH framework from manual dispensing to automated touchless dispensing with closed refill systems during a clinical-in-use study resulted in a sustained reduction of HAI rates over a 3-year period. Increased awareness of HH, touchless hygienic dispensing systems, and HCW improved skin integrity are variables to consider for HAI reduction. Automated touchless dispensing and closed-refill systems minimize touch points that help prevent cross contamination events and reduce dispenser contamination with clinically significant pathogens in healthcare settings. Additionally, most consumers prefer touchless dispensing when using public restrooms. However, many healthcare settings still utilize manual dispensers for soap and sanitizer. Some even have open, bulk, refillable dispensing systems and manual pumps and dispensers. A finding of a clinical in-use study revealed a significant reduction in the incidence of healthcare associated infections (HAIs) following the conversion to automated touchless soap and sanitizer dispensing systems with premeasured dosage amounts in a long-term care (LTC) care facility. A LTC facility was qualified as a testing site for clinical in-use study of hand hygiene (HH) products’ impact on healthcare workers’ (HCWs) hands. The facility replaced all HH manual dispensing systems and locally purchased hygiene products with automated touchless dispensers, closed-refill systems, and quality formulations. In addition to the biophysical measurements of HCWs hands using bioengineering instrumentation, the baseline incidence of HAIs was recorded prior to the intervention and surveillance continued from 2014 to 2018. HAI rates provided by the testing site were compared to the baseline data collected in 2014 with specific emphasis on the infection outbreak season from October to December in each year. Descriptive data analysis of HAI incidence rates revealed significant and sustained reduction in HAI rates from 6.7% in October through December of 2014 to 1.6 % the same period in 2015, 2.8 % in 2016 and 2.4 % in 2017. Converting the HH framework from manual dispensing to automated touchless dispensing with closed refill systems during a clinical-in-use study resulted in a sustained reduction of HAI rates over a 3-year period. Increased awareness of HH, touchless hygienic dispensing systems, and HCW improved skin integrity are variables to consider for HAI reduction.

Quantitative Measurement of Hand Hygiene in Ambulatory Surgery Amongst Anesthesiologists and Perioperative Nurses Using an Automated Personal Hand Hygiene System

<h3>Background</h3> Studies have shown that anesthesia providers can reduce cross contamination events of intravenous tubing and stopcocks, medication syringes, anesthesia carts, and transmission of pathogens to the surgical patient, by maintaining an hourly hand hygiene (HH) rate of four to eight hand hygiene events (HHE) per hour, yet to date there has been no automated way to objectively measure HHE during surgery in ambulatory surgery centers (ASC). The purpose for this study was to measure HHE of anesthesia providers, operating room (OR) registered nurses (RN), and post-anesthesia care (PACU) RN with the implementation of an automated personal hand hygiene system (APHHS). <h3>Methods</h3> The APHHS (personal devices with alcohol gel sanitizer, wireless data transfer, and web-based reporting), was deployed to fourteen anesthesiologists, seven OR RN and nine PACU RN over a four-week period in the ASC where on average twenty-five surgeries are performed daily. The APHHS measured total HHE and HHE per hour of clinical time. A multi-modal approach for HH improvement included a shared group performance dashboard, leadership communication, ongoing positive feedback via the personal device, HH education, and recognition of sustained individual performance. <h3>Results</h3> Prior to automation, 30 to 60 HHE were observed per quarter utilizing the direct observation method and an opportunity-based approach. Following APHHS deployment, 1008 HHE were captured per week. Average hourly HHE rates were measured: Anesthesia 3.3, OR RN 3.5, PACU RN 3.5. Compliance rates to a set goal of 8 per hour were measured: Anesthesia 41% and RN 44% compliant to goal. <h3>Conclusions</h3> Implementing an APHHS in ASC with an evidenced based approach provides robust data sets of HHE with continuous individualized performance feedback and provides unbiased measurement of actual HH performance.

Strategic Preparation for Dental Care Delivery during COVID-19 Transition-An Update

As we all look forward to phasing towards the new normal, COVID-19 has certainly changed the way we would be practicing dentistry. As the global health organizations are working relentlessly laying down guidelines to control the transmission, the dental team should effectively integrate these guidelines to establish safe practices considering the scarcity of available armamentarium. As we cautiously move from treating emergencies to regular care, it would be important to modify and reorganize our existing offices to best contain and prevent cross contaminations of the novel corona virus. Incorporating teledentistry wherever possible, careful management of personal protective equipment, employing strategies for extended use, re use and decontamination of respirators, improvising disinfection protocols will enable us to effectively surmount the existing scarcities and provide quality care. Also it is important that each and every one of the dental team have clear guidelines on how to manage patients with different COVID experiences. These experiences may range from COVID screening to dealing with patients who have active infection or patients who have resolved COVID infection when presented for dental care, and if situations arise, the team should be prepared for self quarantine. It is crucial to be in collaboration with local and state health departments to better understand local disease transmission rates and follow guidelines until we receive evidence based data.

Covid 19 – Impact and new normal for pharmaceutical industry (Part – I)

This review article shares New Normal as part of impact of Covid 19, on Pharmaceutical Industry globally as whole &amp; Manufacturing Operations as preventive measures or cure of Covid 19. Based on known transmissions &amp; spreading routes, the Pharmaceutical Industry Manufacturing Operations needs to learn to avoid such impacts of transmissions &amp; spreads. The pharmaceutical and healthcare operations need to take care to protect personnel As such The Pharmaceutical Industry does take very good care to avoid cross contaminations as part of Good Manufacturing Practices (GMP). But now keeping in mind seriousness of virus spread, the Pharmaceutical Industry has to take precautions to avoid transmission &amp; spread during travel in buses, entry &amp; exit procedures, change rooms, avoid hand touch to doors, handles etc. at office work places &amp; throughout the manufacturing operations at site This article looks at various stages the Pharmaceutical Manufacturing Operation sites has to take care depending types of products &amp; human involvement in such operations As per WHO, key major steps to protect against the infection are: • Social distancing • Use of Masks/Face- Shields • Frequent Washing of Hands with soap &amp; water or Sanitisation with proper sanitisers containing min. 70% Alcohol. • Segregation of staff in essential &amp; non-essential at manufacturing site. • Non-essential staff to work from home Essential staff are the ones who are required to work in person at manufacturing site The Pharmaceutical Industry is moving forward very confidently by amending concerned SOP’s to meet Covid – 19 impact &amp; challenges. This article describes “New Normal – impacts” of Covid-19 &amp; basic requirements like Personal hygiene, Entry/Exit procedures to Protect the Workplace &amp; Safety of the Workforce.

Investigation on time stability of laser-textured patterned surfaces under different temperatures

Patterned surfaces that show different wettabilities on same substrates have important application value in fields like fog collection and liquid transportation. However, superhydrophilic regions on the patterned surfaces prepared tend to become superhydrophobic, which restrains their further applications. Therefore, it is of great significance to explore wettability change of the superhydrophilic regions. In this paper, we prepare patterned aluminum (Al) surfaces by nanosceond laser texturing and fluorosilane modification, and investigate the wettability change of the patterned surfaces (laser parameters: a pulse repetition rate of 20 kHz, a scanning speed of 300 mm/s, a power of 6 W, a pulse width of 100 ns, a beam waist diameter of 46 μm, an optical wavelength of 1064 ± 5 nm, a pulse energy of 0.3 mJ and a laser fluence of 18 J/cm2). Contact angles, surface morphologies and surface chemical compositions are measured and analyzed by an optical angle meter, a scanning electron microscope, and X-ray photoelectron spectroscopy. Compared with a uniform superhydrophilic surface, the superhydrophilic area on a patterned surface becomes superhydrophobic more rapidly, indicating that cross contamination of low surface energy functional groups from the superhydrophobic region promotes wettability change of the superhydrophilic region. In addition, the wettability change rate gradually accelerates when storing under a higher temperature of 100 °C; we perform fog collection experiments on patterned surfaces storing under different temperatures, and find that low temperature can hinder wettability change of functional patterned surfaces, thereby improving service life.

Minimizing cross transmission of SARS-CoV-2 in obstetric ultrasound during COVID-19 pandemic.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-associated infection (COVID-19) is affecting populations worldwide. This statement may serve as guidance for infection prevention and safe ultrasound practices during the COVID-19 pandemic. Ultrasound examination is a fundamental part of obstetric care, yet it is a potential vector for transmission of SARS-CoV-2. Decontamination methods should always be implemented for ultrasound equipment, especially in the presence of suspected or confirmed COVID-19 cases. There must be workflow policies to protect pregnant women and healthcare providers from nosocomial cross transmission of SARS-CoV-2. Cleaning and disinfecting of equipment must be in accordance with their potential of pathogen transmission. Consider using telemedicine and genetic technologies as an adjunctive of obstetric ultrasound to reduce patient crowding. Patient triage and education of healthcare providers of infection prevention are crucial to minimize cross contamination of SARS-CoV-2 during obstetric ultrasound.

Cross Infection in Dentistry and the Dental Aerosols –A Potential Health Hazard

Many hazards are often associated with different occupations and known as occupational hazards. Dentistry is also one of those professions having many occupational risks. Such hazards are broadly categorized into chemical, biological, physical, mechanical and psychological factors. Cross infection is one of such hazards faced by the health care providers’ particularly dental workers. Cross infection is the transmission of infectious agents between patient and staff in clinical environment. Control of cross infection has remained the major concern of the dental community for decades. Various vectors are involved in cross infections in Dentistry including patients, environment (water, air), instruments etc. Particularly among the environmental factors, airborne route is one of the major routes of cross contamination and so aerosols produced in dental environment carry greatest pathogenic potential. Production of aerosols and splatters occur because of many procedures carried out in mouth including crown preparation, ultrasonic scaling, caries excavation etc. Patients, dental instruments and dental unit waterlines (DUWL) are the important sources of contaminated aerosol production in dental operatory. Use of personal Protective equipments, regular use of pre-procedural mouth rinses and high evacuation devices are few of the suggested methods to reduce risk of cross contamination especially through aerosols and splatters in the dental offices. The related articles were searched through PubMed and Google Scholar.

A Defect Defense Approach of Integrated Database Based on Over‐Etched Defect

The aluminum line overetched defect might be called as undercut、PR Hole, etc by different manufacturers. The defect of this case study mainly shows a hole found on the aluminum line after stripper process but there is no any tracable symptom before the ending of dry etch process. That is, it seems no means to prevent or to found the root cause.A defect defense approach via cleanroom air quality database based integrated with TFT manufacturing processes、air sampling、characteristics of manufacturing chemicals、cleanroom circulation and air flow pattern is proposed to demostrate how to figure out the root cause of aluminum line overetched defect, which found after stripper.Via the aid of proposed approach, the analysis shows the defect arises from the cross contamination between photo、PVD and stripper process and the cross contamination comes from manufacturing layout、cleanroom circulation and air flow pattern.

Low mercury, cadmium and lead concentrations in tuna products from the eastern Pacific

Tuna species: Skipjack (Katsuwonus pelamis), yellowfin (Thunnus albacares) and bigeye (Thunnus obesus) are mainly processed into canned products (loins, solid pack, flakes) either in water or oil, and pre-cooked frozen loins. The National Institute of Fisheries of Ecuador (ISO/IEC 17025 certified), which is the official control laboratory, samples and analyses production batches of companies exporting to the European Union in order to ensure the quality control of Ecuadorean tuna product. From 2009 to 2016, 2572 samples have been analysed (by standard methods) for mercury, cadmium, and lead. The averages were 0.24 ± 0.14; 0.03 ± 0.03 and 0.05 ± 0.05 mg kg−1 (wet weight) respectively; which are well below the norms; i.e., total mercury: 1 mg kg−1; Lead: 0.3 mg kg−1 and Cadmium: 0.1 mg kg−1 according to the EU maximum limits. Over time mercury levels in the sample seemed to decrease but for cadmium and lead no clear pattern was observed. Additionally; samples of tuna can products taken at random from local vendor stores gave concentrations of: Mercury: 0.043 ± 0.004 mg kg−1; Cadmium: 0.012 ± 0.002 mg kg−1; Lead: below detection limit (0.01 mg kg−1). There were a few cases (15 out of 2572: 0.58%) of samples with readings near or just over-limit concentrations; of these, 12 corresponded to Cd, two to Pb and one to Hg. Some of them can be considered statistical outliers as well as cross contamination during analytical procedures. Raw tuna samples have given similar or lower concentrations. No significant statistical correlation was found between Hg, Cd and Pb values, this would suggest that the bioaccumulation of each metal is independent of each other. Literature reports that surface dissolved Hg, Cd, and Pb in the eastern Pacific are in the range of 2–18 ng kg−1. Assuming suggested bioaccumulation of 2–6 times, the end concentration in the tuna would be 0.012–0.042; 0.036–0.108 and 0.010–0.027 μg kg−1 of Hg, Cd, and Pb respectively, that would be one order (or more) below the safe consumption limit. Most, if not all the tuna processed in Ecuador is captured in the eastern Pacific and within its EEZ. Ecuadorian canned tuna complies with stringent standards for presence of these metals; therefore, it can be considered safe to be consumed from the point of view of these metal concentrations. However, further studies should assess metal concentrations exclusively from Ecuadorian tuna captured close to coastal and insular areas.

Letter: Strategies for Prevention and Control of 2019 Novel Coronavirus Infection Among Medical Staff.

Letter: Strategies for Prevention and Control of 2019 Novel Coronavirus Infection Among Medical Staff.

Geomagnetic and Solar Dependency of MSTIDs Occurrence Rate: A Climatology Based on Airglow Observations From the Arecibo Observatory ROF

AbstractWe employ in this work the first O(1D) 630.0‐nm airglow data set registered at the Remote Optical Facility (ROF) in Culebra, Puerto Rico, during the descending phase of the solar cycle #24. From 4 November 2015 to 26 September 2019, observations were carried out during 633 nights at ROF using a small all‐sky imager, while MSTID events were identified in 225 of 499 nights classified as clear. A quantitative analysis of these MSTIDs and their dependency by geophysical parameters (solar and geomagnetic activities) are the main focus of this study. We introduce an original statistical methodology that examines the unique features of the data set and minimizes the cross contamination of individual modulators onto one another, avoiding bias in the results. Our findings include a primary peak of MSTIDs occurrence in the December solstice and a secondary peak in the June solstice. We observed a remarkable correlation in the occurrence rate of the MSTIDs with the geomagnetic activity. A notable modulation of the MSTIDs occurrence rate with the solar activity is also found, which includes periods of correlation and anticorrelation depending on the season. This modulation has an annual component that is ~33% and ~83% stronger than the semiannual and terannual components, respectively. We discuss these findings based on a previous study of the thermospheric neutral winds derived from 30 years of Fabry‐Perot interferometer observations at Arecibo Observatory. Our results, which are valid for low to moderate solar activity, point out circumstances that might explain differences in previous climatological studies of nighttime MSTIDs.

High-Throughput Molecular Cancer Cell Line Characterization Using Digital Multiplex Ligation-Dependent Probe Amplification for Improved Standardization of in Vitro Research

Tumor cell lines are widely used for cancer research, but challenges regarding quality control of cell line identity, cross contamination, and tumor somatic molecular stability remain, demanding novel approaches beyond conventional short tandem repeat profiling. A total of 21 commonly used multiple myeloma cell lines obtained from public repositories were analyzed by digital multiplex ligation-dependent probe amplification (digitalMLPA) to characterize germline single-nucleotide polymorphisms, insertions/deletions, and somatic copy number aberrations (CNAs). Using generated profiles and an in-house developed analytical pipeline, blinded experiments were performed to determine capability of digitalMLPA to predict cell line identity and potential spike-in DNA contamination in 41 anonymized cell line samples. The dominant cell line was correctly identified in all cases, and cross contamination was correctly detected in 33 of 37 samples with spike-in DNA; there were no false-positive predictions. The four samples in which spike in was not detected all carried low levels of contamination (1%), whereas levels of contamination ≥5% were correctly identified in all cases. Unsupervised clustering of CNA profiles identified shared commonalities that correlated with initiating Ig heavy locus translocation events. Longitudinal CNA assessment of nine cell lines revealed changes under standard culturing conditions not detected by insertion/deletion profiling alone. Results suggest that digitalMLPA can be utilized as a high-throughput tool for advanced quality assurance for invitro cancer research.

Simultaneous determination of olaquindox, oxytetracycline and chlorotetracycline in feeds by high performance liquid chromatography with ultraviolet and fluorescence detection adopting online synchronous derivation and separation

Olaquindox, oxytetracycline and chlorotetracycline were widely used in feed as antibiotics and growth promoter to improve feed conversion efficiency and increase the rate of weight gain for animals. However, the use of these antibiotics in feed was gradually prohibited because of concerns about contamination and resistance in animals. A quantitative and confirmatory method for determining the presence of olaquindox, oxytetracycline and chlorotetracycline in feed by high performance liquid chromatography equipped with ultraviolet detector in series with fluorescence detector (HPLC-UVD-FLD) was developed, optimized, and validated in three different matrices (compound, concentrated and premix feed). The analytes extraction was performed with a mixture of acetonitrile and 0.1 mol/L ethylenediamine tetraacetic acid disodium-Mcllvaine buffer (1:4, v/v) by one step sample preparation procedure. The validated method presented a broad linear range and good linearity with weighted least square method. The decision limit of the analytes ranged from 0.61 to 0.77 mg/kg for olaquindox, 0.90 to 1.2 mg/kg for oxytetracycline and 1.3 to 2.0 mg/kg for chlorotetracycline. The average recovery values found in intermediate precision conditions were ranged from 88.0 to 99.7% for olaquindox with RSD lower than 11.1%, from 84.4 to 99.0% for oxytetracycline with RSD lower than 9.6%, from 83.8 to 97.5% for chlorotetracycline with RSD lower than 10.0%. By Youden test and bottom-up method, the method was proved to be sufficiently robust and had a small uncertainty for different concentration levels. The developed method was successfully utilized for commercial feed samples to monitor complex cross contamination and residue conditions. Online synchronous derivation and separation using ultraviolet detector in series with fluorescence detector can effectively prevent false positive of chlorotetracycline in feed caused by vegetable meal. Since olaquindox, oxytetracycline and chlorotetracycline are widely used in feed, the developed method provide an important and analytical tool for the simultaneous identification and quantification of them in feed to monitor its risk of cross contamination and excessive content.

Elimination of \u201ckitome\u201d and \u201csplashome\u201d contamination results in lack of detection of a unique placental microbiome

BackgroundA placental microbiome, which may be altered in gestational diabetes mellitus (GDM), has been described. However, publications raising doubts about the existence of a placental microbiome that is different than contaminants in DNA extraction kits and reagents (“kitomes”) have emerged. The aims of this study were to confirm the existence of a placental microbiome distinct from contaminants and determine if it is altered in GDM mothers.ResultsWe first enrolled normal weight, obese and GDM mothers (N = 17) at term elective cesarean section delivery in a pilot case control study. Bacterial DNA was extracted from placental parenchyma, maternal and cord blood, maternal vaginal-rectal swabs, and positive and negative controls with the standard Qiagen/MoBio Power Soil kit. Placentas had significantly higher copies of bacterial 16S rRNA genes than negative controls, but the placental microbiome was similar in all three groups and could not be distinguished from contaminants in blank controls. To determine the source and composition of the putative placental bacterial community identified in the pilot study, we expanded the study to 10 subjects per group (N = 30) and increased the number and variety of negative controls (N = 53). We modified our protocol to use an ultraclean DNA extraction kit (Qiagen QIAamp UCP with Pathogen Lysis Tube S), which reduced the “kitome” contamination, but we were still unable to distinguish a placental microbiome from contaminants in negative controls. We noted microbial DNA from the high biomass vaginal-rectal swabs and positive controls in placental and negative control samples and determined that this resulted from close proximity well-to-well cross contamination or “splashome”. We eliminated this source of contamination by repeating the sequencing run with a minimum of four wells separating high biomass from low biomass samples. This reduced the reads of bacterial 16S rRNA genes in placental samples to insignificant numbers.ConclusionsWe identified the problem of well-to-well contamination (“splashome”) as an additional source of error in microbiome studies of low biomass samples and found a method of eliminating it. Once “kitome” and “splashome” contaminants were eliminated, we were unable to identify a unique placental microbiome.

Permanecer en la inversión: una vía no platónica de acceso a la materialidad del pensamiento

El objetivo de este ensayo es abrir un conjunto de preguntas en torno a la materialidad del pensamiento, sin que ello signifique, a fin de cuentas, establecer una teoría materialista que actúe en desmedro de las ideas. Tampoco se trata, como observará el lector, de reivindicar una teoría de las ideas contra la materia. Lo que se pretende, considerando una contaminación cruzada entre lo sensible y lo inteligible, es rastrear otra verdad para aquello que ha sido considerado, especialmente por el platonismo en sus diversas configuraciones, como lo inesencial frente al andamiaje trascendental de las ideas. En consecuencia, y a partir de un acercamiento pre-liminar, lo que se busca es permitir que los datos sensibles resuenen al interior de lo inteligible, y que lo hagan, además, de un modo no dialectizable.

2019-nCoV: Measures Adopted at the Departments of Oral Surgery and Radiology during the Period of an Uncontrolled Transmission Increase.

A new mutation of 2019-nCoV emerged and has been spreading worldwide. Dental practices are an important person-to-person transmission route. In this regard, preventive measures are required to avoid the cross contamination among professionals and patients. This report brings recommended measures for dental assistance during the pandemic phase. The clinical protocol applied at the Department of Oral Maxillofacial and Surgery, such as at the Department of Radiology, Hospital University Münster, is described. A management protocol was applied to prevent the transmission route of 2019-nCoV. Patients infected with 2019-nCoV are treated only in emergency situations. The use of protective equipment and dental office isolation were the major points to avoid the contact between infected and non-infected patients. Preventive measures should be taken in order to reduce the spread of 2019-nCoV infection.