Understanding Hole Scavenging Activity In CdS Semiconductor Nanocrystal Photochemistry

Semiconductor nanocrystals (NCs) are useful tools for light-based chemistry due to theirtunable energy levels and strong absorption coefficients. Incorporating NCs in systems coupled to redox enzymes allows the use of light to drive useful energy storing reactions e.g. H2 production. The kinetics of the electrons excited within the NC by light and transferred to the enzyme have been studied, but the transfer of the hole left by the excited electron to a sacrificial electron donor to regenerate the NC ground state, also known as hole scavenging, has proven difficult to monitor. The hole scavenger ascorbic acid (AA), which is compatible with many enzymatic systems has been found to be needed in large excess to be effective. The goal of this project is to understand more about hole scavenging in NC systems, with a special focus on why hole scavenging by AA is so inefficient.</p

Praćenje i molekularna epizootiologija epidemijskog proljeva svinja u Ukrajini tijekom 2014.-2018. godine

The rapid spread of porcine epidemic diarrhea (PED) in different countries in a short time while and the significant economic damage caused by it were important reasons for conducting long-term monitoring studies in Ukraine. PED monitoring researches conduct carry out during 2014-2018 using RT-PCR and ELISA showed the presence of infection in 14 (66.67%) of 21 examined regions of Ukraine. For the period 2014- 2018, the proportion of PED cases rate was the lowest in 2017 (1.76%) and the highest in 2016 (48.03%). Over the entire period, the percentage seropositive animals progressively decreased to a seronegative status indicator defined in sows in 2018. The results of determination of the virulence of 40 strains of PED virus from different regions of Ukraine using the RT-PCR method proved the circulation of highly virulent strains. The phylogenetic analysis demonstrated that the endemic strain of PED virus is included in the cluster of North American strains and the Chinese strains. Important is the fact that it is not included in the group of European low- virulent S-INDEL strains. Thus, the obtained data indicate a high probability that the PED virus was introduced into Ukraine from the territory of the Asian continent or the United States of America (a high probability that the PED virus was translocated from the territory of the Asian continent or the United States of America into Ukraine).Brzo širenje epidemijskog proljeva svinja (PED) u različitim zemljama tijekom kratkog razdoblja, koje je rezultiralo znatnom ekonomskom štetom, potaknulo je potrebu za dugoročnim studijama praćenja u Ukrajini. Praćenje PED uporabom RT- PCR i ELISA u razdoblju 2014.-2018. godine pokazalo je prisutnost infekcije u 14 (66,67 %) od 21 ispitane regije Ukrajine. Tijekom ovog razdoblja pojavnost slučajeva PED bila je najniža 2017. godine (1,76 %), a najviša 2016. godine (48,03 %), s progresivnim padom postotka seropozitivnih životinja i seronegativnog indikatora statusa definiranog u krmača 2018. godine. Rezultati određivanja virulencije 40 sojeva PED virusa iz različitih regija Ukrajine uporabom RT- PCR metode dokazali su kruženje vrlo virulentnih sojeva. Filogenetska analiza pokazala je da se endemski soj PED virusa grupirao sa sjevernoameričkim i kineskim sojevima. Potrebno je napomenuti da se nije grupirao s europskim S-INDEL sojevima niske virulentnosti. To navodi na zaključak da je PED virus vrlo vjerojatno unesen u Ukrajinu iz Azije ili SAD-a

Isolation and Genetic Analysis of Bovine Viral Diarrhea Virus from Infected Cattle in Indiana

Species and biotype distribution was determined in 44 bovine viral diarrhea virus- (BVDV-) positive samples submitted to the Animal Disease Diagnostic Laboratory (ADDL) in Indiana during 2006–2008. BVDV RNA was detected in the 5′-untranslated region and Npro region using reverse transcriptase PCR followed by sequencing analysis of the PCR product. Additionally, cases were classified into one of six categories according to history and/or lesions: acute symptomatic, hemorrhagic, respiratory distress, reproductive, persistent infection (PI), and mucosal disease (MD). Of 44 BVDV-positive samples, 33 were noncytopathic (ncp), 10 were cytopathic (cp), and one presented both ncp and cp biotypes. Sequencing analysis demonstrated that all samples belonged to BVDV-1a, BVDV-1b, or BVDV-2. The most common isolate was ncp BVDV-1b, (44%) followed by ncp BVDV-2a (24%). Among the six categories, respiratory clinical signs were the most common (36%) followed by PI (25%) and MD (16%)

Evaluation of Formaldehyde When Complete Feed and Soybean Meal Were Inoculated with Porcine Epidemic Diarrhea Virus, Porcine Reproductive and Respiratory Syndrome Virus, and Seneca Valley Virus 1

Chemical mitigants have been found to decrease virus concentrations in feed and ingredient matrices. Continued research is needed to identify the appropriate inclusion levels and application time for different viruses in these matrices. Therefore, the objective was to evaluate different inclusion levels of formaldehyde when applied either pre- or post-inoculation of porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome virus (PRRSV) and Seneca Valley virus 1 (SVV1) to complete feed or soybean meal. The experiment was designed in a 2 × 2 factorial with a formaldehyde-based product (Termin-8, Anitox Corp. Lawrenceville, GA) applied either before virus inoculation (pre-inoculation) or after inoculation (post-inoculation) at either a 4 or 6 lb/ton. On d 0, samples of the respective matrices were weighed in 50 g aliquots and added to 500 mL bottles. Chemical mitigants were applied to the pre-inoculation samples at their respective inclusion levels and 50 μL each of 1×107 TCID50/ mL PEDV, 1×108 TCID50/mL PRRSV, and 1×108 TCID50/mL SVV1 were added to the post-inoculation samples. All bottles were shaken and allowed to sit at room temperature for 24 hours. On d 1, virus was added to the pre-inoculation samples and chemical mitigants were added to the post-inoculation bottles. Half of the samples were immediately processed (0 hr) and the other half were incubated at room temperature for an additional 24 hours (24 hr). Samples were processed and aliquots were analyzed via a triplex PCR assay at Kansas State University Veterinary Diagnostic Laboratory. Cycle threshold and proportion PCR positive were analyzed using SAS GLIMMIX v 9.4 (SAS, Inc., Cary, NC) with each virus and matrix combination analyzed individually. An application time × inclusion level interaction was observed for PEDV at 0 hr and SVV1 and PEDV at 24 hr in complete feed, where less viral RNA (P \u3c 0.05) was detected in the post-inoculation samples at either inclusion level as compared to the positive controls. In soybean meal, the same interaction was observed in PEDV and PRRSV at 0 hr and SVV1 and PEDV at 24 hr with less detectable RNA observed (P \u3c 0.05) in the post-inoculation samples regardless of inclusion level than the pre-inoculation counterparts and the controls. Overall, an application time effect was noticed in each matrix where less RNA was detected in the post-inoculation samples at 0 hr (P \u3c 0.05) compared to the pre-inoculation samples and the control, and at 24 hr, both the pre- and post-inoculation samples had less detectable RNA (P \u3c 0.05) than the control. Overall, formaldehyde can reduce detectable RNA immediately in both contaminated complete feed and soybean meal, with greater decreases observed as mitigant contact time increases

Evaluation of a Blend of Phytochemicals and Carboxylic Acid When Complete Feed and Soybean Meal Were Inoculated with Porcine Epidemic Diarrhea Virus, Porcine Reproductive and Respiratory Syndrome Virus, and Seneca Valley Virus 1

Chemical mitigants have been found to decrease virus concentrations in feed and ingredient matrices. Continued research is needed to identify the appropriate inclusion levels and application time for different viruses in these matrices. Therefore, the objective was to evaluate different inclusion levels of a product utilizing a synergistic blend of phytochemicals and carboxylic acid (PCA) when applied either pre- or post-inoculation of porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome virus (PRRSV) and Seneca Valley virus 1 (SVV1) to complete feed or soybean meal. The experiment was designed in a 2 × 2 factorial with a PCA-based product, (Finio, Anitox Corp. Lawrenceville, GA) applied either before virus inoculation (pre-inoculation) or after inoculation (post-inoculation) at either 3.5 or 5.5 lb/ton. On d 0, samples of the respective matrices were weighed in 50 g aliquots and added to 500 mL bottles. The PCA blend was applied to the pre-inoculation samples at their respective inclusion levels and 50 μL each of 1×107 TCID50/mL PEDV, 1×108 TCID50/mL PRRSV, and 1×108 TCID50/mL SVV1 were added to the post-inoculation samples. All bottles were shaken and allowed to sit at room temperature for 24 hours. On d 1, virus was added to the pre-inoculation samples and chemical mitigants were added to the post-inoculation bottles. Half of the samples were immediately processed (0 hr) and the other half were incubated at room temperature for an additional 24 hours (24 hr). Samples were processed and aliquots were analyzed via a triplex PCR assay at Kansas State University Veterinary Diagnostic Laboratory. Cycle threshold and proportion of PCR positive were analyzed using SAS GLIMMIX v 9.4 (SAS, Inc., Cary, NC), with each virus and matrix combination analyzed individually. In both soybean meal and complete feed an application time × inclusion level interaction was only observed for PRRSV at 0 hr, where less PRRSV RNA was detected (P \u3c 0.05) in the post-inoculation samples at either 3.5 or 5.5 lb/ton as compared to the pre-inoculation or control samples. For other viruses at 0 hr in complete feed and soybean meal, the post-inoculation samples had less detectable PEDV or SVV1 RNA (P \u3c 0.05) than the pre-inoculation samples. As time continued (24 hr), both pre- and post-inoculation samples had less detectable PEDV RNA (P \u3c 0.05) than the controls in complete feed. Interestingly, the positive controls had less detectable viral RNA (P \u3c 0.05) at 24 hr in soybean meal compared to either the pre- or post-inoculation samples. This effect is hypothesized to reverse as the mitigated samples have a greater contact time. Overall, the use of a PCA-based product reduced viral concentrations in complete feed and had a variable effect when applied to soybean meal. More research is needed to understand the contact time required for viral reduction and the infectivity of these samples at defined contact times

Understanding the Reduction of Porcine Epidemic Diarrhea Virus, Porcine Reproductive and Respiratory Syndrome Virus, and Seneca Valley Virus 1 RNA in Inoculated Feed and the Environment Following Thermal Processing

Pelleting of feed has been demonstrated to be an effective mitigation strategy for porcine epidemic diarrhea virus (PEDV) contaminated feed but has not been evaluated for other endemic swine viruses like porcine reproductive and respiratory syndrome virus (PRRSV) or Seneca Valley virus 1 (SVV1). Therefore, the objective of this experiment was to evaluate the efficacy of pelleting to inactivate PEDV, PRRSV, and SVV1 inoculated feed. Ten replicates were conducted in the Cargill Feed Safety Research Center at Kansas State University (K-State) using a pilot scale mixer, bucket elevator, pellet mill (including conditioner and die), and cooler. First, a virus negative batch of gestation feed was run through all equipment to simulate a commercial feed mill, then a positive batch of feed inoculated with all three viruses was run through all feed manufacturing equipment. Feed was conditioned to a minimum of 180°F with a 30 sec retention time; all feed was cooled for 10 min. Feed and environmental samples were taken from each piece of equipment following both the negative and positive batch. Samples were analyzed via PCR at the K-State Veterinary Diagnostic Laboratory. A four-room bioassay was conducted to evaluate the infectivity of the feed samples. Feed from the mixer and bucket elevator had greater quantities of SVV1, PEDV, and PRRSV RNA (P \u3c 0.05) than the other sampling locations. Similarly, environmental samples from the mixer and bucket elevator had greater SVV1 detection (P \u3c 0.05) than those collected from the conditioner, pellet die, and cooler. Pelleting reduced viral RNA (P \u3c 0.05) for all viruses in both feed and environmental samples. Although SVV1 and PEDV RNA were still detectable following pelleting, no pigs inoculated with the pelleted feed showed signs of SVV1 or PEDV clinical infection. Interestingly, PRRSV RNA was not detectable in pelleted feed samples. However, one pig showed signs of replicating PRRSV virus on d 7 of the bioassay which suggests a greater sensitivity when utilizing a bioassay compared to PCR alone. Overall, pelleting reduced the quantity of detectable viral RNA and reduced the risk of infectivity; yet small quantities of viral RNA remaining in the feed and environment following pelleting may increase the risk of re-contamination

Evaluating the Distribution of Porcine Epidemic Diarrhea Virus, Porcine Reproductive and Respiratory Syndrome Virus, and Seneca Valley Virus 1 Inoculated Feed After the Use of Physical or Chemical Mitigants to Flush a Feed Manufacturing Facility

Contaminated feed is a route of virus transmission between feed mills and swine farms. To reduce the risk of transmission, an understanding of the virus distribution and mitigation strategies are needed. The objective of this study was to evaluate the distribution of porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome virus (PRRSV), and Seneca Valley virus 1 (SVV1) inoculated feed in the environment and feed of a feed mill before and after the use of chemical mitigants. A 50-lb batch of feed was run through a mixer and bucket elevator followed by a batch inoculated with PEDV, PRRSV, and SVV1. Following the virus-inoculated batch, a flush treatment of either 1) ground corn (GC); 2) GC + 1.5% liquid formaldehyde (LF; SalCURB LF Liquid, Kemin, Des Moines, IA); 3) GC + 1.5% LF + 25% abrasive material (SalCURB; Shell & Bone Builder, Iowa Limestone Company, Urbandale, IA); 4) double flush – GC + 25% abrasive material followed by GC +1.5% LF (Shell & Bone Builder; SalCURB); or 5) dry formaldehyde (SalCURB F2 Dry, Kemin, Des Moines, IA) was utilized, followed by 3 virus-free batches of complete feed. Feed and environmental samples were collected from each piece of equipment following every batch. Dust samples were collected after manufacturing from the inoculated, flush, and final batches from non-feed contact surfaces. Non-feed contact surfaces were considered those where dust would accumulate during manufacturing but would not be included in the final diet. The surfaces included the grates of the mixer, the top of the discharge bin following the bucket elevator, and the floor surrounding the same discharge bin. Samples were analyzed via a triplex PCR at the Kansas State University Veterinary Diagnostic Laboratory. A treatment × batch × location interaction was not observed (P \u3e 0.05) in feed or the environment for any of the viruses. A flush treatment × batch interaction was observed for SVV1 where greater quantities of viral RNA (P \u3c 0.05) were present in the positive batches and the ground corn flush than in those batches which used chemical mitigants or the post-flush batches. A lower quantity of viral RNA (P\u3c 0.05) in dust was observed in the last batch of feed compared to the inoculated batch for all viruses; however, SVV1 RNA was still detectable in the dust following the last batch in all treatments. A batch effect (P \u3c 0.05) was observed in all sample matrices for PEDV and PRRSV as viral RNA decreased after the implementation of the flush regardless of treatment. The use of chemical mitigants and the implementation of a flush batch reduced the quantity of viral RNA for PEDV, PRRSV, and SVV1. However, viral presence was still observed in feed and the dust on non-feed contact surfaces which could be a source of contamination if re-introduced into finished feed

Decontamination of a Feed Manufacturing Environment Following Inoculation with Porcine Epidemic Diarrhea Virus, Porcine Reproductive and Respiratory Syndrome Virus, and Seneca Valley Virus 1

Feed mill decontamination is difficult because equipment is not designed to be cleaned with water. Alternate strategies may improve a mill’s ability to decontaminate in the event of viral contamination. The objective of this experiment was to evaluate different decontamination strategies within a mill following the inoculation of swine feed with porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome virus (PRRSV), and Seneca Valley virus 1 (SVV1) run through feed manufacturing equipment consisting of a mixer, bucket elevator, corn cleaner, drag conveyor, and distributor. Afterward, decontamination strategies were implemented with environmental samples collected after each step. Strategy treatments included: 1) complete facility decontamination and heating for 48 hours at 60°C; 2) chlorine dioxide application (ProOxine AH, Bio-Cide International, Inc., Norman, OK); 3) organic matter removal using vacuums (Ridge Tool Company, Elyria, OH) and chlorine dioxide application; 4) heat with portable electric heaters for exactly 48 hours; and 5) organic matter removal and heat with portable heaters for exactly 48 h. A swine bioassay was completed to determine the infectivity of each treatment after decontamination. A treatment × decontamination step × location interaction was observed (P \u3c 0.05) for SVV1, where less RNA was detected post-treatment compared to post-inoculation following the complete facility decontamination treatment on surfaces including the mixer, corn cleaner, drag conveyor, and flooring (P \u3c 0.05) as compared to all other decontamination treatments. Across all treatments, the act of decontamination reduced detectable PEDV (P \u3c 0.05) and PRRSV (P \u3c 0.05) RNA when compared to samples immediately following inoculation, but complete facility decontamination and heating was the only treatment RNA was non-detectable in all locations. Pigs inoculated with samples collected post-treatment showed no evidence of SVV1 or PEDV infection; PRRSV infection was observed in pigs given the chlorine dioxide with and without organic matter removal treatments and the organic matter removal plus heat treatment. Overall, all treatments reduced detectable RNA for all viruses between the inoculation step and the final decontamination step; however, PRRSV particles remained infectious following decontamination