Use of Spinal Anesthesia during Thoracic Endovascular Aortic Repair.

BACKGROUND: The purpose of this study was to assess outcomes after spinal anesthesia (SA) versus general anesthesia (GA) in patients undergoing thoracic endograft placement and to evaluate the adjunctive use of cerebrospinal fluid drainage (CSFD) placement. METHODS: A single-center retrospective review of patients that underwent thoracic endograft placement from 2001 to 2019 was performed. Patients were stratified based on the type of anesthesia they received: GA, SA or epidural, GA with CSFD, and SA with CSFD. Primary outcomes included 30-day mortality and length of stay (LOS). Baseline characteristics were analyzed with Student's t-test and Pearson's chi-squared test. Multivariate logistic regression analysis was performed to identify risk factors for 30-day mortality and longer LOS. RESULTS: A total of 333 patients underwent thoracic endograft placement; 104 patients received SA, 180 patients received GA, 30 patients received GA and CSFD, and 19 patients received SA and CSFD. Of the total patients, 16.2% underwent thoracic endograft placement for type B aortic dissection, 3.3% for type A aortic dissection, and 12.3% for penetrating ulcer. The mean age of the study population was 68.7 years old. Patients undergoing SA were older with a mean age of 73.4 years versus 64.7 years for patients undergoing GA (P < 0.001). Spinal anesthesia (SA) was preferred in patients at high risk for GA (>75 years old: 52.9% vs. 33.3%, P < 0.001; renal comorbidities: 20.6% vs. 10.6%, P = 0.03, and current smokers: 26.7% vs. 9.6%, P < 0.001). Length of stay (LOS) was decreased in the SA group (4.29 days vs. 9.70 days, P < 0.001). There was a lower incidence of spinal cord ischemia in the SA group (1.0% vs. 2.2%, P = 0.44), as well as significantly decreased 30-day mortality (0% vs. 5.6%, P = 0.01), reintervention (19.2% vs. 26.8%, P = 0.02), and return to the operating room (6.8% vs. 12.7%, P = 0.02). Of the 19 patients that had SA + CSFD, there were no signs and symptoms of spinal cord ischemia and decreased incidence of perioperative complications (0% vs. 33.3%, P = 0.01). There was no difference in the risk for intraoperative complications, neurologic complications, or 30-day mortality between GA + CSFD patients versus SA + CSFD patients. Age >75 (P = 0.002), intraoperative complications (P < 0.001), and perioperative complications (P = 0.02) were associated with increased mortality after thoracic endograft placement per multivariate logistic regression analysis. CONCLUSIONS: Spinal anesthesia (SA) in select high-risk patients was associated with reduced 30-day mortality, neurologic complications, and LOS compared to GA. The concurrent use of spinal drainage and SA had satisfactory results compared to spinal drainage and GA.

Body Mass Index Impacts Indication But Not Outcomes of Thoracic Endovascular Aortic Repair.

BACKGROUND: There are limited studies looking at thoracic endovascular aortic repair (TEVAR) outcomes in obese and overweight patients. Our objective was to determine the rate of complications, reintervention, and short-term mortality in normal weight, overweight, and obese patients undergoing TEVAR. METHODS: Patients undergoing TEVAR at a large tertiary hospital from October 2007 to January 2020 were analyzed. Patients were stratified into 3 cohorts based on body mass index (BMI): normal (18.5-25 kg/m2), overweight (25-30 kg/m2), and obese (>30 kg/m2). Primary outcomes were 30-day and 1-year survival. Intraoperative, in-hospital, and postdischarge complications were assessed as secondary outcomes using the Clavian-Dindo classification system. In addition, reinterventions associated with the index TEVAR procedure as a secondary outcome. RESULTS: Among 204 patients fitting the study criteria, we identified 65 with normal BMI, 78 overweight, and 61 obese patients. Obese patients were younger than the overweight and normal BMI patients (mean age 62.2 vs. 66.7 vs. 70.7, respectively, P = 0.003). In terms of TEVAR indication, the obese cohort had the highest percentage of patients with type B aortic dissection (36.4%), while the normal BMI cohort had the higher proportion of patients undergoing TEVAR for isolated thoracic aortic aneurysm (63.9%). Intraoperative complications did not significantly differ between cohorts. Postoperatively, in-hospital complications, postdischarge complications and 30-day return to the operative room did not differ significantly between study cohorts. Odds of reintervention did not differ significantly between cohorts, both on univariate and multivariate analysis. Log-rank test of Kaplan Meier analysis revealed no difference in reintervention-free survival (P = 0.22). Thirty-day mortality and 1-year overall survival were similar across cohorts. Both univariate and multivariate logarithmic regression revealed no difference in likelihood of 30-day mortality between the obese and normal cohort. CONCLUSIONS: There were no measurable differences in complications, reinterventions, or mortality, suggesting that vascular surgeons can perform TEVAR across a spectrum of BMI without compromising outcomes.

The Venous Thrombectomy Armamentarium: An Expanding World.

Acute deep venous thrombosis (DVT) is a common and important public health problem. It affects more than 350,000 people in the United States annually and has a substantial economic impact. Without adequate treatment, there is significant risk of development of post-thrombotic syndrome (PTS) resulting in patient morbidity, worse quality of life, and costly long-term medical care. Over the past decade, the treatment algorithm for patients with acute DVT has significantly changed. Prior to 2008, the treatment recommendation for patients with acute DVT was limited to anticoagulation and conservative management. In 2008, national clinical practice guidelines were updated to include interventional strategies such as surgical- and catheter-based techniques for the treatment of acute DVT. Early strategies for debulking of extensive acute DVT primarily consisted of open surgical thrombectomy and administration of thrombolytics. In the intervening period, a plethora of advanced endovascular techniques and technologies have been developed which reduced the morbidity of operative intervention and risks of hemorrhage associated with thrombolysis. This review will focus on the novel technologies commercially available for management of acute DVT, denoting unique features inherent to each device. This expanded armamentarium gives vascular surgeons and proceduralists the opportunity to individualize their treatment approach to the specific patient's anatomy, lesion, and history.

Resilience, endogenous policy responses to COVID-19, and their impacts on farm performance.

Policy measures aimed at containing the spread of the COVID-19 pandemic had unintended consequences on economic activities globally. In this study, we isolate and investigate the short-term partial impacts of six such measures on the farm and nonfarm incomes of agricultural households and examine the related resilience factors. Using Nigeria as a case study, we find that the COVID containment measures had mixed effects on farm and non-farm incomes in the short run. These varying effects are due to households' resilience and vulnerability factors, including land size, wealth, income diversification, involvement in processing activities, and reliance on hired labor. Our findings highlight the need for more targeted health crisis containment measures which consider the uniqueness, diversity, and regional heterogeneity of agriculture, especially the potential implications for farm viability.

Higher surgeon volume is associated with lower odds of complication following thoracic endovascular aortic repair for aortic dissections.

OBJECTIVE: This study aimed to understand the impact of surgeon volume on outcomes of thoracic endovascular aortic repair (TEVAR) in patients being treated for aortic dissection. METHODS: Patients undergoing TEVAR from January 2014 to March 2021 in the Vascular Quality Initiative database were analyzed. Patients with aortic dissection who underwent TEVAR were divided into quartiles based on the annual TEVAR volume of their vascular surgeon. The highest quartile, middle two quartiles, and lowest quartile were deemed high volume (HV), moderate volume (MV), and low volume (LV), respectively. Multivariable logistic regressions were performed to compare cohort outcomes in terms any postoperative complication, stroke, spinal cord ischemia, reintervention, and 30-day mortality. A Cox proportional hazard model was used to assess the hazard of overall postoperative mortality. RESULTS: Among 1217 patients undergoing TEVAR, 321, 621, and 275 were performed by HV, MV, and LV surgeons, respectively. HV surgeons performed >19 annual TEVARs, MV surgeons between five and 18, and LV surgeons four or less. Adjusted odds of any postoperative complication revealed that HV and MV surgeons had lower odds of overall postoperative complications (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.30-0.85; P = .011 and OR, 0.60; 95% CI, 0.38-0.87; P = .008, respectively) when compared with patients of LV surgeons. Patients of HV surgeons had lower odds of respiratory complications than those of LV surgeons (OR, 0.42; 95% CI, 0.17-0.93; P = .039). Adjusted analysis of outcomes including spinal cord ischemia, stroke, myocardial infarction, 30-day mortality, and overall mortality did not reveal statistically significant differences between cohorts. CONCLUSIONS: Surgeon volume does not to impact 30-day mortality or long-term mortality after TEVAR for aortic dissection, but the odds of overall postoperative complications were lower for HV and MV surgeons when compared with LV surgeons.

The Feasibility and Applicability of Percutaneous Deep Vein Arterialization in Peripheral Artery Disease.

Peripheral artery disease (PAD) can often present with chronic limb threatening ischemia (CLTI), including ischemic rest pain and severe tissue loss. Progression of PAD can lead to "no option" or end-stage disease in which there are no traditional open or endovascular interventions available for revascularization. This cohort of patients have a poor prognosis, with a major amputation rate of 40% and mortality of up to 20% at six months. For this patient population, surgical deep vein arterialization (DVA) is offered as an attempt to provide blood flow to the distal preserved venous bed and reverse the ischemic process. Surgical DVA has traditionally been offered as an option and was pioneered by Herb Dardik. The evolution of endovascular technology has allowed for percutaneous DVA (pDVA). Using ultrasound and fluoroscopic guidance, an arteriovenous channel is created between a tibial artery and vein and reinforced with covered stent grafts to increase distal limb perfusion with the goals of improving wound healing and amputation-free survival. Lysis of venous valves with a valvulotome also aids with reversal of flow into the distal venous system. Investigations of percutaneous deep vein arterialization are underway with one device, the LimFlow System (LimFlow SA, Paris, France), which is undergoing feasibility trials. Here we present the current clinical indications, feasibility, results, and our institutional experience with the use of percutaneous deep vein arterialization.

Large-bore Aspiration Thrombectomy for Acute Venous Thromboembolism.

Pulmonary embolism can occur following dislodgement of deep venous thrombosis into the pulmonary artery circulation, which results in obstruction of the pulmonary artery system and can be fatal. The consequences of pulmonary embolism include hypotension, right heart strain, and hypoxia. In the long term, pulmonary embolism may lead to Chronic Thromboembolic Pulmonary Hypertension (CTEPH). Patients who develop hypotensive massive and submassive pulmonary embolism can be treated with large-bore aspiration thrombectomy. In the acute setting, this improves short-term outcomes by decreasing the ICU stay. It can also reduce the risk of CTEPH. Options for large-bore aspiration thrombectomy include the FlowTriever™ system (Inari Medical, Irvine, CA) and the Lightning 12 vascular thrombectomy system (Penumbra Inc., Alameda, CA). This review discusses the pathophysiology of pulmonary embolism, management, and options for large-bore aspiration thrombectomy.

Transcarotid Artery Revascularization and Advances in Vascular Surgery for Carotid Artery Disease.

Carotid artery atherosclerotic disease impacts over 2 million Americans annually. Since the advent of the carotid endarterectomy by Debakey in 1953, the surgical management of carotid artery stenosis has prevented cerebrovascular accidents. The technology utilized to manage carotid artery stenosis continued to evolve with the utilization of carotid artery stenting in 1989 and more recently transcarotid artery revascularization (TCAR). This review discusses the modern management of carotid artery stenosis with an emphasis on transcarotid artery revascularization (TCAR) and reversal of flow for reversal of flow for embolic protection.

Intravascular Lithotripsy in the Treatment of Lower Extremity Peripheral Arterial Disease.

Endovascular intervention has become first-line treatment for the majority of atherosclerotic lesions associated with peripheral artery disease. Traditionally, treatment modalities have included various types of balloon angioplasty and stenting. However, recent technological advancements have introduced the concept of endovascular lithotripsy as a novel alternative to angioplasty and stenting. This new addition to the armamentarium of surgeons and interventionalists has the potential to alter the treatment paradigm for patients with complex peripheral artery disease.

Deep Profiling of Cellular Heterogeneity by Emerging Single-Cell Proteomic Technologies.

The ability to comprehensively profile cellular heterogeneity in functional proteome is crucial in advancing the understanding of cell behavior, organism development, and disease mechanisms. Conventional bulk measurement by averaging the biological responses across a population often loses the information of cellular variations. Single-cell proteomic technologies are becoming increasingly important to understand and discern cellular heterogeneity. The well-established methods for single-cell protein analysis based on flow cytometry and fluorescence microscopy are limited by the low multiplexing ability owing to the spectra overlap of fluorophores for labeling antibodies. Recent advances in mass spectrometry (MS), microchip, and reiterative staining-based techniques for single-cell proteomics have enabled the evaluation of cellular heterogeneity with high throughput, increased multiplexity, and improved sensitivity. In this review, the principles, developments, advantages, and limitations of these advanced technologies in analysis of single-cell proteins, along with their biological applications to study cellular heterogeneity, are described. At last, the remaining challenges, possible strategies, and future opportunities that will facilitate the improvement and broad applications of single-cell proteomic technologies in cell biology and medical research are discussed.

Unexplained systemic inflammatory response following ileostomy closure after ileal pouch-anal anastomosis: a deeper dive into a rare entity.

AIM: The purpose of this study is to shed light on a rare complication following ileostomy closure after 3-stage IPAA for further study and discussion. METHODS: Our department IPAA database was queried for all patients who underwent 3-stage IPAA creation from 2011 through 2018. Data was reviewed and analyzed using the SPSS application. Chi-square test and Fisher's exact test were used for categorical variables. t test or ANOVA was used for continuous variables. Significance was set at p < 0.05. RESULTS: Three hundred seventy-eight charts were queried. Sixty-eight complications (18.0%) were identified after ileostomy closure. Thirty-seven were small bowel obstruction or partial small bowel obstruction (SBO or pSBO, 9.79%), 5 cases of leak from ileoileostomy anastomosis (7.4%), and 4 cases of leak from pouch (5.9%). There was no significant difference in time between restorative proctocolectomy with IPAA and loop ileostomy closure with cases where a complication occurred and where one did not (p = 0.28). Eight patients developed a SIRS response in the first 5 days after surgery without an identified intraabdominal source after extensive work-up. Of these patients, 87.5% also had negative re-explorations (both open and laparoscopic). None required re-diversion, and all recovered well. CONCLUSIONS: While SBO remains the most common complication following ileostomy closure, a surprisingly large number of presents present with a SIRS response with no identifiable source. All of these patients recovered with supportive care, and none required further intervention or diversion. This is a poorly understood phenomenon which is unique to ileostomy closure after IPAA, and further study is required.

Surgical Techniques and Differences in Postoperative Outcomes for Patients With Crohn's Disease With Ileosigmoid Fistulas: A Single-Institution Experience, 2010-2016.

BACKGROUND: Surgical treatment of ileosigmoid fistulas in Crohn's disease is poorly characterized. OBJECTIVE: The purpose of this study was to identify differences in patient postoperative outcomes for isolated ileosigmoid fistulas by surgical approach (laparoscopic versus open) and sigmoid colon repair type (sigmoid resection versus primary repair). DESIGN: Using a prospectively collected database, we gathered perioperative data from chart reviews to calculate differences and associations between treatment groups. SETTINGS: The study was conducted at a single tertiary care center. PATIENTS: Patients with Crohn's disease who underwent surgery for isolated ileosigmoid fistulas between July 1, 2010, and June 30, 2016 were included. RESULTS: We identified 84 patients, with an average age of 37 years. A total of 51 were men and 33 were women; 34 underwent a sigmoid resection, whereas 50 had a primary repair of the sigmoid. All of the patients underwent an ileocolic resection. A total of 67 surgeries were initially attempted laparoscopically, of which 17 (25.4%) were converted to open, with 50 (59.5%) completed laparoscopically. There were no significant differences in length of stay or incidence of postoperative complications by surgical approach (laparoscopic versus open). For patients who underwent a primary sigmoid repair versus a sigmoid resection, there were no significant differences in postoperative complications, but there was a significant difference in the length of stay (6.36 vs 9.56 d for primary repair versus resection; multivariate p value of 0.022). MAIN OUTCOME MEASURES: Postoperative complications and length of stay were measured. LIMITATIONS: The study was limited by its small sample size, cross-sectional nature of the data, and limited information about preoperative outpatient medical treatment. CONCLUSIONS: Laparoscopic surgery for isolated ileosigmoid fistulas in Crohn's disease is safe and does not result in a different length of stay or incidence of postoperative complications. Primary repair (rather than resection) of the sigmoid colon in these cases, when feasible, appears to be safe and is likely to be cost-effective given the reduced length of stay. See Video Abstract at http://links.lww.com/DCR/A993. TÉCNICAS QUIRÚRGICAS Y DIFERENCIAS EN LOS RESULTADOS POSTOPERATORIOS PARA LOS PACIENTES CON ENFERMEDAD DE CROHN CON FÍSTULAS ILEO-SIGMOIDEAS: UNA EXPERIENCIA EN UNA SOLA INSTITUCIÓN, 2010-2016: El tratamiento quirúrgico de las fístulas ileo-sigmoideas en la enfermedad de Crohn está mal caracterizado. OBJETIVO: Identificar las diferencias en los resultados postoperatorios de los pacientes para las fístulas ileo-sigmoideas aisladas por abordaje quirúrgico (laparoscópica versus abierta) y tipo de reparación de colon sigmoide (resección sigmoidea versus reparación primaria). DISEÑO:: Utilizando una base de datos recopilada de forma prospectiva, se recopilaron datos perioperatorios de las revisiones de los gráficos para calcular las diferencias y las asociaciones entre los grupos de tratamiento. AJUSTE: Un solo centro de atención terciaria. PACIENTES: Pacientes con enfermedad de Crohn que se sometieron a una cirugía para fístulas ileo-sigmoideas aisladas entre el 1 de julio de 2010 y el 30 de junio de 2016. RESULTADOS: Se identificaron 84 pacientes, con una edad promedio de 37 años. Un total de 51 eran hombres y 33 mujeres; 34 se sometieron a una resección sigmoidea, mientras que 50 tuvieron una reparación primaria del sigmoide. Todos los pacientes fueron sometidos a resección ileocólica. Inicialmente, un total de 67 círugias se intentaron por vía laparoscópica, de las cuales 17 (25,4%) se convirtieron en cirugías abiertas, y 50 (59,5%) se completaron por vía laparoscópica. No hubo diferencias significativas en la duración de la estancia o la incidencia de complicaciones postoperatorias por abordaje quirúrgico (laparoscópica versus abierta). Para los pacientes que se sometieron a una reparación sigmoidea primaria versus una resección sigmoidea, no hubo diferencias significativas en las complicaciones postoperatorias, pero sí hubo una diferencia significativa en la duración de la estancia hospitalaria (6,36 versus a 9,56 días para la reparación primaria frente a la resección; p multivariable -valor de 0.022). PRINCIPALES MEDIDAS DE RESULTADOS: Complicaciones postoperatorias y duración de la estancia. LIMITACIONES: Tamaño de muestra pequeño, naturaleza transversal de los datos e información limitada sobre el tratamiento médico ambulatorio preoperatorio del paciente. CONCLUSIONES: La cirugía laparoscópica para fístulas ileo-sigmoideas aisladas en la enfermedad de Crohn es segura y no ocasiona una duración diferente de la estancia hospitalaria ni una incidencia diferente de complicaciones postoperatorias. La reparación primaria (en lugar de la resección) del colon sigmoide en estos casos, cuando es posible, parece ser segura y es probable que sea rentable, dada la duración reducida de la estancia. Vea el Resumen del Video en http://links.lww.com/DCR/A993.

Machine Learning for Characterization of Insect Vector Feeding.

Insects that feed by ingesting plant and animal fluids cause devastating damage to humans, livestock, and agriculture worldwide, primarily by transmitting pathogens of plants and animals. The feeding processes required for successful pathogen transmission by sucking insects can be recorded by monitoring voltage changes across an insect-food source feeding circuit. The output from such monitoring has traditionally been examined manually, a slow and onerous process. We taught a computer program to automatically classify previously described insect feeding patterns involved in transmission of the pathogen causing citrus greening disease. We also show how such analysis contributes to discovery of previously unrecognized feeding states and can be used to characterize plant resistance mechanisms. This advance greatly reduces the time and effort required to analyze insect feeding, and should facilitate developing, screening, and testing of novel intervention strategies to disrupt pathogen transmission affecting agriculture, livestock and human health.

High temperature ferroelectric behaviour in α-MnO2 nanorods realised through enriched oxygen vacancy induced non-stoichiometry.

Nanostructuring followed by incorporation of defect induced non-stoichiometry is an emerging field of prominence due to its capacity to introduce unprecedented properties in materials with potential applications. In this work, crystalline α-MnO2 nanorods are synthesised using a facile co-precipitation method to exhibit ferroelectric behaviour for the first time. The evolution mechanism of the nanorods is investigated using XRD, HRTEM and FTIR spectra, while their thermal stability is probed using TGA/DTA. The novel properties observed are the result of structural rearrangements sparked by electrons in mixed valence cations (Mn3+/Mn4+). The high density of Jahn-Teller active Mn3+ cations breaks the inversion symmetry in α-MnO2, thereby altering the atomic environment inducing distortion in the basic MnO6 octahedra. Since variable temperature XRD analysis confirms the phase stability of the crystal structure up to very high temperatures, the ferroelectric phase exhibited by the material below Tc is an outcome of the combined effects of orbital ordering (OO) of the eg electron in Mn3+ and charge ordering (CO) of Mn3+ and Mn4+ cations. This is confirmed by DSC analysis. The breakdown of the ferroelectric nature is identified to originate as a result of octahedral tilting as suggested by temperature-dependent Raman studies. Magnetic and electrical transport studies provide additional evidence of a CO ferroelectric phase as they predict the existence of double-exchange hopping conduction and surface ferromagnetism in the sample.

The Fungus Raffaelea lauricola Modifies Behavior of Its Symbiont and Vector, the Redbay Ambrosia Beetle (Xyleborus Glabratus), by Altering Host Plant Volatile Production.

The redbay ambrosia beetle Xyleborus glabratus is the vector of the symbiotic fungus, Raffaelea lauricola that causes laurel wilt, a highly lethal disease to members of the Lauraceae family. Pioneer X. glabratus beetles infect live trees with R. lauricola, and only when tree health starts declining more X. glabratus are attracted to the infected tree. Until now this sequence of events was not well understood. In this study, we investigated the temporal patterns of host volatiles and phytohormone production and vector attraction in relation to laurel wilt symptomology. Following inoculations with R. lauricola, volatile collections and behavioral tests were performed at different time points. Three days after infection (DAI), we found significant repellency of X. glabratus by leaf odors of infected swamp bay Persea palustris as compared with controls. However, at 10 and 20 DAI, X. glabratus were more attracted to leaf odors from infected than non-infected host plants. GC-MS analysis revealed an increase in methyl salicylate (MeSA) 3 DAI, whereas an increase of sesquiterpenes and leaf aldehydes was observed 10 and 20 DAI in leaf volatiles. MeSA was the only behaviorally active repellent of X. glabratus in laboratory bioassays. In contrast, X. glabratus did not prefer infected wood over healthy wood, and there was no associated significant difference in their volatile profiles. Analyses of phytohormone profiles revealed an initial increase in the amount of salicylic acid (SA) in leaf tissues following fungal infection, suggesting that the SA pathway was activated by R. lauricola infection, and this activation caused increased release of MeSA. Overall, our findings provide a better understanding of X. glabratus ecology and underline chemical interactions with its symbiotic fungus. Our work also demonstrates how the laurel wilt pathosystem alters host defenses to impact vector behavior and suggests manipulation of host odor by the fungus that attract more vectors.

Assay of Genome-Wide Transcriptome and Secreted Proteins on the Same Single Immune Cells by Microfluidics and RNA Sequencing.

Given vast heterogeneity of immune cells, searching for gene expression and transcriptional networks belonging to specific cellular functions such as cytokine production has been challenging. To overcome this limitation, we developed a splittable single-cell microchip that integrates a high-density antibody array for cytokine protein detection, while the same single cells with protein profiles can be subsequently sequenced to obtain the genome-wide transcriptome. Combined with bioinformatics algorithms, we discovered a subgroup of highly coexpressed genes correlating with TNFα secretion in mouse macrophage cells. This technology and the data analysis may lead to an unprecedented understanding of regulation mechanisms of the immune system and have the potential to impact disease treatment and drug discovery.

Microparticles: Facile and High-Throughput Synthesis of Functional Microparticles with Quick Response Codes (Small 24/2016).

Microparticles carrying quick response (QR) barcodes are fabricated by J. Wang and co-workers on page 3259, using a massive coding of dissociated elements (MiCODE) technology. Each microparticle can bear a special custom-designed QR code that enables encryption or tagging with unlimited multiplexity, and the QR code can be easily read by cellphone applications. The utility of MiCODE particles in multiplexed DNA detection and microtagging for anti-counterfeiting is explored.

Facile and High-Throughput Synthesis of Functional Microparticles with Quick Response Codes.

Encoded microparticles are high demand in multiplexed assays and labeling. However, the current methods for the synthesis and coding of microparticles either lack robustness and reliability, or possess limited coding capacity. Here, a massive coding of dissociated elements (MiCODE) technology based on innovation of a chemically reactive off-stoichimetry thiol-allyl photocurable polymer and standard lithography to produce a large number of quick response (QR) code microparticles is introduced. The coding process is performed by photobleaching the QR code patterns on microparticles when fluorophores are incorporated into the prepolymer formulation. The fabricated encoded microparticles can be released from a substrate without changing their features. Excess thiol functionality on the microparticle surface allows for grafting of amine groups and further DNA probes. A multiplexed assay is demonstrated using the DNA-grafted QR code microparticles. The MiCODE technology is further characterized by showing the incorporation of BODIPY-maleimide (BDP-M) and Nile Red fluorophores for coding and the use of microcontact printing for immobilizing DNA probes on microparticle surfaces. This versatile technology leverages mature lithography facilities for fabrication and thus is amenable to scale-up in the future, with potential applications in bioassays and in labeling consumer products.

Formic and Acetic Acids in Degradation Products of Plant Volatiles Elicit Olfactory and Behavioral Responses from an Insect Vector.

Volatile phytochemicals play a role in orientation by phytophagous insects. We studied antennal and behavioral responses of the Asian citrus psyllid, Diaphorina citri, vector of the citrus greening disease pathogen. Little or no response to citrus leaf volatiles was detected by electroantennography. Glass cartridges prepared with ß-ocimene or citral produced no response initially but became stimulatory after several days. Both compounds degraded completely in air to a number of smaller molecules. Two peaks elicited large antennal responses and were identified as acetic and formic acids. Probing by D. citri of a wax substrate containing odorants was significantly increased by a blend of formic and acetic acids compared with either compound separately or blends containing ß-ocimene and/or citral. Response surface modeling based on a 4-component mixture design and a 2-component mixture-amount design predicted an optimal probing response on wax substrate containing a blend of formic and acetic acids. Our study suggests that formic and acetic acids play a role in host selection by D. citri and perhaps by phytophagous insects in general even when parent compounds from which they are derived are not active. These results have implications for the investigation of arthropod olfaction and may lead to elaboration of attract-and-kill formulations to reduce nontarget effects of chemical control in agriculture.