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Autti S, Bettsworth FC, Grigoras K, Gunnarsson D, Haley RP, Jones AT, Pashkin YA, Prance JR, Prunnila M, Thompson MD, Zmeev DE. Thermal Transport in Nanoelectronic Devices Cooled by On-Chip Magnetic Refrigeration. PHYSICAL REVIEW LETTERS 2023; 131:077001. [PMID: 37656858 DOI: 10.1103/physrevlett.131.077001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/22/2022] [Accepted: 07/12/2023] [Indexed: 09/03/2023]
Abstract
On-chip demagnetization refrigeration has recently emerged as a powerful tool for reaching microkelvin electron temperatures in nanoscale structures. The relative importance of cooling on-chip and off-chip components and the thermal subsystem dynamics are yet to be analyzed. We study a Coulomb blockade thermometer with on-chip copper refrigerant both experimentally and numerically, showing that dynamics in this device are captured by a first-principles model. Our work shows how to simulate thermal dynamics in devices down to microkelvin temperatures, and outlines a recipe for a low-investment platform for quantum technologies and fundamental nanoscience in this novel temperature range.
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Broome JM, Coonan EE, Jones AT, Zelhart MD. Combined Endoscopic Robotic Surgery for Complex Colon Polyps. Dis Colon Rectum 2023; 66:1132-1136. [PMID: 36876961 DOI: 10.1097/dcr.0000000000002689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
Abstract
BACKGROUND Combined endoscopic robotic surgery is a surgical technique that modifies traditional endoscopic laparoscopic surgery with robotic assistance to aid in the removal of complex colonic polyps. This technique has been described in the literature but lacks patient follow-up data. OBJECTIVE This study aimed to evaluate the safety and outcomes of combined endoscopic robotic surgery. DESIGN A retrospective review of a prospective database. SETTING East Jefferson General Hospital, Metairie, Louisiana. PATIENTS Ninety-three consecutive patients who underwent combined endoscopic robotic surgery from March 2018 to October 2021 were included in the study. MAIN OUTCOME MEASURES Operative time, intraoperative complication, 30-day postoperative complication, hospital length of stay, and follow-up pathology report results were the main outcome measures. RESULTS Combined endoscopic robotic surgery was completed in 88 of 93 participants (95%). Among the 88 participants who completed combined endoscopic robotic surgery, the average age was 66 years (SD = 10), BMI was 28.8 kg/m 2 (SD = 6), and history of previous abdominal surgeries was 1 (SD = 1). Median operative time was 72 minutes (range, 31-184 minutes) and polyp size was 40 mm (range, 5-180 mm). The most common polyp locations were the cecum, ascending colon, and transverse colon (31%, 28%, 25%). Pathology mainly demonstrated tubular adenoma (76%). Data on 40 patients who underwent follow-up colonoscopy were available. The average follow-up time was 7 months (range, 3-22 months). One patient (2.5%) had polyp recurrence at the resection site. LIMITATIONS Limitations for our study include a lack of randomization and follow-up rate to assess for recurrence. The low compliance rate may be due to procedure cancelations/difficulty scheduling because of changing coronavirus disease 2019 guidelines. CONCLUSIONS Compared to literature-reported statistics for its laparoscopic counterpart, combined endoscopic robotic surgery was associated with decreased operation times and resection site polyp recurrence. See Video Abstract at http://links.lww.com/DCR/C208 . CIRUGA ROBTICA ENDOSCPICA COMBINADA PARA PLIPOS DE COLON COMPLEJOS ANTECEDENTES:La cirugía robótica endoscópica combinada es una técnica quirúrgica que modifica la cirugía laparoscópica endoscópica tradicional con asistencia robótica para ayudar en la extracción de pólipos colónicos complejos. Esta técnica está previamente descrita en la literatura, pero carece de datos de seguimiento de los pacientes.OBJETIVO:Evaluar la seguridad y los resultados de la cirugía robótica endoscópica combinada.DISEÑO:Revisión retrospectiva de una base de datos prospectiva.AJUSTE:Hospital General East Jefferson, Metairie LouisianaPACIENTES:Noventa y tres pacientes consecutivos y sometidos a cirugía robótica endoscópica combinada por un solo cirujano colorrectal desde marzo de 2018 hasta octubre de 2021.PRINCIPALES MEDIDAS DE RESULTADO:Tiempo operatorio, complicación intraoperatoria, complicación posoperatoria a los 30 días, duración de la estancia hospitalaria y resultados del informe patológico de seguimiento.RESULTADOS:La cirugía robótica endoscópica combinada se completó en 88 de 93 (95%). Entre los 88 participantes que completaron la cirugía robótica endoscópica combinada, la edad promedio fue de 66 años (desviación estándar = 10), índice de masa corporal de 28,8 (desviación estándar = 6) y el historial de cirugías abdominales previas de 1 (desviación estándar = 1). La mediana del tiempo operatorio y el tamaño de los pólipos fueron 72 minutos (rango 31-184 minutos) y 40 milímetros (rango 5-180 milímetros), respectivamente. Las ubicaciones de pólipos más comunes fueron el ciego, colon ascendente y transverso (31%, 28%, 25%). La patología demostró principalmente adenoma tubular (76%). Los datos de 40 pacientes sometidos a una colonoscopia de seguimiento estaban disponibles. El tiempo medio de seguimiento fue de 7 meses (rango 3-22 meses). Un paciente (2,5%) presentó recurrencia polipoidea en el sitio de resección.LIMITACIONES:Las limitaciones de nuestro estudio incluyeron la falta de aleatorización y la tasa de seguimiento para evaluar la recurrencia. La baja tasa de seguimiento puede deberse a la renuencia del paciente en hacerse una colonoscopia o cancelaciones de procedimientos por la dificultad para programar debido a cambios de COVID-19.CONCLUSIÓN:En comparación con las estadísticas reportadas en la literatura para su contraparte laparoscópica, la cirugía robótica endoscópica combinada se asoció con reducción en tiempos de operación y recurrencia de pólipos en el sitio de resección. Consulte Video Resumen en http://links.lww.com/DCR/C208 . (Traducción - Dr. Fidel Ruiz Healy ).
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Jones AT, Moreno-Walton L, Sossamon SD, Tahmeena F, Tran T, Briones C, Stevens R, Isaacson K, He H, Rhodes S, Percak J, Kissinger PJ. Delays in fibrosis staging reduce the likelihood of achieving hepatitis C treatment and cure. Infect Dis (Lond) 2023; 55:309-315. [PMID: 36853886 PMCID: PMC10284034 DOI: 10.1080/23744235.2023.2178670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 01/30/2023] [Accepted: 02/05/2023] [Indexed: 03/01/2023] Open
Abstract
BACKGROUND Updated 2021 hepatitis C virus (HCV) treatment guidelines no longer recommend fibrosis staging for treatment-naïve patients without cirrhosis; however, numerous US state Medicaid plans continue to restrict initiation of HCV therapy by fibrosis stage. The study objective was to determine whether delays from HCV diagnosis to fibrosis staging impact the likelihood of initiating/completing HCV treatment and achieving sustained virologic response (SVR). METHODS A retrospective cohort study was performed among patients diagnosed with chronic HCV by an urban US emergency department who subsequently underwent fibrosis staging. Time elapsed from HCV diagnosis to hepatic fibrosis staging was evaluated on the likelihood of treatment initiation, treatment completion and SVR. RESULTS Among fibrosis staging modalities, hepatic ultrasounds occurred more quickly following HCV diagnosis (3.5 months, IQR = 12.4 months), compared to FibroSure (8.5 months, IQR = 20.4 months) and FibroScan (9.9 months, IQR = 18.0 months) (p<.001). Each six-month delay in fibrosis staging decreased the likelihood of initiating treatment by 5% (adjusted relative risk (aRR)=0.95; 95% confidence interval (CI)=0.91-0.998; p=.04) and the likelihood of SVR by 7% (aRR = 0.93; 95% CI = 0.87-0.995; p=.04) after adjusting for insurance, race/ethnicity and history of HIV testing. CONCLUSIONS Delays in hepatitis fibrosis staging were significantly associated with decreased likelihood of HCV treatment initiation and SVR.
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Jones AT, Briones C, Tran T, Moreno-Walton L, Kissinger PJ. Closing the hepatitis C treatment gap: United States strategies to improve retention in care. J Viral Hepat 2022; 29:588-595. [PMID: 35545901 PMCID: PMC9276641 DOI: 10.1111/jvh.13685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 03/10/2022] [Accepted: 04/05/2022] [Indexed: 12/09/2022]
Abstract
The hepatitis C virus (HCV) treatment landscape is shifting given the advent of direct-acting antivirals and a global call to action by the World Health Organization. Eliminating HCV is now an issue of healthcare delivery. Treatment is limited by the complexity of the HCV care continuum, expensive therapy and competing health burdens experienced by an underserved HCV population. The objective of this literature review was to assess strategies to improve retention in HCV care, with particular focus on those implemented in the United States. We identified barriers in HCV care retention and propose solutions to increase HCV treatment delivery. The following recommendations are herein described: improving the cohesion of health services through localized care and integrated case management, expanding the supply of non-specialist HCV treatment providers, leveraging patient navigators and care coordinators, improving adherence through directly observed therapy and reducing cost barriers through value-based payment and pharmaceutical subscription models.
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Lawson CR, Jones AT, Kockelmann W, Horney SJ, Kirichek O. Neutron imaging of an operational dilution refrigerator. Sci Rep 2022; 12:1130. [PMID: 35064155 PMCID: PMC8783010 DOI: 10.1038/s41598-022-05025-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 01/04/2022] [Indexed: 11/12/2022] Open
Abstract
The invention of the 3He/4He dilution refrigerator opened a new chapter in experimental ultra-low temperature physics. Dilution refrigerators became essential for providing ultra-low temperature environments for nuclear demagnetisation experiments, superconducting-qubit quantum processors and highly sensitive bolometers used in fundamental physics experiments. Development of dilution refrigeration technology requires thorough understanding of the quantum mechanical processes that take place in liquid helium at ultra-low temperatures. For decades the quantum fluids research community provided valuable information to engineers and designers involved in the development of advanced dilution refrigerators. However, the lack of methods that allow the measurement of physical parameters of liquid helium during the operation of a dilution refrigerator was hindering development of the technology. Here we show direct imaging of an operational dilution refrigerator using neutron radiography. This allows direct observation of the dilution process in 3He/4He mixtures and opens an opportunity for direct measurement of the 3He concentration. We observe the refrigerator behaviour in different regimes, such as continuous circulation and single shot, and show that our method allows investigation of various failure modes. Our results demonstrate that neutron imaging applied to the study of dilution refrigeration processes can provide essential information for developers of ultra-low temperature systems. We expect that neutron imaging will become instrumental in the research and development of advanced dilution refrigerators.
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Cironi KA, Jones AT, Hauser EM, Olsen JW, Kissinger PJ. Human Immunodeficiency Virus and Hepatitis C Linkage-to-Care Initiative for New Orleans Residents Experiencing Homelessness During the COVID-19 Pandemic. Sex Transm Dis 2021; 48:595-600. [PMID: 34030154 DOI: 10.1097/olq.0000000000001484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND People experiencing homelessness are disproportionately infected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV). In response to COVID-19, cities nationwide temporarily housed people experiencing homelessness in unused hotels. One such initiative in New Orleans also enacted a screening, counseling, and linkage-to-care model for HIV and HCV treatment for this temporarily housed population between May and July 2020. METHODS A nonconcurrent cohort study was performed assessing follow up in the treatment of HIV and HCV for this population. Outcome data were collected on seropositive patients' electronic medical record to assess patient progression through the treatment cascade. RESULTS Of 102 unhoused residents, 25 (24.5%) tested HCV seropositive. Of the HCV positive 21/25 (84%) were connected to the associated clinic for follow up care and 10 (40%) obtained HCV treatment medication. Furthermore, all 3 patients who tested seropositive for HIV either started or re-initiated antiviral treatment. The greatest barrier to providing medication for the HCV seropositive patients, once care was initiated, was loss-to-follow-up. CONCLUSIONS Targeting homeless persons living in temporary residences for HCV and HIV screening can be effective at promoting access to care for those infected due to this population's high HCV seropositivity especially significant if the patient has a history of intravenous drug use or is older than 40 years. However, continued outreach strategies are needed to assist patients in retention of care.
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Van Gerwen OT, Craig-Kuhn MC, Jones AT, Schroeder JA, Deaver J, Buekens P, Kissinger PJ, Muzny CA. Trichomoniasis and adverse birth outcomes: a systematic review and meta-analysis. BJOG 2021; 128:1907-1915. [PMID: 34036690 DOI: 10.1111/1471-0528.16774] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2021] [Indexed: 01/11/2023]
Abstract
BACKGROUND Trichomoniasis commonly affects women of childbearing age and has been linked to several adverse birth outcomes. OBJECTIVE To elucidate the association between trichomoniasis in pregnant women and adverse birth outcomes, including preterm delivery, prelabour rupture of membranes and low birthweight. SEARCH STRATEGY MEDLINE, EMBASE and ClinicalTrials.gov were systematically searched in December 2020 without time or language restrictions. SELECTION CRITERIA Original research studies were included if they assessed at least one of the specified adverse birth outcomes in pregnant women with laboratory-diagnosed trichomoniasis. DATA COLLECTION AND ANALYSIS Estimates from included articles were either extracted or calculated and then pooled to produce a combined estimate of the association of trichomoniasis with each adverse birth outcome using the random effects model. Heterogeneity was assessed using the I2 statistic and Cochran's Q test. MAIN RESULTS Literature search produced 1658 publications after removal of duplicates (n = 770), with five additional publications identified by hand search. After screening titles and abstracts for relevance, full text of 84 studies was reviewed and 19 met inclusion criteria for meta-analysis. Significant associations were found between trichomoniasis and preterm delivery (OR 1.27; 95% CI 1.08-1.50), prelabour rupture of membranes (OR 1.87; 95% CI 1.53-2.29) and low birthweight (OR 2.12; 95% CI 1.15-3.91). CONCLUSIONS Trichomoniasis in pregnant women is associated with preterm delivery, prelabour rupture of membranes and low birthweight. Rigorous studies are needed to determine the impact of universal trichomoniasis screening and treatment during pregnancy on reducing perinatal morbidity. TWEETABLE ABSTRACT This systematic review and meta-analysis found that in the setting of pregnancy, trichomoniasis is significantly associated with multiple adverse birth outcomes, including preterm delivery, low birthweight, and prelabour rupture of membranes.
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Jones AT, Craig-Kuhn MC, Schmidt N, Gomes G, Scott G, Watson S, Hines P, Davis J, Lederer AM, Martin DH, Kissinger PJ. Adapting Index/Partner Services for the Treatment of Chlamydia Among Young African American Men in a Community Screening Program. Sex Transm Dis 2021; 48:323-328. [PMID: 33137012 PMCID: PMC8043978 DOI: 10.1097/olq.0000000000001325] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Screening for asymptomatic Chlamydia trachomatis (Ct) among men has not been recommended because feasibility and efficacy are unknown. Check It is a seek-test-treat community-based Ct screening program for African American men who have sex with women and who are 15 to 24 years of age. This is an evaluation of adaptations made to the program aimed at improving index/partner notification and treatment rates. METHODS The original Check It intervention included free testing and treatment, contact tracing performed by a third party, expedited index therapy, and expedited partner therapy via pharmacy pickup. The intervention was adapted after a series of in-depth interviews eliciting information to refine the program. Changes included continuity of testing, notification, and treatment by the same staff; expanded hours; and patient-delivered partner therapy with a medication mail-delivery option. Rates of index male and partner treatment were compared using log-binomial models and generalized estimating equations. RESULTS Men in the adapted intervention (n = 85) were more likely than men in the original intervention (n = 99) to be contacted (relative risk [RR], 1.14; 95% confidence interval [CI], 1.02-1.27), make a treatment plan (RR, 1.14; 95% CI, 1.01-1.27), and complete treatment (RR, 1.45; 95% CI, 1.20-1.75). Female sexual partners were significantly more likely to complete treatment in postadaptation (n = 153) compared with preadaptation (n = 161; RR, 3.02; 95% CI, 1.81-5.05). CONCLUSIONS Compared with third-party notification and expedited index therapy/expedited partner therapy available by pharmacy pickup only, patient-delivered partner therapy with mail-delivery option, staff available at nontraditional hours, and staff continuity across testing, notification, and treatment significantly improved index and partner treatment completion.
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Millett GA, Jones AT, Benkeser D, Baral S, Mercer L, Beyrer C, Honermann B, Lankiewicz E, Mena L, Crowley JS, Sherwood J, Sullivan PS. Assessing differential impacts of COVID-19 on black communities. Ann Epidemiol 2020; 47:37-44. [PMID: 32419766 PMCID: PMC7224670 DOI: 10.1016/j.annepidem.2020.05.003] [Citation(s) in RCA: 759] [Impact Index Per Article: 189.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 05/07/2020] [Indexed: 12/18/2022]
Abstract
Purpose Given incomplete data reporting by race, we used data on COVID-19 cases and deaths in U.S. counties to describe racial disparities in COVID-19 disease and death and associated determinants. Methods Using publicly available data (accessed April 13, 2020), predictors of COVID-19 cases and deaths were compared between disproportionately (≥13%) black and all other (<13% black) counties. Rate ratios were calculated, and population attributable fractions were estimated using COVID-19 cases and deaths via zero-inflated negative binomial regression model. National maps with county-level data and an interactive scatterplot of COVID-19 cases were generated. Results Nearly 90% of disproportionately black counties (656/677) reported a case and 49% (330/677) reported a death versus 81% (1987/2465) and 28% (684/2465), respectively, for all other counties. Counties with higher proportions of black people have higher prevalence of comorbidities and greater air pollution. Counties with higher proportions of black residents had more COVID-19 diagnoses (Rate Ratio (RR): 1.24, 95% confidence interval: 1.17-1.33) and deaths (RR: 1.18, 95% confidence interval: 1.00-1.40), after adjusting for county-level characteristics such as age, poverty, comorbidities, and epidemic duration. COVID-19 deaths were higher in disproportionally black rural and small metro counties. The population attributable fraction of COVID-19 diagnosis due to lack of health insurance was 3.3% for counties with less than 13% black residents and 4.2% for counties with greater than or equal to 13% black residents. Conclusions Nearly 20% of U.S. counties are disproportionately black, and they accounted for 52% of COVID-19 diagnoses and 58% of COVID-19 deaths nationally. County-level comparisons can both inform COVID-19 responses and identify epidemic hot spots. Social conditions, structural racism, and other factors elevate risk for COVID-19 diagnoses and deaths in black communities.
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Millett GA, Jones AT, Benkeser D, Baral S, Mercer L, Beyrer C, Honermann B, Lankiewicz E, Mena L, Crowley JS, Sherwood J, Sullivan PS. Assessing differential impacts of COVID-19 on black communities. Ann Epidemiol 2020. [PMID: 32419766 DOI: 10.1016/j.annepidem.2020.05.00] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Abstract
PURPOSE Given incomplete data reporting by race, we used data on COVID-19 cases and deaths in U.S. counties to describe racial disparities in COVID-19 disease and death and associated determinants. METHODS Using publicly available data (accessed April 13, 2020), predictors of COVID-19 cases and deaths were compared between disproportionately (≥13%) black and all other (<13% black) counties. Rate ratios were calculated, and population attributable fractions were estimated using COVID-19 cases and deaths via zero-inflated negative binomial regression model. National maps with county-level data and an interactive scatterplot of COVID-19 cases were generated. RESULTS Nearly 90% of disproportionately black counties (656/677) reported a case and 49% (330/677) reported a death versus 81% (1987/2465) and 28% (684/2465), respectively, for all other counties. Counties with higher proportions of black people have higher prevalence of comorbidities and greater air pollution. Counties with higher proportions of black residents had more COVID-19 diagnoses (Rate Ratio (RR): 1.24, 95% confidence interval: 1.17-1.33) and deaths (RR: 1.18, 95% confidence interval: 1.00-1.40), after adjusting for county-level characteristics such as age, poverty, comorbidities, and epidemic duration. COVID-19 deaths were higher in disproportionally black rural and small metro counties. The population attributable fraction of COVID-19 diagnosis due to lack of health insurance was 3.3% for counties with less than 13% black residents and 4.2% for counties with greater than or equal to 13% black residents. CONCLUSIONS Nearly 20% of U.S. counties are disproportionately black, and they accounted for 52% of COVID-19 diagnoses and 58% of COVID-19 deaths nationally. County-level comparisons can both inform COVID-19 responses and identify epidemic hot spots. Social conditions, structural racism, and other factors elevate risk for COVID-19 diagnoses and deaths in black communities.
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Chawner JMA, Jones AT, Noble MT, Pickett GR, Tsepelin V, Zmeev DE. LEGO® Block Structures as a Sub-Kelvin Thermal Insulator. Sci Rep 2019; 9:19642. [PMID: 31873080 PMCID: PMC6927980 DOI: 10.1038/s41598-019-55616-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 11/30/2019] [Indexed: 11/09/2022] Open
Abstract
We report measurements of the thermal conductance of a structure made from commercial Acrylonitrile Butadiene Styrene (ABS) modules, known as LEGO® blocks, in the temperature range from 70 mK to 1.8 K. A power law for the sample's thermal conductivity κ = (8.7 ± 0.3) × 10-5 T 1.75±0.02 WK-1 m-1 was determined. We conclude that this ABS/void compound material provides better thermal isolation than well-known bulk insulator materials in the explored temperature range, whilst maintaining solid support. LEGO blocks represent a cheap and superlative alternative to materials such as Macor or Vespel. In our setup, <400 nW of power can heat an experimental area of 5 cm2 to over 1 K, without any significant change to the base temperature of the dilution refrigerator. This work suggests that custom-built modular materials with even better thermal performance could be readily and cheaply produced by 3D printing.
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Osborne DM, Sandau US, Jones AT, Vander Velden JW, Weingarten AM, Etesami N, Huo Y, Shen HY, Boison D. Developmental role of adenosine kinase for the expression of sex-dependent neuropsychiatric behavior. Neuropharmacology 2018; 141:89-97. [PMID: 30145320 DOI: 10.1016/j.neuropharm.2018.08.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 08/20/2018] [Accepted: 08/22/2018] [Indexed: 12/28/2022]
Abstract
Deficits in social memory, cognition, and aberrant responses to stimulants are common among persons affected by schizophrenia and other conditions with a presumed developmental etiology. We previously found that expression changes in the adenosine metabolizing enzyme adenosine kinase (ADK) in the adult brain are associated with deficits in various cognitive domains. To distinguish between developmental and adult functions of ADK, we used two transgenic mouse lines with widespread disruption of ADK expression in the adult brain, but differences in the onset of ADK deletion. Specifically, we compared Nestin-Cre+/-:ADK-floxfl/fl (ADKΔBrain) mice with global loss of ADK in the whole brain, beginning in mid-gestation and persisting for life, with Gfa2-Cre+/-:ADK-floxfl/fl (ADKΔAstro) mice that have normal ADK expression throughout development, but lose astrocyte-specific ADK-expression in young adulthood. Because ADK-expression in adulthood is generally confined to astrocytes, adult ADKΔAstro mice show a similar expression profile of ADK in key areas of the brain related to neuropsychiatric behavior, compared to adult ADKΔBrain mice. We sought to determine a neurodevelopmental role of ADK on the expression of psychiatric behaviors in adult male and female mice. Adult ADKΔBrain mice showed significant deficits in social memory in males, significant contextual learning impairments in both sexes, and a hyper-responsiveness to amphetamine in males. In contrast, ADKΔAstro mice showed normal social memory and contextual learning but hypo-responsiveness to amphetamine in males. Our results demonstrate a key developmental role of ADK in mediating behaviors in adulthood related to neuropsychiatric disease and support the greater prevalence of these disorders among males.
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He L, Sayers EJ, Watson P, Jones AT. Contrasting roles for actin in the cellular uptake of cell penetrating peptide conjugates. Sci Rep 2018; 8:7318. [PMID: 29743505 PMCID: PMC5943252 DOI: 10.1038/s41598-018-25600-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 04/25/2018] [Indexed: 12/13/2022] Open
Abstract
The increased need for macromolecular therapeutics, such as peptides, proteins and nucleotides, to reach intracellular targets necessitates more effective delivery vectors and a higher level of understanding of their mechanism of action. Cell penetrating peptides (CPPs) can transport a range of macromolecules into cells, either through direct plasma membrane translocation or endocytosis. All known endocytic pathways involve cell-cortex remodelling, a process shown to be regulated by reorganisation of the actin cytoskeleton. Here using flow cytometry, confocal microscopy and a variety of actin inhibitors we identify how actin disorganisation in different cell types differentially influences the cellular entry of three probes: the CPP octaarginine - Alexa488 conjugate (R8-Alexa488), octaarginine conjugated Enhanced Green Fluorescent Protein (EGFP-R8), and the fluid phase probe dextran. Disrupting actin organisation in A431 skin epithelial cells dramatically increases the uptake of EGFP-R8 and dextran, and contrasts strongly to inhibitory effects observed with transferrin and R8 attached to the fluorophore Alexa488. This demonstrates that uptake of the same CPP can occur via different endocytic processes depending on the conjugated fluorescent entity. Overall this study highlights how cargo influences cell uptake of this peptide and that the actin cytoskeleton may act as a gateway or barrier to endocytosis of drug delivery vectors.
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Roberts-Dalton HD, Cocks A, Falcon-Perez JM, Sayers EJ, Webber JP, Watson P, Clayton A, Jones AT. Fluorescence labelling of extracellular vesicles using a novel thiol-based strategy for quantitative analysis of cellular delivery and intracellular traffic. NANOSCALE 2017; 9:13693-13706. [PMID: 28880029 DOI: 10.1039/c7nr04128d] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Extracellular vesicles, including exosomes, are naturally derived nanovesicles generated in and released by numerous cell types. As extracellular entities they have the capacity to interact with neighbouring cells and distant tissues and affect physiological processes as well as being implicated in numerous diseases including tumorigenesis and neurodegeneration. They are also under intense investigation as delivery vectors for biotherapeutics. The ways in which EVs interact with recipient cells to influence cell physiology and deliver a macromolecular payload are at the early stages of exploration. A significant challenge within these studies is the ability to label EVs directly or indirectly with fluorescent probes to allow visualization without compromising functionality. Here, we present a thiol-based fluorescence labelling method allowing comprehensive analysis of the cellular uptake of prostate cancer derived EVs in live cells using confocal microscopy. Labelling of the EVs in this way did not influence their size and had no effect on their ability to induce differentiation of lung fibroblasts to myofibroblasts. For endocytosis analyses, depletion of key endocytic proteins and the use of chemical inhibitors (Dynasore, EIPA, Rottlerin and IPA-3) indicated that fluid-phase endocytosis and/or macropinocytosis was involved in EV internalisation. Over a period of six hours EVs were observed to increasingly co-localise with lysosomes, indicating a possible termination point following internalisation. Overall this method provides new opportunities for analysing the cellular dynamics of EVs as biological entities affecting cell and whole body physiology as well as investigating their potential as drug delivery vectors.
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Brazzale C, Mastrotto F, Moody P, Watson PD, Balasso A, Malfanti A, Mantovani G, Caliceti P, Alexander C, Jones AT, Salmaso S. Control of targeting ligand display by pH-responsive polymers on gold nanoparticles mediates selective entry into cancer cells. NANOSCALE 2017; 9:11137-11147. [PMID: 28745764 DOI: 10.1039/c7nr02595e] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Selective targeting of cells for intracellular delivery of therapeutics represents a major challenge for pharmaceutical intervention in disease. Here we show pH-triggered receptor-mediated endocytosis of nanoparticles via surface ligand exposure. Gold nanoparticles were decorated with two polymers: a 2 kDa PEG with a terminal folate targeting ligand, and a di-block copolymer including a pH-responsive and a hydrophilic block. At the normal serum pH of 7.4, the pH-responsive block (apparent pKa of 7.1) displayed a hydrophilic extended conformation, shielding the PEG-folate ligands, which inhibited cellular uptake of the nanoparticles. Under pH conditions resembling those of the extracellular matrix around solid tumours (pH 6.5), protonation of the pH-responsive polymer triggered a coil-to-globule polymer chain contraction, exposing folate residues on the PEG chains. In line with this, endocytosis of folate-decorated polymer-coated gold nanoparticles in cancer cells overexpressing folate receptor was significantly increased at pH 6.5, compared with pH 7.4. Thus, the tumour acidic environment and high folate receptor expression were effectively exploited to activate cell binding and endocytosis of these nanoparticles. These data provide proof-of-concept for strategies enabling extracellular pH stimuli to selectively enhance cellular uptake of drug delivery vectors and their associated therapeutic cargo.
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Ovenden JR, Leigh GM, Blower DC, Jones AT, Moore A, Bustamante C, Buckworth RC, Bennett MB, Dudgeon CL. Can estimates of genetic effective population size contribute to fisheries stock assessments? JOURNAL OF FISH BIOLOGY 2016; 89:2505-2518. [PMID: 27730623 DOI: 10.1111/jfb.13129] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 07/28/2016] [Indexed: 06/06/2023]
Abstract
Sustainable exploitation of fisheries populations is challenging to achieve when the size of the population prior to exploitation and the actual numbers removed over time and across fishing zones are not clearly known. Quantitative fisheries' modeling is able to address this problem, but accurate and reliable model outcomes depend on high quality input data. Much of this information is obtained through the operation of the fishery under consideration, but while this seems appropriate, biases may occur. For example, poorly quantified changes in fishing methods that increase catch rates can erroneously suggest that the overall population size is increasing. Hence, the incorporation of estimates of abundance derived from independent data sources is preferable. We review and evaluate a fisheries-independent method of indexing population size; inferring adult abundance from estimates of the genetic effective size of a population (Ne ). Recent studies of elasmobranch species have shown correspondence between Ne and ecologically determined estimates of the population size (N). Simulation studies have flagged the possibility that the range of Ne /N ratios across species may be more restricted than previously thought, and also show that declines in Ne track declines in the abundance of model fisheries species. These key developments bring this new technology closer to implementation in fisheries science, particularly for data-poor fisheries or species of conservation interest.
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Chen R, Rishi HS, Potapov V, Yamada MR, Yeh VJ, Chow T, Cheung CL, Jones AT, Johnson TD, Keating AE, DeLoache WC, Dueber JE. A Barcoding Strategy Enabling Higher-Throughput Library Screening by Microscopy. ACS Synth Biol 2015; 4:1205-16. [PMID: 26155738 PMCID: PMC4654675 DOI: 10.1021/acssynbio.5b00060] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dramatic progress has been made in the design and build phases of the design-build-test cycle for engineering cells. However, the test phase usually limits throughput, as many outputs of interest are not amenable to rapid analytical measurements. For example, phenotypes such as motility, morphology, and subcellular localization can be readily measured by microscopy, but analysis of these phenotypes is notoriously slow. To increase throughput, we developed microscopy-readable barcodes (MiCodes) composed of fluorescent proteins targeted to discernible organelles. In this system, a unique barcode can be genetically linked to each library member, making possible the parallel analysis of phenotypes of interest via microscopy. As a first demonstration, we MiCoded a set of synthetic coiled-coil leucine zipper proteins to allow an 8 × 8 matrix to be tested for specific interactions in micrographs consisting of mixed populations of cells. A novel microscopy-readable two-hybrid fluorescence localization assay for probing candidate interactions in the cytosol was also developed using a bait protein targeted to the peroxisome and a prey protein tagged with a fluorescent protein. This work introduces a generalizable, scalable platform for making microscopy amenable to higher-throughput library screening experiments, thereby coupling the power of imaging with the utility of combinatorial search paradigms.
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Bailey D, Carpenter EP, Coker A, Coker S, Read J, Jones AT, Erskine P, Aguilar CF, Badasso M, Toldo L, Rippmann F, Sanz-Aparicio J, Albert A, Blundell TL, Roberts NB, Wood SP, Cooper JB. An analysis of subdomain orientation, conformational change and disorder in relation to crystal packing of aspartic proteinases. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2012; 68:541-52. [PMID: 22525752 DOI: 10.1107/s0907444912004817] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 02/04/2012] [Indexed: 06/19/2023]
Abstract
The analysis reported here describes detailed structural studies of endothiapepsin (the aspartic proteinase from Endothia parasitica), with and without bound inhibitors, and human pepsin 3b. Comparison of multiple crystal structures of members of the aspartic proteinase family has revealed small but significant differences in domain orientation in different crystal forms. In this paper, it is shown that these differences in domain orientation do not necessarily correlate with the presence or absence of bound inhibitors, but appear to stem at least partly from crystal contacts mediated by sulfate ions. However, since the same inherent flexibility of the structure is observed for other enzymes in this family such as human pepsin, the native structure of which is also reported here, the observed domain movements may well have implications for the mechanism of catalysis.
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Al Soraj M, He L, Peynshaert K, Cousaert J, Vercauteren D, Braeckmans K, De Smedt SC, Jones AT. siRNA and pharmacological inhibition of endocytic pathways to characterize the differential role of macropinocytosis and the actin cytoskeleton on cellular uptake of dextran and cationic cell penetrating peptides octaarginine (R8) and HIV-Tat. J Control Release 2012; 161:132-41. [PMID: 22465675 DOI: 10.1016/j.jconrel.2012.03.015] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 03/13/2012] [Accepted: 03/18/2012] [Indexed: 11/30/2022]
Abstract
Cell penetrating peptides (CPPs) have been extensively studied as vectors for cellular delivery of therapeutic macromolecules. It is widely accepted that they can enter cells directly across the plasma membrane but also gain access through endocytic pathways that are yet to be fully defined. Here we developed siRNA methods in epithelial cell lines, HeLa and A431, to inhibit endocytic pathways regulated by clathrin heavy chain, flotillin-1, caveolin-1, dynamin-2 and Pak-1. In each case, functional uptake assays were developed to characterize the requirement for these proteins, and the pathways they regulate, in the internalisation of defined endocytic probes and also the CPPs octaarginine and HIV-Tat. Peptide uptake was only inhibited in A431 cells depleted of the macropinocytosis regulator Pak-1, but experimental variables including choice of cell line, pharmacological inhibitor, macropinocytic probe and serum starvation significantly influence our ability to assess and assign this pathway as an important route for CPP uptake. Actin disruption with Cytochalasin D inhibited peptide entry in both cell lines but the effects of this agent on dextran uptake was cell line dependent, reducing uptake in HeLa cells and increasing uptake in A431 cells. This was further supported in experiments inducing actin stabilisation by Jasplakinolide, emphasising that the actin cytoskeleton can both promote and hinder endocytosis. Overall the data identify important aspects regarding the comparative mechanisms of CPP uptake and macropinocytosis, and accentuate the significant methodological challenges of studying this pathway as an endocytic portal and an entry route for drug delivery vectors.
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Davies R, Lowings M, Jones AT, Langrish CJ. Central line change in potential catheter-related bloodstream infection: target for intervention to reduce harm. Crit Care 2011. [PMCID: PMC3066904 DOI: 10.1186/cc9650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Futaki S, Nakase I, Tadokoro A, Takeuchi T, Jones AT. Arginine-rich peptides and their internalization mechanisms. Biochem Soc Trans 2007; 35:784-7. [PMID: 17635148 DOI: 10.1042/bst0350784] [Citation(s) in RCA: 176] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
As the versatility and use of CPPs (cell-penetrating peptides) as intracellular delivery vectors have been widely accepted, the cellular uptake mechanisms that enable their efficient internalization have become the subject of much interest. Arginine-rich peptides, including HIV-1 Tatp (transactivator of transcription peptide), are regarded as a representative class of CPPs. Evidence suggests that macropinocytosis plays a crucial role in the cellular uptake of these peptides. We have recently shown that treatment of cells with arginine-rich peptides induces activation of Rac protein leading to F-actin (filamentous actin) organization and macropinocytosis. We have also shown that depletion of membrane-associated proteoglycans results in the failure of this signalling pathway, suggesting that membrane-associated proteoglycans may act as a potential receptor for the induction of macropinocytic uptake of arginine-rich peptides. However, when the macropinocytic pathway is inhibited at a low temperature or by cholesterol depletion, these peptides can be internalized by alternative mechanisms, one of which appears to be direct translocation of the peptides through the plasma membrane. This review summarizes the current theories on both endocytic and non-endocytic aspects of internalization of arginine-rich peptides.
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Pattani H, Wharton S, Hart N, Jones AT. Critical care as part of respiratory medicine training in the UK. Thorax 2006; 61:1013. [PMID: 17071841 PMCID: PMC2121180 DOI: 10.1136/thx.2006.064311] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Jones AT, Hansell DM, Evans TW. Quantifying pulmonary perfusion in primary pulmonary hypertension using electron-beam computed tomography. Eur Respir J 2004; 23:202-7. [PMID: 14979492 DOI: 10.1183/09031936.03.00033803] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Traditionally, a gravitational distribution of pulmonary perfusion has been described in normal subjects. How this may vary in patients with primary pulmonary hypertension (PPH), which is characterised by vascular obstruction due to intimal thickening, smooth muscle cell proliferation and episodes of thrombosis in small and medium sized pulmonary arteries, is unclear. In this study the potential of electron-beam computed tomography in quantifying the distribution of pulmonary perfusion in patients with PPH was investigated. Contrast-enhanced sections were obtained during inspiration in the supine position at baseline and during administration of the vasodilator adenosine in five healthy subjects and five patients with PPH. Under each experimental condition, regions of interest were placed along the nondependent-to-dependent axis and values for relative perfusion derived. In healthy individuals, a marked nondependent-to-dependent gradient in perfusion was observed. By contrast, in PPH, perfusion values were significantly lower and were uniform across the lung section, although the administration of adenosine resulted in increased perfusion in all regions of interest. Electron-beam computed tomography provides physiological and structural information about the pulmonary circulation in subjects with pulmonary vascular disease.
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