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Although disparities in COVID-19 outcomes have been observed, factors contributing to these differences are not well understood.To determine whether COVID-19 hospitalization outcomes are related to neighborhood-level social vulnerability, independent of patient-level clinical factors.Pooled cross-sectional study of prospectively collected data.38 Michigan hospitals.Adults older than 18 years hospitalized for COVID-19 in a participating site between March and December 2020.COVID-19 outcomes included acute organ dysfunction, organ failure, invasive mechanical ventilation, intensive care unit stay, death, and discharge disposition. Social vulnerability was measured by the social vulnerability index (SVI), a composite measure of social disadvantage.Compared with patients in low-vulnerability ZIP codes, those living in high-vulnerability ZIP codes were more frequently treated in the intensive care unit (29.0% vs. 24.5%); more frequently received mechanical ventilation (19.3% vs. 14.2%); and experienced higher rates of organ dysfunction (51.9% vs. 48.6%), organ failure (54.7% vs. 51.6%), and in-hospital death (19.4% vs. 16.7%). In mixed-effects regression analyses accounting for age, sex, and comorbid conditions, an increase in a patient's neighborhood SVI by 0.25 (1 quartile) was associated with greater likelihood of mechanical ventilation (increase of 2.1 percentage points), acute organ dysfunction (increase of 2.8 percentage points), and acute organ failure (increase of 2.8 percentage points) but was not associated with intensive care unit stay, mortality, or discharge disposition.Observational data focused on hospitalizations in a single state.Hospitalized patients with COVID-19 from socially vulnerable neighborhoods presented with greater illness severity and required more intensive treatment, but once hospitalized they did not experience differences in hospital mortality or discharge disposition. Policies that target socially vulnerable neighborhoods and access to COVID-19 care may help ameliorate health disparities.Blue Cross Blue Shield of Michigan (BCBSM) and Blue Care Network as part of the BCBSM Value Partnerships Program, the Michigan Public Health Institute, and the Michigan Department of HealthHuman Services.

Venous thromboembolism (VTE) is an important complication of coronavirus disease 2019 (COVID-19). To date, few studies have described vascular access device use and VTE risk in this cohort. To examine the use of vascular access devices and incidence of VTE in patients hospitalized with COVID-19. We performed a retrospective, multi-center cohort study of patients hospitalized with COVID-19 who received a midline catheter, peripherally inserted central catheter (PICCs), tunneled or non-tunneled central venous catheter (CVC), hemodialysis (HD) catheter or a port during hospitalization. Mixed-effects multivariable logit models adjusting for VTE risk factors in the Caprini risk score were fit to understand the incremental risk of VTE in patients with vascular access devices vs. those that did not receive devices. Management of VTE was determined by examining anticoagulant use pre- vs. post-thrombosis. Results were expressed using odds ratios (ORs) and associated 95% confidence intervals (CI). A total of 1228 hospitalized COVID-19 patients in 40 hospitals, of which 261 (21.3%) received at least one vascular access device of interest, were included. The prevalence of acute, non-tunneled CVCs was 42.2%, acute HD catheters 18.4%, midline catheters 15.6%, PICCs 15.6%, tunneled CVCs 6.8%, and implanted ports 1.4%. The prevalence of VTE was 6.0% in the study cohort, and 10.0% among patients with vascular access devices. After adjusting for known VTE risk factors, patients that had a vascular access device placed were observed to have a four-fold greater odds of VTE than those that did not (OR 4.17, 95% CI 2.33–7.46). Patients who received multiple different catheters experienced more VTE events compared with patients that received only one type (21.5% vs. 6.1%, p

Background:We sought to determine the incidence of community-onset and hospital-acquired coinfection in patients hospitalized with coronavirus disease 2019 (COVID-19) and to evaluate associated predictors and outcomes.Methods:In this multicenter retrospective cohort study of patients hospitalized for COVID-19 from March 2020 to August 2020 across 38 Michigan hospitals, we assessed prevalence, predictors, and outcomes of community-onset and hospital-acquired coinfections. In-hospital and 60-day mortality, readmission, discharge to long-term care facility (LTCF), and mechanical ventilation duration were assessed for patients with versus without coinfection.Results:Of 2,205 patients with COVID-19, 141 (6.4%) had a coinfection: 3.0% community onset and 3.4% hospital acquired. Of patients without coinfection, 64.9% received antibiotics. Community-onset coinfection predictors included admission from an LTCF (OR, 3.98; 95% CI, 2.34–6.76; P < .001) and admission to intensive care (OR, 4.34; 95% CI, 2.87–6.55; P < .001). Hospital-acquired coinfection predictors included fever (OR, 2.46; 95% CI, 1.15–5.27; P = .02) and advanced respiratory support (OR, 40.72; 95% CI, 13.49–122.93; P < .001). Patients with (vs without) community-onset coinfection had longer mechanical ventilation (OR, 3.31; 95% CI, 1.67–6.56; P = .001) and higher in-hospital mortality (OR, 1.90; 95% CI, 1.06–3.40; P = .03) and 60-day mortality (OR, 1.86; 95% CI, 1.05–3.29; P = .03). Patients with (vs without) hospital-acquired coinfection had higher discharge to LTCF (OR, 8.48; 95% CI, 3.30–21.76; P < .001), in-hospital mortality (OR, 4.17; 95% CI, 2.37–7.33; P ≤ .001), and 60-day mortality (OR, 3.66; 95% CI, 2.11–6.33; P ≤ .001).Conclusion:Despite community-onset and hospital-acquired coinfection being uncommon, most patients hospitalized with COVID-19 received antibiotics. Admission from LTCF and to ICU were associated with increased risk of community-onset coinfection. Future studies should prospectively validate predictors of COVID-19 coinfection to facilitate the reduction of antibiotic use.

Purpose Vascular access patterns in the intensive care unit (ICU) have shifted from non-tunneled central venous catheters (CVCs) towards peripherally inserted central catheters (PICCs). We evaluated perceptions of critical care practitioners regarding these devices and variation in evidence-based practice. Materials A 35-question survey on ICU vascular access was deployed in 13 Michigan hospitals. Descriptive statistics summarized responses. Differences in utilization, perceptions and evidence-based practices between PICCs and CVCs, by participant and site-level characteristics, were assessed. Results 314 of 621 eligible providers responded to the survey (response rate 51%). 15% of providers reported not routinely using ultrasound when placing CVCs. Respondents whom were trainees, from larger hospitals, and from closed ICUs were more likely to use ultrasound (p Conclusion Variation in guideline-based vascular access practices exists in the ICU. Defined local protocols may improve guideline adherence. Studies evaluating vascular access decisions and patient safety in the ICU appear necessary.

Objective:To examine the effectiveness of antimicrobial and antithrombogenic materials incorporated into peripherally inserted central catheters (PICCs) to prevent bloodstream infection, thrombosis, and catheter occlusion.Methods:Prospective cohort study involving 52 hospitals participating in the Michigan Hospital Medicine Safety Consortium. Sample included adult hospitalized medical patients who received a PICC between January 2013 and October 2019. Coated and impregnated catheters were identified by name, brand, and device marketing or regulatory materials. Multivariable Cox proportional hazards models with robust sandwich standard error estimates accounting for the clustered nature of data were used to identify factors associated with PICC complications in coated versus noncoated devices across general care, intensive care unit (ICU), and oncology patients. Results were expressed as hazard ratios (HRs) with corresponding 95% confidence intervals (CIs).Results:Of 42,562 patients with a PICC, 39,806 (93.5%) were plain polyurethane, 2,263 (5.3%) incorporated antimicrobial materials, and 921 (2.2%) incorporated antithrombogenic materials. Most were inserted in general ward settings (n = 28,111, 66.0%), with 12, 078 (28.4%) and 1,407 (3.3%) placed in ICU and oncological settings, respectively. Within the entire cohort, 540 (1.3%) developed thrombosis, 745 (1.8%) developed bloodstream infection, and 4,090 (9.6%) developed catheter occlusion. Adjusting for known risk factors, antimicrobial PICCs were not associated with infection reduction (HR, 1.16; 95% CI, 0.82–1.64), and antithrombogenic PICCs were not associated with reduction in thrombosis and occlusion (HR, 1.15; 95% CI, 0.92–1.44). Results were consistent across populations and care settings.Conclusions:Antimicrobial and antithrombogenic PICCs were not associated with a reduction in major catheter complications. Guidance aimed at informing use of these devices, balancing benefits against cost, appear necessary.

BackgroundThe Michigan Appropriateness Guide for Intravenous Catheters (MAGIC) provides evidence-based criteria for peripherally inserted central catheter (PICC) use. Whether implementing MAGIC improves PICC appropriateness and reduces complications is unknown.MethodsA quasiexperimental study design to implement MAGIC in 52 Michigan hospitals was used. Data were collected from medical records by trained abstractors. Hospital performance on three appropriateness criteria was measured: short-term PICC use (≤5 days), use of multilumen PICCs and PICC placement in patients with chronic kidney disease. PICC appropriateness and device complications preintervention (January 2013 to December 2016) versus postintervention (January 2017 to January 2020) were compared. Change-point analysis was used to evaluate the effect of the intervention on device appropriateness. Logistic regression and Poisson models were fit to assess the association between appropriateness and complications (composite of catheter occlusion, venous thromboembolism (VTE) and central line-associated bloodstream infection (CLABSI)).ResultsAmong 38 592 PICCs, median catheter dwell ranged from 8 to 56 days. During the preintervention period, the mean frequency of appropriate PICC use was 31.9% and the mean frequency of complications was 14.7%. Following the intervention, PICC appropriateness increased to 49.0% (absolute difference 17.1%, pConclusionsImplementation of MAGIC in Michigan hospitals was associated with improved PICC appropriateness and fewer complications. These findings have important quality, safety and policy implications for hospitals, patients and payors.

Triple negative breast cancer (TNBC) lacks targeted therapies. Recently, our laboratory and other groups described long non-coding RNAs (lncRNAs) as new drivers of TNBC progression, which represent an exciting new avenue for targeted treatments. LncRNAs are the most versatile and diverse class of non-coding RNAs with roles in the progression of TNBC development, including cell proliferation, differentiation, apoptosis, metastasis and drug resistance. LncRNAs have greater tissue-specific expression compared to proteins and can be targeted using nucleotide sequence-specific RNA therapeutics, leading to reduced systemic toxicities when used as a cancer target. Using a combined approach of computational analysis of patient data and CRISPR functional screening, we identified hundreds of lncRNAs as novel drivers of TNBC. We prioritized one lncRNA target (lncTNBC3) with high translational potential. LncTNBC3 knockdown lead to reduced TNBC cell proliferation in two different loss-of-function models. To gain initial insights into the mechanism via which lncTNBC3 functions, RNA sequencing was carried out on knockdown cells, revealing that lncTNBC3 impacts cell cycle and DNA repair pathways. Cell cycle analysis confirmed an increase in G2/M cell cycle arrest upon lncTNBC3 knockdown. In conclusion, we have identified a promising novel lncRNA target with a role in TNBC growth. Citation Format: Megan O'Malley, Zohaib Rana, Debina Sarkar, Jolyn Chia, Sarah Diermeier. Identification of lncRNAs as potential novel therapeutic targets in triple negative breast cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3961.

Opioid and benzodiazepine prescribing after COVID-19 hospitalization is not well understood. We aimed to characterize opioid and benzodiazepine prescribing among naïve patients hospitalized for COVID and to identify the risk factors associated with a new prescription at discharge. In this retrospective study of patients across 39 Michigan hospitals from March to November 2020, we identified 857 opioid- and benzodiazepine-naïve patients admitted with COVID-19 not requiring mechanical ventilation. Of these, 22% received opioids, 13% received benzodiazepines, and 6% received both during the hospitalization. At discharge, 8% received an opioid prescription, and 3% received a benzodiazepine prescription. After multivariable adjustment, receipt of an opioid or benzodiazepine prescription at discharge was associated with the length of inpatient opioid or benzodiazepine exposure. These findings suggest that hospitalization represents a risk of opioid or benzodiazepine initiation among naïve patients, and judicious prescribing should be considered to prevent opioid-related harms.

Although characteristics and in-hospital outcomes for persons with coronavirus disease 2019 (COVID-19) have been well described, less is known about the longer-term outcomes of hospitalized patients Although characteristics and in-hospital outcomes for persons with COVID-19 have been well described, less is known about the longer-term outcomes of hospitalized patients Here, a study that aims to describe the 6-day postdischarge clinical, financial, and mental health outcomes of patients with COVID-19 using an observational cohort study is offered

ObjectiveTo describe patient characteristics, symptoms, patterns of care and outcomes for patients hospitalised with COVID-19 in Michigan.DesignMulticentre retrospective cohort study.Setting32 acute care hospitals in the state of Michigan.ParticipantsPatients discharged (16 March–11 May 2020) with suspected or confirmed COVID-19 were identified. Trained abstractors collected demographic information on all patients and detailed clinical data on a subset of COVID-19-positive patients.Primary outcome measurementsPatient characteristics, treatment and outcomes including cardiopulmonary resuscitation, mortality and venous thromboembolism within and across hospitals.ResultsDemographic-only data from 1593 COVID-19-positive and 1259 persons under investigation discharges were collected. Among 1024 cases with detailed data, the median age was 63 years; median body mass index was 30.6; and 51.4% were black. Cough, fever and shortness of breath were the top symptoms. 37.2% reported a known COVID-19 contact; 7.0% were healthcare workers; and 16.1% presented from congregated living facilities.During hospitalisation, 232 (22.7%) patients were treated in an intensive care unit (ICU); 558 (54.9%) in a ‘cohorted’ unit; 161 (15.7%) received mechanical ventilation; and 90 (8.8%) received high-flow nasal cannula. ICU patients more often received hydroxychloroquine (66% vs 46%), corticosteroids (34% vs 18%) and antibiotic therapy (92% vs 71%) than general ward patients (pAcross 14 hospitals, the proportion of patients admitted directly to an ICU ranged from 0% to 43.8%; mechanical ventilation on admission from 0% to 12.8%; mortality from 7.9% to 45.7%. Use of at least one COVID-19-specific therapy varied from 32% to 96.3% across sites.ConclusionsDuring the early days of the Michigan outbreak of COVID-19, patient characteristics, treatment and outcomes varied widely within and across hospitals.

Background:Peripherally inserted central catheters (PICCs) are frequently used to deliver intravenous (IV) antibiotic therapy after discharge from the hospital. Infectious disease (ID) physicians are often consulted prior to PICC placement, but whether their approval influences PICC appropriateness and complications is not known. Methods: Using data from the Michigan Hospital Medicine Safety Consortium (HMS) on PICCs placed in critically ill and hospitalized medical patients between January 1, 2015, and July 26, 2019, we examined the association between ID physician approval of PICC insertion for IV antibiotics and device appropriateness and outcomes. Appropriateness was defined according to the Michigan Appropriateness Guide for Intravenous Catheters (MAGIC) as a composite measure of (1) avoiding PICC use for durations ≤5 days; (2) using single-lumen instead of multilumen catheters; and (3) avoiding PICC use in patients with chronic kidney disease (eGFR>45 mL/min). The associations between ID approval of PICC use and odds of PICC-related complications (eg, deep vein thrombosis, central-line–associated bloodstream infection, and catheter occlusion) were also assessed. Multivariable models adjusting for patient severity of illness and hospital-level clustering were fit to both outcomes. Results were expressed as odds ratios (ORs) with corresponding 95% CIs. Results: Data from 36,594 patients who underwent PICC placement across 42 Michigan hospitals were included in the analysis. In total, 21,653 (55%) PICCs were placed for the indication of IV antibiotics; 14,935 (69%) of these had a documented ID consultation prior to placement, whereas 6,718 (31%) did not. Of the 14,935 PICCs with an ID consultation, 10,238 (69%) had ID approval documented prior to device placement (Fig. 1). Compared to no approval, PICCs approved by ID prior to insertion were more likely to be appropriate (OR, 3.51; 95% CI, 3.28–3.77; P < .001). Specifically, approval was associated with higher single-lumen use (OR, 5.13; 95% CI, 4.72–5.58; P < .001), less placement of PICCs with dwell times ≤ 5 days (OR, 0.29; 95% CI, 0.25–0.32; P < .001), and less frequent use in patients with chronic kidney disease (OR, 0.80; 95% CI, 0.73–0.87; P < .001). ID approval of PICCs prior to insertion was associated with a significantly lower odds of PICC-related complications (OR, 0.57; 95% CI, 0.51–0.64) (Table 1). Conclusions: ID approval of PICC use for IV antibiotic therapy in hospitalized patients was associated with greater appropriateness and fewer complications. Policies aimed at ensuring ID review prior to PICC use may help improve patient and device safety.Funding: NoneDisclosures:Valerie M. Vaughn reports contract research for Blue Cross and Blue Shield of Michigan, the Department of Veterans’ Affairs, the NIH, the SHEA, and the APIC. She also reports fees from the Gordon and Betty Moore Foundation Speaker’s Bureau, the CDC, the Pew Research Trust, Sepsis Alliance, and The Hospital and Health System Association of Pennsylvania.

Key Points Question Is approval by an infectious disease physician prior to placement of a peripherally inserted central catheter (PICC) for intravenous antimicrobials associated with appropriate device use or complications? Findings In this cohort study of 21 653 PICCs placed for intravenous antimicrobials in 42 hospitals, 47% of PICCs were placed with approval of an infectious disease physician. Compared with nonapproved PICCs, approved PICCs were more likely to be appropriately placed, and the patients less likely to experience complications. Meaning This cohort study suggests that infectious disease physician approval of PICCs prior to placement for intravenous antimicrobial therapy is associated with more appropriate device use and fewer complications., Importance Peripherally inserted central catheters (PICCs) are frequently used to deliver intravenous antimicrobial therapy. However, inappropriate PICC use may lead to patient harm. Objective To evaluate whether infectious disease physician approval prior to PICC placement for intravenous antimicrobials is associated with more appropriate device use and fewer complications. Design, Setting, and Participants This cohort study of 21 653 PICCs placed for a primary indication of intravenous antimicrobial therapy between January 1, 2015, and July 26, 2019, was conducted in 42 hospitals participating in a quality collaborative across Michigan among hospitalized medical patients. Main Outcomes and Measures Appropriateness of PICCs was defined according to the Michigan Appropriateness Guide for Intravenous Catheters as a composite measure of (1) single-lumen catheter use, (2) avoiding use of PICCs for 5 days or less, and (3) avoiding use of PICCs for patients with chronic kidney disease (defined as an estimated glomerular filtration rate, This cohort study evaluates whether infectious disease physician approval prior to placement of a peripherally inserted central catheter (PICC) for intravenous antimicrobials is associated with more appropriate device use and fewer complications.

Background Healthcare associated infections are associated with indwelling devices. Yet, data regarding prevalence of indwelling devices in noncritically ill hospitalized patients remains scant. Methods Adult, noncritically ill patients on general care, telemetry, and surgical floors at our quaternary care hospital were surveyed on 2 separate days. Data regarding presence of indwelling vascular, urinary, and gastrointestinal devices, as well as nurse to patient ratio on each unit were collected. Results There were 1,229 devices observed among the 857 patients surveyed across 2 days. Of the surveyed patients, 780 (91.0%) had at least 1 indwelling device. Among all devices, intravenous catheters were the most common (90.1%), followed by gastrointestinal devices (12.8%) and urinary catheters (10.2%). The most prevalent device was peripheral intravenous catheters. The median nurse to patient ratio was 3 patients to 1 nurse; no difference in nurse to patient ratio based on the number of devices present was observed. Conclusions Indwelling device use appears highly prevalent in general care settings and variation among devices is common. Healthcare associated infections prevention strategies targeting these devices are necessary.

Background: Use of peripherally inserted central catheters (PICCs) has grown rapidly in patients with hematologic malignancies. Studies demonstrating the safety of PICCs in hematologic malignancies, however, are largely single-center, retrospective designs focused on the outpatient setting. Little is known about inpatient PICC use in patients with hematologic malignancies and how such use varies across hospitals. Methods: Data was prospectively collected between November 2013 and December 2019 from a cohort of patients admitted at one of 42 Michigan hospitals participating in the Michigan Hospital Medicine Safety Consortium (HMS). Patients had a diagnosis of a hematologic malignancy and had a PICC placed during their hospital stay. Adult medical patients admitted to a general ward or intensive care unit were eligible for data collection and data were collected from the medical record using a standardized template. The indications for PICC placement, catheter characteristics, and associated complications from 17 hospitals with more than 25 discrete patients with hematologic malignancy were included in a comparative analysis. Major complications were defined as central line associated bloodstream infection (CLABSI), catheter occlusion, and venous thromboembolism (VTE). Differences across hospitals were tested using the Kruskal-Wallis test for continuous variables and Pearson chi-square test for categorical variables. Results: A total of 2092 PICCs placed in 1798 patients were included in the analysis with a median (IQR) dwell time of 15 (6-30) days. Most patients were male (n=1242, 59.4%), white (n=1720, 82.2%), and 50 to 69 years old (n=950, 45.4%). Patients were primarily admitted to large hospitals (≥375 beds: n=1429, 68.8%) that were teaching centers (n=1600, 76.5%) in metropolitan locations (n=2000, 95.6%). Leukemia (n=752, 36.0%) and non-Hodgkin's lymphoma (n=409, 19.6%) were the most represented malignancies. The most common primary indication for PICC placement was administration of chemotherapy (n=1180, 56.4%). The majority of PICCs were double lumen (n=1457, 69.6%), most often placed by vascular access nurses (n=1520, 72.7%). A concurrent central venous catheter was present at the time of PICC placement in 12.2% (n=264) of patients. A major complication event occurred in over 1 in 4 PICCs placed (n=562, 26.9%). Catheter occlusion occurred in 17.8% (n=372), CLABSI in 8.2% (n=171), and VTE in 3.8% (n=80) of PICCs respectively. There was wide variation in PICC indications, characteristics, and outcomes across hospitals. Placement of PICCs for chemotherapy varied from 33.3% to 85.3% (p Conclusion: Appropriate venous access is critical to the care of patients with hematologic malignancy. This study demonstrates wide variation in the practice patterns and outcomes for PICCs in patients with hematologic malignancies across hospitals in Michigan. Further work is necessary to further understand and improve decision making around choosing vascular access in this vulnerable population. Figure 1 Figure 1. Disclosures Zhang: SIMR, Inc: Ended employment in the past 24 months, Research Funding; AmerisourceBergen: Current Employment. Sood: Bayer: Consultancy.

6572 Background: Peripherally inserted central catheters (PICCs) are widely utilized in oncology. Previous studies have shown a high risk of catheter-related thrombosis and bloodstream infection in the uniquely susceptible oncologic population; however, most studies are limited by single center, outpatient, retrospective designs. Therefore, we performed a multi-center study to further describe PICC use and complications in the solid tumor population within the inpatient setting. Methods: Data was collected on PICC lines inserted across 50 hospitals in Michigan from November 2013 to December 2019. Patients with a solid tumor diagnosis at time of PICC insertion were selected (n = 3,956). Indications for PICC placement, catheter characteristics, and associated complications were compared by metastatic (n = 1,488) and non-metastatic (n = 2,468) disease. Complications were also compared by cancer type. Major complications were defined as central line associated blood stream infection (CLABSI), catheter occlusion, deep vein thrombosis (DVT), and pulmonary embolism (PE). Paired t-test and Pearson Chi-square test were used for analyses. Results: PICCs were most commonly placed for antibiotics (n = 1232, 31%) and chemotherapy (n = 907, 23%). The majority of catheters were multi-lumen with 61% (n = 2362) double lumen and 8% (n = 326) triple lumen. Median dwell time was 13 days. Notably, 17% of patients had another central venous catheter (CVC) at time of placement. Metastatic patients were more likely to have a PICC placed for difficult venous access (24.7% vs 17.7%, p < 0.001) and total parenteral nutrition (20.2% vs 12.3%, p < 0.001) as well as to have a current CVC in place (22% vs 14%, p

Using coherent terahertz time‐domain spectroscopy, we measure the surface impedance of 500‐A‐thick unpatterned superconducting YBa2Cu3O7 films in the normal and the superconducting state. Both real and imaginary parts of the surface impedance are measured simultaneously from the amplitude and phase changes of the terahertz bandwidth pulses transmitted through the superconducting films.

We have incorporated high temperature superconducting technology along with conventional semiconducting elements into a subharmonically-pumped digital phase modulator and demodulator. The appropriate bandpass filters, stopband filters, and matching networks are fabricated from post annealed double sided YBa2Cu307 films on 10 mil LaA103. The modulator/ demodulator pair is subharmonically pumped at 9.5 GHz. The local oscillator is upconverted and multiplied by the digital bit stream via an antiparallel Schottky diode pair to produce a phase encoded RF carrier at 19 GHz. This circuit showed clean eye diagrams of the recovered data trains up to 1.3 GBits/s with corresponding bit error rates of less than 1011. Work is in progress investigating this circuit with a superconducting resonator stabilized pump source on the same substrate as well as using superconducting bridges or junctions as the nonlinear mixing element.

The optoelectronic generation and coherent detection of extremely short electrical pulses with bandwidths in excess of several THz1,2 have made possible to study materials and electronic transport phenomena in a previously hardly accessible region of the electro-magnetic spectrum. These electrical pulses can be propagated in free space and collimated as well as focussed like optical pulses using lenses and mirrors.2 The extremely high signal-to-noise ratio of the electrical pulses generated by the photoconductive dipole antennas together with the phase sensitive detection scheme outperforms conventional Fourier-transform infrared spectrometers in the terahertz range by a large margin. Here, we use collimated terahertz radiation from photoconductive dipoles to study the electronic response of the Cooper pairs and of thermally excited quasiparticles in thin superconducting films. Historically, far-infrared studies of superconductors have been a crucial factor for the theoretical description of superconductivity and the agreement of these studies with BCS theory has been seen as a validity proof of the BCS theory.3-5

In recent years, a variety of techniques have been developed to generate and detect ultrafast electromagnetic transients with bandwidths up to 1 THz [1]. The spectrum of these transients spans part of the microwave, submillimeter wave and far-infrared range of the electro-magnetic spectrum. The spectroscopic benefits include the enormous spectral bandwidth covered, the coherent detection that enables to extract both real and imaginary part of the dielectric response function, and a sensitivity that far exceeds the sensitivity of conventional far-infrared spectrometers in the same spectral range.