Microbiology of infection-related complications after transrectal ultrasound-guided prostate biopsy.

INTRODUCTION: The objective of this study was to describe the incidence, microbiology, and risk factors related to infectious complications after transrectal prostate biopsies. METHODS: This was a single-center, retrospective cohort study of patients undergoing prostate biopsies. Throughout the study period, the institutional standard for antibiotic prophylaxis was cephalexin and ciprofloxacin. Due to the desire to limit fluoroquinolone use, the ciprofloxacin duration of therapy was reduced from 48 to 24 hours in the middle of the study period. The primary outcome was the incidence of infection-related complications, defined as a urinary tract infection or bacteremia within 30 days post-procedure. RESULTS: A total of 1471 transrectal prostate biopsies were included. All patients received antibiotic prophylaxis, with 86.1% (1268/1472) of patients receiving both ciprofloxacin and cephalexin. The incidence of infection-related complications was 1.6% (24/1471). Four patients experienced bacteremia, all of which were due to E. coli and all of these patients had received antibiotic prophylaxis with an active antibiotic. The use of ciprofloxacin was associated with a lower risk of infection-related complications (odds ratio [OR] 0.20, 95% confidence interval [CI] 0.07, 0.55). Bacteriuria within one year prior to the procedure was associated with increased risk of infection-related complications (OR 4.77, 95% CI 1.34, 16.93). Four (0.3%) patients experienced an antibiotic-related adverse event. CONCLUSIONS: We observed a low rate of infection-related complications and antibiotic-related adverse events in the setting of antibiotic prophylaxis with ciprofloxacin and cephalexin for 24 hours, without pre-procedure rectal culture screening. Investigation into procedural or host factors may uncover opportunities to further reduce infection-related complications.

Nonaqueous magnetization following adiabatic and selective pulses in brain: T1 and cross-relaxation dynamics.

Inversion pulses are commonly employed in MRI for T 1 -weighted contrast and relaxation measurements. In the brain, it is often assumed that adiabatic pulses saturate the nonaqueous magnetization. We investigated this assumption using solid-state NMR to monitor the nonaqueous signal directly following adiabatic inversion and compared this with signals following hard and soft inversion pulses. The effects of the different preparations on relaxation dynamics were explored. Inversion recovery experiments were performed on ex vivo bovine and porcine brains using 360-MHz (8.4 T) and 200-MHz (4.7 T) NMR spectrometers, respectively, using broadband rectangular, adiabatic, and sinc inversion pulses as well as a long rectangular saturation pulse. Analogous human brain MRI experiments were performed at 3 T using single-slice echo-planar imaging. Relaxation data were fitted by mono- and biexponential decay models. Further fitting analysis was performed using only two inversion delay times. Adiabatic and sinc inversion left much of the nonaqueous magnetization along B 0 and resulted in biexponential relaxation. Saturation of both aqueous and nonaqueous magnetization components led to effectively monoexponential T 1 relaxation. Typical adiabatic inversion pulses do not, as has been widely assumed, saturate the nonaqueous proton magnetization in white matter. Unequal magnetization states in aqueous and nonaqueous 1 H reservoirs prepared by soft and adiabatic pulses result in biexponential T 1 relaxation. Both pools must be prepared in the same magnetization state (e.g., saturated or inverted) in order to observe consistent monoexponential relaxation.

Association between Industry Payments and Published Position on Use of Devices for the Treatment of Lower Urinary Tract Symptoms.

OBJECTIVE: To determine the impact of industry payments to authors of opinion articles on the Urolift and Rezum devices. We also examined the extent to which authors omitted acknowledgements of financial conflicts-of-interest. METHODS: We searched Google Scholar for all articles that cite either of the respective pivotal trials for these devices. 2 blinded urologists coded the articles as favorable or neutral. A separate blinded researcher recorded industry payments from the manufacturers using the Open Payments Program database. RESULTS: We identified 29 articles written by 27 unique authors from an initial screening list of 235 articles. Of these articles, 15 (52%) were coded as positive and 14 (48%) were coded as neutral. 20 (74%) authors have accepted payments from the manufacturer of the device. Since 2014, these authors have collectively received $270,000 from NeoTract and $314,000 from Boston Scientific. Of the 20 authors with payments, 9 (45%) received more than $10,000 from either manufacturer. Of authors with payments, 65% (13/20) contributed to only positive articles. Authors who received payments had more than 4 times the number of article contributions than did authors without payments (42 vs 10). Authors of at least one favorable article were more likely to have received payments from the device manufacturers than authors of neutral articles (P = .014, Chi-squared test). Most (80%, 16/20) authors with payments did not report a relevant conflict-of-interest within any of their articles. CONCLUSION: These data suggest a relationship between payments from a manufacturer and positive published position on that company's device. There may be a critical lack of published editorial pieces by authors without financial conflicts of interest.

Simulation-Based Percutaneous Renal Access Training: Evaluating a Novel 3D Immersive Virtual Reality Platform.

Introduction: Percutaneous nephrolithotomy (PCNL) is the gold standard treatment for patients with a large stone burden. There are a variety of methods to teach this important endourologic procedure, including simulation. We evaluated three different PCNL simulation platforms for potential use in teaching and assessing percutaneous renal access skills. Materials and Methods: Urology residents, fellows, and faculty were recruited to participate in this study, which included completing standardized tasks on three PCNL simulation platforms: a virtual reality (VR) simulator (PercMentor, 3D Systems™), a porcine tissue simulator (Cook™ Medical), and a new 3D immersive VR simulator-Marion K181 (Marion Surgical™). Participants were asked to complete a standardized task-gaining prone percutaneous renal access using a fluoroscopic-guided technique. Participants were asked to rate the simulators, and performance data were recorded for analysis. Results: A total of 18 participants with varying levels of PCNL experience completed the study. The Marion K181 had higher ratings by participants in all domains (realism, tactile feedback, instrument movement, renal anatomy, fidelity of simulation, utility as teaching tool) compared with the PercMentor (p < 0.05) but did not differ in any domain when compared with the porcine PCNL model. Participants felt that the Marion K181 was comparable with the porcine PCNL model as a teaching tool, but had the advantage of not requiring radiation exposure. Fluoroscopy time was the variable that most consistently correlated with participant PCNL experience and level of training, across all three PCNL simulation platforms. Conclusions: There are a variety of PCNL simulation platforms available for teaching percutaneous renal access skills. Based on our initial comparative study, there is validity evidence to support the use of the novel Marion K181 PCNL simulator as a training tool rather than higher fidelity models requiring real radiation exposure. However, evidence is yet lacking for its use as an assessment tool.

Assessing the Necessity of Routine Crossmatching for Blood Transfusion in Renal Transplantation.

INTRODUCTION: Routine crossmatch of packed red blood cells (pRBCs) is completed preoperatively at many centers despite conflicting evidence on the incidence of blood transfusions with renal transplantation. In the current economic climate, resource adjudication should be judicious and medically appropriate. The objective of this study was to determine the incidence, timing, and predictors of early postoperative pRBC transfusion in patients undergoing renal transplantation. METHODS: A retrospective review of all patients undergoing renal transplantation at our institution from January 2013 to May 2016 was performed. Demographic, biochemical, and clinical parameters were recorded. The primary outcome was early postoperative transfusion, defined as an intraoperative transfusion or within 2 days of surgery. Multivariable logistic regression was performed to identify associations with early postoperative transfusion. RESULTS: We identified 428 patients during the study period (average age 55 years, 60% male, 30% obese, 67% deceased donor, and 43% preoperative antithrombotic use). Forty (9.3%) patients required early postoperative transfusion (mean: 2.8 pRBCs/transfusion) and most did not require blood urgently. Only 20 (4.7%) patients required a transfusion intraoperatively or on the same day of surgery. Lower preoperative hemoglobin (per g/L unit: odds ratio [OR]: 0.943), female gender (OR: 2.752), and preoperative antithrombotic use (OR 2.369) were associated with a need for early postoperative transfusion. CONCLUSION: Transfusion in the early postoperative period following renal transplantation was less than 10%, suggesting that routine crossmatch may not be necessary for all patients. Preoperative hemoglobin, female gender, and preoperative antithrombotic use were associated with increased risk and may be useful to risk-stratify patients who require crossmatch.

Are Routine Laboratory Investigations Necessary Following Percutaneous Nephrolithotomy?

OBJECTIVE: To determine how effective routine postoperative blood work is in identifying complications after percutaneous nephrolithotomy (PCNL), the gold standard treatment for large volume stone disease. Although major complication rates are low, hemorrhagic and sepsis-related complications are serious and can occur. Routine post-PCNL complete blood count is routinely performed by most endourologists but may be a low-value practice. METHODS: A retrospective review was performed of all PCNL procedures at our center over a 3-year period. Patient demographic, stone characteristics and postoperative data were collected and analyzed. RESULTS: Three hundred and eighty-five patients (196 female and 189 males) underwent PCNL for the treatment of urolithiasis. Mean age was 55.8 years and mean length of stay in hospital was 1.74 days. Most patients (82.9%) had neither ureteric stent nor percutaneous tube prior to PCNL. Postoperatively, 4 patients (1.0%) required a blood transfusion and 14 patients (3.6%) developed urosepsis. Patients who required either a transfusion or developed urosepsis demonstrated abnormal vital signs (tachycardia, hypotension, or fever) postoperatively. Sixteen patients (4.2%) had normal vital signs but had an extended hospital stay only to monitor abnormal blood work results. None these patients required a transfusion nor developed urosepsis but had a length of stay that was a mean of 1.5 days longer patients with normal postoperative vital signs and blood work. CONCLUSION: Abnormal vital signs alone identified all patients that required transfusion or treatment for urosepsis after PCNL. Routine complete blood count testing postoperatively may not improve detection of infectious or bleeding complications and may prolong hospital admission unnecessarily.

Late Pleistocene human genome suggests a local origin for the first farmers of central Anatolia.

Anatolia was home to some of the earliest farming communities. It has been long debated whether a migration of farming groups introduced agriculture to central Anatolia. Here, we report the first genome-wide data from a 15,000-year-old Anatolian hunter-gatherer and from seven Anatolian and Levantine early farmers. We find high genetic continuity (~80-90%) between the hunter-gatherers and early farmers of Anatolia and detect two distinct incoming ancestries: an early Iranian/Caucasus related one and a later one linked to the ancient Levant. Finally, we observe a genetic link between southern Europe and the Near East predating 15,000 years ago. Our results suggest a limited role of human migration in the emergence of agriculture in central Anatolia.

Indications and contraindications for shock wave lithotripsy and how to improve outcomes.

For over 35 years shock wave lithotripsy has proven to be an effective, safe and truly minimally invasive option for the treatment of nephrolithiasis. Various technical factors as well as patient selection can impact the success of the procedure. We used published work focusing on outcomes of shock wave lithotripsy, risk of complications, and strategies for improving stone fragmentation to create this review. Multiple patient and technical factors have been found to impact success of treatment. Skin to stone distance, stone density and composition, size and location of the stone within the urinary system all influence stone free rates. A slower rate with a gradual increasing voltage, precise targeting, proper coupling will improve stone fragmentation and decrease risk of complications. The selection of appropriate patients through a shared decision making process and attention to the technical factors that improve stone free rates is key to providing an effective treatment and patient satisfaction.

Radiotherapy with radical cystectomy for bladder cancer: A systematic review and meta-analysis.

INTRODUCTION: Muscle-invasive bladder cancer (MIBC) is associated with high recurrence and mortality rates. The role of radiotherapy as an adjunct to radical cystectomy is not well-defined. We sought to evaluate the efficacy and safety of radiotherapy preoperatively or postoperatively for patients with MIBC receiving cystectomy compared to cystectomy alone. The primary outcome was overall survival. The secondary outcome was adverse effects. METHODS: MEDLINE, EMBASE, and CENTRAL were searched on August 30, 2016 for randomized controlled trials (RCTs) of patients undergoing cystectomy for bladder cancer. A control group receiving cystectomy alone and an intervention group with radiotherapy and cystectomy were required. The Jadad score was used to assess for bias. Fifteen studies representing 10 RCTs met eligibility criteria. RESULTS: A total of 996 patients were randomized in seven trials included in a meta-analysis of neoadjuvant radiotherapy. Insufficient data were available to complete a pooled analysis for adjuvant radiotherapy. There was a non-statistically significant improvement in overall survival for patients who received neo-adjuvant radiotherapy and cystectomy. At three years and five years, the odds ratios were 1.23 (95% confidence interval [CI] 0.72-2.09) and 1.26 (95% CI 0.76-2.09), respectively, in favour of neoadjuvant radiotherapy. Subgroup analyses including higher doses of radiotherapy showed greater effect on survival. CONCLUSIONS: These data suggest that radiotherapy prior to cystectomy may improve overall survival. This review was limited by old studies, heterogeneous patient populations, and radiotherapy treatment techniques that may not meet current standards. There is a need for current RCTs to further evaluate this effect.

A survey of Canadian renal transplant surgeons: Use of ureteric stents and technique of the ureteroneocystotomy.

INTRODUCTION: The role of ureteric stenting in renal transplant has been well-demonstrated. The goal of this survey was to determine the utilization of ureteric stents by Canadian transplant surgeons, and how the ureteroneocystotomy and followup is performed. METHODS: An online survey was sent to the 40 surgeon members of the Canadian Society of Transplantation. The primary outcome was the rate of ureteric stent use at the time of renal transplantation. The secondary outcomes were the ureteric stent dwell time, use and type of prophylactic antibiotics, and the use of routine post-transplant ultrasonography. RESULTS: All respondents (25) used ureteric stent routinely and 92% remove the stent between four and six weeks postoperatively. Prophylactic antibiotics were used 64% of the time for ureteric stent removal. The majority of surgeons do not routinely perform a post-stent removal ultrasound. Fifty-six percent of respondents perform a refluxing anastomosis. CONCLUSIONS: Ureteric stents are routinely used in renal transplant in Canada. Areas for improvement and topics of debate identified from this survey are the need for peri-stent removal antibiotics, the role of post-stent removal ultrasound, the duration of stent dwell time, and the need for a non-refluxing ureteroneocystotomy.

Robotic Autotransplantation and Management of Post-transplant Anastomotic Strictures: the Future Is Here.

PURPOSE OF REVIEW: We set out to review the current published experience with robotic autotransplantation. Although the experience to date is limited, this surgery appears to be safe and technically feasible. We also examined the use of the robotic surgical platform for the management of post-transplant uretero-vesical anastomotic strictures. RECENT FINDINGS: To date, only four reported cases of robotic autotransplantation have been described with two being performed completely intra-corporeally. An intra-corporeal approach is feasible for benign conditions, while malignant masses should be inspected and dissected extra-corporeally. Ureteric strictures after renal transplantation are common. To date, the experience with robotic surgical management is limited but has also been shown to be safe and feasible. While robotic autotransplantation is still in its infancy, it is feasible and appears to be safe. Renal allograft function and surgical outcomes are favorable and provide patients the option to have a historically more morbid surgery performed with a minimally invasive approach.

Is vertebral rotation correction maintained after thoracoscopic anterior scoliosis surgery? A low-dose computed tomography study.

BACKGROUND: Axial vertebral rotation is a key characteristic of adolescent idiopathic scoliosis (AIS), and its reduction is one of the goals of corrective surgery. Recurrence of deformity after surgical correction may relate to rotation changes that occur in the anterior vertebral column after surgery, but whether any change occurs within the fused segment or in adjacent unfused levels following thoracoscopic anterior spinal fusion (TASF) is unknown. An analysis of measurements from an existing postoperative CT dataset was performed to investigate the occurrence of inter- and intra-vertebral rotation changes after TASF within and adjacent to the fused spinal segment and look for any relationships with the Cobb angle and rib hump in the two years after surgery. METHODS: 39 Lenke Type 1 main thoracic patients underwent TASF for progressive AIS and low dose computed tomography scanning of the instrumented levels of the spine at 6 and 24 months after surgery. Vertebral rotation was measured at the superior and inferior endplates on true axial images for all vertebral levels in the fused segment plus one adjacent level cranially and caudally. Intra-observer variability for rotation measurements was assessed using 95% limits of agreement to detect significant changes in inter/intra-vertebral rotation. RESULTS: Significant local changes in inter- and intra-vertebral rotation were found to have occurred between 6 and 24 months after anterior surgical fusion within the fused spinal segment, albeit with no consistent pattern of location or direction within the instrumented fusion construct. No significant en-bloc movement of the entire fused spinal segment relative to the adjacent un-instrumented cranial and caudal intervertebral levels was found. No clear correlation was found between any vertebral rotation changes and Cobb angle or rib hump measures. CONCLUSIONS: Localised inter- and intra-vertebral rotation occurs between 6 and 24 months after TASF, both within the instrumented spinal segments and in the adjacent un-instrumented levels of the adolescent spine. The lack of measurable en-bloc movement of the fused segment relative to the adjacent un-instrumented levels suggests that overall stability of the instrumented construct is achieved, however the vertebrae within the fusion mass continue to adapt and remodel, resulting in ongoing local anatomical and biomechanical changes in the adolescent spine.

Recurrent nephrolithiasis associated with keratinizing desquamative squamous metaplasia.

Keratinizing desquamative squamous metaplasia (KDSM) in the renal pelvis is a rare condition with unclear malignant potential. Recent reports suggest it is likely benign and favor endoscopic treatment approaches. Medical record review was completed on two cases at our center to obtain history, physical examination, radiographic findings, and management. A literature review was completed to identify all published cases of KDSM. Both patients at our center suffered recurrent urolithiasis, hypothesized to be secondary to KDSM. Both were managed with a percutaneous approach to ensure complete stone and KDSM plaque removal. Our cases highlight that percutaneous surgery is an excellent management option for stone and KDSM eradication from the collecting system. This approach also allows adequate oncologic surveillance of the underlying urothelium.

Deceased donor hyperglycemia and liver graft dysfunction.

CONTEXT: Hyperglycemia is common in deceased donors, and provokes numerous adverse events in hepatocytic mitochondria. OBJECTIVE: To determine whether hyperglycemia in deceased donors is associated with graft dysfunction after orthotopic liver transplant. METHODS: Charts on 572 liver transplants performed at the Cleveland Clinic between January 2005 and October 2010 were reviewed. The primary measure was time-weighted averages of donors' glucose measurements. Liver graft dysfunction was defined as (1) primary nonfunction as indicated by death or retransplant or (2) liver graft dysfunction as indicated by an aspartate amino transferase level greater than 2000 U/L or prothrombin time greater than 16 seconds during the first postoperative week. The relationship of interest was estimated by using a multivariable logistic regression. RESULTS: The incidence of graft dysfunction was 25%. No significant relationship was found between the range of donor glucose measurements and liver graft dysfunction after donor characteristics were adjusted for (P= .14, Wald test, adjusted odds ratio [95% CI] for liver graft dysfunction corresponding to a relative doubling in time-weighted average for donor glucose of 1.43 [0.89-2.30]). The results thus do not suggest that strict glucose control in donors is likely to improve graft quality.

Influence of morphology and polymer:nanoparticle ratio on device performance of hybrid solar cells-an approach in experiment and simulation.

We present a thorough study on the various impacts of polymer:nanoparticle ratios on morphology, charge generation and device performance in hybrid solar cells, comprising active layers consisting of a conjugated polymer and in situ prepared copper indium sulfide (CIS) nanoparticles. We conducted morphological studies through transmission electron microscopy and transient absorption measurements to study charge generation in absorber layers with polymer:nanoparticle weight ratios ranging from 1:3 to 1:15. These data are correlated to the characteristic parameters of the prepared solar cells. To gain a deeper understanding of our experimental findings, three-dimensional drift-diffusion-based simulations were performed. Based on elaborate descriptions of the contributions of polymer and nanoparticle phase to device performances, our results suggest that a polymer:CIS volume ratio of 1:2 (weight ratio 1:9) is necessary to obtain a balanced hole and electron percolation. Also at higher CIS loadings the photocurrent remains surprisingly high due to the contribution of the CIS phase to the charge carrier generation.

Controlling the interaction of light with polymer semiconductors.

In this study, a generally applicable strategy is described to manipulate the optical properties of a wide range of polymer semiconductors in the solid state. Blending these materials with a non-conjugated, polar polymer matrix is found to be the processing key to a drastic change and red-shift of the absorption characteristics.

Comparable graft and patient survival in lean and obese liver transplant recipients.

Obesity is among the great health problems facing Americans today. More than 32% of the US population is considered obese on the basis of a body mass index (BMI) exceeding 30 kg/m(2) . Obesity increases the risk for numerous perioperative complications, but how obesity affects the outcome of liver transplantation remains unclear. We compared graft/patient survival after orthotopic liver transplantation performed at the Cleveland Clinic between April 2005 and June 2011 in 2 groups: obese patients with a BMI ≥ 38 kg/m(2) and lean patients with a BMI between 20 and 26 kg/m(2) . We included 47 obese patients and 183 lean patients, whose demographics and baseline characteristics were well balanced after weighting with the inverse propensity score. After we controlled for observed confounding, no significant differences were observed in graft/patient survival between obese and lean patients (P = 0.30). The estimated hazard ratio for obese patients to experience graft failure or death was 1.19 [95% confidence interval (CI) = 0.85-1.67]. There were 134 patients who had follow-up for more than 3 years, and they included 27 obese patients and 107 lean patients. Within this subset, the odds of having metabolic syndrome were significantly greater for obese patients (46%) versus lean patients (21%; odds ratio = 4.76, 99.5% CI = 1.66-13.7, P < 0.001). However, no significant association between obesity and any other long-term adverse outcomes was found. In conclusion, this study shows that transplant outcomes were comparable for lean and obese recipients. We thus recommend that even morbid obesity per se should not exclude patients from consideration for transplantation.

Synthesis and optical characterisation of triphenylamine-based hole extractor materials for CdSe quantum dots.

We report the synthesis and optical characterisation of different triphenylamine-based hole capture materials able to anchor to CdSe quantum dots (QDs). Cyclic voltammetry studies indicate that these materials exhibit reversible electrochemical behaviour. Photoluminescence and transient absorption spectroscopy techniques are used to study interfacial charge transfer properties of the triphenylamine functionalized CdSe QDs. Specifically, we show that the functionalized QDs based on the most easily oxidised triphenylamine display efficient hole-extraction and long-lived charge separation. The present findings should help identify new strategies to control charge transfer QD-based optoelectronic devices.

The association between preoperative anemia and 30-day mortality and morbidity in noncardiac surgical patients.

BACKGROUND: Anemia has been associated with increased postoperative morbidity and mortality. We used the American College of Surgeons National Surgical Quality Improvement Program database to retrospectively assess the relationship between preoperative anemia and 30-day postoperative mortality and morbidity in noncardiac surgical patients, careful to distinguish confounding variables from mediator variables. METHODS: Each patient with preoperative anemia was matched to one without anemia using propensity matching on potentially confounding baseline variables. Logistic regression was used to evaluate the relationship between preoperative anemia and 30-day postoperative mortality and morbidity. The primary hypothesis was evaluated after adjusting for covariables showing residual imbalance after matching. RESULTS: Within the database, 574,860 of 971,455 surgical cases met our inclusion criteria, and among those 145,218 (25.3%) were anemic at baseline. The unadjusted odds ratio (95% confidence interval) for 30-day mortality comparing anemic patients with nonanemic patients was 4.69 (4.01-5.49). Among the propensity-matched group of 238,596 patients, the total effect (i.e., not adjusting for mediator variables) of preoperative anemia was estimated as an odds ratio of 1.59 (1.42-1.78). After adjusting for suspected mediator variables, preoperative anemia was only weakly associated with an odds ratio of 1.24 (1.10-1.40) for 30-day mortality. CONCLUSION: Preoperative anemia appears to be associated with baseline diseases that markedly increase mortality. Anemia per se is a rather weak independent predictor of postoperative mortality. Our analysis also illustrates how analyzing large variable-rich registries challenges investigators to discriminate between confounding variables and mediator variables, i.e., factors that might be considered as "causal pathways" for the effect of the exposure or intervention on outcome.

Influence of crystallinity and energetics on charge separation in polymer-inorganic nanocomposite films for solar cells.

The dissociation of photogenerated excitons and the subsequent spatial separation of the charges are of crucial importance to the design of efficient donor-acceptor heterojunction solar cells. While huge progress has been made in understanding charge generation at all-organic junctions, the process in hybrid organic:inorganic systems has barely been addressed. Here, we explore the influence of energetic driving force and local crystallinity on the efficiency of charge pair generation at hybrid organic:inorganic semiconductor heterojunctions. We use x-ray diffraction, photoluminescence quenching, transient absorption spectroscopy, photovoltaic device and electroluminescence measurements to demonstrate that the dissociation of photogenerated polaron pairs at hybrid heterojunctions is assisted by the presence of crystalline electron acceptor domains. We propose that such domains encourage delocalization of the geminate pair state. The present findings suggest that the requirement for a large driving energy for charge separation is relaxed when a more crystalline electron acceptor is used.