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Bleeding complications during venovenous extracorporeal membrane oxygenation (V-V ECMO) can be critical. However, there is limited information on the associated risk factors. This study investigated the risk factors for bleeding complications during V-V ECMO as a bridge to recovery.This single-center retrospective study enrolled 59 patients (bleeding and non-bleeding groups) who received V-V ECMO from 2012 to 2020, to evaluate whether peak activated partial thromboplastin time (APTT) value, lowest platelet count, and mobilization to sitting on the edge of the bed during V-V ECMO were risk factors for bleeding complications, defined according to the Extracorporeal Life Support Organization guidelines. Age, sex, body mass index, Sequential Organ Failure Assessment score, and ECMO duration before bleeding complications were covariates in the multivariate logistic regression analysis.Thirty-one (53%) participants experienced 36 bleeding complications; the ECMO cannulation site, gastrointestinal tract, and nasopharyngeal region were the most common bleeding sites. The use of transfusion products and length of ECMO and intensive care unit stay were significantly and medical costs were non-significantly increased in the bleeding group. Peak APTT (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01-1.05, p 0.01) was significantly associated whereas the lowest platelet count (OR 0.96, 95% CI 0.82-1.13, p = 0.66) was unassociated with bleeding complications during ECMO. Achieving mobilization (OR 0.14, 95% CI 0.02-1.17, p = 0.07) decreased the trend of risk for bleeding complications.Peak APTT might be an independent modifiable factor for bleeding complications during V-V ECMO. The protective effect of mobilization during V-V ECMO requires further investigation.

Background The benefits of introducing a systematic lung-protective protocol for patients with coronavirus disease (COVID-19) pneumonia and who require invasive ventilation in the intensive care unit (ICU) are unknown. Herein, we aimed to evaluate the clinical effects of introducing such a protocol in the context of mortality, duration of ventilation, and length of ICU stay. Methods In this single-center, retrospective, quality comparison study, we identified patients with COVID-19 pneumonia who received invasive ventilation in our ICU between February 2020 and October 2021. We established a systematic lung-protective protocol for the pre-introduction group until March 2021 and the post-introduction group after April 2021. Patients who did not receive invasive ventilation and who underwent veno-venous extracorporeal membrane oxygenation in a referring hospital were excluded. We collected patient characteristics at the time of ICU admission, including age, sex, body mass index (BMI), comorbidities, sequential organ failure assessment (SOFA) score, acute physiology and chronic health evaluation II (APACHE II) score, and Murray score. The study outcomes were ICU mortality, length of ICU stay, and duration of ventilation. Results The pre-introduction and post-introduction groups included 18 and 50 patients, respectively. No significant differences were observed in sex, BMI, SOFA score, APACHE II score, and Murray score; however, age was lower in the post-introduction group (70 vs. 56, p = 0.003). The introduction of this protocol did not improve ICU mortality. However, it reduced the ICU length of stay (26 days vs. 11 days, p = 0.003) and tended to shorten the duration of ventilation (15 days vs. 10 days, p = 0.06). Conclusions The introduction of the protocol was associated with a decrease in the length of ICU stay and duration of ventilation; however, it did not change mortality. The application of the protocol could improve the security of medical resources during the COVID-19 pandemic. Further prospective multicentre studies are needed.

Functional nucleic acids with the capability of generating fluorescence in response to hybridization events, microenvironment or structural changes are valuable as structural probes and chemical sensors. We now demonstrate the enzyme-assisted preparation of nucleic acids possessing multiple thiazole orange (TO) dyes and their fluorescent behavior, that show a spectral change from the typical monomer emission to the excimer-type red-shifted emission. We found that the fluorescent response and emission wavelength of the TO dyes were dependent on both the state of the DNA structure (single- or double-stranded DNA) and the arrangement of the TO dyes. We showed that the fluorescent behavior of the TO dyes can be applied for the detection of RNA molecules, suggesting that our approach for preparing the fluorescent nucleic acids functionalized with multiple TO dyes could be useful to design a fluorescence bioimaging and detection technique of biomolecules.

OBJECTIVES To determine whether a progressive early mobilization protocol improves patient outcomes, including in-hospital mortality and total hospital costs. DESIGN Retrospective preintervention and postintervention quality comparison study. SETTINGS Single tertiary community hospital with a 12-bed closed-mixed ICU. PATIENTS All consecutive patients 18 years old or older were eligible. Patients who met exclusion criteria or were discharged from the ICU within 48 hours were excluded. Patients from January 2014 to May 2015 were defined as the preintervention group (group A) and from June 2015 to December 2016 was the postintervention group (group B). INTERVENTION Maebashi early mobilization protocol. MEASUREMENTS AND MAIN RESULTS Group A included 204 patients and group B included 187 patients. Baseline characteristics evaluated include age, severity, mechanical ventilation, and extracorporeal membrane oxygenation, and in group B additional comorbidities and use of steroids. Hospital mortality was reduced in group B (adjusted hazard ratio, 0.25; 95% CI, 0.13-0.49; p < 0.01). This early mobilization protocol is significantly associated with decreased mortality, even after adjusting for baseline characteristics such as sedation. Total hospital costs decreased from $29,220 to $22,706. The decrease occurred soon after initiating the intervention and this effect was sustained. The estimated effect was $-5,167 per patient, a 27% reduction. Reductions in ICU and hospital lengths of stay, time on mechanical ventilation, and improvement in physical function at hospital discharge were also seen. The change in Sequential Organ Failure Assessment score and Sequential Organ Failure Assessment score at ICU discharge were significantly reduced after the intervention, despite a similar Sequential Organ Failure Assessment score at admission and at maximum. CONCLUSIONS In-hospital mortality and total hospital costs are reduced after the introduction of a progressive early mobilization program, which is significantly associated with decreased mortality. Cost savings were realized early after the intervention and sustained. Further prospective studies to investigate causality are warranted.

Introduction There are no established risk classification for post-cardiac arrest syndrome (PCAS) patients at the Emergency Department (ED) undergoing targeted temperature management (TTM). The aim of this study was to externally validate a simplified version of our prognostic score, the “post-Cardiac Arrest Syndrome for Therapeutic hypothermia score” (revised CAST [rCAST]) and estimate the predictive accuracy of the risk classification based on it. Methods For the external validation, we used data from an out-of-hospital cardiac arrest (OHCA) registry of the Japanese Association for Acute Medicine (JAAM), which is a multicenter, prospective registry of OHCA patients across Japan. Eligible patients were PCAS patients treated with TTM at 33–36 °C between June 2014 and December 2015. We validated the accuracy of rCAST for predicting the neurological outcomes at 30 and 90 days. Results Among the 12,024 OHCA patients, the data of 460 PCAS patients treated by TTM were eligible for the validation. The areas under the curve of rCAST for predicting the neurological outcomes at 30 and 90 days were 0.892 and 0.895, respectively. The estimated sensitivity and specificity of the risk categories for the outcomes were as follows: 0.95 (95% CI: 0.92–0.98) and 0.47 (0.40–0.55) for the low (rCAST: ≤5.5), 0.62 (0.56–0.68) and 0.48 (0.40–0.55) for the moderate (rCAST: 6.0–14.0), and 0.57 (0.51–0.63) and 0.95 (0.91–0.98) for the high severity category (rCAST: ≥14.5). Conclusions The rCAST was useful for predicting the neurological outcomes with high accuracy in PCAS patients, and the three grades was developed for a risk classification based on the rCAST.

Objective In 2018, the Cabinet Office executed a disaster prevention drill based on the scenario that Nankai had a megathrust earthquake and a large tsunami hit Tokushima Prefecture. The purpose of this study was to summarize the key lessons learned in the review of the Department of Aviation Operation for Tokushima Prefecture in this drill. Methods This report was based on a review using data from the Japan emergency medical information sharing system that can be accessed via the Internet. Results In the disaster drill, the doctor helicopter (DH) headquarters of Tokushima Prefecture at Takamatsu Airport was able to procure 2 actual DHs and 2 mock DHs. The Department of Aviation Operation within the Tokushima Prefectural Government was able to procure 1 actual helicopter belonging to the Coast Guard and 8 mock helicopters (4 belonging to the military and 4 to the fire department). There were 29 flights, including actual and mock flights, and 44 victims were medically transported. Conclusion By making flight plans with each organization concerned, we were able to share the basic rules, concepts, and management approaches of flights among the responding organizations. Disaster planners should have at least a passing familiarity with the aviation capabilities of the local helicopter emergency medical service and other helicopter operations.

Introduction The aim of this study was to evaluate the differential effects of mild therapeutic hypothermia (MTH) in post-cardiac arrest syndrome (PCAS) patients depending on the presence/absence of hypoxic encephalopathy (HE) in the early brain CT images obtained before the initiation of MTH. Methods We conducted a retrospective review of the data of a total of 129 patients with PCAS who were treated by MTH (34 °C) or normothermia treatment (NT) (35 °C or 36 °C), and had undergone brain CT examination prior to the initiation of these treatments. We divided the subjects into 4 groups, namely, the HE(−)/MTH, HE(−)/NT, HE(+)/MTH, and HE(+)/NT groups, for evaluating the interaction effect between the two variables. Then, we compared the neurological outcomes between the HE(−)/MTH and HE(−)/NT groups by multivariate logistic analysis. Good outcome was defined as a Cerebral Performance Category score of ≤2 at 30 days. Results The percentages of subjects with a good outcome in the HE(−)/MTH and HE(−)/NT group were 68.9% (42/61) and 36.1% (13/36), respectively (p = .003), while those in the HE(+)/MTH and HE(+)/NT groups were lower, at 7.4% (2/27) and 20.0% (1/5), respectively (p = .410), suggesting a statistically significant interaction effect between the two variables (pinteraction = 0.002). In the HE(−) group, MTH was associated with a higher odds ratio of a good outcome as compared to NT (OR 6.80, 95% CI 1.19–38.96, p = .031). Conclusions The effect of MTH in patients with PCAS differed depending on the presence/absence of evidence of HE on the early CT images.

In this report, we describe the circularly polarized luminescence (CPL) of the RNA duplexes having one to four 2′-O-pyrene modified uridines (Upy) and the DNA duplexes having two, four, and six pyrene modified non-nucleosidic linkers (Py). Both the pyrene π-stack arrays formed on the RNA and DNA double helical structures exhibited pyrene excimer fluorescence. In the pyrene-modified RNA systems, the RNA duplex having four Upys gives CPL emission with glum value of

Synthetic small molecules with a binding affinity to mismatched base pairs have been widely studied because of their potential applications in chemotherapeutic drugs and diagnostic tools for the detection of single nucleotide variations. In this paper, a luminescent ligand, a perylenediimide (PO) derivative, which is capable of binding to mismatched base pairs within a DNA duplex and generating a strong fluorescence upon the binding event, was demonstrated. Fluorescence enhancement of PO upon the binding to pyrimidine/pyrimidine mismatches were prominent and reached ca. 100-fold for a C/C mismatched base pair, which was visually observed. This result represents the best performance as a fluorescence turn-on response among the existing mismatch binding ligands.

Background In trauma resuscitation with resuscitative endovascular balloon occlusion of the aorta (REBOA), urgent and accurate placement of the catheter in the resuscitation area without fluoroscopy can shorten the time from admission to REBOA, allowing rapid, temporary control of bleeding. Discussion The experience-based protocol in our center for ultrasound-guided REBOA in the resuscitation area without fluoroscopy is as follows: the femoral artery is punctured and a guidewire inserted; sonography is used to verify that the guidewire is in the abdominal aorta; the position of the balloon is confirmed with ultrasound after estimating the distance to the clavicle, and the pressure in the radial artery and sheath is used to monitor correct positioning; connect the pressure transducer to the catheter sheath for continuous monitoring of the blood pressure in the sheath, and inflate the balloon until the blood pressure tracing at the sheath has disappeared; check the pulse in the left radial artery, and withdraw the catheter slightly if the pulse in the radial artery is not palpable or is decreased (if this pulse is not palpable or decreased, the balloon is in the aortic arch). In this retrospective review of our REBOA protocol, between April 2012 and March 2016, 34 patients were enrolled. Two patients had complications, including dissection of the femoral artery in one and difficult percutaneous vascular access in another. Median time needed to complete the procedure was 8 min. Overall, 24 of 34 patients survived more than 24 h (72%), and overall mortality was 47%. Patients who lived more than 24 h, and then died had severe traumatic brain injury or septic shock. Conclusions Ultrasound-guided REBOA is presented. Monitoring the blood pressure in the left radial artery allows us to determine adequate positioning of the balloon, and the blood pressure in the catheter sheath located in the femoral artery should also be monitored to prevent aortic injuries caused by the overinflation of the balloon.

Aim Transporting critically ill patients outside of disaster-affected areas for treatment is an important activity of Japan Disaster Medical Assistance Teams (DMATs). We investigated whether this activity is possible after possible catastrophic damage from a Nankai Trough earthquake. Methods Japan was divided into three areas based on the level of predicted damage (definitely, possibly, and non-affected areas). A survey of DMATs and the locations of emergency base hospitals and intensive care units (ICUs) in each area was carried out, and the ability to support disaster areas was investigated. Next, a survey of wide-area medical transport by Self-Defense Force aircraft and the medical transport abilities of helicopter ambulances was carried out. The numbers of ICU beds in each area were compared, and the capacity to accept patients was investigated. Finally, subjects for further study were examined. Results The number of DMATs that could be sent from non-affected areas was insufficient. The number of patients that can be transported by Self-Defense Force aircraft and helicopter ambulance during the first 3 days was determined to be 1,443. The number of patients that can be accepted by ICUs in non-affected areas was insufficient. A system needs to be developed to provide medical treatment for critically ill patients within disaster areas during the acute phase. This will require DMAT operational reforms and the creation of logistics systems such as the supply of resources for earthquake-reinforced hospitals. Conclusion In addition to patient transport, systems to provide medical care inside disaster-affected areas are needed.

We here describe a photocurrent generation system exploiting gold nanoparticles (AuNPs) that cover perylenediimide-DNA complexes on electrode surfaces. Enhanced photocurrents were generated by the irradiation of the AuNPs, attributed to the efficient excitation of the perylenediimides by a local electric field on the surface of the AuNPs.

Objective The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score is a diagnostic tool for necrotizing soft tissue infection (NSTI), which is validated and is considered to have high diagnostic value. However, some experts criticize LRINEC score for consisting of laboratory test results only. Methods In this single-center retrospective study, we created a new scoring system (NSTI assessment score; NAS), which also incorporated vital signs as another diagnostic tool for NSTI using cases from our hospital and also evaluated diagnostic accuracy of LRINEC score. We identified NSTI predictors by comparing 24 NSTI patients and 80 non NSTI patients using uni- and multivariate logistic regression analysis, and created NAS based on odds ratio of variables which are statistically significant in the multivariate model. Results We identified mean arterial pressure, C-reactive protein, hemoglobin, serum creatinine, and glucose as a predictor for NSTI. The maximum value of NAS was 11 points with the cut-off value of 6. Sensitivity, specificity, positive predictive value, and negative predictive value of the NAS for diagnosis of NSTI were 87.5%, 91.3%, 75.0%, and 96.1%, respectively. Area under the receiver operating characteristic curve was 0.926 (0.851–1.00) for the NAS and 0.903 (0.833–0.973) for the LRINEC score, and they were not statistically different (p = 0.167). Conclusion The NAS has high diagnostic accuracy in predicting NSTI, and is comparable with the LRINEC score. The NAS needs to be validated in other cohorts in the future.

B- to Z-DNA transitions play a crucial role in biological systems and have attracted the interest of researchers for their applications in DNA nanotechnology. DNA and DNA analogues have also been used as templates to construct helical chromophore associations with π interactions. In this work, the B- to Z-DNA transition-induced switching of pyrene in an association manner was evaluated using DNA duplexes with non-nucleosidic pyrene residues in the middle of d(CG) repeat sequences. One of the pyrene-labeled DNAs was shown to exhibit inverted exciton coupled circular dichroism signals upon pyrene association through a B- to Z-DNA transition. This observation indicates that pyrene association switches the DNA conformation from right- to left-handed. Interestingly, the fluorescence of the pyrene-labeled DNA duplex also dynamically changed upon switching of the pyrene in an association-based manner. Taken together, these studies demonstrate that pyrene-labeled DNA shows promise as a chiroptical molecular switch.

Background Disseminated intravascular coagulation (DIC) associated with multiple organ dysfunction syndrome (MODS) plays pivotal roles in severe sepsis. Objectives We performed a multicenter, prospective data collection study and retrospectively analyzed the data to confirm the role of DIC in severe sepsis. Methods Eligible patients were ICU patients who met the definitions of severe sepsis, and 1013 patients were included. DIC scores as well as disease severity and the development of MODS on the day of the diagnosis of severe sepsis (day 0) and at day 3 were evaluated. The primary outcome was hospital mortality, and MODS on days 0 and 3 was the secondary outcomes. Results The overall mortality rate of severe sepsis was 21.5%, and the prevalence of DIC was 50.9% (516/1013). DIC patients were more seriously ill and exhibited a higher prevalence of MODS (32.0% vs. 13.1%) on day 0 and worse mortality rate (24,8% vs. 17.5%) than non-DIC patients. DIC patients also showed a lower survival probability than non-DIC patients (Log rank p = 0.028). Logistic regression analyses after propensity score adjustment for potential confounders confirmed a significant association between DIC and MODS and hospital death in the patients with severe sepsis. The new development of DIC and persistent DIC from days 0 to 3 were associated with a high incidence of MODS and low survival probability. Conclusions The mortality rate of severe sepsis has been improved; however, DIC is still associated with the poor prognosis of these patients. Evaluating the dynamic changes in the DIC status may improve the prediction capability.

Background: Determination of the need for massive transfusion (MT) at the scene of injury is ideal for early activation of a MT protocol. We created and reported The Pre-hospital Traumatic Bleeding Severity Score (ph-TBSS) that is a simple and highly accurate scoring system to predict the need for MT at the scene of injury. However, the comparison study about the predictive value between the ph-TBSS and other MT predictors is not performed. Patients and Methods: A diagnostic comparison study using the registry data of the Gunma Prefectural Helicopter Emergency Medical Service (HEMS) was conducted. Records between Sep. 2012 and Apr. 2017 were reviewed, and adult trauma patients transported by the HEMS were included. A physician in the HEMS is always on board, primary survey including abdominal sonography scanning is performed at the scene of injury, and lactate was measured by portable equipment. The potential predictors of MT (10 units or more of packed red blood cells transfusion within 24 hours of injury) at the scene of injury were defined as following; The ph-TBSS, Assessment of Blood Consumption (ABS) score, the shock index, lactate concentration, and the presence of cold sweat. Each predictor was retrospectively calculated or reviewed from the registry data. Each predictive value was analyzed by the area under the receiver operating characteristic curve (AUROC) and the AUROC comparison analysis was performed. Results: 1025 patients were analyzed. Each AUROC for MT was following; ph-TBSS vs ABC score vs shock index vs lactate concentration vs presence of cold sweat = 0.97 [0.96-0.98] vs 0.83 [0.81-0.85] vs 0.89 [0.87-0.91] vs 0.91 [0.90-0.93] vs 0.70 [0.67-0.72]. The AUROC of the ph-TBSS was significantly higher compared to the AUROC of the other predictors (Bonferroni adjusted p Conclusion: At the scene of injury, the ph-TBSS represented the highest predictive value for MT, compared to the ABC score, shock index, lactate concentration, or presence of cold sweat.

DNA is considered to be a promising biomolecule as a template and scaffold for arranging and organizing functional molecules on the nanoscale. The construction and evaluation of DNAs containing multiple functional molecules that are useful for optoelectronic devices and sensors has been studied. In this paper we report the efficient incorporation of perylenediimide (PDI) units into DNA by using abasic sites both as binding sites and as reactive sites and the construction of PDI stacks within the DNA structure, accomplished through the preorganization of the PDI units in the hydrophobic pocket within the DNA. Our approach could become a valuable method for construction of DNA/chromophore hybrid structures potentially useful for the design of DNA-based devices and biosensors.

More than 6,000 people died in the Great Hanshin (Kobe) Earthquake in 1995, and it was later reported that there were around 500 preventable trauma deaths. In response, the Japanese government developed the helicopter emergency medical service in 2001, known in Japan as the "Doctor-Heli" (DH), which had 46 DHs and 2 private medical helicopters as of April 2016. DHs transport physicians and nurses to provide pre-hospital medical care at the scene of medical emergencies. Following lessons learned in the Great East Japan Earthquake in 2011, a research group in the Ministry of Health, Labour and Welfare developed a command and control system for the DH fleet as well as the Disaster Relief Aircraft Management System Network (D-NET), which uses a satellite communications network to monitor the location of the fleet and weather in real-time during disasters. During the Kumamoto Earthquake disaster in April 2016, 75 patients were transported by 13 DHs and 1 private medical helicopter in the first 5 days. When medical demand for the DHs exceeded supply, 5 patients, 8 patients, and 1 patient were transported by Self-Defense Force, Fire Department, and Coast Guard helicopters, respectively. Of the 89 patients who were transported, 30 (34%) had trauma, 3 (3%) had pulmonary embolisms caused by sleeping in vehicles, and 17 (19%) were pregnant women or newborns. This was the first time that the command and control system for aeromedical transport and D-NET, established after the Great East Japan Earthquake in 2011, were operated in an actual large-scale disaster. Aeromedical transport by DHs and helicopters belonging to several other organizations was accomplished smoothly because the commanders of the involved organizations could communicate directly with each other in person within the Aviation Coordination Section of the prefectural government office. However, ongoing challenges in the detailed operating methods for aeromedical transport were highlighted and include improving shared knowledge and training across the organizational framework. These are particularly important issues to address given the Nankai Trough and Tokyo inland earthquakes that are predicted for the near future in Japan.

The preparation of homo- and heterocomplexes composed of the parent perylene diimide (PH) and pyrrolidine-substituted perylene diimide (PN) in DNA and rapid electron transfer in these complexes, which has been analyzed by steady-state fluorescence and femtosecond transient absorption measurements, have been demonstrated. The DNA molecules possessing PH and PN were prepared through a recently developed method that involved the reaction of enzymatically generated abasic sites with the amino groups of the perylene diimide molecules, through which these molecules can be incorporated as base surrogates within the DNA base stack. Melting temperature analysis showed that the PH and PN monomers, and their homo- and heterodimers, contribute to the stabilization of the DNA duplex, and is comparable to that of natural base pairs. Fluorescence measurements showed that PH in a single-stranded oligopyrimidine showed a strong fluorescence, whereas the fluorescence of PH was completely quenched upon pairing with PN (PH/PN) through duplex formation. The transient absorption measurements showed that a rapid electron-transfer reaction in the stacked PH/PN heterodimer occurred on a sub-picosecond timescale, which allowed highly efficient fluorescence quenching. The PH/PN pair, which served as a fluorophore and quencher, were utilized to design molecular beacon probes with a high signal/noise ratio. The PH/PN pair was also capable of forming a stable, stacked dimer structure and induced rapid electron transfer that could serve as a good signal reporter for fluorescent nucleic acid detection.

Background Early brain CT is one of the most useful tools for estimating the prognosis in patients with post-cardiac arrest syndrome (PCAS) at the emergency department (ED). The aim of this study was to evaluate the prognosis-prediction accuracy of the emergency physicians’ interpretation of the findings on early brain CT in PCAS patients treated by targeted temperature management (TTM). Methods This was a double-center, retrospective, observational study. Eligible subjects were cardiac arrest patients admitted to the intensive care unit (ICU) for TTM between April 2011 and March 2017. We performed the McNemar test to compare the predictive accuracies of the interpretation by emergency physicians and radiologists and calculated the kappa statistic for determining the concordance rate between the interpretations by these two groups. Results Of the 122 eligible patients, 106 met the inclusion criteria for this study. The predictive accuracies (sensitivity, specificity) of the interpretations by the emergency physicians and radiologists were (0.34, 1.00) and (0.41, 0.93), respectively, with no significant difference in either the sensitivity or specificity as assessed by the McNemar test. The kappa statistic calculated to determine the concordance between the two interpretations was 0.66 (0.48–0.83), which showed a good conformity. Conclusions The emergency physicians’ interpretation of the early brain CT findings in PCAS patients treated by TTM was as reliable as that of radiologists, in terms of prediction of the prognosis.

We describe a simple and convenient method for the preparation of photoresponsive DNA-modified electrodes using primer extension (PEX) reactions. A naphthalimide derivative was used as the photosensitizer that was attached to the C5-position of 2'-deoxyuridine-5'-triphosphate (dUTP(NI)). It has been found that dUTP(NI) is a good substrate for the PEX reactions using KOD Dash and Vent (exo-) enzymes in solutions to incorporate naphthalimide (NI) moieties into the DNA sequences. On the electrode surface immobilized with the primer/template DNA, the PEX reactions to incorporate dUTP(NI) molecules into the DNA sequence were found to efficiently proceed. With this solid-phase method, the DNA monolayers capable of generating photocurrent due to the photoresponsive NI molecule can be constructed. It was shown that the photocurrent generation was significantly suppressed by a single-nucleotide mismatch included in the primer/template DNA, which is applicable for the design of photoelectrochemical sensors to discriminate single-nucleotide sequences.

The charge-transfer process in noncovalent perylenediimide (PDI)/DNA complexes has been investigated by using nanosecond laser flash photolysis (LFP) and photocurrent measurements. The PDI/DNA complexes were prepared by inclusion of cationic PDI molecules into the artificial cavities created inside DNA. The LFP experiments showed that placement of the PDI chromophore at a specific site and included within the base stack of DNA led to the efficient generation of a charge-separated state with a long lifetime by photoexcitation. When two PDI chromophores were separately placed at different positions in DNA, the yield of the charge-separated state with a long lifetime was dependent upon the number of A-T base pairs between the PDIs, which was explained by electron hopping from one PDI to another. Photocurrent generation of the DNA-modified electrodes with the complex was also dependent upon the arrangement of the PDI chromophores. A good correlation was obtained between observed charge separation and photocurrent generation on the PDI/DNA-modified electrodes, which demonstrated the importance of the defined arrangement and assembly of organic chromophores in DNA for efficient charge separation and transfer in multichromophore arrays.