Deep‐penetration fluorescence imaging in the second near‐infrared (NIR‐II) window heralds a new era of clinical surgery, in which high‐resolution vascular/lymphatic anatomy and detailed cancerous ...tissues can be visualized in real time. Described here is a series of polymethine‐based semiconducting polymers with intrinsic emission maxima in the NIR‐IIa (1300–1400 nm) window and absorption maxima ranging from 1082 to 1290 nm. These polymers were prepared as semiconducting polymer dots (Pdots) in aqueous solutions with fluorescence quantum yields of 0.05–0.18 %, and they demonstrate promising applications in noninvasive through‐skull brain imaging in live mice with remarkable spatial resolution as well as signal‐to‐background contrast. This study offers a platform for future design of NIR‐IIa or even NIR‐IIb emitting Pdots.
A novel series of polymethine‐based semiconducting polymers were synthesized for the first time and prepared as Pdots in water with both absorption and emission in the NIR‐II window. These Pdots can be further applied for deep‐tissue non‐invasive fluorescence imaging.
Record power conversion efficiencies (PCEs) of perovskite solar cells (PSCs) have been obtained with the organic hole transporter 2,2′,7,7′-tetrakis(
N
,
N
-di-
p
...-methoxyphenyl-amine)9,9′-spirobifluorene (spiro-OMeTAD). Conventional doping of spiro-OMeTAD with hygroscopic lithium salts and volatile 4-
tert
-butylpyridine is a time-consuming process and also leads to poor device stability. We developed a new doping strategy for spiro-OMeTAD that avoids post-oxidation by using stable organic radicals as the dopant and ionic salts as the doping modulator (referred to as ion-modulated radical doping). We achieved PCEs of >25% and much-improved device stability under harsh conditions. The radicals provide hole polarons that instantly increase the conductivity and work function (WF), and ionic salts further modulate the WF by affecting the energetics of the hole polarons. This organic semiconductor doping strategy, which decouples conductivity and WF tunability, could inspire further optimization in other optoelectronic devices.
A radical doping approach
In perovskite solar cells, high power conversion efficiencies (PCEs) are usually obtained with an organic hole transporter called spiro-OMeTAD. This material must be doped to have sufficient conductivity and optimal work function, but the conventional process with lithium organic salts requires a long oxidation step that also affects device stability. Zhang
et al
. added spiro-OMeTAD biradical precursors that convert into stable organic monoradicals. Combined with ionic salts, this doping strategy formed solar cells with high PCEs (>25%) and improved stability. This approach also allows conductivity and work function to be tuned separately and could be applied in other optoelectronic devices. —PDS
Organic radicals and ionic salts enable doping of an organic hole transporter without post-oxidation treatments.
To determine distribution of severe acute respiratory syndrome coronavirus 2 in hospital wards in Wuhan, China, we tested air and surface samples. Contamination was greater in intensive care units ...than general wards. Virus was widely distributed on floors, computer mice, trash cans, and sickbed handrails and was detected in air ≈4 m from patients.
Conjugated polymers with high thermoelectric performance enable the fabrication of low‐cost, large‐area, low‐toxicity, and highly flexible thermoelectric devices. However, compared to their p‐type ...counterparts, n‐type polymer thermoelectric materials show much lower performance, which is largely due to inefficient doping and a much lower conductivity. Herein, it is reported that the development of a donor–acceptor (D–A) polymer with enhanced n‐doping efficiency through donor engineering of the polymer backbone. Both a high n‐type electrical conductivity of 1.30 S cm−1 and an excellent power factor (PF) of 4.65 µW mK−2 are obtained, which are the highest reported values among D–A polymers. The results of multiple characterization techniques indicate that electron‐withdrawing modification of the donor units enhances the electron affinity of the polymer and changes the polymer packing orientation, leading to substantially improved miscibility and n‐doping efficiency. Unlike previous studies in which improving the polymer‐dopant miscibility typically resulted in lower mobilities, the strategy maintains the mobility of the polymer. All these factors lead to prominent enhancement of three orders magnitude in both the electrical conductivity and the PF compared to those of the non‐engineered polymer. The results demonstrate that proper donor engineering can enhance the n‐doping efficiency, electrical conductivity, and thermoelectric performance of D–A copolymers.
1000‐fold enhancements in n‐type electrical conductivity and power factor of a donor–acceptor copolymer are obtained by donor engineering. Donor engineering enhances electron affinity and n‐doping efficiency, prevents phase separation, lowers hopping barrier and keeps mobility unaffected. A record electrical conductivity of 1.30 S cm−1 and a power factor of 4.65 μW mK−2 are achieved in this work.
Organic electrochemical transistors (OECTs) hold promise for developing a variety of high‐performance (bio‐)electronic devices/circuits. While OECTs based on p‐type semiconductors have achieved ...tremendous progress in recent years, n‐type OECTs still suffer from low performance, hampering the development of power‐efficient electronics. Here, it is demonstrated that fine‐tuning the molecular weight of the rigid, ladder‐type n‐type polymer poly(benzimidazobenzophenanthroline) (BBL) by only one order of magnitude (from 4.9 to 51 kDa) enables the development of n‐type OECTs with record‐high geometry‐normalized transconductance (gm,norm ≈ 11 S cm−1) and electron mobility × volumetric capacitance (µC* ≈ 26 F cm−1 V−1 s−1), fast temporal response (0.38 ms), and low threshold voltage (0.15 V). This enhancement in OECT performance is ascribed to a more efficient intermolecular charge transport in high‐molecular‐weight BBL than in the low‐molecular‐weight counterpart. OECT‐based complementary inverters are also demonstrated with record‐high voltage gains of up to 100 V V−1 and ultralow power consumption down to 0.32 nW, depending on the supply voltage. These devices are among the best sub‐1 V complementary inverters reported to date. These findings demonstrate the importance of molecular weight in optimizing the OECT performance of rigid organic mixed ionic–electronic conductors and open for a new generation of power‐efficient organic (bio‐)electronic devices.
n‐Type organic electrochemical transistors (OECTs) underperform compared to p‐type OECTs. By tuning the molecular weight of the rigid ladder‐type poly(benzimidazobenzophenanthroline), n‐type OECTs with record‐high figures of merit are reported. OECT‐based complementary inverters are also demonstrated with high voltage gains of up to 100 V V−1 and ultralow power consumption down to 0.32 nW, depending on the supply voltage.
Summary
Background
There remains an unmet need for convenient biomarkers to assess the risks of discontinuing nucleos(t)ide analogues (NAs) in chronic hepatitis B (CHB).
Aim
To investigate if ...hepatitis B core‐related antigen (HBcrAg) is an independent of surface antigen (HBsAg) for risk prediction of NA cessation.
Methods
This prospective multicentre study enrolled 135 CHB patients who stopped entecavir or tenofovir after achieving viral remission for a median of 25.2 months. All patients stopped NA with negative HBeAg and undetectable viral DNA, and were then observed for clinical relapse and HBsAg loss. Predictors including HBsAg and HBcrAg levels were explored using Cox proportional hazard model and weighted to develop a risk score.
Results
During a median follow‐up of 25.9 months, clinical relapse and HBsAg loss occurred in 66 and eight patients, respectively, with a 5‐year cumulative incidence of 56.1% (95% CI 46.7‐66.0%) and 8.8% (95% CI 4.3‐17.4%), respectively. HBcrAg was an independent relapse predictor, as well as HBsAg, age, ALT and tenofovir use. A score (SCALE‐B) was calculated by the equation of 35*HBsAg (log IU/mL) + 20*HBcrAg (log U/mL) + 2*age (year) + ALT (U/L) + 40 for tenofovir use. The concordance rates for clinical relapse were 0.87, 0.88, 0.87, 0.85 and 0.90 at 1, 2, 3, 4 and 5 years, respectively. Moreover, HBsAg loss occurred exclusively in low‐risk patients predicted by the score.
Conclusions
Serum HBcrAg and HBsAg levels were independent predictors of off‐NA relapse and can be factored into a risk score to guide treatment cessation in patients with CHB.
Future brain-machine interfaces, prosthetics, and intelligent soft robotics will require integrating artificial neuromorphic devices with biological systems. Due to their poor biocompatibility, ...circuit complexity, low energy efficiency, and operating principles fundamentally different from the ion signal modulation of biology, traditional Silicon-based neuromorphic implementations have limited bio-integration potential. Here, we report the first organic electrochemical neurons (OECNs) with ion-modulated spiking, based on all-printed complementary organic electrochemical transistors. We demonstrate facile bio-integration of OECNs with Venus Flytrap (Dionaea muscipula) to induce lobe closure upon input stimuli. The OECNs can also be integrated with all-printed organic electrochemical synapses (OECSs), exhibiting short-term plasticity with paired-pulse facilitation and long-term plasticity with retention >1000 s, facilitating Hebbian learning. These soft and flexible OECNs operate below 0.6 V and respond to multiple stimuli, defining a new vista for localized artificial neuronal systems possible to integrate with bio-signaling systems of plants, invertebrates, and vertebrates.
•Pneumococcal vaccination rates are suboptimal in older adults.•Adult vaccine hesitancy is poorly understood.•Social determinants may be influencing pneumococcal vaccine uptake.•Rural areas and those ...with low health literacy may be prone to lower vaccine rates.•Access to information may also influence pneumococcal vaccine-seeking behavior.
To examine the potential influence of social determinants of health on pneumococcal vaccination in older American adults.
This study used nationwide, US Medicare claims data from 2013 to 2016 to assess uptake of pneumococcal vaccination among adults in the first year after turning age 65. Patients were followed from the point of being 65 years of age and initially enrolled in traditional fee-for-service Medicare or a Medicare Advantage plan through the subsequent year and observed for pneumococcal vaccination in outpatient clinics and pharmacies. Publicly-available data on select social determinants of health were incorporated and guided by the World Health Organization vaccine hesitancy matrix. Logistic regression determined predictors of vaccination while controlling clinical and demographic characteristics.
A total of 307,488 and 74,995 adults aged 65 years were identified from Medicare Advantage and Medicare fee-for-service claims, respectively, and 21.1% of Medicare Advantage and 38.2% of Medicare fee-for-service patients received a pneumococcal vaccine in the first year after turning 65. Those residing in urban areas had a higher likelihood of pneumococcal vaccination in both the Medicare Advantage (OR: 1.31; 95% CI: 1.267–1.344) and Medicare fee-for-service (OR: 1.53; 95% CI: 1.450–1.615) cohorts. Additionally, residing in areas of higher health literacy or communities with more democratic voters were consistently associated with a higher odds of pneumococcal vaccination regardless of Medicare type. Results also pointed to a synergistic relationship between receiving the influenza vaccine and also being vaccinated against pneumococcal disease.
Social determinants of health, including local health literacy, poverty, residing in more liberal areas, and access to information, may be influencing the pneumococcal vaccine-related decisions of older adults. However, additional factors associated with the vaccine hesitancy matrix and more granular data (e.g., zip code-level) are needed to fully determine the impact in this and other vaccines recommended in older adults.
Conducting polymers, such as the p-doped poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), have enabled the development of an array of opto- and bio-electronics devices. However, ...to make these technologies truly pervasive, stable and easily processable, n-doped conducting polymers are also needed. Despite major efforts, no n-type equivalents to the benchmark PEDOT:PSS exist to date. Here, we report on the development of poly(benzimidazobenzophenanthroline):poly(ethyleneimine) (BBL:PEI) as an ethanol-based n-type conductive ink. BBL:PEI thin films yield an n-type electrical conductivity reaching 8 S cm
, along with excellent thermal, ambient, and solvent stability. This printable n-type mixed ion-electron conductor has several technological implications for realizing high-performance organic electronic devices, as demonstrated for organic thermoelectric generators with record high power output and n-type organic electrochemical transistors with a unique depletion mode of operation. BBL:PEI inks hold promise for the development of next-generation bioelectronics and wearable devices, in particular targeting novel functionality, efficiency, and power performance.
Abstract
Background
Hippocampal avoidance whole-brain radiotherapy (HA-WBRT) shows potential for neurocognitive preservation. This study aimed to evaluate whether HA-WBRT or conformal WBRT (C-WBRT) ...is better for preserving neurocognitive function.
Methods
This single-blinded randomized phase II trial enrolled patients with brain metastases and randomly assigned them to receive HA-WBRT or C-WBRT. Primary endpoint is decline of the Hopkins Verbal Learning Test–Revised (HVLT-R) delayed recall at 4 months after treatment. Neurocognitive function tests were analyzed with a mixed effect model. Brain progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan–Meier method.
Results
From March 2015 to December 2018, seventy patients were randomized to yield a total cohort of 65 evaluable patients (33 in the HA-WBRT arm and 32 in the C-WBRT arm) with a median follow-up of 12.4 months. No differences in baseline neurocognitive function existed between the 2 arms. The mean change of HVLT-R delayed recall at 4 months was −8.8% in the HA-WBRT arm and +3.8% in the C-WBRT arm (P = 0.31). At 6 months, patients receiving HA-WBRT showed favorable perpetuation of HVLT-R total recall (mean difference = 2.60, P = 0.079) and significantly better preservation of the HVLT-R recognition-discrimination index (mean difference = 1.78, P = 0.019) and memory score (mean difference = 4.38, P = 0.020) compared with patients undergoing C-WBRT. There were no differences in Trail Making Test Part A or Part B or the Controlled Oral Word Association test between the 2 arms at any time point. There were no differences in brain PFS or OS between arms as well.
Conclusion
Patients receiving HA-WBRT without memantine showed better preservation in memory at 6-month follow-up, but not in verbal fluency or executive function.
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